Abstract: A compact master cylinder suitable, for example, for vehicle clutch or brake systems. An integral fluid reservoir body is connected to a piston stem extending to a piston head in the cylinder. The stem has a longitudinal passage connected to an orifice at the reservoir inlet. This orifice is valved by a valve closure member having a spherical head and an elastomeric cap. In the retracted state a stop secured to the cylinder limits movement of the piston out of the bore and the valve closure member opens to allow entry of make-up fluid from the reservoir.

Abstract: In order to achieve less deformation under gas pressure load and also under thermal load, the bottom piece of a piston with ring-carrying barrel is configured as a supporting cone tapering towards the piston pin and connected with the piston pin bosses by means of supporting elements. Cone, bosses and supporting elements are made in one piece. The supporting elements comprise walls extending essentially parallel to the axis of the piston pin. First distance (A) to the outer perimeter of the piston in the direction of the piston pin axis (Y--Y) are greater than the corresponding second distances (B) normal to this axis. The end parts of the walls are curved inwardly and leave open an area around an axis (X--X) normal to the piston pin axis.

Abstract: A hydraulic master cylinder formed by telescopically fastening together a pair of cylinder housings to form a cylinder. A piston in the cylinder is operative to transfer hydraulic fluid to a slave cylinder connected to the master cylinder. The pressure or power stroke of the piston is effected by exerting a pull on the piston by a pull cable attached to one side of the piston. A body, attached to one of the cylinder housing, provides a reservoir for hydraulic fluids. A cap on the reservoir closes a fluid filling opening. Expansion bellows in the reservoir accommodates changes in the fluid level in the reservoir as the piston is being reciprocated. The bellows is connected to the cap so as to be removed as a unit with the cap when the reservoir is being filled.

Abstract: The cylinder has a sealed back wall through which the rod passes. A piston assembly mounted on the rod between the back wall and a cylinder front end-piece contains a fluid-pressure-activated clamp. The front end-piece also has a clamp. By sequenced operation alternatively fixing the piston or the cylinder to the rod through the respective clamp, the relative travel of cylinder and rod can be extended to any desired length.

Abstract: A piston is moveably arranged in a cylindrical bore of a housing and the piston rod extends through one end of the housing for connection to a unit to be controlled. A very high variable control rate of the piston is made possible by a control slide valve formed as a hollow cylinder that is moveable within a coaxial bore of the piston rod. The hollow, cylindrical, control slide valve contains a plurality of apertures that cooperate with ports formed in the piston rod that extends on either side of the piston. A chamber formed on one side of the piston is connected to a source of pressurized fluid and a chamber at the other side of the piston is connected to a return for such pressurized fluid. A control rod is connected to the control slide valve for moving same within the coaxial bore of the piston rod and by specially forming the guiding or leading edges of the apertures formed in the control slide valve, high variable control rates are possible.

Abstract: A system for the control of a fluid flow control valve which controls the supply of fluid to an actuator to control the movement of a component such as a tractor implement hitch in response to a selected operating parameter such as hitch position or draft force. The system enables the desired value of the selected parameter to be set and this desired value is compared with the actual sensed value of the parameter to provide a parameter error signal. A start-up control function is provided to improve the initial speed of response of the system. The start-up control function is arranged on each detection of a parameter error signal to apply a start-up signal to the valve to initiate movement of the component and, if no movement results, to increase the start-up signal until movement of the component is detected whereupon the increase in the start-up signal is stopped and the magnitude of the signal applied to the valve is dependent on the parameter error signal so as to tend to reduce the error signal to zero.

Abstract: A proportioning valve (40) is disposed within a stepped bore (13) of a master cylinder (10). The proportioning valve (40) defines with the stepped bore (13) a primary pressure receiving chamber (26) and a secondary pressure receiving chamber (28). The proportioning valve (40) includes a two-part piston (58) which includes a primary piston part (52) and a secondary piston part (54) coupled together by a lost motion coupling (53, 55). The piston parts (52, 54) are biased apart by a spring (78), and a sleeve (43) is disposed about the two-part piston (50). Seals (46, 47, 69) are disposed about the primary piston part (52), sleeve (43) and secondary piston part (54) to define an intermediate vented chamber (90), wherein a vent (19) communicates with a reservoir.

Abstract: A composite hydraulic cylinder apparatus which has a pneumatic cylinder mechanism, a braking oil hydraulic cylinder mechanism associated concentrically with the pneumatic cylinder mechanism, an oil passage for communicating between the front chamber and the rear chamber of the oil hydraulic cylinder mechanism, and a control valve provided in the oil passage for controlling the flow of the oil. Thus, the apparatus provides high positioning accuracy, a large holding force, economy and small size as a movable element control system, and can be applied as a buffer for the movable element.

Abstract: The invention provides a brake booster including in a preferred embodiment a housing, first and second annular flexible diaphragms spaced from one another forming a sealed second chamber within the housing and a sealed first chamber between the first diaphragm and the first end of the housing, a generally annular shaped power piston for connection with the master cylinder piston, a chamber valve seat separating the first and second chambers, an inlet valve slidably mounted within the power piston, and a control valve spring biased away from the power piston and connected with the pedal linkage and being slidably and sealably mounted within first end of the housing.

Abstract: An apparatus for generating super-high pressure to produce diamonds, carbide material, and the like, in which fluid pressure generating means for generating fluid pressure introduced into pressure chambers to move a plurality of moving bodies pressing an article to be pressed by a pressing force applied from outside of a casing is provided integral with the casing to simplify the equipment for producing hydraulic pressure.

Abstract: A hydraulically-operated piston machine includes at least one cylinder and a piston axially movably guided in the cylinder. The piston is connected to a crankshaft or the like by means of a connecting rod. The connecting rod and the piston each have spherically-shaped bearing surfaces serving for connecting the connecting rod and the piston with each other in an articulated manner. The connecting rod defines at its end connected to the piston a radially outwardly facing spherical surface portion which is arranged concentrically with the spherical bearing surface of the connecting rod. The spherical surface portion rests against the surface of a recess defined in the piston, so that a hollow space is defined between the surface of the recess and the spherical surface portion. The piston defines a bore for effecting communication of fluids between the interior of the cylinder and the hollow space.

Abstract: A hydraulic power drive unit for connection to the hydraulic system of an agricultural tractor is provided with a pressure release valve to protect the unit seal from damage if connected the wrong way round, and a bleed pipe which bursts to relieve pressure if the pressure release valve fails to operate.

Abstract: A hydraulic brake booster is proposed, in which a coupling is provided between a control valve and a booster piston. The coupling engages the control valve at a slide sheath and upon the movement of the booster piston causes it to move as well, in such a manner that tracking control is provided. A pedal push rod in this manner always keeps a certain distance from the booster piston; that is, it does not touch it. However, if the auxiliary force should fail, then the pedal push rod does touch the booster piston, and its force is transmitted mechanically.

Abstract: A microwave method and apparatus for detecting the position of a piston of a pneumatic cylinder. While the piston is being moved by fluid pressure a microwave signal is applied to a cavity defined by the piston and interior of the cylinder and the reflected microwave signal is detected. The reflected microwave signal is processed to determine piston position.

Abstract: A rotary actuator includes a shaft rotatably mounted on a body, and a servovalve arranged to operate a vane motor for selectively rotating the shaft relative to the body. A portion of the shaft extends beyond the body. Supply and return passages are provided to the body and shaft so that fluid power supplied to the body is supplied to the servovalve and is also available at the end of the shaft beyond the body. Two or more such rotary actuators may be connected by intermediate brackets to provide a wrist actuator capable of movement about axes.

Abstract: A piston head and rod assembly for use, for example, in a gear pump dry valve is disclosed. A cylindrical piston head is provided with a generally oval-shaped cavity formed therein which defines a minor diameter. The cavity opens through one end of the piston head. However, a portion of the opening is blocked by a radially inwardly-extending lip. The lip defines an opening diameter which is smaller than the minor diameter of the cavity. An end portion of a piston rod includes a reduced diameter neck portion and an enlarged diameter tail portion. The neck portion has an outer diameter which is slightly smaller than the opening diameter defined by the lip, while the tail portion has an outer diameter which is slightly smaller than the minor diameter defined by the cavity. To assemble, the tail portion of the piston rod is inserted through the portion of the opening of the piston head which is not blocked by the lip into the cavity.

Abstract: In a system for varying the output flow from a constant rate feed pump with low losses by chopping the said output flow into one flow fraction supplied to the load as a power flow and into another flow fraction returned as a pressureless flow, the loads are aperiodically supplied with proportionated amounts of fluid by chopping, the respective amounts of fluid and the chop frequency being inherently controlled in way dependent on the instantaneous requirement of the load in the system. The system for performing the method has a housing with a number of pressure spaces arranged to be acted upon by different flows and with one or more pressureless spaces, a piston with a piston rod arranged in a piston space, a compression spring preferably arranged in a hole in said piston rod and adapted to act against the sum of the hydraulic forces acting on the piston and spool. The method is applicable to complex hydraulic systems and more especially to hydrostatic drives.

Abstract: A double acting and at the limit positions automatically reversing pressure intensifier. A case has a first bore hole and a second bore hole. A pressure intensifier piston slides in the first bore hole of the case and subdivides the first bore hole into two low pressure work spaces and is furnished with two flat control grooves at the outer circumference and with two cylindrical bore holes. Two high pressure pistons are solidly mounted to the case for sliding relative to and inside of the two cylindrical bore holes of the pressure intensifier piston. A check valve is disposed in the pressure intensifier piston and connects the two bore holes. A control slider is disposed in the case and furnished with two flat control grooves about at its middle region which connect to respective front faces of the slider via cross bore holes and axial bore holes in the control slider. A wide bypass groove is disposed on the outside of the control slider.

Abstract: A hydraulic control system for actuating a switch or related device including an actuator assembly having a housing with a member movable therein and connected to the switch for movement therewith between first and second positions responsive to the application of hydraulic pressure in the housing on opposite sides of the movable member.

Abstract: A hydraulic master cylinder assembly of the type including a reservoir in which a diaphragm is disposed to divide the reservoir chamber into a hydraulic fluid chamber outside of the diaphragm and in communication with the pressure chamber of the master cylinder and a gas chamber within the diaphragm. The diaphragm is generally tubular with an open end and a closed end, and in a cross section transverse to the central axis of the diaphragm, includes a plurality of radially extending arms arranged about the central axis of the diaphragm and each including a pair of side walls defining therebetween a portion of the volume of the gas chamber. The diaphragm is movable between an expanded condition in which it assumes a substantially circular configuration in cross section and a collapsed condition in which each of the pairs of side walls of the arms are collapsed with respect to each other to reduce the volume of the chamber.