GB179256A - Improvements in safety locks - Google Patents

Abstract

179,256. Schulz (nÚe Muller), M., Muller, M., and Muller, W. Jan. 27, 1921. Lock mechanism, lever-type; slider-type; master-key; keys.-A lock is constructed so that the bolt is operable in two or more stages by successive operations of a key in one and the same key hole from one side of a door and comprises one or more groups of tumblers movable with the bolt and each having two or more notches or rises. In the form shown in Fig. 1, the bolt a carries with it a series of tumblers b each formed with two key-engaging notches x, y. According to the arrangement of the notches at these two points, the lock is operated by one or by two different single-bitted keys, or by a double-bitted key, as shown at g. Fig. 3 shows a modification having upper and lower groups of double-notched tumblers. If the groupings at x, w, and y, z, are symmetrical crossways, one double-bitted key operates the lock in two stages with a single turn; while if all are different, four bits are necessary, which may be carried upon one or more keys. Separate key-holes are provided for operation of the lock from both sides of the door, each key acting as described to actuate the bolt successively. If there is only one group of tumblers, one key suffices to work from either side, if the arrangement of the notches is reversely symmetrical; otherwise two keys, or a double key, are required. Similar reasoning applies when two groups of tumblers are fitted. Triple-throw locks, with one or two groups of tumblers, and with or without separate key-holes for use from the two sides of the lock are also described. Fig. 10 shows a double-throw bolt operable from either side through independent key-holes g, g<1>. The complexity of the key, or the number and type of keys necessary, may be reduced by the introduction of various kinds and degrees of symmetry in the arrangement of the tumblers.