Abstract: A framework comprising a pair of parallel angle sections is hung from the cable of a suspended conveyor system or fixedly mounted to a frame member of a conveyor system. An operative structure comprising a drive wheel connected through a shaft to a driven element is pivotally mounted to the framework with the drive wheel being suspended upon the upper surface of the return portion of the conveyor belt. In this manner, the drive wheel is maintained out of contact with the soiled surface of the conveyor belt thereby eliminating the need for periodic cleaning of the wheel and driven structure. An offset mounting can be included on the framework for forcing the wheel into firm engagement with the conveyor belt to insure accurate and continuous drive contact between the belt and wheel.

Abstract: Movement of the roof of a mine shaft is detected by unlatching of a position sensing device in an elevated position causing it to drop to a lowered position pivotally suspended by a link from a bracket yieldably held in abutment with the roof ceiling. The bracket is positioned on the lower end of an elongated support bolt by a nut acting as a latch releasing member engageable with a latch element connected to the link for latched support of the sensing device in the elevated position.