Abstract: A cable tray grounding clamp which comprises two conjoined clamps, for electrically connecting a cable tray, or the like, and a grounding conductor. The body of the conjoined clamps is a high yield strength material for providing strength and rigidity to permit application of appropriate pressure. A conducting member overlays the anvil portion of the body member, and is supported thereby, whereby when the cable tray clamp is secured to a cable tray and a grounding wire both the tray and the grounding wire are in contact with the conducting member to thereby provide a low resistance path between the tray and the grounding wire.

Abstract: When electrical equipment is used in a hazardous atmosphere, it must be enclosed in an explosion proof enclosure so an electrical spark cannot cause a fire or explosion. The present invention provides a means for assuring that an explosion proof enclosure which has been opened for inspection, repair or adjustment of the electrical apparatus is restored to its original condition. To this end, a visually inspectable locking means is provided. The locking means can be engaged only when the enclosure compartment and its associated cover are restored to their original explosion proof relationship. The locking means does not exert any distorting force on the mating threads of the enclosure.