# US 4,395,893 A · Plate tumbler-type cylinder lock mechanism > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,395,893 A - Document ID: US4395893A - Status: Granted - Kind: A - Application number: 06/289,271 - Filed: 1981-08-03 - Granted: 1983-08-02 - Earliest claimed: 1981-08-03 - Assignees: Chicago Lock Co. - Inventors: Robert L. Steinbach - Web page: https://patentgrep.com/patent/US4395893A ## CPC - E05B 29/00: Cylinder locks {and other locks} with plate tumblers which are set by pushing the key in {(fastening of cylinders, rotors, plugs or cores E05B9/084; with magnetic tumblers E05B47/0044; with electromagnetic control E05B47/0611)} - Y10T 70/7599: Transverse of plug - Y10T 70/7672: Cylinder - E05B: LOCKS; ACCESSORIES THEREFOR; HANDCUFFS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An improvement in a plate tumbler-type cylinder lock mechanism including an elongate barrel having a longitudinal bore therein, and a key plug having a body portion and a shaft portion extending therefrom, such plug being received rotatably in the bore with the body portion extending between opposite ends of the barrel and the shaft portion extending outwardly from one end of the barrel, the bore having a draft-induced longitudinal taper widening in the direction of the said one end of the barrel, such improvement including journal means on the body portion and projecting laterally therefrom for journalling the plug in the barrel adjacent to the said one end thereof, thereby to minimize lateral play between the plug and the barrel thereat. Preferred structure for limiting the rotation of the plug embodies stop means for interengaging the journal means and the barrel. ## Claims ### Claim 1 In a plate tumbler-type cylinder lock mechanism including an elongate barrel having a longitudinal bore therein, and a key plug having a body portion and a shaft portion extending therefrom, said plug being received rotatably in said bore with said body portion extending between opposite ends of the barrel and said shaft portion extending outwardly from one end of the barrel, said bore having a draft-induced longitudinal taper widening in the direction of said one end of the barrel, the improvement which comprises journal means on said body portion and projecting laterally therefrom for journalling said plug in said barrel adjacent to said one end thereof, thereby to minimize lateral play between the plug and the barrel thereat. ### Claim 2 (depends on 1) A lock mechanism as defined in claim 1 and including stop means for interengaging said journal means and said barrel, thereby to limit the rotation of said plug. ### Claim 3 (depends on 2) A lock mechanism as defined in claim 2 and wherein said journal means is integral with said plug, and said stop means comprises lug means integral with said barrel internally thereof and adapted to engage said journal means. ### Claim 4 (depends on 3) A lock mechanism as defined in claim 3 and wherein said plug and said journal means together comprise a one-piece casting, and said barrel and said lug means together comprise a one-piece casting. ### Claim 5 (depends on 1, 2, 3, 4) A lock mechanism as defined in claim 1, 2, 3 or 4 and including a transverse shoulder on the wall of said bore adjacent to the end of said barrel opposite to said one end, and wherein said taper extends from adjacent to said shoulder to adjacent to said one end. ### Claim 6 (depends on 1, 2, 3) A lock mechanism as defined in claim 1, 2, 3, or 4 and wherein a part of said body portion extends outwardly from the end of said barrel opposite to said one end, and including means on said extending part of the body portion for mounting a retainer thereon to engage said opposite end of the barrel for securing said plug in the barrel. ### Claim 7 (depends on 1, 2, 3, 4) A lock mechanism as defined in claim 1, 2, 3 or 4 and wherein said body portion is substantially cylindrically shaped, and said journal means comprises a ring-shaped member projecting laterally from said body portion. ### Claim 8 In a plate tumbler-type cylinder lock mechanism including an elongate barrel having a longitudinal bore therein, and a key plug having a body portion and a shaft portion extending therefrom, said plug being received rotatably in said bore with said body portion extending between opposite ends of the barrel and said shaft portion extending outwardly from one end of the barrel, said bore having a draft-induced longitudinal taper widening in the direction of said one end of the barrel and said body portion being substantially cylindrically shaped, the improvement which comprises ring-shaped flange means on said body portion and projecting laterally therefrom for journalling said plug in said barrel adjacent to said one end thereof, said flange means defining a recess between portions thereof, and stop means comprising lug means on said barrel internally thereof and adapted to extend into said recess for interengaging said flange means and said barrel, thereby to limit rotation of said plug. ### Claim 9 (depends on 8) A lock mechanism as defined in claim 8 and wherein said plug and said flange means together comprise a one-piece casting, and said barrel and said lug means together comprise a one-piece casting. ### Claim 10 (depends on 8, 9) A lock mechanism as defined in claim 8 or 9 and including a transverse shoulder on the wall of said bore adjacent to the end of said barrel opposite to said one end, and wherein said taper extends from adjacent to said shoulder to adjacent to said one end. ### Claim 11 (depends on 10) A lock mechanism as defined in claim 10 and wherein a part of said body portion extends outwardly from the end of said barrel opposite to said one end, and including means on said extending part of the body portion for mounting a retainer thereon to engage said opposite end of the barrel for securing said plug in the barrel. ### Claim 12 (depends on 11) A lock mechanism as defined in claim 11 and including a split ring comprising said retainer, said mounting means comprising means forming an annular groove in said body portion part receiving said split ring therein.