Patent GB-390160-A (GB)
Title: Improvements in or relating to locks
IPC: E05B35/08
Filed: 1931-09-28
Abstract: 390,160. Locking mechanisms; keys; keyholes, obstructing. KENNEDY, E. N., 170, Piccadilly, London. Sept. 28, 1931, No. 26997. [Class 44.] In a change-key lock insertion of the key in a key-guide rotates members in engagement with locking members to set the latter to bolt-releasing position, and the bolt is withdrawn by a swinging lateral movement of the key, the key-guide being pivoted to allow this. This movement disengages the operating and locking elements so that the key may be withdrawn and a different key inserted. On returning the guide to locking position and withdrawing the substituted key, the mechanism is set to position corresponding with the last-used key. Fig. 1 shows a form of latch lock with a bolt e operable from one side by a key and from the other by a knob k in the usual way. A key-guide p pivoted at q has pin-and-slot connection with a sliding plate f on which a set of gear-wheels a is pivoted at g, the plate being connected either rigidly, or so as to allow lost motion, with the bolt e. Wheels a project at one side into the passage-way in the guide p, as shown, and at the other mesh with wheels b on a fixed pivot h carried by the lock casing. The key, Fig. 6, is of flat form provided with racks made by apertures n which engage and rotate wheels u as the key is inserted. The racks are of different lengths followed by elongated slots o so that wheels a, b are rotated to correspondingly different extents. Plate f has a projection d and the wheels b have radial slots c. The bolt e can only be withdrawn when the slots c have been brought to register with projection d by insertion of the proper key. The bolt may be retained in shot or retracted position by a transversely sliding bar s co-operating with the bolt in known way. Bar s is connected by lever u with a sliding rod t penetrating the key-guide p and moved to the right when bar s is pulled outwards to locking position. Normally, a notch in rod t registers with the key-way, but when moved to the right the rod prevents insertion of a key. The key has a notch w which allows movement of rod t when the key is in place, so that when a key has been inserted and the bolt retracted, the bolt may be locked in retracted position, thus securing wheels b against movement whilst change of key is being effected. The slots c may be formed in discs secured to wheels b. The slots o may be at the leading end of the key. Instead of the key co-operating with the teeth on wheels a, the latter may have a single projection x, Fig. 5, co-operating with a key of the form shown in Fig. 8. Wheels a, b may be biased to normal position by springs and accidental displacement may be prevented by a spring detent in the key-way co-operating with the teeth of wheels b and released by insertion of the key. Fig. 9 shows a modification in which a hook bolt 43 pivoted at 44 can be retracted from one side against action of a spring 47 by pinching a finger-piece 45 against a fixed abutment 46. From the other side, retraction may be effected by rotating the key-way 32 about its pivot 33, the key-way being connected by a spring connection 55 (which gives way if attempt be made with an improper key to force the lock) with a plate 31 also pivoted at 33. Plate 31 carries a projection 38 entering deep notches 37 in locking discs 21 when these have been correctly positioned, a pin 41 having lost-motion engagement in an aperture 42 in the bolt, and a pin 29 on which are pivoted toothed quadrants 27. Quadrants 27 have projections 34 engaged by the key, and mesh with pinions 22 secured to the locking discs 21 pivoted on a fixed pin 23. When the key is pinched against a fixed fingerpiece 39 to retract the bolt, quadrants 27 are moved out of mesh with pinions 22. The bolt may be blocked in shot or retracted position by a projection, not shown, on a slidable rod 50 which has a cam, not shown, co-operating with a pin 52 on plate 31 to give the plate extra movement and retain it during key-changing. If desired, the mechanism may be remote from the entrance to the keyhole and the key m, Fig. 18, may be inserted and manipulated by a secondary key or a flat rod 75. Figs. 13 and 14 show the application to the bolt member 56 for a safe-door 58. The bolt is operated by arms 62 co-operating with the edges of an aperture in the bolt, and carried by meshing pinions 61, the upper pinion being rotated by a handle 60 having a ball-catch connection with the spindle. 68, which yields and renders the handle idle when the spindle is held against rotation. The spindle has a crank 63 in the path of which a lever 64 may be locked by mechanism 67 of the kind described above. The key is introduced through slot 74 in the door by rod 75. Access for key-changing is allowed by a removable panel 78 on the inside of the door.