GB2289712A - Cylinder locks - Google Patents

Abstract

A cylinder lock 7 is mounted with the axis of rotation of its rotor 16 offset from the axis of an actuating cam 8. In order to accommodate this misalignment without binding or lost motion a transmission member 9 is interposed between the rotor 16 and cam 8 having a transvorse rib 22 which engages in a transverse groove 24 at the driving end of the rotor 16 and having a transverse groove 23, perpendicular to the rib 22, in which engages a transverse rib 25 on the driven end of the cam 8. This arrangement provides two orthogonal axes of adjustment transverse to the cam and rotor axes. The lock is preferably used in a padlock which has a sliding assembly incorporating a shackle 3. The shackle is kept in its locking position by a pair of balls 10 pressed out of the sliding assembly by rotation of the cam 8. <IMAGE>

Description

Locks The present invention relates to cylinder locks, by which we mean locks incorporating cylinder assemblies of the kind comprising a rotatable plug (or "rotor") borne in a cylinder body (or "barrel", "shell" or "stator") and normally blocked against rotation relative to the body by the action of tumbler pins or other mechanical obstruction(s) comprised in the cylinder assembly, but which can be released for turning by the insertion of a proper key. Certain such cylinder assemblies are available with a coaxial plug and body in an overall circular cross-sectional form but more often the cylinder body has a non-circular cross-section (e.g. oval, "Europrofile" "snowman" etc.) with the rotational axis of the plug offset from the median of the body.It follows that in some circumstances there is a need to accommodate a degree of parallel misalignment between the axes of a cylinder plug and of a lock element turned thereby if a profiled-section cylinder assembly is to be incorporated in a limited space within a lock mechanism.

The present invention seeks to provide a solution to this problem and accordingly resides in a lock comprising a cylinder assembly and a lock element adapted to be turned by the plug of the cylinder assembly; the axes of said plug and element being offset but generally parallel to each other; and further comprising a transmission member through which rotation of said plug is transmitted to said lock element; the transmission member having a first formation engaged with a first transverse formation at the driving end of said plug whereby the transmission member is constrained to turn with the plug but is slidable relative thereto in the direction of said first transverse formation, and the transmission member having a second formation, generally perpendicular to its said first formation, which is engaged with a second transverse formation at the driven end of said lock element whereby the lock element is constrained to turn with the transmission member while the transmission member is slidable relative thereto in the direction of said second transverse formation.

In use of the invention the aforesaid transmission member accommodates the misalignment of the driving and driven axes by sliding relative to the cylinder plug and/or lock element as it turns, while maintaining the respective transverse formations of the latter at the same generally perpendicular angle relative to each other as the angle between its own said first and second formations.

In a preferred embodiment the invention is applied to a form of lock comprising: a lock body; and a sliding assembly borne by said body and including a bolt, shackle or other such locking member, adapted to be slid between locking and unlocking positions; the sliding assembly also including said cylinder assembly, lock element and transmission member; the lock element being adapted, in a first rotary position, to cause the sliding assembly to be detained relative to said lock body in its said locking position and, in a second rotary-position, to free the sliding assembly for movement to its said unlocking position; said first rotary position of the lock element corresponding to a rotary position of said cylinder plug in which the latter is blocked against rotation relative to the cylinder body; but the cylinder plug being rotatable by a correct key to turn the lock element to its said second rotary position.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical section through a preferred form of padlock embodying the invention; Figure 2 is a section on the line II-II of Figure 1; Figure 3 is a section on the line III-III of Figure 2; Figure 4 is a section on the line IV-IV of Figure 1; and Figure 5 is a schematic diagram illustrating the transmission of rotation from the cylinder plug to the cam in the lock of Figures 1 to 4.

Referring to Figures 1 to 4, the illustrated lock is intended for use in conjunction with a padbar and staple (not shown) for securing e.g. the external doors of garages, sheds, storerooms, warehouses and the like. An example of a suitable padbar and staple with which this lock may be used is illustrated in our United Kingdom patent application no. 2253005. The lock has a main body 1 defining a recess 2 to engulf the staple, and a shackle 3 slidable in the body 1 between the illustrated locking position in which it traverses the recess 2 to retain the lock upon the staple and an unlocking position in which it withdraws from the recess 2 to permit the lock and staple to be separated.

The shackle 3 is formed as a integral extension of a housing member 4 which is attached by screws 5 to a second housing member 6. The members 4 and 6 collectively define a housing for a cylinder assembly 7, cam 8, transmission member 9 and a pair of balls 10, and the entire assembly 3-10 is slidable as a whole relative to the body 1 within limits set by a cap screw 11 engaging in a slot 12 formed in the peripheries of the housing members 4 and 6. More particularly, in the rotary position of the cam 8 shown in Figures 1 to 3 it presses the balls 10 radially outwards into respective detentions 13 formed in the body 1 to retain the sliding assembly in the locking position. Turning the cam 8 through 900, however, frees the balls 10 to move radially inwards from the recesses 13 and thereby permits the sliding assembly to be withdrawn to its unlocking position.The limits of rotation for the cam 8 are set by a stop pin 14 (Fig. 3) driven through a bore in the wall of housing member 4.

Rotation of the cam 8 to lock and unlock the sliding assembly is under the control of the cylinder assembly 7.

In principle any known form of cylinder assembly may be employed, although in the illustrated embodiment the assembly 7 is of the form described in United States patent specifications nos. 3722240 or 4636456. Thus, with reference to Figure 4, the cylinder assembly comprises a body 15 fast in the housing 4/6 and a rotatable plug 16 normally blocked against rotation in the body 15 both by a row of two-part tumbler pins 17A, 17B biased by respective springs 18, and by a springbiased side bar 19 engaging in a groove 20 in the body 15. The blocked position of the plug 16 of course corresponds to the locking position of the cam 8.Upon insertion of a correct key 21, however, the pins 17A are both lifted and twisted by respective skew cuts on the key, both to align the splits between each tumbler pair with the shear line between the body 15 and plug 16, and to align gates (not shown) in the sides of the pins 17A with corresponding formations on the side bar 19 to permit the latter to be cammed inwards out of the groove 20 when torque is applied to the plug 16.

It will be observed that in order to accommodate the pins 17B and springs 18 the axis of the plug 16 is inevitably offset from the median MM of the cylinder body 15, which in the illustrated embodiment is of "snowman" profile.

In order to accommodate the cylinder assembly in the housing 4/6 without waste of space, it follows that the axis of the plug 16 is offset from the axis of the cam 8, as is apparent from Figure 1. In order to transmit rotation from the plug to the cam without undesirable binding or lost motion, therefore, the mechanism in accordance with the invention incorporates the transmission member 9, also seen in Figure 2. The member 9 is generally in the form of a disc, having a chordwise rib 22 on one of its faces and a chordwise groove 23, perpendicular to the rib 22, in the other of its faces. The inner end of the cylinder plug 16 has a diametral groove 24 into which the rib 22 engages, and the adjacent end of the cam 8 has a diametral rib 25 engaging in the groove 23. As the plug 16 is turned by the key 21, therefore, the member 9 is turned by virtue of the coupling 22/24, and as the member 9 turns the cam 8 is also turned by virtue of the coupling 23/25. The effect is that the member 9, floating between the plug and cam, at all times keeps the cam rib 25 perpendicular to the plug groove 24 and the offset between the axes of the cam and plug is accommodated by the member 9 as it turns by sliding along the groove 24 and rib 25 under the reaction forces generated between the components.

Figure 5, from top to bottom, illustrates schematically the motion of the plug 16, member 9 and cam 8 as the plug 16 is turned clockwise (in the sense as viewed) through 900 to unlock the balls 10. It will be seen how the member 9 describes an arcuate path as it turns through 900 while at all times remaining within the confines of the housing member 4.

In one example of a lock constructed substantially in accordance with the drawings, the offset between the plug and cam axes is approximately 6mm and such a lock has been tested successfully to 60,000 locking/unlocking cycles.

The illustrated lock is also designed for ease of disassembly, e.g. to replace the cylinder assembly 7.

By removing the screw 11 and unlocking the cylinder the entire sliding assembly 3-10 can be withdrawn through the end of the body 1. By removing the screws 5 the housing members 4 and 6 can then be separated, permitting removal and replacement of the cylinder assembly through the inner end of housing member 4.

Claims (9)

1. A lock comprising a cylinder assembly and a lock element adapted to be turned by the plug of the cylinder assembly; the axes of said plug and element being offset but generally parallel to each other; and further comprising a transmission member through which rotation of said plug is transmitted to said lock element; the transmission member having a first formation engaged with a first transverse formation at the driving end of said plug whereby the transmission member is constrained to turn with the plug but is slidable relative thereto in the direction of said first transverse formation, and the transmission member having a second formation, generally perpendicular to its said first formation, which is engaged with a second transverse formation at the driven end of said lock element whereby the lock element is constrained to turn with the transmission member while the transmission member is slidable relative thereto in the direction of said second transverse formation.

2. A lock according to claim 1 wherein said transmission member is of disc-like form, each of its first and second formations comprising a chordwise rib or groove at the respective axial end of the transmission member.

3. A lock according to claim 1 or claim 2 comprising: a lock body; and a sliding assembly borne by said body and including a locking member, adapted to be slid between locking and unlocking positions; the sliding assembly also including said cylinder assembly, lock element and transmission member; the lock element being adapted, in a first rotary position, to cause the sliding assembly to be detained relative to said lock body in its said locking position and, in a second rotary position, to free the sliding assembly for movement to its said unlocking position; said first rotary position of the lock element corresponding to a rotary position of said cylinder plug in which the latter is blocked against rotation relative to the cylinder body; but the cylinder plug being rotatable by a correct key to turn the lock element to its said second rotary position.

4. A lock according to claim 3 wherein said locking member is in the form of a shackle which in the locking position of the sliding assembly extends across a staple recess in the lock body and in the unlocking position of the sliding assembly is withdrawn from said recess.

5. A lock according to claim 3 or claim 4 wherein said lock element is in the form of a cam which in said first rotary position causes one or more detaining elements to extend from the sliding assembly into corresponding detention(s) in the lock body and in said second rotary position permits said detaining element(s) to be withdrawn from said detention(s).

6. A lock according to claim 5 wherein the or each said detaining element is in the form of a ball.

7. A lock according to any one of claims 3 to 6 wherein the limits of sliding movement of the sliding assembly relative to the lock body are set by stop means releasably secured to the lock body whereby release of said stop means while said lock element is in said second rotary position permits the sliding assembly to be removed from the lock body.

8. A lock according to claim 7 wherein the cylinder assembly is demountably secured within the sliding assembly, whereby to permit the replacement of one such cylinder assembly with another.

9. A lock substantially as hereinbefore described with reference to the accompanying drawings.