US 4,963,706 AGranted

Safety switch assemblies

AssigneeEJA Engineering Limited

InventorMehdi Mohtasham

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Abstract

A safety switch assembly comprises a safety switch for securement to an enclosure having an openable closure, and an actuator for operating the safety switch for securement to the closure. The safety switch comprises a housing, containing electrical contacts, and a cam arrangement for operating the electrical contacts and formed with peripheral inwardly directed radial pockets. An axially-movable rod connects the electrical contacts and the cam arrangement. The housing has openings adjacent the cam arrangement for insertion of the actuator. The cam arrangement comprises a shaft bridging lateral walls of the housing, and an actuating cam rotatably supported on the shaft and connected to the rod by a cam follower pin connected to the rod and engaged in cam grooves in the actuating cam. An axially-movable locking cam is supported on the shaft, at each side of the actuating cam, and a spring is disposed between each locking cam and an adjacent housing wall to urge the respective locking cam towards the actuating cam and into engagement with the cam follower pin to lock the actuating cam against rotation. The actuator comprises laterally-spaced limbs insertible between the actuating cam and the locking cams axially to space same apart, and engageable with the actuating cam to rotate same axially to move the rod to operate the electrical contacts.

Claims21

Dependent claims

A safety switch assembly comprising (A) a safety switch for securement to an enclosure having an openable closure, and (B) an actuator for operating the safety switch for securement to the closure;

(C) the safety switch comprising a housing having laterally spaced wall means, an electrical contact arrangement contained within the housing, a cam arrangement also contained within the housing for operating the electrical contact arrangement and spaced from the electrical contact arrangement, radial pocket means formed in the cam arrangement and extending inwardly of the periphery of the cam arrangement, and axially-movable rod means connecting the electrical contact arrangement and the cam arrangement to operate the electrical contact arrangement in accordance with movements of the cam arrangement, the housing defining entry means adjacent the cam arrangement for insertion of the actuator into the housing to engage the radial pocket means to operate the cam arrangement, and the cam arrangement comprising shaft means bridging the wall means of the housing, actuating cam means rotatably supported on the shaft means, connecting means operatively securing the actuating cam means to the axially-movable rod means, the connecting means including cam follower pin means connected to the axially-movable rod means and cam groove means defined by the actuating cam means and within which the cam follower pin means is engaged, locking cam means also supported on the shaft means for movement along the shaft means, and resilient means between the locking cam means and housing wall means to urge the locking cam means towards the actuating cam means and into engagement with the cam follower pin means whereby the pin means serves releasably to lock the actuating cam means against rotation;
and (D) the actuator comprising laterally-spaced limb means (i) insertible between the actuating cam means and the locking cam means to move the locking cam means along the shaft means away from the actuating cam means, and (ii) engagable with the actuating cam means to rotate the actuating cam means axially to move the rod means to operate the electrical contact arrangement.

A safety switch for securement to an enclosure having an openable closure adapted to mount an actuator for operating the safety switch comprising a housing having laterally-spaced wall means, an electrical contact arrangement contained within the housing, a cam arrangement also contained within the housing for operating the electrical contact arrangement and spaced from the electrical contact arrangement, radial pocket means formed in the cam arrangement and extending inwardly of a peripheral surface of the cam arrangement, and axially-movable rod means connecting the electrical contact arrangement and the cam arrangement to operate the electrical contact arrangement in accordance with movements of the cam arrangement the housing defining entry means adjacent the cam arrangement and through which a an actuator cam enter into the housing to engage the radial pocket means to operate the cam arrangement, and the cam arrangement comprising shaft means bridging the wall means of the housing, actuating cam means rotably supported on the shaft means, connecting means operatively securing the actuating cam means to the axially-movable rod means, the connecting means including cam follower pin means connected to the axially-movable rod means and cam groove means defined by the actuating cam means and with which the cam follower pin means is engaged, locking cam means also supported on the shaft for movement along the shaft means, and resilient means between the locking cam means and the housing wall means to urge the locking cam means towards the actuating cam means and into engagement with the cam follower pin means whereby the pin means serves releasably to lock the actuating cam means against rotation.

Dependencies are inferred from the claim text.