GB1128038A - Door locking means - Google Patents

Abstract

1,128,038. Locks; latches. A. M. FISH. 8 Dec., 1965 [18 Dec., 1964], No. 52050/65. Heading E2A. A door locking device comprises a combination lock mechanism having decoding means which must be activated to permit opening of the door, a combination scrambling means, and means for automatically activating the scrambling means if the door is not opened within a predetermined interval after actuation of the decoding means is commenced. As shown, a combination lock mechanism 12 controls a latch mechanism 14 in a door 10, a knob 15 on the inner side of the door being operable at all times to retract a latch bolt 17 from a striker 20, the latch bolt being retractable from the outside of the door by an operating lever 23 of the combination lock mechanism. The latch mechanism 14 includes a dead bolt 21 which is carried inwardly by the striker 20 as the door is closed, in which position it prevents retraction of the latch bolt 17 except by means of the knob 15 or by proper manipulation of the combination lock mechanism. The latter is of a known type comprising push buttons 13 for decoding the lock, and the lever 23, which can be turned in one direction after the correct operation of the push buttons to retract the latch bolt 17, or can be turned in the opposite direction to cancel and scramble the combination. The latch mechanism includes a hub 32 for the knob 15 which carries an arm 39 supporting an idler disc 40 on which bears the ends of a spring 42 which embraces the hub 32 and a pin 36, the arrangement being such that the spring yieldingly resists rotation of the knob 15 and returns it to its centred position after operation. The inner end of the hub 32 is rotatably received in an adjacent end of a fixed hub 34 for a fixed knob 16. Rotation of the knob 15 in a clockwise direction as viewed in Fig. 3 swings the arm 39 to effect tilting through an extension 94 thereof of a latch control lever 63 pivoted at 64 to disengage a hook portion 71 of the lever from the tail of the latch bolt 17 and to then drive the latch bolt inwardly by engagement of a driver 90 on the lever with an abutment 91 on the latch bolt. A second extension 94' is provided to permit use on doors of either hand. The dead bolt 21 is supported for limited sliding movement by a lug-and-slot arrangement 59, 60 between a boss on the latch casing and an arm 62 of the lever 63. The dead bolt is biassed to its projected position by a spring 75 through a lever 80. When the dead bolt is projected, as the door is opened, after operation of the lock mechanism 12, a lug 73 thereon engages a portion 74 of the arm 62 to rock the latter against its spring 66 thereby to lift the hook portion 71 from the tail of the latch bolt. A cam 85 driven by the operating lever 23 and overlying the arm 62, is provided with an abutment 88, which, in the locked condition of the latch bolt, engages an edge 89 of the arm 62, whereby when the lever 23 is operated, cam 85 rotates to rock the lever 63 to free the latch bolt 17 and then to retract it by means, of an arm 92 of the lever 63 which is moved into engagement with an abutment 91 on the latch bolt. A step 97 on the cam 85 is then engaged by a link 99, pivoted on the lever 80 and operative, when the door is reclosed, to rotate the cam and the lever 23 counterclockwise whereby to cancel the combination and to reset the lock mechanism, after which the link 99 rides past a shoulder 98 on the cam 85 and a centring spring on the lever 23 returns the cam to its manual position. The latch bolt may also be retracted by a slidably mounted arm 48 which is movable through an arm 107 of a key actuated cylinder lock to rock the lever 63 in the direction to retract the latch bolt. Access to the combination change member (not shown) of the lock mechanism, is afforded by a keyoperated cylinder lock on the inside of the door, which retains in position on the outside of the door a plate 110 having attached thereto a stem on which is threaded a nut which can be backed off the stem by rotation of the key. Electric switches 118, 119, 120 and (126) Fig. 2 (not shown) located within the latch casing cooperate respectively with a permanent magnet 121 on the door frame, the rear end of the dead bolt 21, the latch bolt 17 and an index or coding shaft (25) Fig. 2 (not shown) of the lock mechanism all switches being "open" when the door is open. The switches form part of an electric circuit, Fig. 11 (not shown), which also includes an electric motor (130) which operates to cancel the combination and reset the mechanism if after a predetermined interval following operation of the coding shaft by the press buttons 13, the door is not opened. The circuit also includes means (139) and (138) for signalling respectively, the "door open" condition and tempering with cables to the door.