Abstract: Zero lap valve includes two cylindrical valve member portions, each having passageways intersecting a bond surface thereof, and to valve body portions, each having a cylindrical cavity with radial ports intersecting the cavity and a bond surface thereof. The bond surfaces of the valve member portions are bonded together to form a valve member having passageways in one portion bounded by the bond surface of the other portion with the passageways in the two portions interconnected. The valve member is positioned in a valve body formed by bonding the bond surfaces of the valve body portions such that common ports in both portions have adjacent ports to either side in different portions. The valve member is axially slidable perpendicular to the bond surfaces such that the bond surfaces of the ports act as metering edges in cooperation with the bond surfaces of the passageways as the passageways interconnect one or the other of the adjacent ports to the common ports.

Abstract: A variable speed drive includes a planetary set of two adjustable V-belt pulleys orbitally driven around a nonrotatable, or fixed, adjustable sun pulley and a rotatable, adjustable output sun pulley attached to an output shaft. The orbiting planet pulleys are carried on a radial arm driven by the input shaft and have adjustable, inversely proportional effective diameters which are wrapped by V-belts connecting the planet pulleys to the sun pulleys. The effective diameter of the fixed sun pulley is adjusted by a control rod and the effective diameter of the output sun pulley is biased towards its maximum effective diameter. When all four pulleys are at the same effective diameter, orbiting of the planetary set will produce zero output. When the effective diameter of the fixed sun pulley is varied by the control rod, the V-belts will assume new effective diameters on all four pulleys causing the output speed to vary.

Abstract: A hydraulic system having pilot line fluid feedback from a fluid motor to valving which operates to change pump output to compensate for motor demand includes a pressure regulator valve for maintaining a predetermined minimum pressure in the pilot line. The pressure regulator valve eliminates the power wasting pressure differential which normally exists between the pump output and the fluid motor demand in demand compensated hydraulic systems.

Abstract: A double-acting hydraulic cylinder includes a hollow cylinder body with a closed end and an end with a first rod opening. A first hollow piston and rod assembly, having a second rod opening at the piston end, projects through the first rod opening and slides in the cylinder body. A second hollow piston and rod assembly, secured at the rod end to the hollow cylinder body, projects through the second rod opening and slides in the first hollow piston and rod assembly. The first and second hollow piston and rod assemblies cooperate to form a first variable volume chamber. A rod secured to the rod end of the first hollow piston and rod assembly slidably projects into the second hollow piston and rod assembly and cooperates therewith to form a second variable volume chamber. The first variable volume chamber is connected to a first port in the cylinder body and is expandable and contractable in response respectively to retraction and extension of the first hollow piston and rod assembly.