[0001] The present invention relates to cylinder locks of the type comprising: a lock body
or stator; a cylinder or rotor, mounted so that it can rotate in the body and having
a passage for introduction of a key; an aligned set of first pins mounted so that
they can slide radially in the cylinder in positions distributed along the axis of
the cylinder and an aligned set of second pins mounted so that they can slide in the
stator and designed to co-operate with the first pins in the neutral position of the
cylinder, said first pins being designed to be engaged by a first pre-set profile
of a key in order to set the second pins in a position such as to enable free rotation
of the cylinder within the body; and at least one third pin, which is mounted so that
it can slide radially in the cylinder and is designed to be engaged by a second pre-set
profile of a key to set itself in a position such as to enable free rotation of the
cylinder within the body.
[0002] A technique of forcing cylinder-lock devices envisages the insertion of a universal
key (the so-called "bump key") and a stress exerted by this through rhythmed blows
on its body, designed to transmit impulses to the first and second pins of the cylinder
lock to bring them into the operating position such as to enable free rotation of
the cylinder within the body. Various cylinder-lock devices referred to as "anti-bumping"
devices have been developed, which present solutions such as to reduce the effectiveness
of this forcing technique.
[0003] The solutions of the known art counteract forcing carried out using the bumping technique
by preventing the action of banging on the key from releasing the interface between
the surfaces of coupling of the cylinder and of the lock body from all the elements
of interposition provided. Additional blocking elements are in fact present, which
operate in the neutral position of the cylinder and upon which in said position no
load is exerted by the impulses transmitted by the bump key.
[0004] Many of these solutions envisage additional elements that lead to a complication
of the lock device and to an increase in the costs and management of the production
process. Furthermore, these solutions, notwithstanding the validity of their principles
of operation, are unable alone to guarantee a complete security on account of the
machining tolerances of the elements making up the lock. The combination of a number
of anti-bumping solutions that act when the cylinder is in the aforesaid neutral position
is, however, problematical on account of the limited space available and the standard
dimensions of the lock body.
[0005] The purpose of the present invention is to provide a lock of the type referred to
above that will guarantee a high degree of security, above all in regard to the forcing
technique of a bumping type, and that will enable the aforesaid target to be achieved
with a lock having a relatively simple, low-cost structure, as well as ensuring reliable
operation.
[0006] In order to achieve the aforesaid purposes, the lock according to the invention is
of the type according to the preamble of Claim 1 and is characterized in that the
third pin has its axis that lies on a plane perpendicular to the axis of the cylinder
and on which there also lie a first pin and the co-operating second pin, so that said
at least one third pin will co-operate with said second pin when it comes into a position
corresponding to an angular position of the cylinder shifted with respect to the aforesaid
neutral position of the cylinder.
[0007] The solution according to the present invention can also be readily associated to
an anti-bumping solution of a conventional type in so far as, since the anti-bumping
security acts in a position rotated with respect to the neutral position of the cylinder,
the elements designed to constitute the further block of the cylinder are shifted
into positions that do not interfere with the positions of engagement of the elements
of the conventional solutions.
[0008] Further characteristics and advantages of the invention will emerge from the ensuing
description with reference to the annexed plate drawings, which are provided purely
by way of non-limiting example and in which:
Figure 1 is a schematic perspective view of a lock according to the invention;
Figure 2 is a side view, with a detail in cross section, of the lock of Figure 1;
Figure 3 is a cross-sectional view according to the line III-III of Figure 2;
Figure 4 is a cross-sectional view according to the line IV-IV of Figure 2;
Figure 5 is a view of the cross section of Figure 3 with the correct key inserted,
Figure 6 is a view of the cross section of Figure 4 with the correct key inserted;
Figure 7 is a view of the cross section of Figure 5, in which the cylinder is in a position
rotated with respect to the neutral position;
Figure 8 is a view of the cross section of Figure 6, in which the cylinder is in a position
rotated with respect to the neutral position;
Figure 9 is a cross section corresponding to the cross section of Figure 5, in which the inserted
key is a bump key;
Figure 10 is a cross section corresponding to the cross section of Figure 6, in which the inserted
key is a bump key;
Figures 11 is a cross section corresponding to the cross section of Figure 7, in which the inserted
key is a bump key; and
Figure 12 is a cross section corresponding to the cross section of Figure 8, in which the inserted
key is a bump key.
[0009] In Figure 1, the reference number 1 designates as a whole a cylinder lock mounted
in the door of a dwelling (not illustrated) and associated to a key 3 having a grip
4 and a laminar body 5 with two opposed faces 6 and two longitudinal edges 7.
[0010] With reference to Figures 2 and 3, the lock 1 comprises a body 8, or stator, traversed
by a cylindrical passage 9, within which a rotor or cylinder 10 is mounted so that
it can rotate.
[0011] Provided in the cylinder 10 is a set of first pins 11, mounted so that they can slide
radially within respective radial holes 10a made in the cylinder 10 and giving out
into a passage 12, made axially through the cylinder 10, for introduction of the key
3.
[0012] The first pins 11 co-operate with second pins or counterpins 13 mounted so that they
can slide radially in the body 8 and recalled by springs 14 against the first pins
11.
[0013] The first pins 11 have end tips designed to co-operate with a first shaped profile,
which in the example illustrated is defined by a plurality of depressions 15 made
on one or both of the faces 6 of the key 3. In this way, the key authorized to open
the lock is able, in the passage 12, to cause axial displacement of the blocking pins
11 in the operating positions illustrated in Figures 5 and 6, in which they do not
project beyond the external surface of the cylinder 10, so that they do not prevent
a rotation of the cylinder 10 with respect to the body 8.
[0014] A plurality of third pins 16, which have parallel axes and are distributed along
the axis of the cylinder, are arranged so that they can slide radially within respective
radial holes 10b within the cylinder 10 in a direction rotated with respect to the
direction in which the first pins 11 slide. In the non-binding embodiment of Figures
3 to 12, the third pins 16 are arranged perpendicular to the first pins 11. Each third
pin 16 has its own axis that lies on a plane perpendicular to the axis of the cylinder
10, on which also one of the second pins 13 and one of the first pins 11 lie. In this
way at the moment in which, during rotation of the cylinder, the holes 8a and 10b
are brought into mutual correspondence, the third pins 16 and the second pins 13 are
in a condition of co-operation.
[0015] The third pins 16 have first projections 16b designed to co-operate with cavities
7a of the edge 7 of the key 3.
[0016] The plurality of third pins 16 comprises third pins of a first set 16' and third
pins of a second set 16". The third pins 16' of the first set have second projections
16a in the radial direction of the cylinder 10 that face the surface of the cylindrical
passage 9. The projections 16a are designed to be engaged in a groove 9a made on the
surface of the cylindrical passage 9. The third pins 16" of the second set are without
the projection 16a and are such as to possess an encumbrance in the radial direction
of the cylinder smaller than the encumbrance of the third pins 16' of the first set.
[0017] Starting from the condition in which the cylinder 10 is in a neutral position (Figures
3 and 4), the key 3 is inserted in the passage 12 (Figures 5 and 6), in this way displacing
the first, second and third pins 11, 13, 16 into respective operating positions. The
first and second pins 11, 13 set themselves flush with the mutually facing ends of
the hole 10a of the cylinder 10 and of the hole 8a of the lock body 8, respectively.
Said position assumed by the first and second pins 11, 13 enables rotation of the
cylinder 10. The third pin 16" of the second set, co-operating with the edge 7 of
the key 3, is brought flush with the end of the hole 10b, which faces the surface
of the cylindrical passage 9. The third pin 16' of the first set sets itself in such
a way that the tip of the projection 16a sets itself flush with the end of the hole
10b that faces the surface of the cylindrical passage 9.
[0018] When the key is turned (Figures 7 and 8) the first, second and third pins 11, 13,
16 maintain the aforesaid operating positions, enabling the lock to complete the travel
of actuation in opening or closing of the cylinder 10 of the cylinder lock 1.
[0019] In the case where an attempt is made to force the lock using a bump key, the person
forcing the lock inserts a key 3' that is not correct within the passage 12. With
banging on the bump key that has been inserted, the first and second pins 11, 13 receive,
via the key 3', impulses designed to make them slide within the respective guide holes
8a, 10a. An expert thief is able to understand the instant in which the first and
the second pins 11, 13 are in the respective operating positions described above so
that the cylinder 10 can be rotated. If we imagine the first and second pins 11, 13
in said operating positions, in the case where the incorrect key is of a first type
and presents, in a position corresponding to the third pin 16' of the first set, a
second profile along the edge 7' such that the projection 16a of the third pin 16'
projects beyond the end of the guide hole 10b, the cylinder 10 is prevented from rotating
on account of the engagement of the projection 16a with the groove 9a made on the
surface of the cylindrical passage 9.
[0020] However, usually bump keys, owing to the experience acquired by picklocks, have edges
7' with profiles having deep depressions, which by co-operating with the third pins
of the first set cause the projections 16a to reside within the respective guide hole
10b. More specifically, picklocks use bump keys that have a continuous groove along
the edge 7' that extends throughout the longitudinal length of the edge 7' and is
characterized by a depth such as to cause the projections 16a to reside within the
respective guide hole 10b. In this case then, the person forcing the lock using the
bump key, from the neutral position of the cylinder manages to turn the latter and
execute part of the travel of opening of the cylinder lock 1 (Figures 9 to 12).
[0021] In the cylinder locks according to the invention, when the angular position of the
cylinder illustrated in Figures 9 and 10 is reached, since the third pins 16 lie on
planes perpendicular to the axis of the cylinder on which also corresponding second
pins 13 lie, the third pins 16 are then in a condition of co-operation with these
second pins 13.
[0022] Represented in Figures 9 to 12 is the situation where a third pin 16' of the first
set, co-operating with the edge 7' of the incorrect key, is brought into a radial
position in which the projection 16a is flush with the end of the hole 10b.
[0023] Consequently, in the aforesaid condition of co-operation of the third pin 16' of
the first set with the corresponding second pin 13 (Figure 12), the third pin 16'
and the corresponding second pin 13 are flush with the facing ends, respectively,
of the hole 8a of the lock body 8 and of the hole 10b of the cylinder 10, this position
enabling rotation of the cylinder 10. The third pin 16" of the second set instead
(Figure 11), since it does not have the projection 16a and is thus shorter, in the
aforesaid condition of co-operation between third pins 16 and second pins 13, assumes
a position such that the second pin 13 projects within the hole 10b, in this way preventing
rotation of the cylinder.
[0024] In the situation where the edge 7' of the bump key has a profile, which, when it
co-operates with the third pin 16' of the first set, brings the projection 16a into
a position inside the hole 10b, the same third pin 16' of the first set, in the aforesaid
condition of co-operation with a corresponding second pin 13, assumes a position such
as to cause the second pin 13 to project within the hole 10b, in this way preventing
rotation of the cylinder.
[0025] Obviously, the third pins 16, which, in the embodiment illustrated in the figures
lie on a plane perpendicular to the longitudinal axis of the cylinder 10, can, however,
be arranged on planes differently inclined with respect to said axis, so that in any
case they will co-operate with the corresponding second pins 13 for angular positions
of the cylinder 10 rotated with respect to the aforesaid neutral position of the cylinder
itself.
[0026] A further embodiment envisages that the third pins 16 are all third pins 16' of the
type of the first set, i.e., that are all provided with the projection 16a, but envisages
that said pins 16' are characterized by overall dimensions, in the radial direction
of the cylinder 10, that are different.
[0027] Another embodiment envisages that the third pins 16 are all third pins 16" of the
type of the second set, i.e., that are all without the projection 16a, but envisages
that said pins 16" are characterized by overall dimensions, in the radial direction
of the cylinder 10, that are different.
[0028] In a further embodiment, the cylinder lock 1 comprises pairs of third pins 16, each
pair having third pins arranged on one and the same plane perpendicular to the axis
of the cylinder 10 and positioned diametrally opposite to one another with respect
to the laminar body 5 of the key 3. The projection 16b of each third pin 16 of the
pair co-operates with the cavity 7a of the corresponding edge 7 of the key 3.
[0029] The lock device according to the present invention, can moreover be associated to
anti-bumping devices of a conventional type.
[0030] From the foregoing description, it is evident that the lock according to the invention
presents a high degree of security and in particular enables an extremely large number
of different opening combinations, corresponding to an equally high number of keys.
At the same time, the lock operates efficiently and reliably and has a relatively
simple and low-cost structure.
[0031] Of course, without prejudice to the principle of the invention, the details of construction
and the embodiments may vary widely with respect to what has been described and illustrated
herein purely by way of example, without thereby departing from the scope of the present
invention.
1. A cylinder lock, comprising: a lock body or stator (8); a cylinder or rotor (10),
mounted so that it can rotate in the body (8) and having a passage for the introduction
of a key (12); an aligned set of first pins (11) mounted so that they can slide radially
in the cylinder (10) in positions distributed along the axis of the cylinder (10)
and an aligned set of second pins (13) mounted so that they can slide in the stator
(8) and designed to co-operate with the first pins (11) in the neutral position of
the cylinder (10), said first pins (11) being designed to be engaged by a first pre-set
profile (15) of a key (3) to set the second pins (13) in a position such as to enable
free rotation of the cylinder (10) within the body (8); and at least one third pin
(16), mounted so that it can slide radially in the cylinder (10) and designed to be
engaged by a second pre-set profile (7) of a key (3) to set itself in a position such
as to enable free rotation of the cylinder (10) within the body (8),
said cylinder lock being characterized in that said at least one third pin (16) is set, with respect to the axial dimension of the
cylinder (10), in a position substantially corresponding to that of a first pin (13)
and of the co-operating second pin (11), so that said at least one third pin (16)
will co-operate with said second pin (13) when it comes into a position corresponding
to an angular position of the cylinder (10) rotated with respect to the aforesaid
neutral position of the cylinder (10).
2. The cylinder lock according to Claim 1, characterized in that it comprises a plurality of said third pins (16), which have axes distributed along
the axis of the cylinder (10).
3. The cylinder lock according to Claim 2, characterized in that said plurality of third pins (16) has first projections (16b) in the radial direction
of the rotor (10) facing the passage of the key (12), designed to engage said pre-set
second profile (7) of said key.
4. The cylinder lock according to Claim 3, characterized in that said plurality of third pins (16) has a first set and a second set of said third
pins (16', 16") , said third pins (16', 16") of said first and second sets having
different overall dimensions in the radial direction of the cylinder (10).
5. The cylinder lock according to Claim 4, characterized in that said stator (8) has a groove (9a) made on the internal cylindrical surface (9) of
the stator (8).
6. The cylinder lock according to Claim 5, characterized in that said third pins (16') of said first set have second projections (16a) facing the
internal cylindrical surface (9) of the stator, designed to engage said groove (9a)
of said internal surface (9) of the stator (8).
7. The cylinder lock according to Claim 6, characterized in that said second projections (16a) of said third pins (16') of said first set have a conical
development.
8. The cylinder lock according to Claim 3, characterized in that said first projections (16b) of said third pins (16) have a conical development.
9. The cylinder lock according to Claim 4, characterized in that said third pins (16) of said first and second sets have second projections (16a)
facing the internal cylindrical surface (9) of the stator, designed to engage said
groove (9a) of said internal surface of the stator.
10. The cylinder lock according to Claim 2, characterized in that said plurality of third pins comprises pairs of third pins (16), each pair having
third pins arranged on one and the same plane perpendicular to the axis of the cylinder
(10) and positioned diametrally opposite to one another with respect to the laminar
body (5) of the key (3), the projection (16b) of each third pin (16) of the pair co-operating
with the corresponding edge (7) of the key (3).
11. The cylinder lock according to Claim 1, characterized in that it moreover comprises anti-bumping means of a conventional type.
The foregoing substantially as described and illustrated herein and for the purposes
specified.