Abstract: An elevator door interlock incorporates cast parts thereby drastically reducing the number of parts required for assembly. Other elements are also incorporated to further reduce complexity in manufacturing, servicing, and configuration.

Abstract: A cable operated switching mechanism is provided with a positive locking method that latches a cam structure in place after the cable is pulled by an operator and does not permit the cam structure to return to its normal operating position until manual intervention is used to push a reset plunger. The cable operated switching mechanism provides this positive stop by incorporating a tab on a latching device which is associated with the reset plunger and moves with it when a reset button is pushed by an operator. The tab of the latching device slides along a first surface of the cam structure until the cable is pulled to activate the mechanism. Then, under the influence of a spring, the latching device moves upward to cause the tab to move into a blocking position relative to a second surface of the cam structure. The prevents the cam structure from moving from its actuated position to its normal operating position until a reset button is pushed.

Abstract: A cable switch actuating mechanism is provided with a shaft and a cam structure that slides on the shaft. When the associated cable is pulled to exert an axial force on the shaft, the cam actuator is pushed by the shaft into a deactuating position that moves a switch operator plunger against a plunger of an associated electrical switch. If the cable breaks, the reduction enforced on the shaft causes an internal spring to move the shaft against the cam structure and, as a result, move the switch operator into its deactuating position. Appropriate gaps between the opposite ends of the cam structure and associated surfaces of the shaft allow for thermal expansion and contraction of the cable without adverse affects on the mechanism.

Abstract: A low-cost, easy-to-manufacture and easy-to-use switch enclosure is described. The switch enclosure is comprised of a housing having an interior cavity, an operator opening and a conduit opening. The operator opening permits an external operator to mechanically communicate with an electrical switch, while the conduit opening allows a plurality of external wires to electrically connect to the switch. A cover plate, joined to the housing, encloses the interior cavity.

Abstract: A key operated door interlock switch is provided with a cam structure having a first cam and a second cam connected together for rotation about a first axis. A key is shaped to have first and second actuator portions that can be moved into a switch housing to engage first and second lobes of the first and second cams. The first and second actuator portions of the key engage the lobes sequentially to rotate the cam mechanism about the first axis. Rotation of the cam mechanism causes a plunger to move linearly relative to the support structure and operate an electrical switch that permits associated equipment, such as machinery to be actuated. The relative lengths of the first and second actuator portions of the key can be selected to match the arcuate displacement of the lobes of the cams relative to the first axis. This flexibility allows the switch to be customized so that only particular keys can actuate particular switches even though their general appearance is similar.