Abstract: A peristaltic pump having a single pumping roller mounted on an eccentric portion of a drive shaft for compression of an elastomeric tube wrapped at least one revolution therearound. The peripheral surface of the roller around which the tube is disposed comprises a frusto-conical surface. A tube compressor includes a central bore having a frusto-conical surface coaxial with the drive shaft and corresponding to the surface of the roller. Means are provided for selectively adjusting the axial position of the tube compressor to either increase or decrease the degree to which the tube is compressed upon rotation of the roller, thereby providing selective control of the output pressure of the pump. The output of the pump may be selectively varied by variation of the speed of the drive shaft.

Abstract: A mechanically actuated pinch valve for high pressure use which opens to a full round configuration and which closes to a leak tight locked condition. A novel valve actuating mechanism permits the full closure of the valve even with working pressures in the range of 400 psig by a relatively small rotary closing force acting through a 90.degree. arc. A linkage within the valve housing provides a decreasing pinch bar movement with increased actuator rotation so that the maximum mechanical advantage is achieved at the point of valve closure. The thrust of the line pressure, which may be carried on either side of the valve, is borne by bearings at the ends of the pinch bars which ride in grooves in the housing. The actuator automatically locks in the closed position regardless of the direction of the line pressure.