Device for anchoring a protective boss for locks, particularly of the cylinder type

Abstract

 A device for anchoring a protective boss to a lock, particularly of the cylinder type, comprising a plate-like element (8) which is rigidly coupled to the lock (1) and has an opening (9) whose rim surrounds the cylinder (3) and forms an undercut seat, the opening being suitable to receive the boss (13), means (15) being provided which are suitable to engage in the seat and retain the boss (13) anchored to the plate-like element (8), the boss (13) being provided with holes for engaging screws (16) for fixing the boss (13) to the lock (1).

Description

[0001] The present invention relates to a device for anchoring a protective boss for locks, particularly of the cylinder type.

[0002] In order to protect cylinder locks against external break-in attempts, it is known to use protective devices which consist of bosses made of particularly tough material which are fixed to the door in front of the lock and have an opening for inserting the key that actuates the lock. Since such bosses protrude through a hole of the external trim panel, there are problems when the door entails inserting the external panel sideways into a suitable seat of the door frame. In this case, insertion of the panel is in fact prevented or at least hindered by the protruding boss.

[0003] The aim of the present invention is to provide a device which obviates the shortcomings of conventional devices and in particular can be installed even after fitting the external trim panel.

[0004] This aim and other objects which will become apparent hereinafter are achieved with a device for anchoring a protective boss to a lock, particularly of the cylinder type, characterized in that it comprises a plate-like element which is rigidly coupled to the lock and has an opening whose rim surrounds said cylinder and forms an undercut seat, said opening being adapted to receive said boss, means being provided with said boss which are suitable to engage in said seat and retain said boss anchored to said plate-like element, said boss being provided with holes for engaging screws for fixing said boss to said lock.

[0005] Further characteristics and advantages of the present invention will become apparent from the following detailed description on the basis of the accompanying drawings, wherein:

Figure 1 is an exploded perspective view of the device according to a first embodiment of the present invention;

Figure 2 is a sectional view of the device of Figure 1;

Figure 3 is a front view of the device of Figures 1 and 2 in the assembled position;

Figure 4 is an exploded perspective view of the device according to a second embodiment of the present invention;

Figure 5 is a sectional view of the device of Figure 4;

Figure 6 is a front view of the device of Figures 4 and 5 in the assembled position.

[0006] With reference to Figures 1-3, the reference numeral 1 generally designates a lock with a plurality of bolts 2 which can be actuated by means of a cylinder 3. The lock 1 comprises a box-like body 4 which is protected, on the outer side, by a metal plate 5 which is in turn fixed to a sheet metal panel 5a which is installed for burglar-proofing in the door frame.

[0007] The metal plate 5 has, at a region that surrounds the seat 6 for the insertion of the cylinder 3, a quadrangular opening 7 against which an escutcheon 8, also made of metal, is fixed. The escutcheon 8 is fixed by means of a peripheral weld which preferably does not exceed the thickness of the escutcheon 8.

[0008] The escutcheon 8 has a circular opening 9. Along the rim of the opening 9 there is a set of three recesses 10 which are angularly spaced by 120°, a corresponding number of lobes 11 being formed between such recesses. When the escutcheon 8 is rigidly coupled to the front face of the metal plate 5, the lobes 11 form, together with the wall of the box-like body 4, an undercut seat 12 whose thickness is equal to the thickness of the metal plate 5.

[0009] The opening 9 is meant to receive a boss 13 for protecting the cylinder 3. The boss 13 comprises a cylinder made of a material which is particularly resistant to break-in stresses (drilling, traction) and is provided with a protected hole 14 for the insertion of the key that operates the lock.

[0010] Three expansions 15 protrude radially from the boss 13, are shaped complementarily to the recesses 10 and are thinner than the seat 12. The boss 13 is provided with two threaded holes for the engagement of screws 16 which are driven through the box-like body and by virtue of which the boss is fixed in order to neutralize undue rotational stresses.

[0011] The assembly of the device is entirely evident from the above description. In particular, it should be noted that the recesses 10 and the expansions 15 allow a bayonet coupling of the boss 13 by virtue of which the expansions 15, once inserted in the seat 12 through the recesses 10 and turned so as to engage the lobes 11 formed between the recesses 10, prevent, with the cooperation of the screws 16, the removal of the boss 13 from the lock protection position.

[0012] The innovative prerogative of the present invention is constituted by the fact that the boss 13 can be applied in the position for protecting the lock 1 after applying the door trim panel 17, as shown more clearly in Figure 2.

[0013] Conveniently, a ring 18 is arranged around the boss 13 and is meant to be fixed to the panel 17 in order to cover the boss insertion hole.

[0014] The described invention is susceptible of numerous modifications and variations, all of which are within the scope of the same inventive concept. Figures 4, 5 and 6 are views of a solution in which the opening 9 of the escutcheon 8 is perfectly circular and instead of the recesses and lobes rigidly coupled to the boss, as in the previously described example, there is a ring 19 which is provided with an internal thread 20 and with a collar 21 which protrudes externally. The collar 21 has a thickness which allows it to be accommodated in the seat 12, whereas the ring 19 has an outside diameter which is complementary to the diameter of the opening 9, so that it can be centered therein. In order to allow the coupling of the boss 13 to the ring 19, the boss 13 has, at one end, a thread 22 on which the ring 11 can be screwed by resorting to an adapted tool which acts in diametrically opposite notches 23 of the ring 19. The rotation-preventing locking of the boss is achieved by the screws 16.

[0015] The disclosures in Italian Utility Model Application No. BO99U000011 from which this application claims priority are incorporated herein by reference.

[0016] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A device for anchoring a protective boss (13) to a lock (1), particularly of the cylinder type (3), characterized in that it comprises a plate-like element (8) which is rigidly coupled to the lock and has an opening (9) whose rim surrounds said cylinder (3) and forms an undercut seat (12), said opening being suitable to receive said boss (13), means (15) being provided with said boss which are suitable to engage in said seat (12) and retain said boss (13) anchored to said plate-like element (8) , said boss (13) being provided with holes for engaging screws (16) for fixing said boss (13) to said lock (1).

2. The device according to claim 1, characterized in that the lock (1) comprises a box-like body (4) which is protected, from the external side, by a sheet metal panel (5a) having, at the region that surrounds the seat (6) for inserting said cylinder (3), an opening (7) against which an escutcheon (8) is fixed, a circular opening (9) being formed in said escutcheon, said opening being provided, along its rim, with a plurality of angularly offset recesses (10) between which a matching number of lobes (11) is formed, said lobes (11) forming said undercut seat (12) which can be engaged with a bayonet coupling by a plurality of radial expansions (15) which are formed in said boss (13) and driven through said recesses (10).

3. The device according to claim 1, characterized in that the lock (1) comprises a box-like body (4) which is protected, from the external side, by a sheet metal panel (5a) which has, at the region that surrounds the seat (6) for the insertion of said cylinder (3), an opening (7) against which an escutcheon (8) is fixed, said escutcheon having a circular opening (9) whose rim forms said undercut seat (12), a ring (19) being further provided which has an internal thread (20) and a collar (21) which protrudes externally, said collar (21) being suitable to be accommodated in said undercut seat (12), and said ring (19) having an outside diameter which is complementary to the diameter of said opening (9) so that it can be centered therein, said boss (13) being provided, at one end, with a thread (22) for screwing into said ring (19).

4. The device according to one of the preceding claims, characterized in that a ring (18) for covering the insertion hole of said boss is arranged around said boss (13).

Drawing