Abstract: A front loading refuse vehicle includes at least one positive displacement pump having an associated valve system in fluid communication with drive mechanism that operates a lifting arm, packer, a rear door of the vehicle, and a hoist for a refuse storage body. The valve system includes at least one closed-centered valve with a spool mechanism having a pressure compensator to maintain a constant flow rate of fluid through the valve regardless of differential in pressure across the valve for any given position of the spool mechanism. Two pumps with two separate hydraulic control systems are used with a side loading refuse vehicle. An electrical/electronic control system including a microprocessor operates the valve systems for each vehicle.

Abstract: A front loading refuse vehicle includes at least one positive displacement pump having an associated valve system in fluid communication with drive mechanism that operates a lifting arm, packer, a rear door of the vehicle, and a hoist for a refuse storage body. The valve system includes at least one closed-centered valve with a spool mechanism having a pressure compensator to maintain a constant flow rate of fluid through the valve regardless of differential in pressure across the valve for any given position of the spool mechanism. Two pumps with two separate hydraulic control systems are used with a side loading refuse vehicle. An electrical/electronic control system including a microprocessor operates the valve systems for each vehicle.

Abstract: A front loading refuse vehicle includes at least one positive displacement pump having an associated valve system in fluid communication with drive mechanism that operates a lifting arm, packer, a rear door of the vehicle, and a hoist for a refuse storage body. The valve system includes at least one closed-centered valve with a spool mechanism having a pressure compensator to maintain a constant flow rate of fluid through the valve regardless of differential in pressure across the valve for any given position of the spool mechanism. Two pumps with two separate hydraulic control systems are used with a side loading refuse vehicle. An electrical/electronic control system including a microprocessor operates the valve systems for each vehicle.

Abstract: A front loading refuse vehicle includes at least one positive displacement pump having an associated valve system in fluid communication with drive mechanism that operates a lifting arm, packer, a rear door of the vehicle, and a hoist for a refuse storage body. The valve system includes at least one closed-centered valve with a spool mechanism having a pressure compensator to maintain a constant flow rate of fluid through the valve regardless of differential in pressure across the valve for any given position of the spool mechanism. Two pumps with two separate hydraulic control systems are used with a side loading refuse vehicle. An electrical/electronic control system including a microprocessor operates the valve systems for each vehicle.

Abstract: A flow pressure sensing control valve system is disclosed for use with blowout preventers having an operator cylinder and piston for closing of the blowout preventer, wherein the operator cylinder and piston have a closing side and an opening side and wherein the closing side has a greater effective surface area than the opening side. The system includes a sensing means for dropping pressure of flow directed to the closing side relatively with increases in the flow velocity of the fluid flow. A fluid return system is included for selectively directing the fluid from the opening side of the operator piston to the closing side of the operator piston when the drop in pressure across the sensing means attains a magnitude above a predetermined value in order to reduce fluid capacity requirements and alternatively to direct flow from the closing side to a discharge point when the drop in pressure decreases below the predetermined value.

Abstract: A method and apparatus are disclosed for displacing a crane lift hook and hook cable to follow the relative vertical motion between a crane and a loading deck such as occurs between floating vessels and a fixed crane. In the method, the hook cable is paid out or reeled in to maintain the hook a substantially constant distance from the deck in order to facilitate loading or unloading of cargo from the hook. The apparatus for achieving the method includes a vertically displaceable sheave over which the lift cable is reeved, a power ram to displace the sheave, and motive means operating the power ram. Preferably, the power ram is subjected to a constant upward pneumatic force to provide at least a portion of the force for displacing the moveable sheave upwardly to reel in the cable, such as in response to an upward heave of the deck relative to the crane.

Abstract: A fluid pressure device such as a hydraulic pump is provided having an improved inlet porting arrangement to permit a greater output flow rate for a given input speed. The pump is of the type including a housing defining an inlet chamber and an outlet chamber and inner and outer rotors having spaced apart axes of rotation defining a line of eccentricity. The teeth of the rotors interengage to define a plurality of expanding and contracting volume chambers. The housing includes an end face adjacent the rotors at which the inlet chamber defines an inlet port communicating with the expanding volume chambers. The inlet port is generally arcuate and extends circumferentially from approximately the line of eccentricity on one side of the device to the line of eccentricity on the opposite side of the device.