US 4,794,772 AGranted

Axial wafer tumbler lock and key

AssigneeK.X.L. Manufacturing, Inc.

InventorsSidney Falk, James M. Alex

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Abstract

An improved tubular axial wafer tumbler lock that can be fully automatically manufactured and assembled along with a cast combinated key at very low cost without machining operations is made up of three basic components including a shell, spindle plug and rear cap wherein generally T-shaped wafer tumblers are held in open notches in the spindle plug by springs and a multi-purpose cam stop washer at the forward end retains the tumblers in the plug during assembly and after assembly conceals the outside readability of the tumbler lock-up combinations as well as defining the rotational limits of travel of the sprindle plug. A lockup of the lock is accomplished with forward and rearward notches tha co-act with radial blade portions of the tumblers and the notches are disposed at 15.degree. increments which thereby provide 24 of such notches to permit a large variety of different key pulls. The low cost, mass producible lock construction lends itself to numerous specialty applications where the internal components can be incorporated into different shells loaded from the rear as well as from the front with a fixed head or a removable bezel and thereby even enable the combination of a cam lock and switch lock.

In a tubular lock having axial wafer tumblers operable by a tubular key, the combination comprising:

a cylindrical shell having a central bore extending longitudinally from front to rear,
a rotatable spindle plug disposed within the shell bore,
said spindle plug including a cylindrical portion intermediate its ends,
a key receiving shaft projecting forwardly from said cylindrical portion, an actuating member projecting rearwardly from said cylindrical portion, and a plurality of radial slots disposed about the periphery of the key receiving shaft and extending into said cylindrical portion with the cylindrical portion having the same plurality of radial slots disposed about its periphery, each of the cylindrical portion slots having a spring bore extending longitudinally from its front and terminating adjacent the rearward end of said cylindrical portion,
a tumbler spring disposed in each of said bores,
a plurality of generally T-shaped wafer tumblers having a radially outwardly extending blade portion, a forwardly extending combination leg and a rearwardly extending tail slidably disposed in said slots such that the tail rides in the slots radially inwardly of said springs, and the rearward ends of said blade portions engage said springs,
means including a first plurality of notches disposed about the periphery of the shell cylindrical bore at the forward end of the shell positioned to be slidably engaged by forward ends of the tumbler blade portions in the lock-up positions of said tumblers,
a second plurality of notches in the front face of a rear sleeve member adapted to be positioned at the rear of said shell bore and fixed to said shell such that slidable movement of the tumblers rearwardly can result in rearward portions of the blade members engaging with the rear notches to maintain lockup,
said key shaft being adapted to receive the tubular key having internal radial fins that are combinated longitudinally to engage with the combination legs of the tumblers when the key is positioned around the shaft and inserted to slidably move the tumbler blade portions to an intermediate position free of the front or rear end notches thereby allowing the spindle plug to be rotated within the shell.

6 more elements

Abstract

Claims12