Abstract: A vacuum motor operatively connected to a slave cylinder operates same via pressure differential variations across a reciprocatable vacuum motor piston to pump working fluid from a reservoir to an accumulator through two one way valves. The pressure differential variation can be derived from gear changing of the vehicle, induced through a three way electromagnetic valve controlled by a circuit characterized by either an unstable multivibrator, a dual stable multivibrator, a thyristor or a self maintaining relay, or induced through a purely mechanically operated valve characterized by lost motion and snap action position maintain devices. A pressure relief valve may be provided which dumps excessive pressurized fluid in the accumulator and returns same to the reservoir.

Abstract: A hydraulic system pressure fluid accumulator apparatus is disclosed that meets peak load demands beyond the flow capacity of the system pump. Gas cylinder actuation of the accumulator piston augmented by system pressure feedback actuation of the piston metered by a pressure regulator valve maintains accumulator output pressure level substantially independent of piston displacement.

Abstract: A device for controlling the pressure in an inflatable cuff surrounding an endotracheal or tracheostomy tube is described.

Abstract: A fluid driven power system is located in a borehole for driving a downhole pump for pumping water to the surface. An uphole pump driven by a windmill is provided for pumping fluid from a storage system downhole for operating the fluid driven power system. An energy storage system is provided for operating the downhole fluid driven power system when the wind velocity is low. The energy storage system comprises a fluid accumulator which is pressurized by fluid from the uphole pump during low velocity wind. As the pressure in the accumulator builds up to a certain level, fluid from the accumulator is released to operate the downhole fluid driven power system.

Abstract: In an hydraulic system in which an hydraulic accumulator is charged with hydraulic fluid under pressure by means of an hydraulic pump which draws hydraulic fluid from a tank, and an unloader valve disposed in a supply line between the pump and the accumulator is operative to prevent the accumulator from being overcharged and to allow the pump to re-charge the accumulator should the pressure stored therein fall below a desired minimum value, the unloader valve incorporates a control valve, and a pressure responsive slave which is operated by fluid pressure under the control of the control valve.

Abstract: An accumulator charging valve has a housing with an inlet and two outlet orifices respectively connected to the pump outlet, to a fluid accumulator and to an open center hydraulic circuit. A main passage is provided between the inlet orifice and the second outlet orifice, with a movable valve member mounted in the main passage, and operated by a differential piston having a face of smaller diameter exposed to the pressure prevailing at the inlet orifice and a face of larger diameter projecting into a control chamber, forming a resilient variable volume enclosure. A leakage passage is provided between the inlet orifice and a low pressure reservoir and has a first portion with an orifice of restricted cross-section situated between the inlet orifice and control chamber, and a second portion also with an orifice of restricted cross-section situated between the control chamber and the reservoir.

Abstract: A compressed air engine having specially designed cylinder heads and piston configurations in order to reduce friction and maximize the application of air from a pressurized air source. The disclosure includes a lubrication system whereby the mechanical parts receive oil via a lubrication arrangement including a conveyor chain continually bathed in oil.

Abstract: Variable differential pressure control apparatus is used in a hydraulic system including a pump, an accumulator for receiving hydraulic fluid under pressure from the pump and for discharging hydraulic fluid to a work device, and an unloading valve in the circuit between the pump and the accumulator for regulating pressure of the fluid to the accumulator. The control apparatus is connected with the unloading valve for opening and closing the latter and is adjustable (1) for selectively setting the maximum fluid pressure to the accumulator and (2) for selectively setting the variation between the maximum pressure to the accumulator, at which pressure the unloading valve will open, and the minimum pressure to the accumulator at which pressure the unloading valve will close for recharging the accumulator.

Abstract: An improved pressure sensitive valving arrangement is provided for a power steering unit for a lift truck, and in particular for a battery powered lift truck. To the conventional implement valve is added an accumulator charging means which includes an additional valve, herein called a "blocking or control valve", which additional valve is downstream from the implement valve and which additional valve, when actuated, blocks the flow of fluid through the implement valve to thereby build up pressure for charging an accumulator. The blocking valve includes a blocking spool which operates against a pressure-actuated pilot plunger such that when the pressure in the accumulator reaches or exceeds a predetermined amount, the pilot plunger shifts the blocking spool to permit the fluid to again flow through the implement valve.

Abstract: An improved valving arrangement and actuator is provided for a power steering unit for a lift truck, and in particular for a battery powered lift truck. To the conventional implement valve is added an accumulator charging means which includes an additional valve, herein called a "blocking valve," which additional valve is downstream from the implement valve and which additional valve, when actuated, blocks the flow of fluid through the implement valve to thereby build up pressure for charging an accumulator. The blocking valve includes a blocking spool which operates against a pressure-actuated pilot plunger such that when the pressure in the accumulator reaches or exceeds a predetermined amount, the pilot plunger shifts the blocking spool to permit the fluid to again flow through the implement valve.

Abstract: A steering system for a vehicle having a hydraulic steering mechanism, and including an accumulator for maintaining a supply of pressurized hydraulic fluid to the steering mechanism. The hydraulic fluid for the steering mechanism is supplied in some circumstances by a hydraulic pump which operates only when the vehicle is moving. Two valves are connected in series and arranged to discharge the accumulator when both valves are open, one of the valves arranged to be opened when the engine stops and the other arranged to be opened when the vehicle driven pump stops.

Abstract: A control valve assembly for use in a pump-operated vehicle hydraulic braking system as disclosed in which the output from the pump flows through the control valve, which selectively directs the output to steering gear of the vehicle or to an accumulator for connection to brakes. The valve is also provided with a bleed passage through which a proportion of the output is continuously supplied to the steering gear.

Abstract: A. Charging an oleopneumatic accumulator with energy.B. Automatic charging of the oleopneumatic accumulator (1) by the intermediary of the heat engine (101) driving the hydraulic pump with variable displacement (104), whose displacement is altered with the aid of a jack (122) supplied by a three-position valve (120), provided with two control coils (120a and 120b). A logic block (70) is connected to a sensor (5) of the accumulator pressure, to a speed sensor (11) of the rotation of the engine, and to a sensor (25) of the displacement of the pump (104) and produces control signals for the two coils (120a and 120b) and for a discharge electrovalve (121).C. Used for hybrid vehicles or for storing energy in oleopneumatic form.

Abstract: In a hydraulic circuit used in an electrically operated vehicle having hydraulically operated steering apparatus and a hydraulically operated working device, such as a lifting fork for example, the same pump means supplies working medium to both the steering apparatus and the working device. Arranged in the system of pipes serving the steering apparatus is a device for detecting the pressure in the pipe system. The device is adapted to co-act with the pump means in such a way that when a low pressure value prevails in the system the pump means is activated and is de-activated when a high pressure prevails in said system. Forming part of the steering apparatus is a control valve which can be adjusted so that when the wheels of the vehicle are set for the latter to be driven in a straight line, the valve assumes a neutral position which prevents the flow of working medium so as to prevent movement of said wheels.

Abstract: The invention relates to a hybrid vehicle of the hydrostatic transmission type comprising a main driving engine, a hydraulic, variable volumetric capacity pump driven from said main engine, a hydraulic motor and a hydropneumatic power accumulator mounted in a delivery conduit of said pump. Said vehicle further comprises an auxiliary hydraulic motor hydraulically mounted in parallel relationship to said first hydraulic motor and having a common output shaft therewith, the volumetric capacity of said auxiliary motor being equal to one fraction of the volumetric capacity of said first hydraulic motor.

Abstract: A double-acting rotary hydraulic jack having two jack compartments, comprising a rotary hydraulic joint for the supply of hydraulic liquid to and the evacuation of hydraulic liquid from the compartments. The two compartments of the jack each communicate with at least one axial boring in a rotary part of the jack which is not axially movable. In this boring a movable piston bears against the head of a guide rod for a spring which itself bears against the rotary part of the jack. The ends of the rods, externally of the borings, are secured to a member coaxial with the jack, for example a sleeve, whose axial position is monitored by a displacement detector, so as to give an indication of the working pressure in the active jack compartment.

Abstract: A hydraulic system for an electrically powered lift truck or the like supplies pressurized fluid for powering implements and for powering a hydraulic power steering system which is provided with hydraulic accumulator means for accumulating a supply of pressurized fluid for providing fluid for steering the vehicle for a predetermined period of time. A pressure-responsive charging valve is provided for maintaining a minimum amount of pressure in the accumulator and includes control means responsive to system pressure for activation and deactivation of an electric motor for powering a pump for the system.

Abstract: A hydraulic accumulator is provided in the hydraulic system of an electric vehicle, such as a lift truck, for conserving its battery power by minimizing the frequency of energy draining pump start-ups during operation. Pressurized fluid stored in such accumulator is utilized for powering any of the various hydraulically actuated work elements employed on the vehicle when the pump is not being run. The system further provides for automatically starting and stopping the pump to keep the pressure in the accumulator within a predetermined operating range and for starting the pump when required to achieve the desired actuation of a particular work element.

Abstract: A closed center hydraulic system is provided for a lift truck which includes an accumulator, a motor driven pump for supplying fluid under pressure to the accumulator, a plurality of closed center proportional electrohydraulic control valves for a plurality of hydraulically operated devices on the truck such as the lift jack, the mast tilt jack and the hydraulic powered steering mechanism. The pressure to the steering control valve is reduced by a pressure reducing valve and the pressure fluid supply circuit from the accumulator to the lift and tilt circuits is controlled by a blocking valve which is opened when the manual control member for either the lift or tilt control valve is moved from neutral to an operating position. Initial movement of either manual control member causes the blocking valve to open and further movement meters flow, thus permitting the operator to regulate lift and tilt speeds.

Abstract: A hydraulic system for use in the propulsion of motor vehicles includes at least two volume multipliers each having a high pressure port, a low pressure port, and a piston in a chamber separating the high and low pressure ports. A prime mover and associated main hydraulic pump is arranged to alternately supply high pressure fluid to the high pressure ports of the multipliers, so as to produce a reciprocating motion in the pistons and create a continuous flow of high pressure fluid from a reservoir through the pump, into the high pressure port of one volume multiplier, out of the high pressure port of the other multiplier, and back to the reservoir. The reciprocating pistons are used to create a second, separate continuous flow of low pressure hydraulic fluid which circulates from the low pressure port of one volume multiplier through one or more hydraulic driving motors adapted to propel the vehicle, and back to the low pressure port of the remaining multiplier.

Abstract: A vehicle having a hydraulic power brake system and a hydraulic power steering system, each having its own pump may utilize the power steering system pump as an emergency back up pump for the power brake system should the pump for the power brake system fail. The fluid under pressure in the accumulator for the power brake system will act upon failure of the power brake pump to initiate the switch over to the power steering pump.