Abstract: Apparatus for applying an optimum tensioning force to an endless belt or the like, including a first pivot axis, a belt engaging pulley eccentrically supported for rotation about a second axis displaced from the first pivot axis, a torsional biasing spring for urging the belt-engaging pulley into belt-tensioning engagement with the belt and for automatically maintaining the tension force applied to belt. The torsion spring is disposed about the first axis within the eccentric pulley, which includes further springs for releaseably gripping the pivot to adjustably limit the applied tensioning force in a first direction and in a second direction, whereby the tension in the belt is optimally maintained throughout the engine operating temperature cycle.

Abstract: Apparatus for applying an optimum tensioning force to an endless belt or the like, including a pivot defining a first pivot axis, a belt engagement element supported for rotation about the first pivot axis, a biasing element for urging the belt engagement element in a first direction of rotation about the pivot axis into belt-tensioning engagement with the belt, and a belt tension adjuster, responsive to externally induced changes in tension of the belt, for automatically varying the tensioning force applied to belt. The belt tension adjuster is disposed within the biasing element and includes a limiter for limiting the amount of decrease in applied tensioning force, whereby the tension in belt is optimally maintained.

Abstract: Apparatus for maintaining a predetermined optimum tension on an endless power transmission member, including a first cylindrical housing including a radially extending arm member, a pulley member carried by an arm member at the end thereof remote from the first housing, a pivot member for first housing, pivot member defining a pivot axis, and including a second cylindrical housing and one-way clutch member permitting pivoting of second housing in one direction only, second housing being disposed within first housing. Members coupled between the pivot member and first housing are included for rotatably driving said first housing about said pivot member in a first direction to move pulley member into tensioning engagement with endless power transmission member.

Abstract: A hospital bed is provided with a safety mechanism for preventing the upper frame from moving with respect to the lower frame when an object or person is wedged therebetween. The safety mechanism includes an elongate detection device such as an air-tight, flexible tube or a ribbon switch. It is mounted to one of the frames so that a person wedged between the frames will contact it prior to incurring serious injury. The detection device is connected to a switch which deactuates the bed raising/lowering motor.