Abstract: A hydro-pneumatic pressure transformer with a storage piston fixed between storage oil and compressed air, which furthermore is centrally penetrated by a plunger piston, wherein, for the separation of oil from water, relief grooves are provided on the jacket face as well as in the wall of the central bore, which are connected with each other and are pressure-relieved via a ventilating bore leading to the exterior.

Abstract: A brake system (10) comprising: a master cylinder (20) including a primary (24) and a secondary (26) chamber and a reservoir (26); an accumulator (40), a pump (42) having first inlet port connected to a reservoir (26) of the master cylinder (20) and the second outlet port (b) connected to the accumulator (40), a motor (50) for selectively driving the pump as a function of system pressure, a pressure boost mechanism (60) connected to the accumulator (40) and the primary and secondary chambers of the master cylinder for generating a boosted pressure at a fixed multiple of the pressure in either the primary or secondary master cylinder chambers.

Abstract: The present invention is drawn to an isolation system for separating two diverse fluid mediums from each other and, more particularly, an isolation system for prohibiting leakage of the diverse mediums around the peripheral surface of a piston movably mounted within a chamber. The present invention further relates to an improved multi-piston air-oil pressure intensifier employing the improved isolation system for separating and preventing leakage of the air and oil mediums during operation of the pressure intensifier.

Abstract: The combined pneumatic-hydraulic press with controlled stroke, includes a body inside which a substantially cylindrical main chamber is defined; the main chamber accommodates, so that it can slide along an axial direction, a working piston which protrudes from the body with its stem. The working piston delimits, in the main chamber, a first compartment which contains a liquid and is connected, through a passage, to a secondary chamber which is provided with elements for exerting pressure on the liquid contained in the secondary chamber in order to transfer at least part of the liquid from the secondary chamber to the first compartment in order to axially move the working piston.

Abstract: The combined pneumatic-hydraulic press head includes a body inside which a substantially cylindrical main chamber is defined; the chamber accommodates a main piston and a secondary piston so that they can slide along an axial direction. The main piston has a stem which protrudes from an axial end of the main chamber, and the secondary piston is spaced from the main piston on the side opposite to the stem. The two pistons sealingly divide the main chamber into three chambers: two end chambers, which can be connected to a source of compressed air or to the atmosphere in order to move the two pistons along the axis of the main chamber during the approach of the main stem or spacing motion with respect to the part to be treated, and an intermediate chamber which contains a liquid. An actuation stem is furthermore accommodated in the main chamber and sealingly passes through the secondary piston.

Abstract: A pressure intensifier drive unit has walls that form a cylinder with an intermediate divider plug separating a working chamber and a pressure intensifying chamber aligned in the cylinder. The working chamber has a working piston and a working piston rod extending from an end of the cylinder. A carrier piston is located between the working piston and the divider plug and has a cylindrical recess receiving the working piston, a hydraulic fluid chamber, and a bore. A locking piston is movably mounted on the carrier piston and locks the carrier piston in place when the working piston rod initially contacts a workpiece. A pressure intensifier piston in the pressure intensifying chamber has a pressure intensifier piston rod extending through a bore in the divider plug and through the bore in the carrier piston into the hydraulic fluid chamber.

Abstract: The hydraulic cylinder comprises a cylinder jacket (1), a piston-rod guide flange (2), and a cylinder bottom (3). Disposed within the cylinder are a primary piston (4) provided with a piston rod (6) and a secondary piston (11) connected to two plungers (7, 8). The plungers enter two bores (5, 6) in the primary piston. Two spring-biased (19, 20), openable check valves (17, 18) are disposed in the cylinder bottom. In each valve there is a bore (41, 42) connecting the front and rear sides of the valve. The rear portions (24, 25) of the valve chambers (26, 27) each contain a spherical unstopping piston (21, 22). Two supply ducts (23, 30) for the hydraulic fluid are connected to the valve chambers, these chambers in turn having supply ducts at various locations (36, 40, 45) of the interior of the cylinder. A very compact construction is possible for the hydraulic cylinder with pressure transmission.

Abstract: A hydraulic braking system includes the third piston slidably disposed between the first piston and the second piston of the tandem master cylinder so as to define the third pressure chamber between the third piston and second piston. The third pressure chamber is communicated with the dynamic hydraulic pressure generator. Thereby, due to supply the output hydraulic pressure of the dynamic hydraulic pressure generator to the third pressure chamber, the initial stroke of the brake pedal is reduced and the braking force is ensured as the ordinaly tandem master cylinder when the dynamic hydraulic pressure generator is not operated. Moreover, if the leakage of the brake fluid generates in the wheel cylinders, the flow of the brake fluid of the dynamic hydraulic pressure generator does not generate.

Abstract: A hydraulic actuator is formed by an assembly including a first element, a cylinder, a body section and a chamber. The first element is provided with a first set of a plurality of different sized piston cavities and piston elements which cooperate with a second set of piston elements and piston cavities respectively formed on a second element. The second element forms a piston in cylinder. The body sides incorporates, preferably in symmetrical relationship around the axis, of the assembly a plurality of valves, one valve for each of the pairs of cooperating pistons and cavities. A piston divides the chamber into a high pressure reservoir and a low pressure reservoir with the piston being urged toward the high pressure reservoir to maintain a difference in pressure between the high and low pressure reservoirs.

Abstract: A hydraulic-pneumatic cylinder device of the invention comprises a tubular housing closed at both ends, and an actuating piston slidably guided in the housing and connected to a piston rod. A pair of hydraulic units, each of which comprises a pair of volume-variable liquid chambers in communication with each other through a flow control passage, are arranged within the housing on both sides of the piston to act thereon in opposite axial directions. A pair of air chambers, which are selectively connectable to an air supply source, are also provided within the housing to act on the respective hydraulic units. Operation of the cylinder device can be reliably adjusted by a flow regulating valve provided at each flow control passage.

Abstract: A method for topping off a reservoir chamber of a hydropneumatic pressure intensifier with oil, and the embodiment of such a hydropneumatic pressure intensifier, in which the reservoir chamber has a vent bore, which being usable as an overflow protection means as well is controlled by a flow control valve and is uncovered preferably by the reservoir piston in its outset position. In the event of improper aeration, the reservoir piston is thrust against a stop determining its extreme position, in a further feature of the invention a second vent bore can be uncovered by such movement.

Abstract: An oleopneumatic load intensifier apparatus for creating a rapid advance of a tool carrying piston rod followed by slow advance of the piston rod at an increased load. The apparatus has a master cylinder and an actuating cylinder that can assume different positions with respect to the master cylidner while maintaining fluid communication therewith. An enclosed hydraulic system is shared by the master and actuating cylinders. Pneumatic pressure actuates a piston within the master cylinder that causes a rapid advancement of a hydraulic fed piston within the actuating cylinder, causing a piston rod and a tool associated therewith to contact a workpiece. Pneumatic pressure then causes a piston and associated piston rod, located in the master cylinder, to increase the hydraulic pressure in the line to the hydraulic fed piston located within the actuating cylinder, thus, increasing the load delivered to the workpiece.

Abstract: This brake booster is for a vehicle whose tandem type brake master cylinder has a first piston and a second piston operating in tandem, with first and second pressure chamber and a reservoir chamber for the second brake fluid supply pressure chamber being defined in it. The brake booster has a power piston, one side of which is presented to an actuating pressure chamber, and which is driven by supply of pressurized brake fluid to that actuating pressure chamber so as to push the first piston of the master cylinder so as to expel fluid from the first and second pressure chambers towards the vehicle brakes. Brake fluid is supplied by a valve to the booster actuating pressure chamber upon brake pedal depression. A conduit is provided for directly conducting fluid from the actuating pressure chamber of the brake booster to the reservoir chamber for the second pressure chamber of the master cylinder.

Abstract: A vehicle brake system, with the usual arrangement of a power booster axially aligned with the brake master cylinder piston and engaged between it and the brake pedal, has a fluid pressure differential-operated actuator offset from the conjoint axis of the power booster and the master cylinder piston. The actuator is coupled to the master cylinder piston through a mechanical linkage which provides a substantial mechanical advantage. The actuator causes the brakes to be applied independent of the brake pedal in response to any of several sensed conditions which dictate that the vehicle should not be moving.

Abstract: Hydraulic pressure transducer having an operating cylinder (10) with an operating piston (12) and operating piston rod (14) adapted for rapid traverse, and a transducer piston (22) and piston rod (24) guided within an axially connected power cylinder (20). The transducer piston rod (24) is of a smaller diameter than the operating piston rod (14) and is capable of plunging into the operating cylinder volume (16), the transducer piston rod (24) extending through a seal (58) separating said operating cylinder volume (16) from the power cylinder.

Abstract: To protect brake fluid against evaporation under extreme braking conditions, the brake fluid contained in the wheel brake cylinders is kept at a minimum pressure between 5 and 10 bar even after completion of a braking operation, thereby increasing the boiling point of the brake fluid. The wheel brake cylinders are designed as stepped cylinders with a counterpressure space, into which a likewise constantly kept counterpressure can be introduced, which maintains equilibrium with the admission pressure prevailing in the inlet pressure space of the respective wheel brake cylinder. A non-return valve arrangement, connected between the brake booster and the inlet pressure spaces of the wheel brake cylinders, blocks the return of the brake fluid to the brake booster when the pressure differential between the wheel brake cylinders and the brake booster drops below a threshold value P.sub.S.

Abstract: A braking pressure generator for slip-controlled brake systems of automotive vehicles comprises dynamic (III) and static (I, II) pressure fluid circuits into which pressure fluid from the dynamic circuit (III) is metered during braking with slip control. A differential pressure pilot valve (4) is provided which compares the pressure in a booster chamber (15) of the hydraulic circuit (III) with the pressure in a prechamber (5) into which pressure is metered during braking with slip control. The differential pressure pilot valve (4) is connected to an alarm switch (9). The switching position of this alarm switch is logically combined with the switching position of a brake-actuating switch (8) and with the brake slip control signal (10) and an error signal is derived therefrom.

Abstract: A hydraulic brake system for automotive vehicles with a master brake cylinder (51) and with a hydraulic power booster (49) connected upstream of the master brake cylinder, in which a pressure medium pump (18) which may be driven by an electric motor (17) is used for providing an auxiliary hydraulic energy, the drive of which may be switched on by a pressure accumulator (1), on the one hand, and by a brake pedal contact (58), on the other hand, in the unbraked operation of the automotive vehicle the pressure accumulator (1) permanently being kept on a pressure level sufficient for an initial actuation of the brake and the charge of the pressure accumulator (1) being monitored by a pressure control valve (19).

Abstract: The invention concerns a hydraulic amplifier for a braking system incorporating a body (10, 110), a first component (18, 124) capable of being displaced in the body (10, 110) under the effect of the operation of a brake pedal, between a first position causing a first chamber (16), joined to a braking circuit, to communicate with a low pressure reservoir (44, 138), and isolating this chamber (16) from a high pressure source (32, 130), and a second position isolating the chamber (16) from the low pressure reservoir (44, 138) and causing it to communicate with the high pressure source (32, 130), characterized in that it incorporates a second chamber (12, 112) formed in the body (10, 110), a circuit (42) causing this second chamber (12, 112) to communicate with the low pressure reservoir (44, 138), and a valve means (34, 116) responsive to the pressure of the high pressure source (32, 130) normally closing this circuit under the effect of the pressure of the high pressure source (32, 130).

Abstract: A brake system comprises a tandem master cylinder (24) with working pistons (19, 27), each of which confining a working chamber (25, 29). Upstream of the tandem master cylinder (24) a power booster (1) is connected which is connected to an auxiliary energy source (8) for the pressure supply. Connected to the booster chamber (3) are valves (22, 23) which are controllable by the pressure of the booster chamber (3) and by which a pressure medium communication may be established from the auxiliary energy source (8) to the working chambers (25, 29) of the tandem master cylinder (24) and a dynamic inflow of pressure medium takes place.

Abstract: A hydraulic cylinder device for power multiplication includes a cylinder (1) containing a single-stage piston (2) having a piston rod (4) and a two-stage secondary piston (3), the piston rod (4) extending through a bore in the secondary piston. The cylinder (1) is closed by a cylinder cover (16) through which the piston rod (4) also extends. Two stop-pistons (22, 24) with different strength springs (21, 23) are located in projection (20) integral with cylinder (1) and opposite the stop-pistons are two opening-pistons (33, 34).

Abstract: An actuating device for a vehicle hydraulic brake system of the type having electromagnetically operated valves in the hydraulic circuits to each wheel brake for providing slip control wherein the device includes a master cylinder having a brake pedal force responsive hydraulic booster piston for actuating a master cylinder piston slidably mounted within a slidable positioning sleeve within the bore of the master cylinder. The positioning sleeve is adapted to be mechanically coupled to the booster piston in the brake actuation direction. A stationary projection on the interior end of the master cylinder protrudes into the positioning sleeve and cooperates with the sleeve and master cylinder piston to vary the master cylinder volume.

Abstract: This invention relates to a hydraulic brake system for automotive vehicle with a master cylinder (2) and with a hydraulic power booster (1) connected upstream of the master cylinder (2) and having a pressure chamber (4) in which an auxiliary pressure depending on the actuating force (F) may be modulated via a pedal-operable brake valve (7). Wheel brakes (51, 53) of a first brake circuit are connected at the pressure chamber (4), wheel brakes (50, 52) of a second brake circuit being connected at the master cylinder (2). The braking pressure active in the wheel brakes (50 through 53) is controllable by valve members (39, 54 through 59) controllable in dependence on the slip. In case of control, a hydraulic communication will be established between the pressure chamber (4) of a hydraulic power booster (1) and the master cylinder.

Abstract: A vacuum brake booster includes a pair of diaphragms which move in opposite directions during a brake application. One of the diaphragms is connected to a valve assembly to generate a first force assisting braking while the other diaphragm generates fluid pressure in an output chamber formed substantially by the valve assembly. The fluid pressure in the output chamber generates a second force assisting braking.

Abstract: The invention relates to a pneumatically controlled pressure transducer for operating hydraulic work tools having a dual operating cylinder, on one side of which a pneumatically operable piston, on the other side a hydraulically operable piston is provided and, to the hydraulic side of which a hydraulically operable working tool can be joined.The essence of the invention resides in that a control valve is provided which is coupled with the primary space located in front of the piston of the pneumatically operable cylinder of the operating cylinder and, which is connected into an operating relationship with a starting valve, and wherein the control valve is connected over a throttle-check valve to a further valve on one side, while on the other side, over a quick exhaust valve, is connected with a hydraulic container, respectively, over a valve with the secondary space of the pneumatically operable cylinder.

Abstract: There is disclosed an air operated demand only hydraulic power unit for supplying hydraulic fluid under presure to one or more hydraulic working motors, comprising an extensible pneumatic power motor including an extensible power transmitting member, an extensible hydraulic slave motor including an extensible slave member powered by said power transmitting member, said slave motor being connected to each said hydraulic working motor to power same, valving for controlling the supply of air and oil to said power and slave motors, and a reset valve for insuring full volume cycling of said slave member in said slave motor. In one embodiment the reset is indicated by sensing the various pressure changes after all working motors are extended and then valving leftover oil to a reservoir. A second embodiment accomplishes the reset on a time delay basis.

Abstract: A pressure die casting machine having a working cylinder enclosing a working piston adjacent a multiplier cylinder having a multiplier piston slideably mounted therein. The working chamber intermediate the working piston and the multiplier piston is connected to a pressure medium supply line which includes a check valve. The check valve is separated from the pistons and is attached on the outside of the working cylinder and multiplier cylinder so that the pistons are not weakened and the valve is made accessible for maintenance. The supply of pressure medium to the pressure chamber is controlled by a valve arrangement actuable independently of the check valve.

Abstract: A closed-center hydraulic servo apparatus (10) includes a closed-center valve device (112) which is coupled to an input member (60) to control the communication of fluid among a fluid pressure source (12,14), a fluid reservoir (36), and a fluid pressure responsive device (a vehicle brake) (16) in response to movement of the input member (60). The coupling (158, 160) between the closed-center valve device (112) and the input member (60) provides a movement ratio therebetween which is greater than unity. As a result, the inherent deadband (D) of the closed-center valve device (112) is reduced by the inverse of the movement ratio to a level (d) which is sensible to an operator at the input member (60).

Abstract: A toggle assembly for vehicles or cars comprising a relay cylinder mounted on an end plate including a booster cylinder and an output cylinder, a control chamber arranged in coaxial relation to the relay cylinder, a control valve for controlling a gas by a hydraulic pressure of a master cylinder, said valve being arranged in operable association with the control chamber, and a booster piston disposed in the booster cylinder and in operable association with the controlled gas, wherein said end plate is provided with a shell for said booster cylinder as an integral piece, said shell is integrally provided with a first compressed air passage having its one end being open in the back chamber of the booster cylinder for the booster piston and its other end passing through said end plate and being open at the end of a relay valve body, and a second compressed air passage is provided to extend from a casing for said control chamber, said second passage having its one end in communication with the other open end of s

Abstract: An air/hydraulic servomotor unit for providing power assistance for a clutch hydraulic operating system and comprising a compressed air cylinder, a hydraulic slave cylinder, a load proportioning means that determines what ratio of the unit output is derived from the hydraulic and air cylinders, and a clutch operating member.The hydraulic slave cylinder is secured to one end of the air cylinder housing and has a piston which passes through the air cylinder piston so that both pistons can act against the proportioning means. All the unit output loads pass through the proportioning means prior to being transmitted to the operating member.

Abstract: A fluid pressure intensifier in which a body has a side wall and first and second end walls. A tube extends inwardly in the body from the first end wall and a piston head is slidably disposed on the tube. A cylindrical element in spaced relation to the body side wall extends from the piston head toward the second end wall. A fluid inlet in the second end wall supplies pressurized fluid to move the piston head on the tube. A fluid outlet through the tube transfers pressurized fluid from within the element out of the intensifier. The amount of pressure intensification is proportional to the surface area differential of the piston head and a cross section of the element.

Abstract: In a boosted hydro-pneumatic drive for rapid traverse and power stroke, particularly for driving punching tools, a cylinder housing (1, 4) with partition (12), a disc piston (7) with plunger (8), a working piston (2) which can be loaded with compressed air for the return stroke and an annular piston (9) surrounding the plunger (8) are provided. The cylinder spaces between the working piston (2) and the annular piston (9) on both sides of the partition (12) are filled with hydraulic oil.In order to reduce the consumption of compressed air and to increase the speed of response, and for the purpose of simplification, the working piston (2) is provided with an annular surface (16a) which can be loaded with compressed air in the direction of advance, and a compression spring (10) is clamped between the disc piston (7) and the annular piston (9). The space accommodating the compression spring (10) is in constant connection with the outside air, preferably via a filter (11).

Abstract: The invention relates to a pneumo-hydraulic booster with rapid-traverse feature, particularly for driving punching tools, with a working piston which executes a rapid-traverse positioning stroke, a power stroke and a return stroke, with at least one further piston, and with chambers which adjoin these pistons and which, according to a program can be connected to a source of compressed air, in which arrangement a first chamber is pressurized during the positioning stroke and the power stroke, a second chamber is pressurized only during the power stroke and a third chamber is pressurized only during the return stroke and all chambers are vented at other times.

Abstract: A hydraulic brake pressure control installation with a master brake cylinder actuatable by a plunger of the pedal. The plunger acts on the master brake cylinder by way of a piston rod of an adjusting cylinder which is arranged ahead of the master brake cylinder and which includes a connecting nipple on the side of the adjusting cylinder piston facing the brake pedal, with which a feed line leading to an electro-hydraulic two-stage control valve is connected. The control valve is adjusted by a control signal, and is operable to connect the feed line with either with a supply pressure line or with a pressureless return line.

Abstract: A controllable hydraulic valve mechanism for reciprocating engines or pumps including a drive piston, operable by a cam is provided with control edges and projects into a drive cylinder; a working piston which operates the valve directly and is guided in a working cylinder. The valve mechanism provides a continuous communication between the drive cylinder interior and a second reservoir which absorbs a substantial part of the energy produced by the lift of a cam. Control sleeves surround the drive piston and are operable by actuating means operable from outside the drive cylinder. Each of the control sleeves has a control ring groove which cooperates with control edges provided in the drive piston. A further sleeve in the working cylinder surrounds the working piston, is rotatable by actuating means operable from outside the working cylinder, and is provided with a control ring groove for varying the valve lift.

Abstract: Method of and apparatus for fabricating spiral wrapped cartridge cases or the like, in which an expandable bladder positioned within the interior of the cartridge case is initially expanded by application of hydraulic fluid at relatively low hydraulic pressure levels and at relatively high flow rates until the bladder substantially fills the cartridge case and then is pressurized at relatively high hydraulic pressure levels to form the cartridge case within a die cavity. Hydraulic pressure is applied to the bladder by a hydraulic pressure generator which is powered solely by the closure of the platens of a conventional industrial press between which the die and the pressure generator are mounted. The pressure generator shifts automatically from its low pressure to its high pressure mode of operation as the press platens close.

Abstract: An apparatus for mixing and ejecting at least two interacting components to provide a foaming material. The apparatus comprises an injection head connected to supply circuits of the individual components, which head includes a mixing and ejecting chamber; the chamber has a cleaning plunger axially reciprocable therein and operated by a double acting cylinder connectable through a first sliding valve to a first pressure fluid supply conduit comprising a one-way valve, and respectively to a branched-off conduit connected to a pressure multiplier cylinder. The control side of multiplier cylinder is in turn connected to the pressure fluid supply through a second sliding valve operatively connected to the first sliding valve.

Abstract: An automatic device for supplying an elastomer or like material for an intion machine comprising an injection cylinder and a piston, wherein the piston is controlled by a hydraulic multiplier device formed by two stages, the first stage being called the downstream stage and the second stage being called the upstream multiplier stage, and wherein the device comprises a sensor for controlling the supplying of the cylinder with material so as to stock said cylinder by an electrically driven tape advance unit, the sensor being brought into play when the piston is moved in the forward direction, a pressure controller for tripping the upstream multiplier stage to multiply the pressure in the injection cylinder, the pressure controller being controlled from a pressure threshold of the fluid supply of the first downstream stage and an end of travel sensor for tripping the return of the first and second stages to make the piston return at the end of the injection.

Abstract: A fluid pressure amplifier for intensifying fluid pressure, the amplifier comprising a housing including a hydraulic fluid reservoir therein. A first chamber includes a slave piston mounted for reciprocation therein and for abutting engagement with a workpiece. A hydraulic fluid path extends intermediate the reservoir and the first chamber and a second chamber lies in the path intermediate the first chamber and the reservoir and includes check means intermediate the first and second chambers. A third chamber includes a fluid intensifier piston having a head end and a tail end, the head end being mounted for reciprocation in the third chamber and the tail end being mounted for reciprocation in the second chamber, the head end of the piston having a larger diameter than the tail end. Gas admittance means admit a pressurized gas to a gas path which lies intermediate the gas admittance means and the reservoir.

Abstract: Apparatus for hydraulic control of friction brakes of an automobile vehicle which comprises a first master-cylinder directly connected to the hydraulic brake circuit and operated by the driver's brake pedal and a second master-cylinder operated by release of the gas pedal, and connected to the first master-cylinder in place of the reservoir thereof. The first master-cylinder is a tandem master-cylinder which comprises a first piston connected by the intermediary of a linkage to the brake pedal and a second piston dividing the interior of the first master-cylinder into first and second chambers. The first chamber is located between the two pistons and is connected to a first hydraulic brake control-circuit, while the second chamber is situated at an end of said cylinder and is connected to a second hydraulic brake control-circuit. The two chambers are supplied with liquid.

Abstract: Apparatus and controls therefor are provided for piercing sheet material. A punch is driven by a cylinder and piston positioned in tandem with a second cylinder and piston. The arrangement is such that a small pressure applied to the second piston results in a large force applied by the punch to the sheet material. Controls for the apparatus include means to sense a sudden drop in pressure in the second cylinder and means to then supply return air to the rod ends of the cylinders. The controls are quickly responsive so that as the punch breaks through the sheet material, it is immediately reversed toward its original position. The noise and jarring ordinarily resulting when a punch breaks through sheet material being pierced are thereby substantially eliminated.

Abstract: A combined hydraulic and vacuum booster includes hydraulic and vacuum boosters coaxially mounted in series and having a common force output member. The combined booster includes common operating means for energizing the boosters in sequence for first applying substantially the full force of the hydraulic booster to the output member while the vacuum booster is substantially inoperative, and then applying the force of the vacuum booster to the output member.

Abstract: An operator cylinder comprising, in combination with a hydraulic piston-cylinder unit, an idle transmission piston for supplying to the hydraulic cylinder a pressure of control, and a stress multiplier for supplying when necessary an increased pressure simultaneously excluding the operation of the transmission piston.

Abstract: A vehicle brake having a vacuum suspended operating section. The assembly is arranged so that initial braking is accomplished by the operator admitting atmospheric pressure to the pressure side of a diaphragm that has a vacuum on its opposing side. The assembly is further arranged so that the wheel cylinder can be used to convert hydraulic pressure to air pressure. When the vehicle operator first applies a force to the brake pedal, a valve is actuated which allows vacuum and atmospheric pressure to impart sufficient force to provide initial braking. When greater brake pressures are required as indicated by increased brake pedal force exerted by the vehicle operator, a valve leading to atmospheric pressure closes, allowing the hydraulic pressure in the wheel cylinder to convert the trapped atmospheric pressure to air pressure.

Abstract: An apparatus for the expansion of tube ends inside of a tube plate by means of a probe insertable in the respective tube ends, the probe forming an annular space with the tube member to be widened by means of two seals spaced from one another, a pump operatively feeding the annular space with a pressure medium for the expansion, and a pressure intensifier for bringing the pressure medium to a required pressure. A medium separator is connected via a back-pressure valve to a secondary-sided space of a primary-sided hydraulic oil driven pressure intensifier. A piston displaceably disposed in the medium separator is biased by a return spring in the medium separator, and the pump feeds the hydraulic oil displacing the piston against the restoring force of the return spring for the filling of the secondary space of the pressure intensifier with an operating medium. The operating medium flows from an operating medium-supply container and another back-pressure valve to the secondary side of the medium separator.

Abstract: Apparatus for transferring gas from a first container to a second container of higher pressure comprising a free-piston compressor having a driving piston and cylinder, a smaller diameter driven piston and cylinder, and a rod member connecting the driving and driven pistons for mutual reciprocation in their respective cylinders. A conduit may be provided for supplying gas to the driven cylinder from the first container. Also provided is control apparatus for intermittently introducing gas to the driving piston, from the first container, to compress gas by the driven piston for transfer to the second higher pressure container.

Abstract: A fastener for joining a first force transmitter to an independent second force transmitter to assure continuity in movement therebetween. The first force transmitter has a hub with an axial bore therein. A first slot and a second slot, each of which has a recessed section on the bottom, are located on the housing surrounding the bore. The second force transmitter has a cylindrical body with an oval groove located adjacent the end thereof. First and second wishbone shaped clip members which surround the oval groove have first and second tabs located thereon. The cylindrical body is located in the axial bore of the hub means and the first and second tabs are positioned in the recesses of the slots. When the tabs are located in the recesses in the slots the cylindrical body is locked to the hub.

Abstract: This invention embodies an intensifier cylinder assembly within the main hydraulic ram of a plastic molding machine whereby the clamping force holding the mold halves together can be increased during the shot cycle of the machine by at least three times the normal clamp force of the machine. Additionally, the location of the intensifier reduces the number of high pressure hydraulic fittings in the machine improving the safety factor while reducing the overall cost of the intensifier itself since the ram piston now becomes the housing for the intensifier piston.

Abstract: The method and apparatus for producing an oil well, by the provision of a pumpjack unit which reciprocates an engine assembly located within the upper extremity of a wellbore. The engine assembly has a power piston which hydraulically drives a lift piston by means of hydraulic fluid being transferred therebetween. The lift piston is directly attached to and reciprocates a string of sucker rod, which in turn reciprocates the downhole production pump.The hydraulic fluid associated with the engine assembly is contained within a closed system, and the relative sizes of the power and lift pistons are of a ratio to cause the lift piston to travel a greater distance respective to the power piston, thereby enabling a relatively short stroke of the polish rod to impart the piston of the subsurface pump with a relatively larger stroke.

Abstract: A hydro or oleopneumatic device comprises a pressure transformer consisting of a single or multiple pneumatic cylinder having one or a number of stages in which the piston is rigidly coupled to an accumulator. The accumulator piston discharges the liquid to a function jack which utilizes the energy produced by the pneumatic pressure. The pneumatic cylinder is not provided with compressed-air exhaust ports and is freely connected to a compressed-air reservoir at the working pressure. The volume VR of the reservoir is large in comparison with the volume VC of the pneumatic cyclinder, the ratio VC/(VR + VC) being equal to the permissible variation in the working pressure of the air according to the intended use of the device.