Patent GB-1281980-A (GB)
Title: Combination locks
IPC: E05B37/16
Filed: 1970-12-29
Abstract: 1281980 Combination locks TIME RESEARCH & DEVELOPMENT CORP 29 Dec 1970 [27 Jan 1970] 61636/70 Heading E2A A push-button combination lock comprises a plurality of rotatably mounted toothed discs 40, a plurality of push buttons 46A-46D, one push button being provided for each disc, friction means connected between the discs and the push buttons whereby pushing movement of any of the buttons will tend to rotate all the discs, holding means on each push button for preventing rotation of the associated disc when a push button is depressed and unlocking means for unlocking the lock when the discs are brought to a predetermined alignment. As shown, a latch 18 is operated by a knob 20 which is located on a half round shaft 22 mounting an arm 24 provided with notches 26 engageable by the finger 28 of a pivoted, spring-biased lever 30, the shaft being rotatable in a bearing 34 on a frame 36. The discs 40 are each provided with a slot 42 which slots, when aligned are engaged by a rod 44 on the lever 30 and when the finger 28 is in the notch 26 of the arm and allowing the shaft 22 to turn to operate the latch. Spring biassed push buttons 46A - 46D, slidably mounted in a bracket 48, each have respectively, advancing members 50A - 50D and holding fingers 52A - 52D which bear against flanges 62 of a slidable U-shaped member 60, the latter, by pushing any one of the buttons being caused to move upwardly; the member 60 is biassed downwardly and has an advancing pawl 66. On the outer surface of the bearing 34 is a rotatably sleeve 70 carrying a ratchet wheel 72 having a return arm 74 and a spring-loaded arm 76 provided with a detent 78 holds the ratchet wheel in any position when advanced by the push-buttons through the pawl 66; a spring 80 tends to rotate the wheel clockwise and keeps the wheel in contact with the detents. The identical discs 40 each have a series of teeth 82 and a return lever 84 and are mounted for rotation on the sleeve 70, friction washers between the discs being keyed to the sleeve and which causing the advancement of those discs which are not retarded by engagement of a holding finger with a tooth of a disc when a push button is operated. A pivoted locking and reset plate 21 has an arm 94 in contact with arm 76 and which has a projection 95 which bears against the advancing pawl 66 so that when the plate is pushed upwardly the arm 94 causes the detents 66, 78 to be disengaged from the ratchet wheel 72 which under the influence of the spring 80 rotates to move return arm 74 against levers 84 whereby all the discs 40 are rotated so that the levers 84 abut stop 96. Slidably mounted within hub 34 is a halfround sleeve 102, extending from arm 24, formed with a cam surface 104 and disposed diametrically opposite shaft 22. A shaft 106 mounted within the shafts 22, 102 is rotated by the key lock 23 and carries a pin 108 acting on cam surface 104 so that when the shaft 106 is rotated by a key the arm 24 is displaced from a locked position and out of engagement with finger 28 when the latch bolt 18 may be withdrawn by turning of the knob 20; rotation of the shaft 106 to re-lock the door allows spring 118 to displace arm 24 back into alignment with lever 30. The discs 40 have a series of slots forming tabs any one of which can be removed so that the lock can be adjusted to any desired combination.