Abstract: A revolution speed controller for a continuously variable speed transmission has an air cylinder unit for operating a speed-control section of the transmission, and a command pressure chamber partly defined by a diaphragm operable in response to a command air pressure. The diaphragm and the air cylinder unit are connected by a resilient member. A valve member is movable in response to operation of the diaphragm to connect or disconnect a working air pressure source to or from the interior of the air cylinder unit and to disconnect or connect the interior of the air cylinder unit from or to the atmosphere. When the pressure in the command pressure chamber is balanced with a force exerted to the diaphragm by the resilient member, the valve member cuts off the supply of the working air pressure to the air cylinder unit and also interrupts the communication between the air cylinder unit and the atmosphere.

Abstract: A pulley device has a shaft provided at its one end with a disk extending radially outwardly therefrom, a tubular member provided at its one end with a disk extending radially outwardly therefrom and concentrically enclosing the shaft to cooperate with the disk of the shaft to define therebetween a V-shaped annular groove for a driving belt, and a roll pin extending in the shaft in the diametrical direction of the shaft so as to engage with both of the shaft and the tubular member. In order to facilitate the relative sliding movement between the shaft and the tubular member, oilless bearings are provided to both ends of the tubular member. Furthermore, an oilless bushing is disposed between the roll pin and the tubular member or the shaft to facilitate the rolling of the roll pin.

Abstract: A pulley device comprises a pair of discs both slidably mounted onto a driving shaft and urged by the respective coil springs, three roll pins provided in the respective discs and extending radially, and a pair of end members each having a cylindrical portion in which three axial notches are formed for receiving the roll pins. These roll pins are borne in the openings of the discs by means of the oilless bearings disposed therein for a rotation about the axis of the roll pin and for a slidable movement along the axis thereof.

Abstract: An air cylinder including a piston adapted to be stopped freely in any position as desired includes an automatic restoring type air cylinder member and a hydraulic cylinder member. The piston is formed with a hydraulic cylinder chamber having fitted therein a hydraulic fixed piston of the hydraulic cylinder member so that the piston can move freely in a cylinder body. An oil chamber defined by the end of the hydraulic fixed piston and the end of the hydraulic cylinder chamber is communicated with an oil tank via an oil passage mounting a check valve that can be opened by pressing means including a pilot piston and other parts.