TECHNICAL FIELD
[0001] The inventive concept relates to the field of dual-cylinder lock assemblies. A lock
assembly is disclosed as well as a method for operating a dual-cylinder lock assembly.
A dual-cylinder lock assembly may be unlocked and locked by different keys to operate
a door locking mechanism.
BACKGROUND
[0002] A dual-cylinder lock assembly typically includes a first and a second lock cylinder
operable by different keys. Each lock cylinder comprises a housing and a key-receiving
plug rotatably received in the housing. Insertion and turning of an appropriate key
into one of the plugs allows rotation of the plug to an unlock position. Especially,
the first lock cylinder may be operable by a regular or resident key, and the second
lock cylinder may be operable by a service personal key. Each lock cylinder may be
mechanical or electromechanical. As an example, the resident key may be a mechanical
key for operating a mechanical lock cylinder, while the service key may be a programmable
electronic key for operating an electromechanical lock cylinder. A dual-cylinder lock
assembly is typically arranged to operate a door locking mechanism, such as a rotatable
latch.
[0003] US 474 783 discloses a lock operable by a master key or by a change key. A master-key cylinder
is completely separated from a change-key cylinder. Each cylinder is provided with
an associated gear. The cylinders are arranged such that the plug of each cylinder,
when its mechanical tumblers are set by an appropriate key, may be pushed axially
inwards by the key causing the associated gear to move axially and mesh with a common
gear operating a door lock mechanism.
[0004] US 3 203 210 discloses a lock with two lock cylinder for operating a common latch mechanism, each
lock cylinder including a rotatable plug. A key slot in each rotatable plug extends
through the rear of the plug. A gear is mounted for free rotation on an inner end
of each plug. When an appropriate key is inserted into a plug, the key tip extends
through the rear of the plug to create a rotational connection between the plug and
the associated gear.
[0005] US 10 253 526 discloses a dual-cylinder lock arrangement comprising first and second lock cylinders
having first and second rotatable plugs. First and second cams are arranged each to
actuate a door lock mechanism. The cams are co-axial and arranged to rotate independently
of each other about the same axis as the first plug. The first cam is coupled to and
rotatable directly by the first plug involving no gear transmission. The second cam
is operated independently from the first cam by rotation of the second plug and via
a gear transmission drivingly connecting the second plug to the second cam. The gear
transmission is operatively associated with the second cylinder only.
[0006] EP 3 733 999 A1 discloses a dual-cylinder lock assembly comprising a gear and clutch mechanism for
selectively connecting a first or a second cylinder plug to an output tailpiece. Four
gears are moved axially in and out of engagement during operation. The solution requires
keys extending rearwardly through the back side of one of the plugs to operate a clutch
mechanism.
[0007] EP 3 899 173 A1 discloses a door lock assembly comprising a first key receiving member which is selectively
rotatable in a first cylinder body. The first cylinder body, in its turn, is arranged
in a 360 degree rotatable cylinder housing. A second locking device is arranged to
selectively allow the cylinder housing to pop out and to rotate together with the
first cylinder body.
[0008] Prior-art dual-cylinder lock assemblies as disclosed in the above-mentioned documents
suffers from various drawbacks. Some prior-art solutions require mechanical lock cylinders
and are thus not suitable for use in assemblies using one or two electromechanical
lock cylinders. Some prior-art solutions require rearward open key-receiving cylinder
plugs, which among other things is a drawback with respect to contamination of the
interior of the cylinder plug . Some prior-art solutions requires complicated and
fail-prone meshing and un-meshing of gears during operation to selectively connect
the plugs to a tailpin operating a door locking mechanism. Some prior-art solutions
involves an undesired rotational lag between key rotation and output rotation. Some
prior-art solutions require complicated, fail-prone, and costly clutch mechanisms.
Some prior-art solutions require additional manual unlock maneuvers, in addition to
key turning, such as axial plug displacement. In general, the prior-art fails to provide
a simple, cost-effective and yet reliable and secure solution for operating a common
latch mechanism by dual lock cylinders, and which is suitable for use with mechanical
keys as well as electromechanical lock cylinders.
SUMMARY OF INVENTION
[0009] An object is to provide an enhanced dual-cylinder lock assembly and a method for
operating a dual-cylinder lock assembly which solve at least some of the above-mentioned
problem of prior-art solutions.
[0010] According to one aspect of the inventive concept, there is provided a dual-cylinder
lock assembly, comprising:
a housing;
a first cylinder body arranged in the housing;
a second cylinder body rotatably arranged in the housing;
a key-receiving first plug rotatably arranged within the first cylinder body and provided
with a first lock mechanism arranged to interact with the first cylinder body;
a key-receiving second plug rotatably arranged in the second cylinder body and provided
with a second lock mechanism arranged to interact with the second cylinder body, said
second plug being arranged to operate a tailpiece;
a first gear connected to the first plug so that the first gear rotates with the first
plug; and
a second gear connected to the second cylinder body so that the second cylinder body
rotates with the second gear, said second gear also being rotatably connected to the
first gear so that the first plug, the first gear, the second gear, and the second
cylinder body rotate with each other.
[0011] The first plug may be permanently, directly or indirectly, connected to the first
gear. The first plug and the first gear may be arranged to rotate together about a
first rotational axis. The rotatable second cylinder body may be permanently connected
to the second gear. The rotatable second cylinder body and the second gear may be
arranged to rotate together about a second rotational axis. The first cylinder body
may be arranged in the housing such that the first cylinder body is prevented from
rotating about a first rotational axis of the first plug. The first cylinder body
may be completely fixedly arranged in the housing.
[0012] The inventive lock assembly is of dual-cylinder type, indicating that the lock assembly
comprises at least two lock cylinders, each lock cylinder including at least a cylinder
body and a key-receiving plug at least partly received in the cylinder body for rotation
therein. Each plug is provided with an associated lock mechanism selectively interacting
with the associated cylinder body in response to insertion of an appropriate key into
the plug. The lock mechanism may be arranged partly in the plug and partly in the
cylinder body.
[0013] In operation of the inventive lock assembly, a rotatable tailpiece (sometimes also
referred to as a drive pin or a carrier) is drivingly connected to and operated by
the second plug, optionally via a tailpiece adapter. In preferred embodiments, the
second plug and the tailpiece are arranged to rotate together about the rotational
axis of the second plug. In a final assembled state on a door, the tailpiece may extend
out from a rear side of the lock assembly and into a door locking mechanism for operating
a latch or bolt of a door locking mechanism. In some embodiments, the tailpiece may
be directly connected to the second plug. In some embodiments, the tailpiece may be
indirectly connected to the second plug via a tailpiece adapter. In some embodiments,
the tailpiece may be coupled to a rear connecting member forming a rear part of the
cylinder plug being axially movable in relation to a front part of the plug. In preferred
embodiments.
[0014] When the lock assembly has been unlocked by an appropriate key, it can be operated
to rotate the tailpiece between a locked rotational position and an unlocked rotational
position for unlocking and locking the door locking mechanism. These rotational positions
of the tailpiece correspond to a locked rotational position and an unlocked rotational
position, respectively, of the second plug.
[0015] As will be described in more detail below, during unlocking and locking of the door
locking mechanism by operation of the inventive lock assembly by either an appropriate
first key inserted into the first plug, or by a second appropriate key inserted into
the second plug, the second plug is always rotated to rotate the tailpiece. A feature
resulting from the inventive concept is that operation by the second key involves
rotation of the second plug only, whereas operation by the first key involves rotation
of the first plug and, via the gear transmission and the rotatable second cylinder
body, also rotation of the second plug for rotating the tailpiece.
[0016] The lock assembly has basically three operational states: a locked state in which
the second plug cannot be rotated between its locked and unlocked rotational positions;
and a first and a second unlocked state in which the second plug can be rotated between
its locked and unlocked rotational positions.
[0017] When no appropriate key has been inserted into the lock assembly, the lock assembly
is in its locked state. The locked state may be present when no key has been inserted
at all, or if an inappropriate key has been inserted. In the locked state, neither
the first lock mechanism of the first plug, nor the second lock mechanism of the second
plug has been activated by an appropriate key.
[0018] In the locked state, relative rotation between each plug and its associated cylinder
body is restricted by the lock mechanism of the plug. In the locked state, the tailpiece
cannot be rotated to its unlock rotational position. This is accomplished by the second
plug being prevented from rotating to its corresponding unlocked rotational position.
Specifically, the second plug is prevented from rotating to its unlocked rotational
position by "using" or "borrowing" the rotation-restricted state of the first plug.
Since the first lock mechanism of the first plug is restricting rotation of the first
plug relative the first cylinder body, rotation of the first gear and the second gear
is also restricted. This in its turn also restricts rotation of the rotatable second
cylinder body, which is drivingly connected to the second gear. Finally, since the
second lock mechanism of the second plug in the locked state of the lock assembly
is arranged to restrict rotation of the second plug in relation to the second cylinder
body, rotation of the second plug is also restricted. Consequently, the tailpiece
is prevented from being rotated between its locked rotational position and its unlocked
rotational position.
[0019] When an appropriate first key has been inserted into the first plug and no appropriate
second key has been inserted into the second plug, the lock assembly is in its first
unlocked state. In response to turning the first key in the first unlocked state,
the tailpiece can be rotated to its unlocked rotational position for unlocking the
door locking mechanism. In the first unlocked state of the lock assembly, the first
lock mechanism of the first plug is operated by the appropriate first key to not restrict
rotation of the first plug in relation to the first cylinder body. In the first unlocked
state of the lock assembly, the second lock mechanism of the second plug is not operated
by any appropriate second key and, thereby, is arranged to restrict rotation of the
second plug in relation to the rotatable second cylinder body. Since the first plug,
the first gear, the second gear, and the second cylinder body are drivingly or rotatable
interconnected to each other, turning the appropriate first key will result in a rotation
of the components in the following order: first plug → first gear → second gear →
second cylinder body → (via second lock mechanism of second plug) → second plug →
driving pin. It may be noted that both the first plug and the second plug rotate when
the lock assembly is operated in its first unlocked state. It may also be noted that
the gear transmission and the rotatability of the second cylinder housing is used
when operating the lock assembly in its first unlocked state to transfer rotation
of the first plug into a rotation of the second plug.
[0020] When an appropriate second key has been inserted into the second plug and no appropriate
first key has been inserted into the first plug, the lock assembly is in its second
unlocked state. In response to turning the second key in the second unlocked state,
the tailpiece can be rotated between its unlocked rotational position and its unlocked
rotational position. In the second unlocked state, the second lock mechanism of the
second plug is operated by the appropriate second key to not restrict rotation of
the second plug in relation to the second cylinder body. Thereby, the second plug
is drivingly disconnected or decoupled from the components "first housing - first
plug - first gear - second gear - second cylinder body". As a result, the second plug
can be rotated in relation to the second cylinder body to rotate the tailpiece between
its locked unlocked rotational position and its locked rotational position. It may
be noted that the second plug thus rotates both when the lock assembly is operated
in its first unlocked state by a first key and when the lock assembly is operated
in its second unlocked state by a second key.
[0021] According to a second aspect of the inventive concept there is provided a method
for operating a door locking mechanism connected to a dual-cylinder lock assembly,
said method comprising, when using an appropriate first key of a set of appropriate
keys including an appropriate first key and an appropriate second key:
inserting the appropriate first key into a first plug for causing a first lock mechanism
of the first plug to allow the first plug to rotate in relation to an associated first
cylinder body;
turning the appropriate first key for rotation of the first plug in relation to the
first cylinder body;
transferring said rotation of the first plug into a rotation of a second plug rotatably
received within an associated rotatable second cylinder body and arranged to receive
the appropriate second key as an alternative of using the appropriate first key; and
transferring said rotation of the second plug into a rotation of the tailpiece for
operating the door locking mechanism,
wherein said transferring of the rotation of the first plug into a rotation of the
second plug is accomplished by transferring the rotation of the first plug into, in
order, a rotation of a first gear drivingly connected to the first plug, a rotation
of a second gear rotationally connected to the first gear and drivingly connected
to the rotatable second cylinder body, a rotation of the second cylinder body, and
a rotation of the second plug via a second lock mechanism of the second plug interacting
with the rotatable second cylinder body.
[0022] All optional features described below are options both for the inventive assembly
and the inventive method.
[0023] In some embodiments, the lock assembly further comprises at least one intermediate
gear drivingly interconnecting the first gear and the second gear, such that the first
gear and the second gear rotate in the same direction. This may be an advantage in
that the key rotational direction will be the same for both keys. For example, if
the door locking mechanism is designed to be unlocked by a counterclockwise rotation
of the tailpiece, then the intermediate gear ensures that the lock assembly 1 may
be unlocked either by counterclockwise rotation of the first key or by counterclockwise
rotation of the second key. As an alternative to using an intermediate third gear,
it is also possible to drivingly connect the first gear and the second gear to each
other by other means, such as a chain. In other embodiments, the first and the second
gear may be in direct meshed engagement with each other, thus rotating in opposite
directions.
[0024] In some embodiments as an option, at least one of the gears of the lock assembly
is a displaceable gear, which is displaceable, in a direction transversely relative
to a rotational axis of the displaceable gear, between a non-displaced normal position
and at least one displaced position, wherein the lock assembly further comprises means
for restricting rotation or blocking rotation of the displaceable gear in response
to the displaceable gear being displaced to its displaced position. Such an embodiment
may be advantageous for protecting certain weaker parts of the lock assembly if the
latter is subjected to a burglary attempt. Such a weaker part may be a central part
of a gear. As a result of the displaceable gear being displaced into its displaced
position, in which the displaced gear is subjected to either a rotational lock or
a brake force/torque by the at least one brake member, restricting rotation of the
displaced gear, an applied tampering torque for forcibly unlocking the lock assembly
is prevented from being transferred to and damage weaker parts of the assembly, especially
rotationally locked and mechanically weaker parts of the gear transmission. Such optional
embodiments have at the advantage of preventing mechanical failure of such weaker
parts of the assembly, thereby preventing a forcible unlocking attempt from succeeding.
The inventive solution has also the advantage of limiting the manufacturing costs
of the lock assembly, especially since the inventive solution makes it possible to
avoid the need for using very strong and expensive gears in the gear mechanism for
preventing forcible unlocking
[0025] In the inventive lock assembly, each plug is provided with a lock mechanism arranged
to either restrict rotation of the plug in relation to its associated cylinder body
when no appropriate key has been inserted, or to not restrict rotation of the plug
in relation to its associated cylinder body in response to insertion of an appropriate
key. In some embodiments, the lock mechanism of one plug or both plugs may be arranged
to prevent essentially any rotation of the plug in relation to the associated cylinder
body when no appropriate key has been inserted. In such embodiments, the lock mechanism
of the plug may form a rotational lock, for instance implemented by a conventional
mechanical solution including key operated tumblers, or an electrically operated lock
pin or similar. However, the lock mechanism of one plug or both plugs may also be
arranged to form a rotation restriction rather than a rotational lock between the
plug and the associated cylinder body. In such embodiments, the lock mechanism of
the plug may be arranged to restrict initial rotation of the plug in relation to the
cylinder body to a few degrees only, insufficient to rotate the tailpiece its unlocked
rotational position. After such an initial limited rotation of the plug, the lock
mechanism operates as a rotational lock preventing any further rotation of the plug
in relation to the cylinder body.
[0026] PCT/SE2021/050298 with the same applicant as the present application discloses an electronic lock in
which an electromechanical plug can be rotated a few degrees only in relation to a
cylinder body when no appropriate electronic key has been inserted, and which can
be rotated to an unlocked rotational position only if an appropriate key has been
inserted. If an inappropriate key is inserted, the key may be turned only a few degrees.
An attempt to further turn the inappropriate key activates a rotational lock between
the plug and the cylinder body, preventing any further relative rotation.
[0027] In some embodiments where at least one of the lock cylinders is electromechanical,
the electronic key may be programmable. Such a programmable key, which is used to
operate an electromechanical lock, may comprise an energy source, such as a battery,
and a control unit powered by the energy source. The electronic key can access a cloud
based or locally hosted access control system which transfer authorization data to
the electric key and/or log information from the key via internet and a synchronization
unit or via a mobile communication system such as the GSM net and a mobile device,
such as a mobile phone.
[0028] The electronic key is accessed from the synchronization unit or the mobile device
by a physical contact, by near field communication, such as NFC, or by radio communication,
such as Bluetooth. The electronic key can store all data necessary to access at least
one specific electromechanical lock cylinder but cannot access any electromechanical
lock cylinder for which it does not have the appropriate authorization data. Locking
and unlocking using the programmable key is rendered possible only if the programmable
key is synchronized appropriately via the synchronization unit or a mobile device.
Further, such a programmable key may be provided with means by which electrical power,
data and mechanical effort can be transm itted.
Terminology
[0029] The term lock plug or plug refers to a part into which a key is inserted and which
the key turns. A mechanical lock plug may house the bottom pins of a pin tumbler cylinder
mechanism or the discs and springs of a disc tumbler cylinder mechanism. An electromechanical
or electronic lock plug may be provided with an electronically controlled lock mechanism.
[0030] The term "rotatably connected" as used in the present disclosure refers to a connection
or coupling between two rotatable members structured and arranged such that a rotation
of one member is transferred, directly or indirectly, into a rotation to the other
member, and such that if the first member is prevented from rotating then the second
member is also prevented from rotating.
[0031] The term appropriate key as used in the present disclosure refers to a key which
allows, when inserted into a rotatable plug, to turn the plug.
[0032] The term tailpiece as used in the present disclosure refers to a member that extends
from the rear of the housing. The rotation of the tailpiece is what mechanically actuates
the door locking mechanism.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] The inventive concept, some non-limiting embodiments, and further advantages of the
inventive concept will now be described with reference to the drawings in which:
- Fig. 1
- is a perspective view of a first embodiment of a lock assembly.
- Fig. 2
- is an exploded view of the first embodiment.
- Fig. 3
- schematically illustrates a locked state.
- Figs 4A to 4D
- illustrate a first unlocking sequence.
- Fig. 5A to 5C
- illustrate a second unlocking sequence.
- Fig. 6A to 6C
- schematically illustrates the operation of a second embodiment of a lock assembly.
- Fig. 7
- is an exploded view of an electromechanical lock cylinder.
- Fig. 8A to 8D
- illustrate the operation of the electromechanical lock cylinder in Fig. 7.
- Fig. 9
- is an exploded view of a third embodiment of a lock assembly.
- Fig. 10
- is a rear view of a fourth embodiment of a lock assembly.
- Fig. 11
- is a rear view of a fifth embodiment of a lock assembly.
- Fig. 12A to 12E
- illustrate an embodiment of a lock assembly with brake function.
- Figs 13A to 13C
- illustrate an alternative embodiment with brake function.
[0034] The inventive concept will now for the purpose of exemplification be described in
more detailed by means of examples and with reference to the accompanying drawings
illustrating embodiments and non-limiting examples of the inventive concept. The present
invention may, however, be embodied in many different forms and should not be construed
as limited to the embodiments set forth herein.
1st embodiment
[0035] The description in connection with Figs 1, 2, 3, 4A to 4D, and 5A to 5C aims to describe
the structure and the operation of a first embodiment of a lock assembly according
to the inventive concept.
[0036] Figs 1 and 2 illustrate a dual-cylinder lock assembly 1 according to a first embodiment.
The lock assembly 1 is arranged to be connected via a tailpiece 2 to a door locking
mechanism 3 in a door 4. The door locking mechanism 3 may be of any kind known in
the art and may be is arranged in a lock housing in a cavity of the door 4. As is
also well known in the art, the locking mechanism 3 cooperates, via a lock bolt or
latch 5, with a striking plate (not shown) arranged in a door frame (not shown) to
lock the door 4. The door locking mechanism 3 controls the lock bolt 5 via the lock
assembly 1 from the exterior side of the door 4.
[0037] The dual-cylinder lock assembly 1 comprises an elongate housing 6 containing the
various parts of the assembly. In the illustrated first embodiment, the housing 6
has an elongate and rather narrow shape arranged to be mounted at an entrance door
4 of an apartment building, and is arranged to support a handle 7. The handle 7 does
not have to form part of the lock assembly 1. Embodiments for mounting on a door of
a private residence may have other shapes of the housing 6 and not including support
for the handle 7.
[0038] The lock assembly 1 is of dual-cylinder type, including a first lock cylinder 10
and a second lock cylinder 20. In the present disclosure, a lock cylinder comprises
at least a cylinder body and a key-receiving plug rotatably received in the cylinder
body. A lock mechanism is arranged to selectively interact with the cylinder body
to selectively restrict rotation of the plug in relation to the cylinder body. The
lock mechanism may be entirely or partly arranged in the plug and/or the cylinder
body. Accordingly, in the illustrated first embodiment, the first lock cylinder 10
comprises a first cylinder body 11 and a first plug 12 arranged to receive an appropriate
first key K1 (Fig. 4A), and the second lock cylinder 20 comprises a second cylinder
body 21 and a second plug 22 arranged to receive an appropriate second key K2 (Fig.
5A). The door locking mechanism 3 may be unlocked or locked by using either key K1
or K2.
[0039] Each one of the first and the second lock cylinders 10 and 20 may be either a mechanical
lock cylinder or an electromechanical lock cylinder. Thus, the two lock cylinders
10 and 22 may be of the same type or of different types. In the illustrated first
embodiment, the first lock cylinder 10 is mechanical and is arranged to be operated
by an appropriate mechanical first key K1, while the second lock cylinder is electromechanical
and is arranged to be operated by an appropriate electronic second key K2. As is known
per se in the art, the mechanical cylinder lock 10 may be operated for instance by
a resident's mechanical key K1, while the electromechanical lock cylinder 20 may be
operated by an electronic service personnel key K2, especially a programmable electronic
key programmed to operate the second plug 22 of a plurality of lock assemblies.
[0040] In use, the lock assembly 1 is operatively connected to the door locking mechanism
3 via the tailpiece 2 to unlock and lock the door locking mechanism 3. The tailpiece
2 may be of different length, and in some embodiments it may be adjustable in length
for adaptation to different door dimensions. As an example, the tailpiece may be telescopic.
As shown in Fig. 2, the illustrated first embodiment also uses a separate tailpiece
adapter 2a for connecting the lock assembly 1 to the tailpiece 2. The tailpiece 2
or the tailpiece adapter 2a may or may not be considered as forming part of the lock
assembly 1.
[0041] For unlocking and locking of the door locking mechanism 3, the tailpiece 2 is rotatable
between a locked rotational position and an unlocked rotational position, for instance
a rotational movement of about 90 degrees. This rotation is accomplished in response
to turning the appropriate first key K1 or turning the appropriate the second key
K2. In preferred embodiments of the invention, the tailpiece 2 is rotated directly
in response to turning of the first key K1 or the second key K2, i.e. with no rotational
lag between the key turning and the tailpiece rotation. In preferred embodiments,
there is a 1:1 rotational relation between the key turning and the tailpiece rotation,
i.e. the tailpiece 2 is rotated the same number of degrees as the key.
[0042] Only a single tailpiece 2 is used to operate the door locking mechanism 3 of the
door 4. Specifically, the single tailpiece 2 is operated by the second plug 22. The
tailpiece 2 may be directly connected to the second plug 22, or indirectly connected
to the second plug 22 as in the first embodiment using a tailpiece adapter 2a. In
preferred embodiments, the second plug 22 and the tailpiece 2 are arranged to rotate
together about a common second rotational axis A2. From a functional perspective,
the connection between the second plug 22 and the tailpiece 2 means that if the second
plug 22 is prevented from rotating, then as a consequence the tailpiece 2 cannot be
rotated and the door locking mechanism 3 cannot be unlocked. Also, as a consequence
of the tailpiece 2 being operated by the second plug 22, any unlocking or locking
of the door locking mechanism 3 will involve rotation of the second plug 22, not only
when using an appropriate second key K2 but also when using an appropriate first key
K1 as will be described in detail below.
[0043] In the first embodiment, the electromechanical second lock cylinder 20 is designed
in accordance with applicant's international application
PCT/SE2021/050298, filed 1 April 2021, the contents of which is hereby incorporated by reference. Other electromechanical
designs may also be used.
[0044] A specific functional feature of the electromechanical lock cylinder 20 designed
according to applicant's PCT application mentioned above is that the rotatable second
plug 22 is actually not in a rotationally locked state in relation to the second cylinder
body 21 when no key has been inserted into the second plug 22. Instead, the illustrated
electromechanical lock cylinder 20 is designed so that the lock mechanism of the second
plug 22, when an inappropriate second key K2, or some tool such as a screwdriver,
is inserted and initially turned, will allow only a very limited rotation of the second
plug 22 in the order of few degrees (e.g. 2-4 degrees) before the locking mechanism
of the second plug 22 effectively prevents further rotation of the second plug 22
in relation to the second cylinder body 21. On the other hand, if an appropriate electronic
second key K2 is inserted into the electromechanical second plug 22, the appropriate
electronic second key K2 will activate the locking mechanism of the second plug 22
to allow rotation of the second plug 22 in relation to the second cylinder body 21
between its locked rotational position and its unlocked rotational position. It should
be noted that this specific design of the electromechanical second lock cylinder 20
is not essential to the inventive concept, and the inventive principle may be implemented
with electromechanical lock cylinders arranged to form a complete rotational lock
when no appropriate key has been inserted.
[0045] The electromechanical second lock cylinder 20 may be configured to be powered by
and communicate a programmable electronic second key K2 upon the insertion of the
electronic second key K2 in the second plug 22. To this end, the second electromechanical
lock cylinder 20 may comprise power receiving means, communication means and an electrical
control unit (all not shown). The electromechanical second lock cylinder 20 may further
comprise an access control device (not shown) for controlling access of an inserted
electronic key K2. Further details regarding the structure and the operation of this
specific electromechanical cylinder lock 20 will be provided later in the description
with reference to Fig. 7 and Figs 8A to 8D.
[0046] In other embodiments of the lock assembly 1 including one or two electromechanical
cylinder locks, such locks may have a different design, for instance a design where
the lock mechanism of the electromechanical second plug 20 is provided by at least
one selectively movable lock pin, which in the locked state of the electromechanical
cylinder lock provides a complete rotational lock between the plug and the cylinder
body. For illustration purposes only, in the schematic figures (see Fig. 3 and Fig.
4D) illustrating the operation of the lock assembly 1, the electromechanical second
cylinder lock 20 is shown as comprising such a selectively movable lock pin 23.
[0047] As mentioned above in the summary section, each one of the first plug 12 and the
second plug 22 is provided with a locking mechanism arranged to either restrict rotation
of the plug in relation to its associated cylinder body when no appropriate key has
been inserted, or to not restrict rotation of the plug in relation to its associated
cylinder body in response to insertion of an appropriate key. The term "restrict rotation"
covers embodiments where the lock mechanism of a plug is arranged to prevent any rotation
of the plug in relation to its associated cylinder body when no appropriate key has
been inserted. In such embodiments, the lock mechanism of the plug is arranged, when
no appropriate key has been inserted, to restrict rotation by forming a complete rotational
lock where no plug rotation is possible in relation to the associated cylinder body.
This is the case for the mechanical first lock cylinder 10 in the illustrated embodiment
where tumblers 13 create such a rotational lock unless the appropriate mechanical
first key K1 is inserted.
[0048] However, the term "restrict rotation" also covers embodiments where the lock mechanism
of a plug is arranged to form a rotation restriction rather than an initial complete
rotational lock between the plug and the associated cylinder body. Also, such a restriction
may be activated first when someone tries to turn the plug without having an appropriate
key inserted. Put in other words, in some embodiments, the plug of a cylinder lock,
especially an electromechanical cylinder lock, may actually be non-locked in the absence
of an appropriate key, but becomes rotationally locked in response to the plug being
initially turned by inappropriate means. Applicant's above-mentioned PCT application
discloses an electronic lock in which an electromechanical plug can be initially rotated
a few degrees in relation to a cylinder body when no appropriate electronic key has
been inserted, and which can be rotated freely to an unlocked rotational position
only if an appropriate key has been inserted. If an inappropriate key is inserted,
the key may be initially turned a few degrees only, insufficient to turn the tailpiece
to its unlocked rotational position. Any attempt to further turn the inappropriate
key beyond such few degrees brings the lock mechanism of the plug to activate a complete
rotational lock between the plug and the cylinder body, preventing any further relative
rotation.
[0049] The first cylinder body 11 is arranged in the housing 10 such that it is prevented
from rotating about the first rotational axis A1 of the first plug 11. Other movements
of the first cylinder body may be possible in certain embodiments. In the illustrated
first embodiment of the lock assembly 1, the first cylinder body 11 is fixedly arranged
within the housing 6 in a first opening 51 with a shape corresponding to the shape
of the first cylinder body 11. In contrast and for reasons that will become apparent
in the following, the second cylinder body 21 is rotatably arranged within the housing
10 for rotation about the second rotational axis A2 of the second plug 22. In the
illustrated embodiment, the housing 6 is provided with a cylindrical second opening
52 in which the second cylinder body 22 is rotatably received.
[0050] In the present description, the expression "arranged within the housing 10" also
covers embodiments where a lock cylinder 10, 20 is only partly received within the
housing 6. A lock cylinder 10, 20 may be insertable into and retractable from the
housing 6 as a separate unit during installation, which especially allows an existing
mechanical lock cylinder to be reused during installation of a dual-cylinder lock
assembly 1 according to the invention. As is known in the art, suitable means may
be provided to prevent the cylinder bodies 11 and 21 from being retracted from the
housing 6.
[0051] As shown in the figures, first cylinder body 11 may have a non-cylindrical elongate
and general oval shape and is received in the correspondingly shaped cavity 51 in
the housing 10, thus preventing rotation of the first cylinder body 11 about the first
rotational axis A1 relative to the housing 10. In preferred embodiments as shown in
the figures, the rotatable second cylinder body 21 may have a general shape of a cylinder
or cylindrical sleeve, rotatably received in the correspondingly shaped cylindrical
cavity 52 of the housing 6, thereby allowing the second cylinder body 21 to be rotatably
supported by the housing 6. However, the inventive concept may be implemented by other
non-cylindrical shapes of the second cylinder body 21, provided that it is rotatably
arranged within the housing 6.
[0052] It may be noted that in the illustrated embodiment there is no direct locking mechanism
between the rotatable second cylinder body 21 and the housing 6. The rotatability
of the rotatable second cylinder body 21 in relation to the housing 6 is controlled
by other means as will be described below.
[0053] The lock assembly 1 further comprises a first gear 14 connected to the first plug
12 so that the first gear 14 rotates with the first plug 12. In the illustrated embodiment,
the first gear 14 is permanently and directly connected to the first plug 12, and
arranged to rotate together with the first plug 12 about the first rotational axis
A1, parallel and spaced from the second rotational axis A2 of the second cylinder
lock 20. The term "permanently" in the present disclosure means that the direct connection
between the first plug 12 and the first gear 14 is present during all normal operation
of the lock assembly 1. During repair and installation situations as an example, the
first gear 14 may be removed from the first plug 12.
[0054] No clutch mechanism or gear shifting movement is needed between the first plug 12
and the first gear 14. Especially, the connection between the two parts 12 and 14
is not dependent on or responsive to any key insertion as in some prior art solutions.
In the illustrated embodiment presented as an example only, the rotational or operative
connection between the first plug 12 and the first gear 14 is accomplished by a cross-shaped
end portion 15 of the first plug 12 (see Fig. 4B) received in a corresponding cross-shaped
central opening 16 of the first gear 14. Other designs are possible regarding portions
15 and 16. For instance, the central opening may have the form of a longitudinal slit,
arranged to receive a correspondingly shaped end portion 15 of the first plug 12.
[0055] In alternative embodiments, the first gear 14 may be drivingly connected to the first
plug 11 in other way, for instance indirectly connected. Also, it would be possible
to form the first plug 11 and the first gear 14 as a one-piece, integrally formed
member.
[0056] The lock assembly 1 further comprises a second gear 24 connected to the rotatable
second cylinder body 21. It may be noted that the second gear 24 is not directly coupled
to the second plug 22, but instead connected to the rotatable second cylinder body
21. The second gear 24 and the second cylinder body 21 are arranged to rotate together
about the second rotational axis A2. From a functional perspective, they may be considered
as forming a single rotatable part.
[0057] In the illustrated embodiment, the second gear 24 is permanently and directly connected
to the second cylinder body 21, and is arranged to rotate together with the second
cylinder body 21 about the second rotational axis A2. In the illustrated first embodiment
presented as an example only, the rotational or operative connection between the rotatable
second cylinder body 21 and the second gear 24 is accomplished by a non-cylindrical
end portion 25 (see Fig. 2) of the second plug 22 being received in a corresponding
non-cylindrical central opening 26 of the second gear 24.
[0058] The purpose using a gear transmission in the lock assembly 1, including at least
the first gear 14 and the second gear 24, is to provide an operative or rotatable
connection between the first plug 12 and the rotatable second cylinder body 21. The
first plug 12 and the second cylinder body 21 are connected to each other via a gear
transmission which includes at least the first gear 14 and the second gear 24 and
which is arranged such that the first plug 12 and the rotatable second cylinder body
21 either rotate together or stand still together.
[0059] In some embodiments, the gear transmission may include the first and second gears
14, 24 only, wherein the two gears 14, 24 are in direct meshed engagement with each
other during all operation of the lock assembly 1. Such an alternative embodiment
is shown in Fig. 10. In such an alternative embodiment, the two gears 14, 24 rotate
in opposite directions. However, it may be an advantage especially for a user if the
first plug 12 and the second plug 22 are rotated in the same rotational direction
(normally counter-clockwise) when unlocking the door 4, and rotated in the same rotational
direction (normally clockwise) when locking the door 4. In alternative embodiments,
this could have been accomplished by a chain or the like between the first gear 14
and the second gear 24. However, in the illustrated first embodiment, the gear transmission
further includes an intermediate third gear 34, which is drivingly arranged between
the first gear 14 and the second gear 24. The main purpose of the third gear 34 is
to ensure that the first gear 14 and the second gear 24 rotate together in the same
rotational direction, which in its turn ensures that the user can unlock the door
4 by turning either the first key K1 or the second key K2 in the same rotational direction.
Fig. 11 illustrates an alternative embodiment including two intermediate gears 34a,
34b. The operation is essentially the same.
[0060] In the first embodiment, the three gears 14, 24, and 34 are located in a common vertical
plane. The third gear 34 is in meshed engagement with both the first gear 14 and the
second gear 24. In the first embodiment, the third gear is in permanent meshed engagement
with both the first gear 14 and the second gear 24 during all normal states of the
lock assembly 1. This is an advantage compared to certain prior art solutions in which
the operation relies on selective gear coupling and decoupling.
[0061] Referring to Fig. 2 and 4A, a cover member 53 is secured by four screws (not shown)
to the rear side of the housing 6 for covering the gears 14, 24, 34 and for keeping
the gears in correct axial position. Two screws 54 extend through corresponding openings
55 in the cover member 53 and are in engagement with the first cylinder body 11 to
prevent the first lock cylinder 10 from being retracted from the housing 6. The cover
member 53 is further provided with a first opening 56 coaxial with the first rotational
axis A1, and a second opening 57 coaxial with the second rotational axis A2. The second
opening 57 allows the tailpiece 2 to be connected to the second plug 22 via the tailpiece
adapter 2a.
[0062] In the illustrated first embodiment, the first gear 14 is partly received in the
first opening 56 of the cover member 53. The first opening 56 may act as a rotational
control or bearing for the first gear 14. The second opening 57 may act as a rotational
control or bearing for the second gear 24.
[0063] The number of teeth of each one of the three gears 14, 24, and 34 may be varied compared
to the illustrated embodiment. In the first embodiment, the number of teeth of the
first gear 14 is equal to the number of teeth of the second gear 24, resulting in
that a certain angular rotation of the first plug 12 by the first key K1 is translated
into the same angular rotation of the tailpiece 2. Furthermore, the number of teeth
of the intermediate third gear 34 is less than the number of teeth of the first gear
14 and the second gear 24. Its diameter is also smaller. This allows a reduced overall
dimension of the lock assembly 1, and it also allows the two lock cylinder 10, 20
to be located closer to each other. The gears 14, 24, and 34 are preferably made from
metal, such as steel.
[0064] It will be appreciated that there is a sequential and permanent rotational connection
present between the following five parts and in named order: the first plug 12 - the
first gear 14 - the intermediate third gear 34 - the second gear 24 - the rotatable
second cylinder body 21. This rotational connection between these five parts ensures
that they either all rotate together, or that they all do not rotate. Especially,
if one of these five parts is prevented from rotating, rotation of the other four
parts is also prevented as a consequence. This is especially the case when no appropriate
first key K1 has been inserted into the first plug 12, preventing the first plug 12
from rotating and, consequently, preventing the other four parts from rotating.
Operation
[0065] The operation of the first embodiment will now be described. The details of the operation
of the electromechanical lock mechanism of the second lock cylinder 20 will not be
provided at this time since the understanding of such details is not needed for the
understanding of the overall inventive concept.
[0066] In general, the illustrated dual-cylinder lock assembly 1 has three operational states:
a locked state when the lock mechanism 3 of the door 4 cannot be unlocked; a first
unlocked state where the lock mechanism 3 of the door 4 can be operated using an appropriate
first key K1; and a second unlocked state where the lock mechanism 3 of the door 4
can be operated using an appropriate second key K2. The general description of the
operation of the first embodiment applies to all other embodiments. Thus, what is
stated in the description of the first embodiment in terms of structure and operation
applies also to embodiments where both lock cylinders are mechanical, and where both
lock cylinders are electromechanical.
[0067] Fig. 3 is provided to give a better understanding of the locked state. Fig. 3 schematically
illustrates the various parts. In all schematical figures, parts that are prevented
from rotating are marked with an x inside a circle. In the locked state in Fig. 3,
all parts are marked as being prevented from rotating. In order to simplify the schematical
illustration in Fig. 3, the second lock mechanism of the second plug 22 is not shown
in accordance with the more advanced design in Fig. 7, but is instead schematically
illustrated as a movable lock pin 23, which can be selectively moved into and out
of engagement with the rotatable second cylinder body 21 in response to insertion
of an appropriate electronic second key K2. In Fig. 3, the lock pin 23 is in its locked
position. Movement of the lock pin 26 can be accomplished in any suitable electromechanical
way, such as by using solenoids.
[0068] The locked state is present when no appropriate key K1 or K2 has been inserted into
the lock assembly 1. The locked state may be present when no key has been inserted
at all, or if only a non-appropriate key has been inserted. In the locked state, neither
the first lock mechanism of the first plug 12, nor the second lock mechanism of the
second plug 22 has been activated by an appropriate key. In the locked state, relative
rotation between each plug 12, 22 and its associated cylinder body 11, 21 is restricted
by the lock mechanism of the plug.
[0069] A specific feature of the inventive concept is that, in the locked state of the lock
assembly 1, the second plug 22 is prevented from rotating to its unlocked rotational
position by "using" or "borrowing" the rotation-restricted state of the first plug
12: in the locked state, the second plug 22 is prevented from rotating to its unlocked
rotational position as a consequence of the first lock mechanism 13 of the first plug
12 is restricting rotation of the first plug 12 in relation to the stationary first
cylinder body 11. As a result, rotation of the entire gear transmission 14, 24, 34
is also restricted. This in its turn also restricts rotation of the rotatable second
cylinder body 21 which is drivingly connected to the second gear 24. Finally, since
the second lock mechanism 23 of the second plug 22 in the locked state of the lock
assembly 1 has not been activated and thus restricts rotation of the second plug 22
in relation to the second cylinder body 21, rotation of the second plug 22 is also
restricted and it cannot be rotated to its unlocked rotational position. As a final
consequence, the tailpiece 2 is prevented from being rotated to its unlocked rotational
position in the locked state of the lock assembly 1.
[0070] Figs 4A to 4D illustrates the first unlocked state of the lock assembly 1 starting
from the situation in Fig. 4A where the assembly is still in its locked state. In
Fig. 4B, an appropriate first key K1 has been inserted into the first plug 12 and
no appropriate electronic second key K2 has been inserted into the second plug 22.
The assembly 1 is now in its first unlocked state. As shown in Fig 4C and 4D, in response
to turning the appropriate mechanical first key K1, the tailpiece 2 can be rotated
from its locked rotational position to its unlocked rotational position for unlocking
the door locking mechanism 3. As an example, this may be a rotational movement counterclockwise
over an angle of about 90 degrees.
[0071] When the first key K1 is inserted, the mechanical first lock mechanism 13 of the
mechanical first plug 12 is operated by the appropriate mechanical first key K1 to
no longer restrict rotation of the first plug 12 in relation to the stationary first
cylinder body 11. In the first unlocked state, the second lock mechanism 23 of the
second plug 22 is not operated or activated by any appropriate second key K2 and,
thereby, is arranged to restrict rotation of the second plug 22 in relation to the
rotatable second cylinder body 21. This is illustrated schematically by the lock pin
23 in Fig. 4D. Now, since the above-mentioned five interconnected components (the
first plug 12, the first gear 14, the third gear 34, the second gear 24, and the second
cylinder body 21) are all drivingly interconnected to each other, turning the appropriate
first key K1 in relation to the first cylinder body 11 will result in a rotation of
the components in the following order: the first plug 12 → the first gear 14 → the
third gear 34 → the second gear 24 → the second cylinder body 21 → (via the second
lock mechanism 23 of second plug 22) → the second plug 22 → the pintail 2.
[0072] Specific features of the inventive concept may here be noted: First, the second locking
mechanism (represented by the lock pin 23 in Fig. 4D) of the second plug 22, in the
absence of an inserted appropriate second key K2, is not used as normally done in
the art to prevent the second plug 22 from rotating. Instead, the non-activated second
lock mechanism 23 of the second plug 22 is here instead used to actually transfer
rotation to the second plug 22 to make it rotate. Second, it may also be noted that
both the first plug 12 and the second plug 22 rotate when the lock assembly 1 is operated
in its first unlocked state. In addition, it may be noted that the gear transmission
14, 24, 34 and the rotatability of the second cylinder body 21 is used when operating
the lock assembly 1 in its first unlocked state to transfer rotation of the first
plug 12 into a rotation of the second plug 22. It will be appreciated that the gear
transmission 14, 24, 34 has in fact at least the following two functions:
- First function of the gear transmission: in the locked state of the lock assembly
1, the gear transmission 14, 24, 34 operates to transfer the rotational locked state
of the first plug 12 into a rotationally locked state of the rotatable second cylinder
body 21, ensuring that the second plug 22 and the tailpiece 2 cannot be rotated.
- Second function of the gear transmission: In the first unlocked state of the lock
assembly 1, the gear transmission 14, 24, 34 instead operates to transfer the turning
of the first key K1 and the rotation of the first plug 12 into a rotation of the rotatable
second cylinder body 21, with the result that also the second plug 22 and the tailpiece
2 are rotated since relative rotation between the second plug 22 and the second cylinder
body 21 is restricted in the first unlocked state by the second lock mechanism (represented
by the lock pin 23) of the second plug 22.
[0073] Figs 5A to 5C illustrate the second unlocked state of the lock assembly 1. An appropriate
electronic second key K2 has been inserted into the second plug 22 and no appropriate
mechanical first key K1 has been inserted into the first plug 12. In response to turning
the appropriate electronic second key K2 in the second unlocked state, the tailpiece
2 can be rotated to its unlocked rotational position for unlocking the door locking
mechanism 3. In the second unlocked state of the lock assembly 1, the second lock
mechanism 23 of the second plug 22 is activated by the appropriate second key K2 to
not restrict rotation of the second plug 22 in relation to the second cylinder body
21. In this second unlocked state of the lock assembly 1, the second plug 22 is thereby
drivingly disconnected from the five interconnected components "first housing 10 -
first plug 12 - first gear 14 third gear 34 - second gear 24 - second cylinder body
21", and can be rotated in relation to the second cylinder body 21 for rotating the
tailpiece 2 to its unlocked rotational position. It may be noted that the second plug
22 thus rotates both when the lock assembly 1 is operated in its first unlocked state
by the appropriate first key K1 and when the lock assembly 1 is operated in its second
unlocked state by the appropriate second key K2.
2nd embodiment
[0074] Figs 6A to 6C schematically illustrate the structure and operation of a second embodiment
in which both lock cylinders are mechanical. The operation of this embodiment is essentially
the same as for the first embodiment.
Electronic plug
[0075] The details of the more advanced design of the electromechanical second cylinder
lock 20 will now be described with reference to Fig. 7 and Figs 8A to 8D. The embodiment
of the lock cylinder 20 in Fig. 7 differs in one aspect from the embodiment shown
in the previous figures, in that the second cylinder body 21 shown in Fig. 7 is not
cylindrical, but rather of the same oval elongate shape as the mechanical first cylinder
lock 10. However, the operation is essentially the same, and for functional aspects
involving rotation of the second cylinder body 21 the latter can just be imagined
as cylindrical and rotatably mounted, as illustrated in for example Fig. 2 and Fig.
4A illustrating a cylindrical second cylinder body 21. If the first cylinder lock
10 is instead of electromechanical type, the design of the cylinder body 21 shown
in Fig. 7 may be used.
[0076] The second lock cylinder 20 includes, going from the left to the right in the exploded
view in Fig. 7, the following components: the second plug 22, a blocking member 100,
a biasing member 101 in the form of a spring, a rotatable and slidable annular member
102, an electromechanical coupling device 103, a connecting member 104, the second
cylinder body 21, and the tailpiece adapter 2a.
[0077] The blocking member 100 is fixedly arranged in the cylinder body 21, and is especially
prevented from rotating in relation to the cylinder body 21. To this end, the blocking
member 100 is provided with a peripheral groove 105 arranged to receive a locking
pin (not shown) to engage the cylinder body 21. The rear side of the blocking member
100 is provided with a tooth-shaped blocking surface 100b the purpose of which is
to prevent the annular member 102 from rotating in certain states of the cylinder
lock 20.
[0078] The annular member 102 is rotatably mounted on the second plug 22 for rotation about
the second rotational axis A2 in relation to the plug 22. The annular member 102 is
also mounted for axial displacement relative to the second plug 22 along the second
rotational axis A2. The annular member 102 can be rotationally locked relative to
the second plug 22 by inserting an appropriate key K2. If instead an inappropriate
key is inserted and turned, the annular member 102 will rotate and/or axially move
relative to the second plug 22 as described below. The front side of the annular member
102 is provided with a tooth-shaped blocking surface 102a corresponding to the tooth-shaped
blocking surface 100b of the locking member 100. The rear side of the annular member
102 is provided with a wave-shaped engagement surface 102b.
[0079] The biasing member 101, here in the form of a spring, is arranged between the blocking
member 100 and the annular member 102 to bias the annular member 102 away from contacting
the blocking member 100 and into engagement with the connecting member 104.
[0080] The electromechanical coupling device 103 is received in and rotated together with
the plug 22. The coupling device 103 is arranged to, upon insertion of an appropriate
key K2, to rotationally couple the annular member 102 to the plug 22. This mechanical
locking is indicated by a dotted arrow in Fig. 7. The rotational lock is accomplished
by a selectively movable locking pin at 105 (which should not be confused with the
schematical lock pin 23 in Fig. 3) of the electromechanical coupling member 103 engaging
an opening 106 in the annular member 102. To this end, the coupling member 103 may
comprise an actuator configured to communicate with an access control device (not
shown). The electromechanical coupling member 103 is thus arranged, upon the insertion
of an appropriate electronic second key K2, to rotationally lock the annular member
102 to the plug 22. As will be described below, this will prevent the cylinder lock
20 from being locked upon turning the key K2.
[0081] The front side of the connecting member 104 is provided with a wave-shaped engagement
surface 104a, arranged to interact with the wave-shaped engagement surface 102b of
the annular member 102. The rear side of the connecting member 104 is rotationally
connected to the tailpiece adapter 2a. The connecting member 104 is further provided
with side openings 104c arranged to receive a break pin 120 shown in Fig. 8B.
[0082] The purpose of the connecting member 104 is to rotationally connect the plug 22 to
the tailpiece adapter 2a. To this end, the connecting member 104 is rotationally secured
to the plug 22 by means of a locking arrangement 110, 112 (Fig. 8A) which is arranged
to rotationally secure the plug 22 to the connecting member 104 in an absence of an
axial movement of the annular member 102, and to rotationally unsecure the connecting
member 104 from the plug 22 upon a rotation of the plug 22 relative to the annular
member 102 when the annular member 102 is in engagement with the stationary blocking
member 100.
[0083] The operation of the electromechanical cylinder lock 20 in Fig. 7 will now be described
with reference to Figs 8A to 8D.
[0084] In a resting state of the cylinder lock 20 with no key inserted, the spring 101 holds
the annular member 102 biased to the right in Fig. 8C against the connecting member
104. In this position, there is a full engagement between the two wave shaped engagement
surfaces 102b and 104a. In this resting state of the cylinder lock 20, there is also
a rotational connection between the rear end of the plug 22 at 110 and the front end
of the connecting member 104 at 112, i.e. a rotational connection between the plug
22 and the tailpiece adapter 2a.
[0085] In response to insertion of an appropriate key K2, the electromechanical coupling
device 103 will activate to form a rotational lock between the plug 22 and the annular
member 102 at 105/106. As a consequence, a subsequent turning of the inserted appropriate
second key K2 will rotate the annular member 102 together with the plug 22. As a result,
the plug 22, the annular member 102, the connecting member 104, and the tailpiece
adapter 2a will all rotate together, whereby the door locking mechanism 3 may be opened.
It may be noted that the plug 22 was actually not rotatably locked before the second
key K2 was inserted, and that the second key 2 actually did not unlock any rotational
lock. Instead, the appropriate second key activated the coupling member 103 to prevent
the lock cylinder 20 from being locked upon key turning.
[0086] Fig. 8D illustrates the operation if an inappropriate key is inserted and turned.
Since the key is not an appropriate key, the electromechanical coupling device 103
will not be activated. Therefore, no rotational lock will be formed between the plug
22 and the annular member 102 at 105/106. In this state, the annular member 102 is
rotatable in relation to the plug 22. On the other hand, the annular member 102 is
subjected to a force holding it in a rotational position in relation to the cylinder
body 21. To this end, the annular member 102 is provided with an axial engagement
groove 102c (Fig. 7). A spring loaded engagement element (not shown) arranged in the
cylinder body 21 is in engagement with the axial engagement groove 104c of the annular
member 104, thereby preventing rotation of the annular body 104 in this state. This
engagement at groove 104c is disengaged when the plug 22 and the annular member 102
is rotated by an appropriate key K2.
[0087] An initial turning of the inappropriate key, in the order of a few degrees only,
the following will take place: Turning of the inappropriate key results in a slight
rotation of the plug 22 and thereby the connecting member 104. Since the annular member
102 is not forced to rotate together with the plug 22 and is held in a nonrotating
state by the engagement at groove 104c, the wave-shaped engagement at engagement surfaces
102b and 104a will make the annular member 104 move to the left in Fig. 8D into blocking
contact with the blocking member 100 at the blocking surfaces 100b and 102a. The annular
member 102 is now completely rotationally blocked and also cannot move any further
axially to the left. Since the annular member 102 cannot be rotated, a continued rotation
of the plug 22 will make the connecting member 104 move away from the plug 22 to the
right, due to the engagement at the wave shaped engagement surfaces 102b and 104a.
As a result, the rotational connection at 110/112 between the plug 22 and the connecting
member 104 is disconnected, and the tailpiece adapter 2a can no longer be operated.
[0088] The design shown in Fig. 7 further comprise an additional feature implemented by
a break pin 120. As described above, the plug 22 and the connecting member 104 are
normally rotationally connected at 110/112 by complementary shaped parts arranged
to transfer rotational forces. However, the connecting member 104 may also be connected
to the plug 22 via a break pin 120. The break pin 120 is located in a through-going
opening in the end portion of the plug 22 as shown to the left in Fig. 8A. End portions
of the break pin 120 are located in the side openings 104c of the connecting member
104. During normal unlocking of the cylinder lock 20, the rotational forces applied
to the plug 22 are transferred to the connecting member 104 at the rotational connection
at 110/120 with no rotational forces acting on the break pin 120. However, in the
situation described above with a continued turning of an inappropriate key, the connection
member 104 will be axially separated from the annular member 102. As a result, the
break pin 120 will break and the lock cylinder 20 has to be repaired before being
possible to unlock. It will be appreciated that the break pin 120 is accordingly not
designed to take up rotational forces during normal unlocking, but design to brake
if subjected to strong enough axial forces.
[0089] The electromechanical lock cylinder 20 shown in the first embodiment is of the design
now described with reference to Fig. 7 and Figs. 8A to 8D. the operation of the lock
cylinder 20 is special in the first unlocked state of the lock assembly 1, as now
will be explained. It will first be recalled that the blocking member 105 is rotationally
locked to the housing body. Thus, referring to Fig. 2, the blocking member 105 is
rotationally locked to the rotatable and sleeve-shaped second cylinder body 22. Accordingly,
when the second cylinder body 22 is rotated in the first unlocked state by turning
the first appropriate key K1, then also the blocking member 105 will be rotated. It
will also be recalled that the annular member 102 is held in rotational position in
relation to the second housing body 21 by mean of spring loaded engagement members
engaging the axial engagement groove 102c of the annular member. Furthermore, it will
be recalled that the second plug 22 is not activated by a second key K2 in the first
unlocked state. Accordingly, in the first unlocked state, the annular member 102 is
not rotationally locked to the second plug 22 at 105, 106.
[0090] With these facts in mind, it will be appreciated that the following will occur when
the first key K1 is turned in the first unlocked state of the lock assembly 1. The
key turning is transferred via the gear transmission into a rotation of the rotatable
second cylinder body 21. This rotation, in its turn, is transferred into a rotation
of the annular member 102 due to the engagement at the engagement groove 102c. At
this situation, there is an engagement at the wave-shaped engagement surfaces 102b
and 104a. Depending on the friction of the door locking mechanism 3 (low or high)
the following will occur.
[0091] If the friction of the door locking mechanism 3 is relatively low, the engagement
at the engagement groove 102c will be sufficiently strong to rotate the connecting
member 104 and thereby the tailpiece 2 for unlocking the door locking mechanism 3.
[0092] If, on the other hand, the friction of the door locking mechanism 3 is relatively
high, the connecting member 104 will initially not rotate due to the frictional-induced
rotational resistance from the tailpiece 2. A continued turning of the first key K1
will therefore now instead cause the annular member 102 to move axially away from
the connecting member 104 into blocking engagement with the blocking member 100. It
may be noted that the rotational connection between the plug 22 and the connection
member 104 at 110, 112 is still intact. However, the blocking member 100 is fixed
to and rotates together with the rotating second cylinder body 21. Therefore, the
second cylinder body 21 and the annular member 102 will rotate together. As a consequence,
due to the engagement between the wave-shaped engagement surfaces 102b and 104a the
rotating annular member 102 will cause the connecting member 104 to rotate. The situation
is now as illustrated in Fig. 8D. Thus, as a final result, the turning of the first
key K1 and the first plug 12 is transferred into a rotation of the first plug 22 and
the tailpiece 2 for unlocking the door locking mechanism 2. A specific feature of
this unlocking sequence is that the blocking member 100 is actually used to cause
the tailpiece 2 to rotate
3rd embodiment
[0093] Fig. 9 illustrates an embodiment with two electromechanical lock cylinders 10, 20,
both of the design and operation as described in connection with Fig. 7 and Figs 8A
to 8D.
Embodiments with brake function
[0094] Reference is now made to Figs. 12A to 12E. A dual-cylinder lock assembly according
to the inventive concept, which may be implemented in accordance with any of the embodiments
illustrated and described above, may optionally further be provided with a feature
termed "brake function". In short, the brake function is designed to restrict rotation
of part of the gear transmission, such as rotationally brake or rotationally block
part of the gear transmission, in case someone tries to unlock the lock assembly 1
by inserting an inappropriate key or some tool, such as a screwdriver, and applies
an excessive torque to the second plug. In the following, such a situation will be
referred to as an attempted burglary. All statements above regarding structure and
operation of embodiments without brake function apply also to embodiments provided
with a brake function.
[0095] In order to explain the reason for adding the brake function, reference is first
made to Fig. 3, which schematically illustrates the locked state of the lock assembly
1. The most critical part of the assembly 1 in terms of mechanical strength withstanding
a burglary attempt is the mechanical connection between the first plug 12 and the
first gear 14, at reference numerals 15 and 16. The weakest part will be at the center
of the first gear 14 at its opening 16. If a tool T (Figs 12C and 12D) such as a screwdriver
is inserted into the second plug 22 during an attempted burglary, and an excessive
torque is applied to the second plug 22 by the tool T, this torque will be transferred
to the rotationally locked first plug 11 via the second cylinder body 21 and the gears
24, 34, 14. Since the first plug 21 is rotationally locked, the gear mechanism will
be subjected to excessive torques and forces. In the illustrated embodiments, especially
including connections of the type shown at reference numerals 15 and 16, such an excessive
torque may result in that the center of the first gear 14 will break at reference
16, disconnecting the first gear 14 from the first plug 12. In such a break condition,
the second plug 22 and the tailpiece 2 can be rotated freely by the tool T, thereby
unlocking the door locking mechanism 3.
[0096] As described above in connection with Fig. 7 and Fig. 8A to 8D, the illustrated design
of the electromechanical second lock cylinder 20 in the shown embodiment is provided
with a break pin 120. As described above, the break pin 120 will break if the second
plug 22 is subjected to an excessive axial force applied by inappropriate means, thereby
disconnecting the tailpiece 2 from the second plug 22.
[0097] As a non-limiting example only, the weak connection at 15, 16 between the first plug
11 and the first gear 14 may brake if an inappropriate torque in the order of 7 Nm
or higher is applied to the second plug 22 in the locked state of the assembly 1.
As a non-limiting example only, the break pin 120 of the second plug 22 may break
if an inappropriate axial force in the order of 13 Nm or higher is applied to the
second plug 22 in the locked state of the assembly 1. In such embodiments presenting
these two break values, the connection at 15, 16 will break before the break pin 120
breaks, whereby the door locking mechanism 3 may be unlocked. The purpose of the optional
brake function is to prevent this situation from occurring. The optional brake function
is also useful in embodiments without a break or collapse function 120 in the second
plug 22, for preventing damage to weak parts of the gear transmission.
[0098] In embodiments provided with the brake function, at least one of the gears of the
lock assembly 1 is displaceable. The displaceable gear is displaceable in a direction
transversely relative to a rotational axis of the displaceable gear, between a non-displaced
normal position and displaced position. The displacement direction may for instance
be 90 degrees in relation to the rotational axis. Figs 12A to 12E show an embodiment
with brake function where the intermediate gear 34 forms the displaceable gear. Further,
in embodiments provided with the brake function, the assembly is arranged to restrict
rotation of the displaceable gear when the latter is in a displaced position. The
rotational restriction may a complete rotational block arranged to prevent any further
rotation of the displaced gear, or a more "conventional" brake function arranged to
take up a substantial amount of the torque applied to the displaced gear.
[0099] In Figs 12A and 12B, the brake function is implemented by parts 90, 91, 93, 94, 96,
98a and 98b. A slider 90 is received in the housing 6 for linear displacement in a
direction transversely to the third rotational axis A3. In the illustrated embodiment,
the slider 90 is displaceable in opposite directions, i.e. both left and right. In
other embodiments, the slider 90 is displaceable in one direction only. The slider
90 is provided with a projecting axle 91 forming a rotational axle for the intermediate
gear 34. The slider 90 and the gear 34 are thus displaceable together in the directions
indicated by arrows in Fig. 12B. The gear 34 is received in the housing 6 with a clearance
sufficient to allow a certain displacement of the gear 34.
[0100] Means may be arranged to bias the slider 90 towards its normal non-displaced position.
In this embodiment, such biasing means comprises one or more springs 94 arranged on
piston-like members 96 received in holders 93. The members 96 are in engagement with
opposite sides of the slider 90.
[0101] The implementation of the optional brake function comprises at least one structure
arranged to restrict rotation of the displaceable gear when it is in a displaced position.
Restricting rotation may be implemented as a rotational brake and/or a rotational
block. Such a brake structure may interact with the displaceable gear either directly
with the gear, or indirectly with the gear, such as interacting with a rotational
part arranged on the same axle as the displaceable gear, or interacting directly with
the rotational axle. The brake structure may be implemented as one or more break members,
for mounting in the housing, or be implemented as an integral part of the housing,
or a combination thereof.
[0102] In the embodiment illustrated in Fig. 12A to 12E, the brake structure includes two
brake members 98a and 98b arranged on either side of the gear 34. Each brake member
98a, 98b has a brake side facing the gear 34. The brake side may be concave as shown,
or have other shapes. These brake members 98a and 98b are fixedly connected to the
housing 6. In other embodiments, the structure for braking can be implemented directly
in the housing 6. Such an embodiment with a housing 6 having an integrated brake structure
is illustrated in Figs 13A to 13C.
[0103] In the normal position of the gear 34, there is a clearance between the gear 34 and
the brake members 98a, 98b. In a displaced position of the gear 34 (see Figs 12C,
12D and 12E), the gear 34 is in contact with the brake side of one of the brake members
98a, 98b. In this displaced position, the contacting brake member will restrict rotation
of the displaced gear 34. In the illustrated embodiment, the brake sides of the brake
members 98a, 98b are provided with engagement grooves shaped to receive one or more
teeth of the gear 34. Accordingly, in the displaced state in Figs 12C, 12D and 12E,
there is mechanical engagement forming a complete rotational lock of the gear 34 in
its displaced position. In other embodiments, the brake function may be implemented
by a non-grooved brake surface acting as a conventional brake against the periphery
of the gear 34. In such an embodiment, the brake structure may be designed to take
up a majority of the torque applied to the gear 34 such that only a minor torque is
transferred to the first gear 14. In general, the brake structure should be designed
to at least restrict rotation of the displaceable gear.
[0104] The operation of the brake function will now be described with reference to Figs
12C to 12E, which illustrate an attempted burglary situation where a screwdriver T
has been inserted into the second plug 22 and a substantial torque has been applied
by the screwdriver T on the second plug 22, in an effort to unlock the door locking
mechanism 3. In this embodiment, the lock assembly 1 is designed to be unlocked by
turning the plugs 11, 21 counterclockwise. The torque applied by the screwdriver T
is transferred from the second plug 22 and the second cylinder body 21 to the gear
transmission. The first gear 14 is rotationally locked due to the first lock cylinder
10 being locked. As a result, when the applied torque is transferred from the second
plug 22 into a slight rotation of the second gear 24, as indicated by a dashed arrow
to the right in Fig. 12E, the intermediate gear 34, having contact both with the rotating
second gear 24 and the rotationally locked first gear 14, will be displaced to the
left in the figures, as indicated by an empty arrow in Fig. 12E. The gear 34 is displaced
into brake contact with the brake member 98a, whereby the gear 34 is rotationally
locked. As a result, the brake function prevents the torque applied on the second
plug 22 from being transferred to the weaker connection at 15, 16 between the first
gear 14 and the first plug 12, eventually preventing unauthorized unlocking of the
door.
[0105] Should the attempted burglary situation stop in the situation shown in Fig. 12D,
i.e. if the applied torque should be removed, then the springs 94 will return the
slider 90 and the gear 34 to their normal position, and the lock assembly 1 is again
fully functional.
[0106] On the other hand, should the applied burglary attempt torque continue and increase,
then the brake function will continue to protect the connection at 15, 16. A continued
increase of the applied torque will eventually result in breaking of the break pin
120 and disconnection of the second plug 22 from the tailpiece 2.
[0107] Fig. 12D illustrates the brake function in a lock assembly 1 where the door lock
mechanism 3 is instead unlocked by a clockwise rotation of the tailpiece 2. In this
embodiment, the gear 34 will instead move to the right into engagement with the opposite
brake member 98b. It will be appreciated that an advantage of providing a lock assembly
1 with dual brake members 98a, 98b, and displaceability of the slider 90 in opposite
directions, allows the lock assembly 1 to be used on doors having either counterclockwise
unlocking or clockwise unlocking.
[0108] Figs 13A and 13B shows an embodiment including brake function but having two gears
14, 24 only. In this embodiment, it is the first gear 14 which forms the displaceable
gear. In order to make the first gear 14 displaceable as shown in Fig. 13A, the entire
first lock cylinder 10 is slightly movably arranged in the housing 6. The cavity 51
is a bit oversized. However, the first cylinder body 11 is prevented from rotating
about the first rotational axis A1. In the illustrated embodiment, the first cylinder
body 11 is movably arranged in the housing 6 such that the displacement of the first
gear 14 and the first rotational axis A1 is possible. For instance, the first cylinder
body 11 may be slightly linearly displaceable in relation to the housing 6, or it
may be arranged to rotate slightly about a vertical rotational axis.
[0109] In the embodiment shown in Fig. 13A and 13B, the brake structure is not implemented
by separate brake members as in the embodiment in Figs 12A to E. Instead, the brake
structure is implemented directly in the housing 6. The housing 6 is provided with
a brake structure 198a and 198b integrally formed with the housing 6. In this example,
the brake structure comprises a pair of brake edges 198a, 198a, and 198b, 198b, respectively,
on either side of the first gear 14. Upon gear displacement, the teeth of the first
gear 14 will be in rotational lock engagement with such brake edges as shown in Fig.
13C.
[0110] Figs 13B and 13C illustrate a burglary attempt, resulting in a displacement of the
first gear 14 into engagement with the integrated brake member 98a.
[0111] If nothing else is stated, relevant parts of the electromechanical lock assembly
1 may manufactured from a durable material such as stainless steel, aluminum, brass,
or any suitable compound thereof. Involved electrical conductors typically comprise
highly conductive metals, such as copper, silver, gold, or any adequate highly conducting
alloy.
1. A dual-cylinder lock assembly, comprising:
a housing (6);
a first cylinder body (11) arranged in the housing (6);
a second cylinder body (21) rotatably arranged in the housing (6);
a key-receiving first plug (12) rotatably arranged within the first cylinder body
(11) and provided with a first lock mechanism arranged to interact with the first
cylinder body (11);
a key-receiving second plug (22) rotatably arranged in the second cylinder body (21)
and provided with a second lock mechanism arranged to interact with the second cylinder
body (21), said second plug being arranged to operate a tailpiece (2);
a first gear connected to the first plug so that the first gear rotates with the first
plug; and
a second gear connected to the second cylinder body (21) so that the second cylinder
body (21) rotates with the second gear, said second gear also being rotatably connected
to the first gear so that the first plug, the first gear, the second gear, and the
second cylinder body (21) rotate with each other.
2. The lock assembly according to claim 1, wherein, in a locked state of the lock assembly
when no appropriate key (K1, K2) has been inserted in any of the first and second
plug (12, 22), the first lock mechanism is arranged to restrict relative rotation
between the first plug (12) and the first cylinder body (11), and the second lock
mechanism is arranged to restrict relative rotation between the second plug (22) and
the second cylinder body (21).
3. The lock assembly according to claim 1 or 2, wherein, in a first unlocked state of
the lock assembly (1) when an appropriate first key (K1) has been inserted into the
first plug (12), the first lock mechanism is set to not restrict relative rotation
between the first plug (12) and the first cylinder body (11), whereby the lock assembly
(1) is arranged in its first unlocked state to transfer a rotation of the first plug
(12), caused by turning the appropriate first key (K1), into a rotation of the second
plug (22) via the first gear (14), the second gear (24), the rotatable second cylinder
body (21) and the second lock mechanism of the second plug (22).
4. The lock assembly according to any of the preceding claims, wherein, in a second unlocked
state of the lock assembly (1) when an appropriate second key (K2) has been being
inserted into the second plug (22), the second lock mechanism is set to not restrict
relative rotation between the second plug (22) and the second cylinder body (21),
whereby the lock assembly (1) is arranged to allow rotation of second plug (22) in
relation to the second cylinder body (21) by turning the appropriate second key (K2).
5. The lock assembly (1) according to any of the preceding claims, wherein the first
gear (14) and the first plug (12) are permanently drivingly connected to each and
arranged to rotate together about a common first rotational axis (A1).
6. The lock assembly (1) according to any of the preceding claims, wherein the first
cylinder body (11) is arranged in the housing (6) such that the first cylinder body
(11) is prevented from rotating relation to the housing (6) about a rotational axis
(A1) of the first plug (12).
7. The lock assembly according to any of the preceding claims, wherein the second gear
(24) and the second cylinder body (21) are permanently drivingly connected to each
other.
8. The lock assembly according to any of the preceding claims, wherein the second gear(24)
and the rotatable second cylinder body (21) are arranged to rotate together about
a common second rotational axis.
9. The lock assembly according to any of the preceding claims, wherein the rotatable
second cylinder body (21) has the shape of a cylinder or sleeve rotatably mounted
in the housing (6).
10. The lock assembly according to any of the preceding claims, further comprising at
least one intermediate gear (34) arranged between and drivingly interconnecting the
first gear (14) and the second gear (24), such that the first gear (14) and the second
gear (24) rotate in the same direction.
11. The lock assembly according to any of the preceding claims, wherein at least one of
the gears of the lock assembly (1) is a displaceable gear (14; 34), which is displaceable,
in a direction transversely relative to a rotational axis (A1; A3) of the displaceable
gear (14; 34), between a non-displaced normal position and at least one displaced
position; and wherein the lock assembly (1) further comprises at least one brake member
(98a) arranged to rotationally brake or block the displaceable gear in response to
the displaceable gear being displaced into its displaced position.
12. The lock assembly according to claim 10 and 11, wherein the intermediate third gear
(34) forms said displaceable gear (34).
13. The lock assembly according any of claims 11 and 12, further comprising means (94)
for biasing the displaceable gear (14; 34) towards its normal position.
14. The lock assembly according to any of the preceding claims, wherein the first plug
(12) is either a mechanical or an electromechanical plug, and the second plug (22)
is either a mechanical or an electromechanical plug.
15. A method for operating a door locking mechanism connected to a dual-cylinder lock
assembly (1), said method comprising, when using an appropriate first key (K1) of
a set of appropriate keys including an appropriate first key (K1) and an appropriate
second key (K2):
inserting the appropriate first key (K1) into a first plug (12) for causing a first
lock mechanism of the first plug (22) to allow the first plug (12) to rotate in relation
to an associated first cylinder body (11);
turning the appropriate first key (K1) for rotation of the first plug (12) in relation
to the first cylinder body (11);
transferring said rotation of the first plug (12) into a rotation of a second plug
(22) rotatably received within an associated rotatable second cylinder body (21) and
arranged to receive the appropriate second key (K2) as an alternative of using the
appropriate first key (K1); and
transferring said rotation of the second plug into a rotation of the tailpiece (2)
for operating the door locking mechanism,
wherein said transferring of the rotation of the first plug (12) into a rotation of
the second plug (22) is accomplished by transferring the rotation of the first plug
(12) into, in order, a rotation of a first gear (14) drivingly connected to the first
plug (14), a rotation of a second gear (24) rotationally connected to the first gear
(14) and drivingly connected to the rotatable second cylinder body (21), a rotation
of the second cylinder body (21), and a rotation of the second plug (22 via a second
lock mechanism of the second plug interacting with the rotatable second cylinder body
(21).
16. The method according to claim 14, further comprising, when using the appropriate second
key (K2) of said pair of appropriate keys (K1, K2) for operating the door locking
mechanism:
inserting the appropriate second key K2 into the second plug (22) for causing the
second lock mechanism of the second plug (22) to allow the second plug (22) to rotate
in relation to the second cylinder body (21);
turning the second key (K2) for rotation of the second plug (22) in relation to the
second cylinder body (21); and
transferring said rotation of the second plug (22) into a rotation of the tailpiece
(2) for operating the door locking mechanism (3).