ES348713A1 - Combination lock - Google Patents

Abstract

A combination lock comprises a plurality of combination rings equally spaced from a central axis, an actuating mechanism mounted for rotation about the central axis whereby the combination rings are selectively rotatable each to a predetermined angular position, a bolt movable from a locking to a withdrawn position when the combination rings are in the predetermined angular positions and bolt actuating means for withdrawing the bolt on rotation of the actuating mechanism when the combination rings are in the predetermined angular positions. The lock has seven combination rings, each ring comprising a pair of discs 52, 61 mounted to rotate in a wall 3 of the lock casing and equally spaced around an operating shaft 320 which is rotated to set the combination so that a notch in each disc 61 connected to each disc 52 by a spring catch 72 is aligned with the teeth of a slidable bolt locking plate 140 to allow withdrawal of the bolt. To set the combination, a knob 211 on the shaft 320 is pressed and moves inwardly, against the action of a spring 196, a knob 201 secured to a tube 322 coaxial with the shaft 320 to free the tube for rotation by disengaging bosses 106 on a plate secured to the wall 3 from holes in a plate 230 secured to the tube 322. The knob 201 is turned to bring a mark thereon opposite a numeral on a fixed dial 190 and to bring a gear into alignment with a disc 52. The knob 211 is then released and moves outwardly and is then turned so that the gear previously positioned by rotating knob 201 is driven by a gear 255. On the shaft 320, and engages the gear teeth of the disc 52 to set the ring. The operations are repeated until all the rings are set according to the combination. The knob 201 is then rotated to zero on the dial 190 to bring the gear into alignment with the gear of a bolt driver and the knob 211 is turned to drive the bolt driver which has a stud engaging in a slot in the latch bolt to withdraw the bolt. The bolt driver also meshes with a pinion with a shaped interior surrounding parts of catches 90, to disengage catches from the teeth of discs 52 and allow them to rotate to the initial position under the action of a spring 80. A projection on the bolt driver displaces the locking plate 140 so that the teeth thereon disengage the slots in the discs 61. To change the combination, the discs 52 are set to the combination, an external knob 291 is turned and a cam 294 thereon moves a member 170 adjacent plate 140 so that the teeth thereon engage the catches 72 joining the discs 51, 61 to disengage the discs. The discs 52 are then turned to another position. To lock the bolt a spring urged lever engages a recess in the plate 140 and abuts a projection on the bolt drive to prevent its rotation to withdraw the bolt. The lever is moved from the projection to allow withdrawal of the bolt when the knob 201 is moved to the zero position.