Plunger-operated lock
AssigneeE. J. Brooks Company
InventorSigurd M. Moberg
Life of this patent
Estimating the term…
Abstract
A lock of the type having an internal plunger with a stem for being gripped by a tool to pull the stem axially to release locking means, the stem being biased to the locking position by a coil spring so dimensioned that when the spring is fully compressed with the coils touching each other, the pin just reaches the unlocking position. Hence if an attempt is made to open the lock by inserting a bent wire or the like into a spring coil and pulling to compress the spring, the pin will not be able to move to the unlocking position.
Claims4
A lock of the plunger-operated type, having a housing with an opening at one end, a lock-operating plunger axially movable in the housing between a locking and an unlocking position and biased forwardly away from the opening by a coil spring, and a tool-engagable member mounted on the plunger, said components being so arranged that pulling on the tool-engagable member compresses the coil spring and moves the plunger toward the unlocking position, the components being so dimensioned that complete compression of the coil spring is required to permit the plunger to reach the unlocking position.
A plunger-operated lock of the type having a housing open at one end, a plunger in the housing and axially movable therein between a forward position in which the plunger retains locking elements in a locking position and a rear position in which the locking elements can move to a non-locking position, said plunger being biased to the locking position by a coil spring, said spring being positioned to be compressed when the plunger moves toward the unlocking position, the components being so dimensioned that the plunger reaches the position at which the locking elements can move to the unlocking position only when the coil spring is fully compressed with adjacent coils touching each other.
Dependencies are inferred from the claim text.