Abstract: A double-acting, floating, frictional coupling mechanism including an air-operated diaphragm-type piston with integral rack guided for axial movement in meshed engagement with a rotatably connected pinion. A cam on the pinion shaft cooperates with a second piston and intensifies the force transmitted through the rack and pinion by the air-operated piston.

Abstract: A double-acting, floating, frictional coupling mechanism including an air-operated diaphragm-type piston having a piston rod in meshed engagement with a set of different gears. The differential gearing intensifies the force transmitted through the piston rod by the air-operated piston.

Abstract: Because of its physical properties, mercury can be very effective as hydraulic fluid in a double-action piston and cylinder assembly mounted to float between opposed discs of a friction brake or clutch. The mercury is contained within a chamber of the piston-cylinder assembly and the high surface tension of the fluid prevents leakage.

Abstract: The rate of rotation of the shaft of a winding apparatus for webs of sheet material is controlled by means of a transmission system comprising a plurality of non-slip drive clutches arranged for successive engagement to provide stepwise reduction in the output speed of the system. The drive clutches are arranged to provide different ratios of speed reduction. As one drive clutch is disengaged, the next drive clutch is engaged and output speed is reduced. These drive clutches in turn drive the shaft of the winding apparatus through a slip clutch. The means for engaging and disengaging the drive clutches can be an automatic sensing device or a preset timer. The system can be used for winders, rewinders and unwinding apparatus.