Abstract: An inexpensive frictional coupling mechanism, useful in smaller brakes and clutches includes an air operated piston and cylinder assembly for single or double-acting use in either a dual disc, single disc or caliper type frictional brake or clutch arrangement.

Abstract: A valve for introducing air or other fluid into a fluid actuated mechanical device has an L-shaped passage through a valve stem. The valve stem is movable lengthwise between open and closed positions. In a fully open position the L-shaped passage delivers fluid from a source of fluid under pressure to a channel in a housing. In closed position the delivery end of the L-shaped passage is blocked. The valve stem also provides means for venting fluid from the channel while the L-shaped passage is blocked, when the stem is in an intermediate position.

Abstract: Friction brakes or clutches having pivotable or dismountable pods carrying friction members are provided with standard pods having adapters for use in brakes and clutches of various sizes. The standard pod can be used without adapters in small installations and with adapters in larger units. Simplified valve and fluid connection arrangements are employed.