Patent GB-748360-A (GB)
Title: Improvements in and relating to locks
Inventor: GREENER FRANK WALTER GEORGE
IPC: E05B37/00
Filed: 1953-06-29
Abstract: 748,360. Permutation locks. CHUBB & SON'S LOCK & SAFE CO., Ltd. May 3, 1954 [June 29, 1953 ; July 20, 1953], Nos. 17908/63 and 20068/53. Class 44. In a permutation lock of the kind comprising a bolt, a driver rotatable by a spindle accessible outside the bolt casing, means for interconnecting the bolt and driver whereby the bolt may be activated by the driver, and control means adapted when moved to unique settings to allow the interconnecting means to connect the bolt and the driver, the spindle is axially movable in relation to the driver. In the arrangement according to Fig. 1 in which the lock comprises a driver 1 secured to a rotatable spindle 2 extending through a pillar carrying wheels 4, each with a peripheral slot and in which a fence lever 6 having a fence 8 is pivoted to the lock bolt, a cam member 9 slidable in guides 10 co-operates with an extension 11 on the fence 8 to support the latter out of contact with the wheels 4. The position of the cam member 9 is controlled through a spring-loaded lever 20 by a spring-loaded slide 23 which is moved inwardly to free the fence 8 by the spindle 2 which is longitudinally slidable in its bearings. The arrangement is such that if the wheel slots and a recess in the driver 1 are aligned, the fence 8 engages the wheel slots. When upon closure of the bolt the fence lever 6 is raised by rotation of the driver 1, the cam member is forced rearwardly until the extension 11 rides past the tip of the cam member whereafter the cam member can lift the fence lever 6 to the position shown. A slide 23 is movable by means of an extension 27 of the spindle 2 which on rotating engages a bearing pillar 28 for the slide, thus preventing rotation of the driver 1 with or without the wheels 4 while the fence 8 is in contact with the wheels. Lever 20 may be provided with duplicate springs and a counterweight 30. In a modification, Figs. 2, 3 and 4 (not shown), the extension 27 and slide 23 may be interconnected by a lost-motion device. In another arrangement, Figs. 5 and 6 (not shown), the driver 1 is disengageable from and is kept stationary when the spindle 2 is pushed inwards by means of a latch arrangement. In the arrangement according to Fig. 7, the spindle 2 actuates a trigger mechanism for momentarily releasing only the fence lever supporting means to prevent the fence being kept in contact with the wheels 4. As shown, the slide 23 is located above the extension 27 and is provided with a transversely slidable pin 37 which normally abuts the extension. As the slide is pushed inwards by the spindle 2 the pin 37 is raised by the action of lever 38 and the slide is forced forward by its spring 26 to move the cam member 9 back to the supporting position shown. The arrangement may include the arrangement according to Figs. 5 and 6 and or Figs. 1 to 4. Slide 23 in Fig. 7 may be provided with a rib or flange to engage a pin or lug on the extension 27 in the event of failure of the springs 26. In any of the above arrangements the spindle 2 may be weakened at one point to shear or buckle upon excessive force being applied thereto. In the arrangement according to Figs. 10 to 12 in which the driver is rigidly secured, the spindle 2 which is mounted for axial sliding movement, the lock is provided with a toggle system for holding the fence lever out of engagement with the driver until released. The toggle system which may be as disclosed in Specification 735,148 comprises a lever 50 pivoted at 51 to a base 52 secured to the lock casing and a superposed lever 53 pivoted at 54 to the lock casing and extending downwards below'the pivot 51 of the lever 50 where a pin 55 projecting from lever 53 engages in a slot 56 of plate 52, and limits the locking movement of lever 53 about its pivot. The lever 50 is loaded by a tension spring 57. As shown, the lever 50 engages beneath a roller 59 on the lever 6 which is thus held up out of contact with the wheels 4. The displacement of lever 53, in order to throw the toggle system is effected by the sliding movement of the spindle 2, the lever 53 being rocked about its pivot 54 by an arm 60, which is engaged by a block 61 on the driver, when the latter is rotated to bring the block and the arm into alignment and the driver is moved inwardly. A spring 63 beneath a plate 62 overlapping lever 53, withdraws the latter and the lever 50 when the spindle is withdrawn and removes the block 61 from engagement with arm 60. In order to prevent rotation of the spindle driver assembly when moved inwards to release the fence lever, a gap 64 is provided between abutments on the inner surface of the rear cover plate of the lock casing between which the block 61 moves when the spindle slides axially inwards. This gap is aligned with the arm 60 and is dimensioned so that the block 61 is a sliding fit therein. The abutments are sufficiently deep to ensure that the block 61 becomes engaged between them, thus rendering rotation of the driver impossible, before the inclined surfaces of the block 61 interact to displace lever 53. Preferably the abutments extend as a circular ridge 65 round the axis of the spindle and are of such depth that the spindle and driver are adjacent to the upper surface of the ridge 65. This prevents inward sliding movement of the spindle in any angular orientation other than that which the block 61 is aligned with gap 64. A recess 66 is provided in the rear cover plate to accommodate the guide plate 62. Specification 705,729 also is referred to.