GB1340932A - Combination of a lock mechanism and a set of disc-actuating members - Google Patents

Abstract

1340932 Locks WARTSILA AB OY 19 April 1971 [20 April 1970] 9914/71 Heading E2A A cylinder lock of the kind having rotatable disc tumblers which are selectively rotated by angled key bittings to a releasing position, e.g. in which an axial locking bar is received in grooves in each tumbler, is provided with a further key which displaces one or more tumblers to a position which prevents full insertion of the main key, and a third key which resets these tumblers to their normal position. As shown, the lock has a series of rotatable tumblers 12 turned to appropriate angles 0-5, Fig. 2, by bitting on the main key, and, if desired, one or more fixed tumblers 13 acting as wards for which cut-outs 16 are required on the keys. The disabling key, Fig. 3, has a cut-back surface 15 which leaves the last tumbler incompletely turned back which prevents full insertion of the main key. Insertion of the third key, Fig. 4, causes surface 17 to reset this tumbler to its normal position for insertion of the main key.