Cylinder lock

Claim 1

A safety cylinder lock comprising a hollow cylinder, a keyresponsive inner cylindrical plug member rotatably mounted within said cylinder and rotatable by a removable key formed with notches and insertable into said plug member, and key-operated locking means carried by said plug member and releasably engageable with said cylinder, wherein the improvement consists in that said cylinder comprises an outer cylindrical casing portion and an inner substantially cylindrical core portion at least partially co-extensive in coaxial relationship with said outer casing portion to leave therebetween an intermediate annular space, the lateral peripheral surface of said inner core portion being formed with a number of circumferentially spaced grooves whereas said locking means comprise resiliently flexible strips made fast with said rotor member and extending in generally parallel relation to the longitudinal axis of said lock and to said grooves, said strips being arranged according to an at least approximately cylindrical configuration coaxially surrounding said cylinder core portion and fitted with clearance in said annular intermediate space to be rotatable therein, said strips being circumferentially distributed in spaced relationship to be on the one hand removably engageable in their free unstrained rest positions with at least some of said grooves provided in said cylinder core portion to hold said plug member against rotation when said key is removed, and on the other hand located in their resiliently radially outward deflected positions in a same substantially cylindrical surface within said intermediate annular space in a given rotary postion of said rotor member to be disengaged from said cylinder core portion and allow free rotation of said plug member, each strip being formed with a radially inward projecting catch element engageable with said key in the fully inserted position of the latter for moving said strips out of and into said grooves.