GB1076739A - Improvement in or relating to combination locks - Google Patents

Abstract

1,076,739. Change combination locks. SARGENT & GREENLEAF Inc. Oct. 2, 1965, No. 41888/65. Heading E2A. A tumbler wheel for combination locks comprises a hub member 11 with external teeth enclosed by two interengaging annular members, a case 26 and a cover 27 which have corresponding recesses defining a force receiving gate when they are secured to the hub member by rotating one annular member relatively to the other whereby sliding shoes 37, engaged in spaced walls 32 on the case slide into engagement with the serrated periphery 15 of the hub member and are disengaged therefrom to free the rim members for relative rotation so that the recesses are not in alignment to allow changing the combination by rotating the dial of the lock. To disengage the annular member from the hub a cam 53 supported in apertures 49, 33 in the annular members and anchored to the case 26 by a knob 56 is rotated anti clock- -wise by the combination change key. The cam strikes a shoulder 60 on the cover 27 which rotates so that shaped zones 52 thereon disengage an inclined surface on the shoes 37 and disengages them from the hub rim. After changing the combination the cam is then rotated clockwise striking another shoulder 59 on the cover which rotates moving the shoes to engage with the teeth on the hub member, and peripheral recesses 34, 48 on the case and cover are aligned to receive a fence. In a modification the shoes are replaced by two arcuate members slidably supported by the case and serrated on one side to engage the hub serrations and with projections on the other side which cooperate with spaced recesses in the cover. Alternatively the case may have a series of resilient members with serrated surfaces. A fly 19 supported by the hub member has a recess 22 for accommodating a drive pin 17 which drives the next tumbler wheel. The rim portion is formed of low density plastics material to prevent X ray and other photographs being taken.