Abstract: A hydraulic valve provides infinitesimally variable flow in both directions through the valve including a position of no flow. The valve can be operated either hydraulically or mechanically. It includes a housing with a bore therethrough, a sleeve slidably mounted inside the bore, and endplates enclosing the ends of the bore. Ports allow controlled passage of hydraulic fluid through the housing, the sleeve, and extensions from the endplates so that fluid from a hydraulic pump enters ports in the housing, flows controllably through the valve, out one of the endplates, through a use apparatus, back into the remaining endplate, and to a sump.

Abstract: A rotary displacement mechanical coupling device having a casing containing a first and second axially aligned chamber, said chambers having a partition therebetween. A hub is rotatably mounted through the partition and extending into both of the first and second chambers. A plurality of outer gear teeth are circumferentially spaced around the outer periphery of the first chamber. A crescent is attached to the hub means in the first chamber and has an outer radius substantially identical with the inner radius of the outer gear teeth. A pinion gear has a plurality of teeth on its periphery and has a radius substantially less than the inner radius of the outer gear teeth, is journaled on the hub so that the pinion gear teeth engage at least a portion of the outer gear teeth. The inner radius of the crescent is adjusted to have substantially the same radius as the radius of the periphery of the teeth around the pinion gear.