The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 1982
Filed:
Jan. 14, 1980
Robert L Steinbach, Glendale Heights, IL (US);
Chicago Lock Co., Chicago, IL (US);
Abstract
A plate tumbler for a cylinder lock mechanism, such mechanism including a tubular barrel provided with an internal longitudinal groove, and a key plug assembly rotatable in the barrel, such assembly including a key plug, a plurality of plate tumblers transversely reciprocally movable in slots in the plug and each having an end received in the barrel groove in a locking disposition of the mechanism, and spring means biasing such tumbler ends into the groove, such tumbler being relieved along the side edges of a body portion thereof, as compared to conventional tumblers, at diagonally opposite corners of the body portion, to provide a trailing edge having an arcuate end portion received in the barrel groove in the locking disposition of the mechanism and an adjacent oblique portion at one of the corners, and a leading edge having an oblique end portion at the diagonally opposite corner, whereby the arcuate end portion of the trailing edge hooks over the key plug while the oblique end portion of the leading edge engages the adjacent wall of the tumbler slot when picking torque is applied and the tumbler is manipulated, thereby to prevent the tumbler from being moved into a plug-release position within the plug in a picking operation.