Abstract: The present specification relates to a piston and cylinder arrangement for use in a vehicle disc brake. Such arrangements are either hydraulically or pneumatically operable. In disc brakes the piston and cylinder of the brake actuator are usually sealed against the ingress of dirt, by a flexible boot arranged between the piston and cylinder at the cylinder open end. Additionally a separate pressure seal is advantageously provided between the piston and cylinder. The present invention provides for a flexible boot which engages in retaining grooves provided on the outside of the piston and on the inside wall of the cylinder adjacent to the open end of the cylinder, the part of the flexible boot engaging in the retaining groove in the inside wall of the cylinder, being compressed radially of the cylinder to thus act as a pressure seal between the piston and cylinder. By virtue of this dual function, the piston can be shortened and the weight of the arrangement induced. Also assembly is simplified.

Abstract: A fluid flow control system has a capability of operating selectively in a power matching mode, in which power consumption is low, and a maximum flow mode in which high responsivity and high speed features can be appreciated. For this purpose, a mode selector valve is used to switch the system between these two modes.

Abstract: An infinitely variable, double-acting positioning linear actuator which responds proportionally to fluid pressure includes a hollow cylindrical housing and an actuating rod axially movable through the housing. Two partitions cooperate with the actuating rod for movement therewith and define within the housing a spring chamber and first and second actuating chambers which are at opposite ends of the spring chamber. A compression spring is mounted within the spring chamber and each actuating chamber has a fluid port to communicate with pressurized fluid. First and second retaining structures within the spring chamber cooperate with respective ends of the spring and each have a respective stop. The spring chamber has a limiting structure which cooperates with the stops to hold the stops spaced apart at a particular spacing when the actuator is centered.

Abstract: A hydraulic brake valve system for use in a hydraulic circuit consisting of driving and braking fluid lines and including therein at least a hydraulic motor for the actuation of an inertia body such as, for example, a construction vehicle or work implements thereof has a counterbalance valve, a cross-over safety valve, a drain change-over valve and a timer valve. The cross-over safety valve consists of two common relief valves, each having two pressure receiving surfaces and adapted to relieve pressurized fluid acted on one of the pressure receiving surfaces at a low pressure and relieve pressurized fluid acted on the other pressure receiving surface at a high pressure, wherein the first port of one of said relief valves is connected with said driving fluid line and the second port thereof is connected with said braking fluid line, whilst the first port of the other relief valve is connected with said braking fluid line and the second port thereof is connected with said driving fluid line.

Abstract: A turbocharger, supercharger or like apparatus for delivering pressurized airflow to an engine, with a housing and valve structure associated with the compressor for permitting selective recirculating flow from the high pressure compressor exhaust to the inlet thereof. A diaphragm acts both as the valve and to define a signal chamber.

Abstract: In a dual master cylinder assembly comprising two independently and simultaneously operable master cylinders, primary pressure spaces between primary and secondary pistons are interconnected by a pipe-line, and secondary spaces between the secondary piston and adjacent ends of the master cylinders are connected to a common auxiliary braking system through a pipe-line. Each secondary piston is provided with an arrangement of passages in communication at all times with a reservoir for fluid, and normally open primary and secondary recuperation valves provide communication between the passages and the respective pressure spaces when the pistons are in their retracted positions. Simultaneous operation of both master cylinders causes both pairs of primary and secondary recuperation valves to close followed by pressurization of the fluid in both pairs of primary and secondary pressure spaces, whereby to apply simultaneously the brakes on opposite sides of the vehicle and to operate the auxiliary braking system.

Abstract: A power steering gear for controlling the dirigible wheels of an automotive vehicle comprising steering gear elements and a fluid motor adapted to drive the steering gear elements to supplement the manual steering effort comprising a rotary valve assembly for controlling distribution of steering pressure from a pressure source to the fluid motor including a sleeve element and a spool element, each valve element having cooperating lands for controlling distribution of pressurized fluid therethrough to effect a pressure buildup in a pressure supply port that communicates with a working chamber of the fluid motor and chamfered surfaces on the valve lands of the internal valve element whereby pressure drop in the pressurized fluid circulated through the valve system and fluid noise is reduced and response of the valve system to steering maneuvers is improved.

Abstract: An electric hydraulic control device for controlling hydraulic cylinders of work tools in a construction vehicle, in which control valves of the hydraulic cylinders are controlled in two ways. For some work tools which need not be controlled smoothly and finely, the corresponding control valves are controlled directly by an electric signal outputted according to the position of the operation levers, and for other work tools which must be controlled smoothly and finely, the corresponding control valves are controlled through an electric servo mechanism which is operated by an electric signal representative of the amount by which the operation lever is manipulated. In addition, there is provided a detector for detecting as to whether the transmission lever is in the locked condition, and electric systems of all of the control valves are rendered inoperative when the transmission lever is in the locked condition.

Abstract: A heat exchange device for mounting between the front fork and the engine of a motorcycle comprises two vertical coolant outflow tanks on either side of a core area, and a coolant inflow tank located midway between the outflow tanks and connected to the latter. The lower part of the device comprises a series of bent tubes having cooling fins therebetween, to form an inverted U-shaped space which straddles the top of the engine, so as to provide sufficient clearance to accommodate the expansion and contraction strokes of the front fork.

Abstract: Pivot angle adjusting means for the arm of a material handling device such as industrial robots are disclosed. An arm connected to a rotary shaft via a mount is pivotably mounted to a support. A cylindrical vane chamber having a rotary vane therein is mounted to the support, wherein the rotary vane secured to the rotary shaft is pivoted by a fluid supplied to the cylindrical vane chamber. A stopper is mounted to the rotary shaft and its pivot angle is detected by a pair of sensors mounted to the support. A stop is mounted to the support and is movable at a certain distance in the direction of the movement of the stopper. The stop can be placed in the locus of the movement of the stopper so as to stop the stopper at a certain intermediate point within the pivot movement of the stopper in its clockwise and counterclockwise movements, thereby stopping the arm at the intermediate point.

Abstract: A servovalve device assembly is provided with an electronic matching circuit positioned upstream of the servovalve. The matching circuit supplies electric control signals whose purpose is to modify the hydraulic flowrate response curve of the servovalve as a function of the electrical control signal, so as to make it substantially identical to an ideal desired response curve.

Abstract: A heat exchange unit suitable for combination with a propeller fan comprises at least one pipe for coolant having porous passages for coolant inside thereof, said pipe being either spirally wound or one of a plurality of substantially circular pipes which are coaxially arranged. An inlet header are and an outlet header respectively connected to the inlet or the outlet of the pipe for coolant. At least one corrugated fin is interposed in a space formed between the adjacent pipes or portions of the spirally wound pipe. The heat exchanger is provided with a space at the central portion, and a fan motor is positioned in the central space of the heat exchanger. A propeller fan is fitted to the rotary shaft of the fan motor to feed air to the heat exchanger.

Abstract: The power engine includes at least two separate fluid-tight enclosures. A solid mass is associated with each enclosure. A coupling rigidly interconnects the enclosures. A pivot shaft defines an axis of rotation and pivotally supports the engine for rotation from a first position, whereat a first enclosure is located at a first level above the axis of rotation, to a second position, whereat the first enclosure is located at a second level below the axis of rotation. A motive fluid is enclosed within each enclosure whose pressure varies in response to temperature changes. Each solid mass is movable in response to a pressure change in its associated enclosure. The engine is responsive to alternating thermal effects which cause alternating variations in the pressures of the enclosures resulting in alternating shifts of the center of gravity of the engine, thereby rotating the engine about the axis of rotation.

Abstract: A piston member is mounted in a cylinder body to be axially movable and unrotatable relative thereto. A ball nut retaining balls is fixed to the piston member, and a screw shaft having a helical groove in engagement with the balls is mounted to be rotatable and axially immovable relative to the cylinder body. The screw shaft makes many rotations when the piston under fluid pressure slightly advances axially inside the cylinder.

Abstract: A reduced impact piston assembly including a cylindrical body with a cavity formed therein and having a cross-bore formed therethrough which intersects the cavity. The cross-bore receives a piston pin which has an exposed intermediate portion aligned with the cavity for attachment of a connecting rod thereto. A wide groove is formed about the outer circumference of the cylindrical body which has its center aligned with the center of the cross-bore. Positioned within this groove are a pair of C-shaped inserts, the legs of which abut the ends of the piston pin to prevent axial movement of the pin within the cylindrical body. The C-shaped inserts cooperate with the pin to form a closed loop having a circumferential length which is larger than the circumferential length of the cylinder body. In addition, a portion of each of the C-shaped inserts is in constant contact with a cylinder wall.

Abstract: A hydraulic pumping unit is provided that is especially adapted for use for pumping oil from a well, and that provides for independent upstroke and downstroke speed control of the well sucker rod. The pumping unit includes a load sensing, pressure and flow compensated pump that is destroked under no load conditions, a pumping cylinder including a polished rod coupled to the sucker rod, and a unique hydraulic valving assembly that couples the hydraulic fluid pump with the pumping cylinder. The hydraulic valving assembly includes a cylinder control module for independent control of the rates at which the polished rod is raised and lowered, and a signal control module for indicating the upper and lower limits of polished rod travel within the pumping cylinder. The cylinder control module provides for soft turnaround of the polished rod, thereby guarding against stretching of the sucker rod and subsequent degradation of the unit's pumping capacity.

Abstract: The actuating mechanism comprises a force step-up transmission with an output member (25) and an input member (17) connected to a control system via a hydraulic distributor (16), these input and output members being coaxial, the step-up transmission consisting of a coaxial train of epicyclic gears (32, 37, 38), and the double-acting power-assistance motor comprises a likewise coaxial rotor (9) with blades (10) which is connected to the output member (25) and which rotates in a cavity (7) formed by the box (4) of the mechanism.

Abstract: A heat exchanger, e.g. that used in an air-conditioner, having a plurality of spaced plate-fins with narrow distance in parallel and a plurality of heat transfer pipes passing through said fins, said fins being coated with an aqueous coating composition comprising 100 parts by weight of a resin composition for water paint in solids content, 5 to 95 parts by weight of a surface active agent and 5 to 65 parts by weight of synthetic silica and baked at a temperature of 120.degree. C. to 200.degree. C. for 10 to 40 minutes to give a coating film of 3 to 20 .mu.m, has excellent hardness and corrosion resistance without damaging hydrophilic properties.

Abstract: The invention provides an apparatus and method for heating a vessel having a vessel bottom and at least one vessel side wall. The invention includes a furnace housing which is adapted to contain the vessel and which has a housing bottom and at least one housing side wall. A heater mechanism, located at the housing bottom and at the housing side wall, heats the vessel and is adapted to contact selected portions of the vessel bottom and vessel side wall. Thermal insulation is disposed about the housing for reducing heat loss therefrom, and an extendable temperature sensor is adapted to contact the vessel and monitor the temperature thereof.

Abstract: Disclosed is apparatus for providing for increased heat transfer efficiency f a heat exchanger by separating contiguous fluid conductive channels by means of a flexible sheet fabricated from a piezoelectric polymer. An electrode pattern of predetermined configuration is applied to one or both sides of the piezoelectric sheet and an electrical signal applied thereto in order to set the sheet into a flexual resonance condition whereupon a standing wave pattern is established to not only break up the boundary layer of fluid which adheres to each side of the sheet, but also minimizing the thickness of the laminar sub-layer.