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:
Jun. 06, 1989
Filed:
Jul. 01, 1987
Brian J Monahan, Evergreen, CO (US);
Other;
Abstract
A lock apparatus includes a lock provided with a cylindrical plug having a set of blind holes angularly spaced from the set of pinways in the plug. A longitudinal slot through the center of the blind holes accepts a programming member that lifts one or more master pins out of the blind holes and into housing pinways when the lock is unlocked with a master key and the plug is rotated into a rekeying position to align the blind holes with the housing pinways. The programming member has a hole or notch near its front end to facilitate removal when the lock is unlocked and the plug is in the rekeying position. The programming member may be in the form of a set blade or a set rod, and may be reversible end-to-end to provide additional rekeying combinations. A method includes programming the lock to operate with only one exclusively differently-bitted change key or sub-master key at a time by requiring a shallower bitting depth at a tumbler station from which a master pin has been removed and permitting and having a deeper bitting depth at a tumbler station to which a master pin has been inserted and thus rendered active.