Back-lighted push-button switch with safety stop

Abstract

A panel-mounted push-button assembly having an illuminated push-button removable from the front of the panel has a safety locking mechanism for preventing accidental operation of the push-button switch when the push-button is reinserted into operative position. The locking mechanism includes a cam member having a groove engaged by a cam follower. The groove is in the form of a closed loop path. The push-button is linked to the locking mechanism so that movement of the push-button moves the cam follower relative to the cam member along the groove. In the normal operating position the cam follower is in an intermediate position along the loop. When the push-button is pulled from the panel to remove it from the switch assembly, the cam follower is moved from the initial position to an end position. When the push-button is replaced by pushing it back into position, the cam follower is moved along a return path portion of the loop against a stop, limiting the movement of the push-button and allowing the push-button to be reseated in the switch assembly. When the push-button is released, a spring returns it to the initial position. Subsequent pushing action of the push-button causes the cam follower to move along a branch path away from the loop, allowing the push-button to be depressed sufficiently to actuate the switch mechanism.