GB2243866A - Lock assembly - Google Patents

Abstract

The lock assembly has a lock body 10 and a bar 44 rotatably mounted in the lock body 12 and operable by a key operated lock mechanism 22. The bar 44 has curved recesses 54, and 56 therein which are disposed in recesses in the lock body 10 which are adapted to receive the respective legs of a shackle 12. The legs of the shackle 12 have respective grooves 64 and 66 therein which cooperate with the recesses 54 and 56 to lock or unlock the shackle depending upon the rotary position of the bar 44. The lock body 10 includes core members 16, 18 in a shell 14 - details of materials are given. The shackle 12 may have one or more sets of grooves to allow it to be locked into any one of a number of positions relative to the lock body 10. In the padlock of Figures 4. 5 the shackle (112) is not designed to be separated from the lock body (110) and a sleeve (170) is disposed within a shell (114) in the lock body. <IMAGE>

Description

LOCK ASSEMBLY This invention relates to a lock assembly and is more particularly concerned with a lock assembly of the type having a lockable shackle which may or may not be completely removable from the lock body in the unlocked position.

It is an object of the present invention to provide a lock assembly having improved security.

According to the present invention, there is provided a lock assembly comprising a lock body, a shackle, the lock body including a pair of spaced recesses in which respective legs of the shackle are received, a lock mechanism mounted in the lock body, and an axially rotatable bar which is mounted in the lock body so as to extend between said recesses and which is operably connected with the lock so as to be rotatable thereby, the bar and the legs of the shackle having respective mutually cooperating formations thereon such that (a) when the lock mechanism is in a locked position with the legs in the respective recesses, the bar engages the legs to prevent the latter from being removed from the recesses and (b) when the lock mechanism is in an unlocked position the bar is in a position in which the legs of the shackle are released.

The engagement of the bar with both legs of the shackle in the locked position means that a continuous loop is defined by the shackle and the bar. The shackle and the bar are normally solid and formed, for example, of hardened steel.

The bar is preferably rotatable in non-ferrous bearings in the lock body so that there is a reduced risk of corrosion causing the bar to become immovably engaged with the lock body.

Preferably, the lock body comprises at least one nonferrous core member which defines the bearings in which the bar is rotatably mounted, and an outer hardened steel shell in which the non-ferrous core is secured.

The shackle may have a plurality of sets of said cooperating formations on its legs, the sets being spaced apart longitudinally of the legs so that the shackle can be locked in a position in which the portion interconnecting the legs thereof is as close as possible to the lock body having regard to the shape and size of the item to be secured in use. A detent mechanism may be provided for releasably retaining shackle in each of its positions so that correct positioning of the shackle relative to the lock body is facilitated.

Preferably, said at least one core member is slidable relative to the outer shell but fixed in position by suitable fixing means such as a screw, the shell having holes therethrough which are aligned with holes in the core member(s), the aligned holes defining the recesses in which the legs of the shackle are received, respectively. It will therefore be appreciated that, when the shackle is locked in position, the core member(s) cannot be removed from the shell even if the fixing means is unfastened.

Most preferably, the lock mechanism is of a type which is removable from the lock body for replacement purposes, eg a cylinder lock mechanism of the pin tumbler type. This has the advantage that the lock mechanism itself can be changed for security reasons without having to replace the whole lock assembly, or a special lock mechanism can be fitted into the lock body to match other lock mechanisms used, for example, on the same premises.

Thus, if desired, the lock assembly can be provided with a lock mechanism which matches one or more other lock mechanisms so as to enable the same key to be used for more than one lock mechanism.

The lock assembly is preferably provided with a shackle which is so mounted in the lock body that it can be completely removed therefrom only after it is in its unlocked condition.

We have developed a novel shackle mounting mechanism which can enable a smaller sized lock body to be employed and which is suitable for use not only with a lock assembly of the type defined above, but also with other types of lock assembly.

Thus, also according to the invention, there is provided a lock assembly comprising a shackle, a lock body including a pair of spaced recesses in which legs of the shackle are respectively slidably received so that the shackle can be moved between a locked position in which both legs of the shackle extend into the body and an unlocked position in which one of the legs of the shackle is disengaged from the respective recess in the lock body, a lock mechanism mounted in the lock body for releasably retaining the shackle in its locked position, and a mounting mechanism serving to mount the other of the legs of the shackle in the body, said mounting mechanism including (a) a sleeve which is mounted in the lock body (preferably for rotation relative thereto) and extends externally of the lock body through the respective recess, said sleeve slidably receiving the other of said legs of the shackle, and (b) a lug which extends inwardly of the sleeve and cooperates with a recess in that portion of the leg which is disposed internally of the sleeve so that the leg is retained against disengagement from the sleeve but is slidable to a limited extent axially relative to the latter, the leg preferably being fixed against rotation relative to the sleeve.

Most preferably, the sleeve is mounted in the lock body so as to be removable therefrom only when the shackle is in its unlocked position.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a part cut-away perspective view of one form of lock assembly according to the present invention, Fig. 2 is an axial section through the lock body of the assembly of Fig. 1, Fig. 3 is an axial section taken at right angles to Fig.

2, Fig. 4 is an axial section through another form of lock assembly according to the present invention, and Fig. 5 is a scrap section showing part of the lock assembly of Fig. 4.

Referring now to Figs 1 to 3 of the drawings, the lock assembly comprises a multi-part lock body indicated generally by arrow 10, and a shackle 12 formed of boron steel which been case hardened by carbonitriding and then zinc plated for corrosion protection.

The lock body is of generally race-course cross section and comprises cold drawn steel shell which has been hardened by carbonitriding and then zinc plated for corrosion protection. The lock body 10 further includes a pair of zinc diecast core members 16 and 18. The core member 16 includes a recess 20 which receives a brass pin tumbler cylinder lock mechanism 22 of a conventional type for operation by a key (not shown). The core member 16 further includes a passage 24 which opens at one of its ends into recess 20 and which receives a slotted rotary shaft 26 of the lock mechanism 22. The passage 24 intersects a circular hole 28 which extends through the core member 16 at right angles to the passage 24. The circular hole 28 is aligned with a corresponding circular hole 30 in the shell 14, the holes 28 and 30 together defining a recess for one leg of the shackle 12.

The core member 18 includes a passage 32 which is axially aligned with the passage 24 and which does not extend completely through the core member 18. The passage 32 intersects a circular hole 34 which extends at right angles to the passage 32 completely through the core member 18 and which is aligned with a circular hole 36 in the shell 14. The holes 34 and 36 together define a recess for receiving the other leg of the shackle 12.

The core members 16 and 18 are separated by a cold drawn steel strengthening tube 38 which engages over a boss 40 on the core member 16 at one of its ends and in a recess 42 in the core member 18 at the other of its ends so as to be maintained with its longitudinal axis aligned with those of the passages 24 and 32.

A case hardened alloy steel bar 44 which has been zinc plated extends through the tube 38 and is a close fit within the passages 24 and 32 whose walls act as bearings for the bar 44. The bar 44 has a lug 46 engaging in the slotted end of the rotary shaft 26 of the lock 22. The bar 44 has an annular groove 48 in which a C-shaped washer 50 is fitted, the washer 50 being trapped between the tube 38 and the base of the recess 42 in the core member 18 so as to hold the bar 44 axially in position.

At its lock-remote end, the bar 44 is provided with a shallow recess 52 whose ends define abutment surfaces for engagement with corresponding abutment surfaces in the core member 18 so as to limit rotation of the bar 44 to a 180 arc of movement. The bar 44 is provided with a pair of curved recesses 54 and 56 which, in the longitudinal direction of the bar 44, are aligned with the respective holes 28 and 34.

The end of the body 10 adjacent the lock mechanism 22 is closed by a hard drawn mild steel end plate 58 which is secured to the shell 14 by a clinching operation. The end plate 58 is apertured to receive a case hardened, zinc plated nozzle 60 of the lock mechanism 22. It will be appreciated that, with the shackle 12 completely detached from the lock body 10, the various components described above which are disposed within the shell 14 can be inserted into the shell 14 from the end plate-remote end thereof. The parts can then be secured in position by means of a grub screw 62 (see Fig. 1) which extends into an internally screw threaded hole (not shown) in the core member 18. As an alternative, the screw 62 may be replaced by a rivet. However, a screw is preferred since it allows the lock assembly to be more easily dismantled for servicing and/or lock replacement purposes.

The shackle 12 is provided with a set of recesses 64 and 66 which cooperate with the bar 44. In a locked position of the lock mechanism 22, the bar 44 is in the rotary position illustrated in Fig. 1 where the recesses 54 and 56 face away from the recesses 64 and 66, respectively, whereby regions of the bar 44 enter the recesses 64 and 66 to lock the shackle 12 against removal. It will be appreciated that, in this position, a continuous loop of hardened steel is provided by the shackle 12 and the bar 44 to improve security. In this position, it will be appreciated that the shackle 12 also serves to prevent the various components of the lock assembly from being withdrawn from the shell 14, even when the grub screw 62 is removed.

In an unlocked position, the bar 44 is in the position illustrated in-Figs 2 and 3 where the recesses 54 and 56 face the recesses 64 and 66 so that there is no region of the bar 44 which lies within the recesses 64 and 66 and so the shackle 12 can be completely detached from the lock body 10. In this condition, the lock assembly can be dismantled when the grub screw 62 has been removed.

The above-described lock assembly is extremely secure and can be readily dismantled to enable servicing and/or replacement of the lock mechanism 22 by a wide variety df makes of cylinder lock mechanism, thus enabling keycompatibility with other lock mechanism used on the same site.

In a modification (not shown), instead of only a single set of grooves 64 and 66, the shackle 12 may be provided with two or more sets of grooves which are disposed progressively nearer to the portion of the shackle interconnecting the legs. Under these circumstances, the shell 14 is provided with additional holes on the opposite side of the body to the holes 30 and 34 so as to permit the legs of the shackle 12 to pass completely through the lock body 10. Thus, the shackle 12 can be locked into any one of a number of positions relative to the lock body 10. Having regard to the article or articles to be locked by the assembly, the shackle 12 can be closed down as far as possible onto the article or articles and locked in that position making it more difficult to attack the lock assembly with a bolt cropper or the like.

Referring now to Figs 4 and 5 of the drawings, the lock assembly illustrated therein is a padlock. The construction and operation of the padlock illustrated in Figs 4 and 5 is similar to the lock assembly of Figs 1 to 3 and similar parts are accorded the same reference numerals but in the 100 series. In this embodiment, lock body 110 and shackle 112 are much shorter than in the preceding embodiment and the shackle 112 is not designed to be freely separated from the lock body 110 in the unlocked position. For this reason, a sleeve 170 is disposed within hole 136 in shell 114 and has an annular peripheral groove 172 adjacent its inner-end. The groove 172 is disposed internally of the shell 114 and is exposed in a shallow recess 174 in core member 118.The recess 174 extends to the outer end of the core member 118 and slidably receives a retaining clip 176 which engages in the groove and thereby prevents disengagement of the sleeve 170 from the lock body 110. Screw 162 serves not only to retain core member 118 but also passes through an end plug 178 serving to close the end of the shell 114. Thus, the shackle 112 and sleeve 170 can be removed (eg for servicing purposes or for fitting with a shackle of different size and/or shape) once the shackle 112 has been moved into its unlocked position, and the retaining clip 176 removed. It will also be appreciated that, with the shackle 112 and sleeve 170 removed, the core members 116 and 118, the bar 144 and the lock mechanism 122 can be completely removed for servicing or replacement purposes.Indeed, the lock mechanism supplied, being of a commonly available design, can be replaced by any other type of lock mechanism of similar design which the user may care to employ.

A shallow flat groove 180 (see Fig. 5) is provided on that portion of the leg of the shackle 112 which is disposed within the sleeve 170. A lug 182 (Fig. 5) is defined by inwardly deforming a portion of the sleeve 170 at the upper end thereof using a suitable tool so that the lug 182 enters the groove 180. The shackle, being formed of hardened steel, acts as a die or anvil during this operation. This lug 182 cooperates with the upper and lower ends of the groove 180 to permit sufficient axial displacement of the shackle 112 to enable it to be opened whilst also permitting limited pivotal movement of the shackle 112 about the axis of the leg thereof which is engaged with the sleeve 170. Thus, the shackle 112 is capable of being engaged with the article or articles to be secured by manipulating the padlock in a per se known way.

In this embodiment, the ends of the legs of the shackle 112 are stepped inwardly and, when in the locked position, engage with clearance in correspondingly stepped holes 184 and 186 which are formed in the lock body 110 in alignment with the respective holes 128,130 and 134,136. This arrangement serves to improve the resistance of the lock to torque attack. The reduced diameter of the ends of the legs of the shackle 112 facilitates correct location of the legs in the holes 184 and 186 when moving the shackle 112 into its locking position. Also, the provision of the holes 134,136 facilitates drainage of rainwater etc from the interior of the lock body 110.

The padlock of Figs 4 and 5 will not be described in any further detail since its construction, operation and advantages will be apparent from the description hereinabove in relation to Figs 1 to 3.

Claims (12)

1. A lock assembly comprising a lock body, a shackle, the lock body including a pair of spaced recesses in which respective legs of the shackle are received, a lock mechanism mounted in the lock body, and an axially rotatable bar which is mounted in the lock body so as to extend between said recesses and which is operably connected with the lock so as to be rotatable thereby, the bar and the legs of the shackle having respective mutually cooperating formations thereon such that (a) when the lock mechanism is in a locked position with the legs in the respective recesses, the bar engages the legs to prevent the latter from being removed from the recesses and (b) when the lock mechanism is in an unlocked position the bar is in a position in which the legs of the shackle are released.

2. An assembly as claimed in claim 1, wherein the lock body comprises at least one non-ferrous core member which defines bearings in which the bar is rotatably mounted, and an outer hardened steel shell in which the nonferrous core is secured.

3. An assembly as claimed in claim 1, wherein the lock body comprises at least one core member in which the bar is mounted for rotation, an outer shell in which said at least one core member is slidable, and fixing means for fixing said at least on core member in position, the shell having holes therethrough which are aligned with holes in the core member(s), the aligned holes defining the recesses in which the legs of the shackle are received, respectively.

4. An assembly as claimed in any preceding claim, wherein the lock mechanism is of a type which is removable from the lock body.

5. An assembly as claimed in any preceding claim, wherein the shackle has a plurality of sets of said cooperating formations on its legs, the sets being spaced apart longitudinally of the legs.

6. An assembly as claimed in any preceding claim, wherein the shackle is mounted in the lock body so that it can be completely removed therefrom only after it is in its unlocked condition.

7. A lock assembly comprising a shackle, a lock body including a pair of spaced recesses in which legs of the shackle are respectively slidably received so that the shackle can be moved between a locked position in which both legs of the shackle extend into the body and an unlocked position in which one of the legs of the shackle is disengaged from the respective recess in the lock body, a lock mechanism mounted in the lock body for releasably retaining the shackle in its locked position, and a mounting mechanism serving to mount the other of the legs of the shackle in the lock body, said mounting mechanism including (a) a sleeve which is mounted in the lock body and extends externally of the lock body through the respective recess, said sleeve slidably receiving the other of said legs of the shackle, and (b) a lug which extends inwardly of the sleeve and cooperates with a recess in that portion of the leg which is disposed internally of the sleeve so that the leg is retained against disengagement from the sleeve but is slidable to a limited extent axially relative to the latter.

8. An assembly as claimed in claim 7, wherein the sleeve is mounted for rotation relative to the lock body.

9. An assembly as claimed in claim 7 or 8, wherein the leg is fixed against rotation relative to the sleeve.

10. An assembly as claimed in any one of claims 7 to 9, wherein the sleeve is mounted in the lock body so as to be removable therefrom only when the shackle is in its unlocked position.

11. A lock assembly as claimed in claim 1 which has the combination of features specified in claim 7.

12. A lock assembly substantially as hereinbefore described with reference to Fig 1 to 3 or Figs 4 and 5 of the accompanying drawings.