Double action barrel lock

A lock of the type having a housing with an internal elongated aperture opening to the rear end thereof, and an operating plunger assembly movable axially in the aperture, said assembly comprising a first member spring biased forwardly in the housing and a second member carried by the first member and being spring biased rearwardly in relation thereto so that said plunger assembly has a predetermined normal length, said second member having a forwardly extending locking portion which normally maintains locking means in a locking position, movement of said locking means rearwardly to a predetermined position by pulling on said first member being required to release said locking means, a rear portion of said second member being so positioned in relation to said first member as to be encountered by a picking tool inserted into the housing aperture to cause said second member to be moved forwardly in relation to the first member to increase the overall length of the plunger assembly, whereby movement of said first member rearwardly as far as possible does not move the locking portion of the second member to the position required to release the locking means.

A lock of the type having a housing with an elongated apertute opening to the rear of the housing, a lock operating plunger axially movable in the housing aperture, spring means biasing the plunger to a locking position, and means disposed between the plunger and the adjacent surface of the housing to provide frictional engagement between the plunger and the housing, said frictional engagement being great enough to prevent movement of the plunger, in the absence of the biasing force of the spring, by impulses manually applied to the housing, yet not great enough to prevent the biasing force of the spring from returning the plunger to the locking position after the plunger is displaced therefrom.