Technical Field of the Invention
[0001] The present invention relates to a locking assembly, more precisely to a door locking
assembly with hook-shaped latches showing improved security characteristics.
Background of the Invention
[0002] Locks offering high security characteristics, that is to say, locks with hook-shaped
dual latches engaging in suitable slots within the door frame are well-known in the
circles of security lock manufacturers. Those are especially advantageous in that
when fully locked, they simply provide multiple axes locking so as to withstand both
vertical and horizontal forces produced in association with and during burglary attempts.
[0003] Multiple patent literature references may be provided herein, all with hook-shaped
latches rotated by a set of actuator mechanism driven axles. Among others, one of
the patents/patent applications available to the public is the Italian patent
ITT020000226, which is issued in the name of Tesio S.r.l. The same discloses hook-shaped latches
in the form of curvilinear projections interlocking with latch slots laid on the lock
panel. Said curvilinear latches are rotated by way of axles connected thereto. Rotation
of the axles by an actuation mechanism is realized by a movable element commanding
an arm incorporating suitable pivots rotating said axles and therefore said curvilinear
latches.
[0004] GB2309996A discloses a lock assembly comprising a bolt pivotally mounted upon a support, and
a drive member slidable with respect to the support, the bolt being provided with
a projection engageable with the drive member to move the bolt between an open position
and a closed position on sliding movement of the drive member, and wherein when the
bolt is in its closed position, further movement of the drive member to a locked position
restricts pivotal movement of the bolt with respect to the support.
[0005] US3695068A discloses a combination locking and latching assembly for mounting between the side
faces of a narrow tubular stile frame member of a door to provide both locking and
latching operations, respectively, by means of a locking bolt and a latch member,
and wherein the latch member is spring urged to a latched position and is independently
operable by a latch handle to an unlatched position, while the locking bolt is arranged
to be actuated in a normal manner being further operable, in an unlocked position
of the locking bolt, to move the latch member to a retracted or unlatched position.
[0006] The disclosure herein differs from the available prior art in that it features a
special arrangement designed to prevent burglary attempts specifically aiming at rendering
hook-shaped latches non-functional by damaging their rotation mechanisms. Although
locks with those types of latches are substantially advantageous over a regular linear
latch lock, they still incorporate certain vulnerabilities.
[0007] It is a well-known fact that various techniques are used for releasing a door lock
in burglary attempts. One of those techniques is to employ a perpetual screw or endless
screw, like that of a jack, a screw that is fixed so that it cannot move longitudinally
as it rotates. Accordingly, once fixed at two sides of the door frame at a position
parallel to the door surface, it remains stationary and forces the door frame to bend
toward hollow spaces outside the door. This can eventually bend the frame to the extent
that hook-shaped latches reach their limit strength and therefore either their hook
ends break through a line defining the outer part hook head or the pivoting pins on
which said curvilinear latches are rotatably mounted -and therewith also fixed to
the side sheet of the lock case- and the latch actuation pins guided on the latches
tend to advance in the frame direction by tearing said lock case side sheet throughout
the distance up to the panel on the lock side. In the latter case, it is probable
that said pivot axles and guided actuation pins get broken off.
[0008] In both cases, on the other hand, all security aspects of the door will practically
become nonfunctional since respectively either the latches will no more be engaging
in the slots on the frame side lock panel without the hooking portions or they will
no more be secured neither by pivot axles nor by guided actuation pins.
[0009] The lock case side walls and several individual components of lock hardware are typically
secured to each other within the case in several points. The pins on the rotation
axes of the hook latches are also secured to the sheet material side wall. This becomes
a serious drawback especially in the event of a burglary attempt as exemplified earlier.
The linear tension produced by the perpetual screw along the transversal axis of the
door in the direction of the door frame especially requires the hook latches to resist
against the outward force induced on the hook ends.
[0010] When burglary takes place, the hook ends are in a position interlocked with the slots
on the frame side lock panel. This latter is made of a strong material and will not
break off in most cases. As the perpetual screw rotates, however, it will tend to
bend outward and the slots on the panel along with the hook ends interlocked therewith
will be deformed to the extent that a gap will occur in between the lock side and
the frame side panels.
[0011] Break of the hook-shaped latches can be prevented and remedied by way of appropriate
material selection. On the other hand, with the assumption that the outer hook portions
of the hook latches can resist against breaking off due to appropriate material selection,
the break away force will then exert on the axles and on the guided hook latch actuation
pins. Upon breaking off of the pivoting pins, whose primary function is not retaining
the integrity of the system and resisting against outside forces but to constitute
the rotation center thereof, the hook latches will first loose contact with the case
side sheet and by a certain damage on the guided actuation pins, the latches will
practically be free and not anymore secured to the lock case.
[0012] As will be apparent in the proceeding parts, the present invention solves the specific
problem identified above by making use of the lock panel, which is already made of
a strong material and which is suitable for resisting against forces that are to cause
movement of the latches outside their predetermined outermost limit positions.
Objects of the Invention
[0013] Primary object of the present invention is to provide a high security door locking
assembly with hook-shaped latches the outward movement of which is kept within a predetermined
range and can not be removed from the lock case, as is defined by the features of
claim 1.
Summary of the Invention
[0014] The present invention proposes a security lock comprising a regular sliding bolt
along with a set of separate hook-shaped latches in the form of curvilinear projections
operating jointly in the manner to interlock with suitable latch slots on the door
frame. According to the present invention, said curvilinear latches are additionally
provided with a plurality of pins vertically projecting from the lateral surface thereof
in the manner to face either of the case side sheets. In case of an unauthorized attempt
to release the lock by bending the lock panel on the door frame outwardly so as to
cause the latches to move in the direction of the frame, the vertically projecting
pins within the inside of the case will abut against the lock panel on the lock side
and prevent movement of said latches.
Brief Description of the Figures
[0015] Accompanying drawings are given solely for the purpose of exemplifying a locking
assembly whose advantages over prior art were outlined above and will be explained
in detail hereinafter:
Fig. 1a demonstrates a transversal perspective side view of the lock case according
to the present invention.
Fig. 1b demonstrates the door frame side lock panel according to the present invention.
Fig. 2 demonstrates a longitudinal perspective side view of the lock case according
to the present invention.
Fig. 3 demonstrates another transversal perspective side view of the lock case according
to the present invention.
Fig. 4 demonstrates the hook-shaped latches according to the present invention.
Fig. 5 demonstrates the lock case side sheet according to the present invention.
Detailed Description of the Invention
[0016] Referring now to the figures outlined above, the lock assembly in Fig. 1a, generally
referred to as 11, comprises a plurality of latches (12, 13 and 14) movable relative
to said assembly (11) in the manner to engage in suitable slots (15, 16) on the lock
panel (18), an actuator mechanism for switching said plurality of latches between
a locking and an unlocking positions and last but not least a transmission mechanism
transferring motion to said plurality of latches (13, 14).
[0017] According to the present invention, beside a regular sliding latch (12), a set of
separate hook-shaped latches (13, 14) in the form of curvilinear projections operating
reciprocally in an integral manner are employed so as to interlock with a suitable
latch slot (19) laid on the frame side lock panel (20). Said curvilinear latches (13,
14) are designed to be operated jointly and to be rotating by way of axles (21) connected
thereto. The hook-shaped latches (13, 14) are conventionally designed to have a curvilinear
side on the outer portion of the head part, the latter extending inward in the form
of a right-angled corner and forming therein a space between two blocks. One of those
blocks is actually the head portion, which engages into the slot (19) on the frame
side lock panel (20).
[0018] The linearly sliding latch (12) according to the present invention is conventionally
controlled by a handle hub in the form of a spring loaded structure actuated by the
handle rotating a mechanism transferring motion to the spring loaded structure. The
actuator mechanism of the sliding latch (12) and the transmission mechanism thereof,
are widely practiced in the art and need not be further mentioned herein. The behavior
of the sliding latch (12) with regard to the handle hub is apparent to the person
skilled in the art.
[0019] As for the curvilinear latches (13, 14), rotation of the axles (21) so as to effect
movement of the same is realized by an actuation mechanism started by insertion of
a key into the keyhole (22) in the manner to advance a rotatable element (not shown),
the latter commanding an arm suitable for engaging in a groove (22) to advance said
actuation mechanism for curvilinear latches (13, 14). The function of a lock cylinder
is apparent to the person in the art. The actuator means for the latches (13, 14)
is typically comprised of a linearly guided unidirectionally sliding plate (25) with
two gripping arms (29) extending to the latches' (13, 14) rotation center (21).
[0020] According to the present invention, the curvilinear lock bolts (13, 14) are designed
to provide a single-turn 90-degree displacement ensuring engagement position into
the panel slot (19) in one turn. Turning of an appropriate key in the keyhole (22)
causes the axles (21) and a couple of redirection pins (23) that are guided within
the latches (13, 14), to rotate said latches (13, 14) accordingly. Each of said pins
(23) is driven back and forth between two edges of a guiding channel (24, Fig. 2),
depending on the engaging and disengaging positions of said latches (13, 14). Synchronous
movement of said redirection pin (23) together with said axle (21) leads to a full
step 90-degree slip of the curvilinear latches (13, 14) in a reciprocal manner.
[0021] Synchronous movement of said axles (21) together with said redirection pins (23)
can be explained by referring to the structure of each gripping arm (29) extending
from said linearly guided unidirectionally sliding plate (25). To this end, each gripping
arm (29) extending to each latch (13, 14) comprises an open end recess in order for
laterally receiving said axles (21), whose bottom surfaces are secured to a suitable
slot on at least one of the lock case sidewalls (28). When fully locked, the axles
(21) are fully encircled with the exception of the recess's open end, which is preferable
to limit movement thereof.
[0022] Beside said recesses on each arm, a slot for vertically accommodating said redirection
pin (23), which is only allowed a limited linear movement within said guiding channel
(24), is located. Movement of this latter to move the latch (13, 14) is directly effected
by said gripping arm (29) since it is placed into both the gripping arm (29) slot
and the latch channel (24) coaxially. In the very beginning of the locking sequence,
each gripping arm (29) reciprocally advances to slip said redirection pins (23) to
the channel (24) limits and further advancing of the gripping arms (29) causes the
redirection pins (23) to carry said latches (13.14) around each rotation centers (21)
to the full-locked position. Single turn 90-degree movement of the latches (13, 14)
is not possible without the redirection pins (23) properly advance to the outermost
limit position in the guiding channels (24). In other words, rotation is effected
by the redirection pins' (23) inclined movement within the channels (24) inclined
with regard to the lock panel (18) direction. The fact that the location of the rotation
center (21) is on the direction of the inclined channels (24), provides an effective
single-turn 90-degree slip. An effective single step full rotation would not be possible
in an alternative design in which the rotation centers (21) are not directly located
on the channels' (24) longitudinal direction.
[0023] To avoid a burglary attempt of the type defined earlier, in which an endless screw
is used to bend the frame side lock panel (20) in the direction of the door frame
in the manner to load stress on the most critical security components of the lock
such as the redirection pins (23) and the axles (21), the present invention features
a set of special arrangements to keep the redirection pins (23) and the axles (21)
away from the induced force components. Accordingly, said curvilinear latches (13,
14) are additionally provided with a plurality of pins (26) vertically projecting
from the lateral surfaces of their body portions that remain within the lock case
in locked position. In case of an unauthorized attempt to release the lock by bending
the frame side lock panel (20) on the door frame outwardly so as to cause the latches
(13, 14) to move in the direction of the frame, the vertically projecting pins within
the inside of the case will abut against the lock panel (18) and stops displacement
of said latches (13, 14).
[0024] The reinforcement pins (26) are the first barriers to contact the lock panel (18)
in any attempt to slip said latches outwardly, that is, in the direction of the door
frame. Since they are longitudinally embedded in the latch (13, 14) body in a secure
manner with the head portions slightly running over the latch (13, 14) surfaces in
a manner to form a sufficient contact surface with the lock panel (18) portion outside
the latching slot (19), letting the latter stop the entire latch (13, 14) body moving
and resisting against outward forces otherwise exerted on the redirection pins (23)
and the axles (21).
[0025] The reinforcement pins (26) are located substantially close to the lock panel (18)
considering the locked position layout of the latches (13, 14). In other words, the
distance of the reinforcement pins (26) to the lock panel (18) is smaller than the
radius of the reinforcement pin (26) itself. More precisely, the smallest distance
between a point of the reinforcement pins (26) and the lock panel (18) is smaller
than the radius of the reinforcement pin (26) itself.
[0026] According to the present invention, reinforcement pins may also be installed on the
far end of the latch (13, 14) to the lock panel (18). Such a pin (27) is shown in
Fig. 4. Such pins (27) projecting symmetrically from both surfaces of a curvilinear
latch (13, 14) will further delay removal of latch (13, 14). In the country of the
applicant, it is known that the risk for a burglar to fully release a high security
lock sharply decreases as the duration consumed in front of a single lock increases.
[0027] In a nutshell, the present invention proposes a locking assembly (11) comprising
a plurality of regular and curvilinear latches (12, 13 and 14) movable relative to
said assembly (11) in the manner to engage in suitable slots (15, 16) on the lock
panel (18), actuator mechanisms for actuating said regular and curvilinear latches
(12, 13 and 14) and transmission mechanisms transferring motion to said plurality
of latches (13, 14), said curvilinear latches (13, 14) being provided with at least
one reinforcement pin (26) projecting from the lateral surfaces of the latch (13,
14) body portions that remain within the lock case in locked position.
1. Verriegelungsbaugruppe (11), umfassend einen Schieberiegel (12) und gekrümmte rotierende
Riegel (13 und 14) die relativ zu der Baugruppe (11) in einer Weise beweglich sind,
um in geeignete Aussparungen (15, 16) auf einer Schlossplatte (18) einzugreifen, Betätigungsmechanismen
zum Betätigen des Schieberiegels (12) und der gekrümmten rotierenden Riegel (13 und
14) und Übermittelungsmechanismen, die an die Vielzahl von Riegeln (12, 13 und 14)
Bewegung übertragen, dadurch gekennzeichnet, dass
die gekrümmten Riegel (13, 14) mit mindestens einem von den seitlichen Oberflächen
der Rumpfteile des gekrümmten Riegels (13, 14) vorstehenden Verstärkungsstift (26)
versehen sind,
wobei die seitlich von den Seitenflächen der gekrümmten Riegel (13, 14) vorstehenden
Verstärkungsstifte (26) bei jedem Versuch, die Riegel (13, 14) nach außen gleiten
zu lassen, eine seitliche Kontaktoberfläche mit den Teilen der Schlossplatte (18)
unmittelbar über und unter der Verriegelungsaussparung (15) bilden,
wobei sich die Verstärkungsstifte (26) bezüglich der Anordnung der Riegel (13, 14)
in geschlossener Position im Wesentlichen nahe zu der Schlossplatte (18) befinden.
2. Verriegelungsbaugruppe (11) gemäß Anspruch 1, wobei die kleinste Entfernung zwischen
jedem Punkt der Verstärkungsstifte (26) und der Schlossplatte (18) kleiner ist als
der Radius des Verstärkungsstiftes (26) selbst, wenn die gekrümmten rotierenden Riegel
(13, 14) sich in der geschlossenen Position befinden.