Patent GB-870874-A (GB)
Title: Combination locks
IPC: E05B37/08
Filed: 1958-12-13
Abstract: 870,874. locks SARGENT & GREENLEAF Inc. Dec. 13. 1958, No. 40257/58. Class 44. A combination lock comprises a plurality of peripherally-gated tumblers 22, 23, 24, Fig. 3,' rotatably journalled in axial alignment within a housing body 15, a driving cam 27 rotatably mounted adjacent the tumblers having a known type of lost-motion connection with the latter and having a peripheral gate 28, Fig. 5, for receiving a portion 58 of a pivotally-mounted spring-loaded fence lever 56 on which is a fence 57 extending across the peripheries of the tumblers 22, 23, 24 for entry into the gates 22<SP>1</SP>, 231, 241 therein, the fence lever 56 being adapted to retract a resiliently-loaded bolt 60. A dial 38 is connected to the cam 27 to rotate the tumblers 22, 23, 24 for alignment of the gates 221, 23<SP>1</SP>, 24<SP>1</SP> and a slide 31 is supported on the cam 27 for movement radially thereof, a disc 45 being provided which is connected to a cam 51 for movement of the slide 31 from a position shielding the gate 28 from entry of the fence lever portion 58 to a position exposing the gate 28. Spaced fixed shoulders provided by arcuate stop members (not shown) on a bottom cover-plate 16 accommodate therebetween a portion of the slide 31 when it is in the gateexposing position and thereby restrict rotation of the cam 27 to a minor arc, and movement of the slide 31 to the latter position is prevented by the arcuate stop members when the cam 27 is in an angular position outside the minor arc. A pin 81, Fig. 8, is pivotally mounted on the dial 38 and is moved into and out of engagement with a notch 88 in the housing body 15 by a guide groove 87 in the disc 45 when the dial 38 is in a given position and the disc 45 is rotated relative to the dial 38 to move the slide 31. In operating the lock the dial 38 is moved to align the gates 221, 231, 241 in the tumblers 22, 23, 24 and then, with the dial 38 in the position in which the pin 81 is aligned with the notch 88, the disc 45 is rotated to move the slide 31 to expose the gate 28 thus allowing the fence lever 56 to move so as to engage the fence 57 in the gates 221, 231, 241, subsequent movement of the dial within the limits of the minor arc operating the fence lever 56 to retract the bolt 60. The slide 31 is provided with a pin 35 which, when the slide 31 is in the gate-shielding position, transmits the movement of the cam 27 to the tumblers 22, 23, 24 and, when the slide 31 is in the gate-exposing position, is moved to a position in which the movement of the cam 27 is not transmitted to the tumblers. The bolt 60 normally engages behind a shoulder 67 on a spring-loaded plunger 65 to retain the latter in its locking position, the plunger 65 being operatively connected to a linkage system 14 normally locking a cabinet incorporating the lock. When the bolt 60 is retracted the plunger 65 moves to a position in which an integral finger button 72 projects from a top framing strip 12 of the cabinet, unlocking the latter, and to re-lock the cabinet the plunger 65 must be manually depressed to allow the bolt 60 to reengage the shoulder 67. To frustrate an attempt to drill through the cabinet top to the tumblers 22, 23, 24, a drill-proof plate 20 is provided on the housing body 15, overlying the tumblers, and to prevent the introduction of a shim for the purpose of actuating the bolt 60, a drill-proof-plate 74 provided in the housing body 15, projects into a recess 73 in the plunger 65. In a modification, Figs. 10, 11 and 12 (not shown) the pivotally mounted pin 81 is replaced by a pin which is slidingly mounted on the dial.