Abstract: In a hydraulic reservoir of a master cylinder for vehicle including: a main body having an internal space for storing brake fluid; a float provided with permanent magnet, so arranged as to be vertically movable in the internal space of the main body; a reed switch attached to the outside surface of the main body, the reed switch being actuated by magnetic force of the permanent magnet, when the float with permanent magnet is positioned under a predetermined level; and a hollow for attaching the reed switch to the outside surface of the main body, the reed switch is supported by a support member in the hollow, a rubber bush is tightly and elastically fitted to the inside wall of the hollow and a fixing member is so fitted to the hollow as to push the rubber bush to the support means, terminals of the reed switch being inserted tightly through holes of the rubber bush whereby the reed switch is held in the hollow.

Abstract: A piston type accumulator has a detection device that informs a user about the position of the piston incorporated therein. Abnormalities in the hydraulic system operations e.g., a gas leak from a gas chamber bounded by the piston or the sudden turning on of a fluid-actuated device in the system, can cause an excessive movement of the piston; likewise, clogging of lines or the sudden stoppage of a fluid-actuated device may cause a fluid pressure rise in the system and, consequently, a displacement of the piston to actuate the detection device. In this invention, the position of the piston is detected by use of a permanent magnet that actuates a reed relay or moves a magnetic inductive indicator installed on the outside of a accumulator shell to be readily visible thereat.

Abstract: Apparatus for training an operator in theory and practice of electrohydraulic control systems in accordance with a presently preferred embodiment of the invention comprises a plurality of electrohydraulic devices for performing hydraulic operations as differing functions of associated electronic control signals. A plurality of differing electronic controllers are each adapted to generate electronic control signals to operate at least one of the electrohydraulic devices. The electronic controllers bear indicia identifying the controller and associating each controller with corresponding electrohydraulic devices on the training unit. Each controller has a plurality of available input, output and control connections, which may be selectively interconnected with each other and with the electrohydraulic devices by suitable cables for configuring the controller and associated device in a multiplicity of differing operating modes.

Abstract: A geared air actuator comprising a piston mounted for movement within a housing. The piston has a front wall and a hollow body portion which extends rearwardly from the front wall. A spring is mounted within the hollow body portion of said piston. When pneumatic fluid is introduced into the housing and against the front of the piston, it moves the piston back against the action of the spring. When the introduction of pneumatic fluid is terminated the spring will move the piston back to its original position. The front wall of the piston is substantially thinner than the length of the body portion.

Abstract: An improvement in a conventional air-operated diaphragm spring brake is provided by a guide (100) being disposed in registry with an aperture (26) in a service brake housing (16). A push-rod (10) extends from a diaphragm (58) within the housing (12) through the bushing (102) to pivotably connect to a slack adjuster (6). The bushing (102) serves to maintain the push-rod (10) at a preselected angle relative to the slack adjuster (6) when the push-rod is in the inoperative position.

Abstract: An enclosed adjustable servo-actuator is provided. This servo-actuator includes an elongated hollow cylinder; a first closed end member; a second closed end member; a through passageway is provided in each closed end member; an enclosed housing attached exterior of the hollow cylinder at or near the center of the cylinder, said housing adapted to comunicate with the interior of the hollow cylinder; an elongated piston assembly is slidably carries interior of said hollow cylinder; A torque arm is arrayed to engage said piston assembly by means of a closed-end transverse groove provided in said piston assembly; an output shaft is journaled in said enclosed housing, said output shaft engages said torque arm for converting the linear displacement of the piston to an arcuate rotation of said output shaft; and an adjustment means is provided to selectively limit the arcuate rotation of the output shaft.

Abstract: A power actuator has a hollow cylinder housing generally centered on an axis, a piston axially displaceable but non-rotatable in the housing and defining therein a pair of axially opposite pressurizable compartments, and a piston stem centered on the axis, fixed to the piston, extending axially from the piston, and formed with a pair of separate feed passages each having one end opening into a respective compartment and an opposite end opening axially on the stem. A distributor body rotatable about the axis on the stem at the opposite ends of the passages but axially nondisplaceable on the stem is provided with respective connections communicating with the opposite ends. Thus the compartments can be pressurized via the respective passages and connections for axial movement of the piston and stem in the housing. A pair of axially spaced guides are fixed on the distributor body and a bearing has a race axially rotatable on the housing about the axis but axially nondisplaceable on the housing.

Abstract: An apparatus for measuring the thickness of piston rider rings includes a probe disposed in the vicinity of the piston rod of a piston in a horizontal reciprocating machine to determine the vertical distance between the probe and the rod. Changes in the vertical distances are used to calculate wear of the piston rider rings. The apparatus may synchronize vertical distance measurements with the rotation of the crankshaft of the piston so that the distance measurements are taken at the same position of each stroke.

Abstract: An electrohydraulic control system includes an actuator having a cylinder and a piston variably positionable therewithin. An electrohydaulic valve is responsive to valve control signals for coupling the actuator to a source of hydraulic fluid. A coaxial transmission line extends through the actuator, and includes an outer conductor formed by the actuator cylinder and a center conductor operatively coupled to the piston, such that length of the coaxial transmission line is effectively directly determined by position of the piston within the cylinder. An rf generator is coupled to the coaxial transmission line for launching rf energy therewithin, and valve control electronics is responsive to rf energy reflected by the coaxial transmission line for indicating position of the piston within the cylinder and generating electronic control signals to the valve. A second coaxial transmission line of fixed length is connected the valve and actuator so that the hydraulic fluid flows therethrough.

Abstract: A fluid operated actuator includes a housing having a longitudinally extending aperture with open ends. First and second end caps are attached to opposite ends of the housing forming a chamber within the housing. A longitudinally reciprocal piston and attached rod are disposed within the chamber with the rod extending externally of the chamber through one of the end caps. The piston is adapted for reciprocal movement from one end limit of travel adjacent the first end cap to a second end limit of travel adjacent the second end cap. At least one of the first and second end caps includes a longitudinal aperture in communication with the chamber and a transverse aperture communicating between the longitudinal aperture and an exterior of the end cap. A sleeve is connected to the rod adjacent the piston and is engageable within the longitudinal aperture of the end cap when the piston is in the end limit of travel.

Abstract: A diaphragm assembly includes a pair of superposed flexible diaphragms adhesively secured to an annular spacer ring. The space between the diaphragms and the interior of the rings is filled preferably with de-ionized water. The resistivity of the water is monitored to detect conductivity changes upon leakage or diaphragm rupture when pumped materials or pump lubricant mix with the water. Diaphragm assembly and rupture detection methods are disclosed.

Abstract: An electrohydraulic control system includes an actuator having a cylinder and a piston variably positionable therewithin. An electrohydraulic valve is responsive to valve control signals for coupling the actuator to a source of hydraulic fluid. A coaxial transmission line extends through the actuator, and includes an outer conductor formed by the actuator cylinder and a center conductor operatively coupled to the piston such that length of the coaxial transmission line is effectively directly determined by position of the piston within the cylinder. An rf generator is coupled by an antenna to the coaxial transmission line for launching rf energy therewithin, and valve control electronics is responsive to rf energy reflected by the coaxial transmission line for indicating position of the piston within the cylinder and generating electronic control signals to the valve.

Abstract: A first visual indicium (44) and a second visual indicium (50) are provided on a push rod (10) in an air operated diaphragm spring brake. The push rod (10) is mounted for reciprocal movement between an operative position and an inoperative position through an opening (26) in a service brake housing (16). The first indicium (44) comprises a discontinuity (45) in the surface of the push rod (10) having a leading edge (46) and grooves (48). The first indicium is positioned on the push rod such that the leading edge (46) will be exterior to the service chamber (12) only when the push rod is in the operative position and the brakes are substantially out of adjustment. The second visual indicium (50) comprises a second discontinuity formed of at least a leading edge (52) and a trailing edge (54). The second visual indicium (50) is positioned on the push rod whereby the trailing edge (54) will normally be exterior of the service chamber 12 adjacent the opening (26) when the push rod is in the inoperative position.

Abstract: A cavity such as a chamber (10) of a hydraulic cylinder (2) containing a movable piston (4) is equipped with transducers (12) for transmitting alternating pressure signals into a fluid in the chamber and for receiving signals from it. The fluid chamber acts as a resonant tank circuit for determining the frequency of an external electronic oscillator (24). The frequency of oscillation of the circuit indicates the depth of the cavity, i.e., the position of the piston in the cylinder. Multiple modes of oscillation are employed (34, 36) in the same chamber to provide high accuracy and resolution of ambiguities. In one embodiment chambers (10', 66) on both sides of the piston (4') of a double-acting cylinder (2') are measured, and the readings are combined (76) to reduce errors that would otherwise result from changes in temperature, pressure, viscosity and other parameters unrelated to the position of the piston.

Abstract: In accordance with the present invention, a diaphragm pump having a housing, a first chamber within said housing, a second chamber within said housing and a pair of diaphragm elements mounted in said housing between said first chamber and said second chamber, is provided with a failure sensing system for the diaphragm. The failure sensing system including a failure sensing device which is between the two parts of the diaphragm and an indicator circuit which includes the conductive liquid which is being pumped and an alarm. The two parts of the diaphragm element are clamped together proximate their peripheral edge such that a circumferentila fluid tight compression seal region is provided. The sensing device includes an electrically conductive lead which extends from the exterior of the housing, through the circumferential fluid tight seal region into the region peripherally inward of the seal region.

Abstract: A brake failure warning system for a dual hydraulic master cylinder for use with a motor vehicle. The warning system employs a pair of Hall Effect magnetic sensors which are positioned on the exterior of a plastic cylinder in association with the two pistons mounted within the bore of the cylinder. The pistons have ferrous frustoconical portions which coact with the respective sensors to generate position signals that vary as the pistons move in the bore past the respective sensors. The two position signals are fed to a logic board which compares the signals and generates an error or warning signal in the event that the difference between the two signals exceeds a predetermined amount indicative of failure of one of the two braking systems of the vehicle.

Abstract: A diaphragm for a diaphragm-actuated fluid-transfer control device, which comprises a flexible, substantially non-stretchable diaphragm body of a substantially circular outline surrounded and delimited by a beaded rim, the body having a substantially dish-like, bi-stable shape invertible from the first stable state, in which a first body surface is convex and a second body surface, concave, to the second stable state, in which the first body surface is rendered concave and the second body surface, convex. The device further comprises at least one substantially rigid, elongated arm fixedly embedded in the diaphragm to a depth exceeding the radial width of the beaded rim, the free end of which arm projects beyond the beaded rim. There is also described a diaphragm-actuated fluid transfer control device including the diaphragm.

Abstract: A method of assembling a motor vehicle in which a multicontact switch is provided on the input rod of the master cylinder of a prefilled master and slave cylinder hydraulic apparatus; the master cylinder is positioned in the engine compartment of a vehicle and the input rod, with the switch mounted thereon, is passed from the engine compartment through an aperture in the firewall of the vehicle to position the input rod and switch in the passenger compartment of the vehicle and position the master cylinder housing adjacent the fire wall; the master cylinder is secured to the fire wall; and the plug of a wiring harness including several electrical vehicle circuits is plugged into a multiple contact outlet socket on the switch so as to provide a plurality of electrical control systems for the vehicle respectively controlled by the contacts of the switch. For example, the switch contacts may control a cruise control disconnect circuit, an electronic fuel injection circuit, and an ignition interlock circuit.

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 hydraulic cylinder (1) with a piston (5) made completely or partially of electrically conductive material comprises at least one opening (19, 20) for the mounting of an electric position indicator (21, 22). The openings (19, 20) are closed in a liquid and pressure-proof manner towards the interior of the cylinder (1) by means of circular plate-shaped bodies (17, 18) glued to the inner surface of the cylinder (1). As the plate-shaped bodies (17, 18) are made of a ceramic material, preferably steatite, they may allow passage of the magnetic field transmitted from the electric position indicators (21, 22). The openings (19, 20) are adapted in the end covers (2, 3) of the cylinder (1) for the determination of the end positions of the piston (5). Furthermore the cylinder may be provided with piston-braking means in the form of seal rings (12, 13).

Abstract: A fluid cylinder assembly comprising a fluid cylinder having ports disposed at opposite ends thereof communicable with a source of fluid under pressure, a piston disposed in said cylinder having a first rod section extending through an end of said cylinder, extendable and retractable relative to said cylinder, the first piston rod section having an axial bore, a second piston rod section having a guide portion disposed in the axial bore of the first piston rod section and axially displaceable relative the first piston rod section, and means for detachably locking the first piston rod section to the second piston rod section.

Abstract: The electric and/or electrical sensor or detector device is intended to cooperate with a movable element surrounded by a shell, it comprises an annular clamping collar adapted to be clamped in position on a shell and connected to at least one connecting conductor, the collar carrying at least one mechanical and electrical removable member for connection to a removable detector element and the device is applied to a position detector to be quickly and removably secured onto a fluid cylinder body.

Abstract: A piston-cylinder assembly wherein in the cylinder housing there is provided a cylinder chamber extending in axial direction, in which cylinder chamber a piston is movably guided in axial direction. Both the piston and also the cylinder chamber have a cross section which is different from a circular shape. A permanent-magnet piece is arranged fixedly in the area of the outer circumference of the piston. A switch arranged in the area of the linear path of movement of the permanent-magnet piece is provided on the outside on the cylinder housing, which switch can be operated without contact by the magnetic field of the permanent-magnet piece.

Abstract: A rotary actuator for converting a linear reciprocatory movement of a piston into a rotary reciprocatory movement of an output shaft through a connecting member. The rotary actuator includes a cylinder case formed with a pedestal in a position in which the output shaft extends vertically out of the cylinder case. The pedestal is formed with a substantially square elevated portion, and a depressed portion defined by the elevated portion. A plurality of projections spaced apart from each other by a predetermined angle are formed integrally with the pedestal in the depressed portion to constitute dividing lines of a scale for indicating the angle of rotation of the output shaft by means of a pointer.

Abstract: The invention provides a piston and cylinder unit comprising a piston adapted to be displaced in the axial direction, a piston rod arranged coaxially and connected with the piston on at least one axial face thereof and which extends through an associated cylinder end cover in a sealing and sliding manner. The section of the piston rod outside the piston are provided with load attachment means. The piston rod is tubular and defines a continuous bore extending essentially from one end of such rod to the other end thereof in the axial direction. The bore is provided at least at its end sections with a female threaded section. The piston end of the piston rod is provided with a threaded part connected with the piston and in the opposite external end the male threaded section of a connecting part may be screwed with is adapted to be coupled with a load attachment means to be operated by said piston and cylinder unit.

Abstract: A pneumatic actuator includes a tubular body made of a rubber-like elastic material and a braided structure made of organic or inorganic high-tensile-strength fibers reinforcing an outside of the tubular body. Closure members sealingly close ends of the tubular body; at least one of the closure members has a fluid connecting passage. The tubular body deforms to expand its diameter when pressurized fluid is introduced through the connecting passage to cause contractive force in the longitudinal direction. Contraction-detecting strain gauges at one closure member provide signals corresponding to the contractive force of the actuator.

Abstract: Various forms of hydraulic cylinders having axial bores formed in their piston rods, and probes projecting axially from the closed end of the cylinder body with two spaced coils thereon are disclosed. The coils are connected into external circuitry which responds to change in inductance of either coil whereby to generate a reference signal upon the occurrence of preselected changing conditions of inductance of either coil caused by movement of that coil into or out of mutual induction with a shorted turn arrangement formed by or carried by the piston. The coils may be the drive coils of a displacement transducer arranged to indicate either end of the stroke of the piston. Alternatively either a supplementary shorted turn or an additional drive coil may be provided to generate an intermediate stroke reference signal. The reference signals may be used in operation of a system for effecting automatic continuous reciprocation of the piston.

Abstract: In order to obtain a reliable position determination in a hydraulic cylinder optionally exposed to hard frost, it is suggested to mount a magnetically sensitive component in the form of a Hall-effect transducer in a bore in the cylinder wall and placed between a permanent annular magnet (17) and a magnetically conducting sheet (14). In the middle of the bore a magnetically conducting post (16) is placed and towards the inner side of the cylinder the bore is sealed by a non-magnetic material (19) e.g. brass. The Hall-effect transducer (15) forms thus part of a closed magnetic circuit comprising the permanent magnet (17), the magnetically conducting post (16), the magnetically conducting disc (14) and the hydraulic cylinder wall surrounding the bore. When the piston in the hydraulic cylinder opposes the sensor, a second closed magnetically conducting circuit is formed comprising the permanent magnet, the magnetically conducting post, the piston, and the steel wall of the cylinder.

Abstract: A servocylinder (1, 3, 4) with an electric piston end position transmitter is suggested. It is constructed as a piezoelectric converter (17 and 18). By means of applying voltage to the piezoelectric converter (17 and 18) the latter becomes a regulating element which overcomes a force holding the piston (2) in its stroke end position and removes the piston (2) from its position in which the feed line (7 and 8) of the pressure medium is sealed.

Abstract: A fluid actuator characterized by a linear variable differential transformer (LVDT) feedback mechanism driven off the actuator screw shaft for indicating actuator position. A protective clutch mechanism prevents possible damage to the LVDT or actuator in the event that the actuator stroke exceeds the design stroke of the LVDT.

Abstract: The invention relates to a linear motor with a cylinder (5) containing a piston linked to a piston rod (8) projecting from either of the end faces of the cylinder (5). To secure the piston rod against torsion and rotation, a guide comprising at least two guide ribs (22, 22') arranged on the circumference of the cylinder (5) is provided, these ribs being arranged at a distance from each other and extending in the axial direction of the cylinder (5). A slide (19) seated on the outside of the cylinder (5) and guided on the guide ribs (22, 22') while at least partially encompassing them is fixed to the piston rod (8).

Abstract: A method for easy and accurate positioning of a magnetic sensor in a fluid-power cylinder facing a magnetic scale on the lateral surface of a piston rod, wherein the sensor is supported by a hole in the cylinder, a piece of friction-resistant, non-magnetic material attached to the sensor projects from its detection surface towards the piston rod, and the non-magnetic material is made to keep in touch with the lateral surface of the moving piston rod by a pressure-applying bias. The friction-resistant, non-magnetic material is either fitted to the magnetic detection surface, or is formed into a tubular shape and fitted to the outer circumference of the sensor.

Abstract: A measuring system is disclosed which is integrated into a feed arrangement in such a way that the structural size of the feed arrangement is not increased significantly. In the disclosed embodiments, the feed arrangement includes a compressed air cylinder which includes a hollow profile and a piston movable within a cylinder defined by the profile. In one embodiment, a measuring scale is positioned within a groove formed within the hollow profile and this measuring scale defines a magnetic measuring graduation which is scanned by a scanning unit accommodated in the piston of the air cylinder.

Abstract: A coil assembly including primary coils disposed at predetermined locations axially spaced from one another and secondary coils provided in association with these primary coils is fixed at one end of a fluid powered cyliner. A piston rod is slidably disposed through a space in the primary and secondary coils. Rings made of magnetic substance are provided on the piston rod with a predetermined axial interval therebetween. Each of the primary coils is excited with one of reference AC signals which are out of phase with one another and an output signal which is electrically phase-shifted in accordance with the position of the piston rod is obtained as a sum of output signals from the secondary coils. Piston rod position data is obtained by measuring the amount of the phase-shifting and is utilized for positioning control of the cylinder.

Abstract: A sensing means is provided to indicate an operating condition of a spring brake cylinder assembly in which such operating condition may be one of a brake applied and a brake release position. The sensing means engages a clutch control mechanism which includes means to engage the sensing means at different locations to make a determination of such operating condition.

Abstract: A pneumatic drive mechanism for use with positioning apparatus or the like, having a drive housing, a drive element such as diaphragm disk, piston or the like, movably seated therein and rigidly connected to a drive rod or similar device. The drive element is responsive to compressed air on one side thereof and to forces from at least one spring operating in opposed action to the compressed air. The spring is arranged within the drive housing. The drive mechanism also has a signal processing device such as a position controller, position encoder, limit signal generator, solenoid valve or i/p converter or similar devices. The signal processing device or devices are integrated within the drive housing in an accomodation space which is free of the spring or springs, of the drive rod and of the drive element.

Abstract: In a piston position detector for a fluid pressure cylinder operating by fluid pressure such as air pressure or oil pressure, a permanent magnet is mounted on a piston sliding in a non-magnetic cylinder, and a magnetic detection element to respond to the magnetic field formed by the permenent magnet and to generate detection signals is mounted to any position of the cylinder. A magnetic induction piece in sheet form is interposed between the cylinder and the magnetic detection element, so that when the permanent magnet faces the front of the magnetic detection element, the magnetic induction piece is magnetically saturated by performing bypass induction of only a part of the magnetic flux of the permanent magnet to act on the magnetic detection element and most of the magnetic flux acts on the magnetic detection element.

Abstract: A hydraulic piston and cylinder arrangement retains the outer surface of a sleeve forming the piston in dry condition. The cylinder provides an outer wall and an inner stem with the sleeve sliding inwardly of the outer wall and outwardly of the stem. A head on the end of the stem cooperates with the inner surface of the sleeve. A bearing member on the end of the sleeve remote from the head cooperates with the outer surface of the stem. A first chamber is thus defined between the head and a closure cap on the sleeve to provide an expansion chamber. An annular chamber between the outer surface of the stem and the inner surface of the sleeve and closed by the bearing member provides a return chamber. Two fluid channels coaxially arranged within the stem provide the communication of fluid to the chambers.

Abstract: In accordance with the present invention, a dipharagm pump having a housing, a first chamber within the housing, a second chamber within the housing and a pair of diaphragm elements mounted in the housing between said first chamber and the second chamber, is provided with a failure sensing system for the diaphragm. The failure sensing system including a failure sensing device which is between the two parts of the diaphragm and an indicator circuit which includes the conductive liquid which is being pumped and an alarm. The two parts of the diaphragm element are clamped together proximate their peripheral edge such that a circumferential fluid tight compression seal region is provided. The sensing device include an electrically conductive lead which extends from the exterior of the housing, through the circumferential fluid tight seal region into the region peripherally inward of the seal region.

Abstract: A back pressure sensor for a positive displacement pump comprises at least one flexible beam having a pivot end and a drive connector end, and a pump actuator mounted between the pivot end and the drive connector end. The pump actuator connects with a positive displacement member of a pump. At least one sensor beam is connected to the flexible beam at a mounting position between the distal end and vibration damping end thereof. A first capacitor plate is mounted on the flexible beam at a position adjacent to the pivot end thereof, and a second capacitor plate is mounted adjacent the distal end of the sensor beam in a position facing the first capacitor plate at a distance which permits a capacitance coupling between the capacitor plates. A vibration damping mass is secured to the vibration damping end of the sensor beam for damping drive motion vibrations in the sensor beam.

Abstract: A fluid controlled actuating device is described which facilitates rapid and controllable actuation of devices adapted for momentary actuation.

Abstract: A spring brake cylinder assembly having a spring-biased piston positioned therein. A pushrod is engaged with the piston through a clutch, which clutch includes both a clutch control device and a clutch operating mechanism that can manually release a brake application being applied by the assembly.

Abstract: Apparatus for monitoring the diaphragm integrity in a diaphragm pump. A single continuous circuit trace is supported on a pump diaphragm. An electrical circuit is connected to the continuous circuit trace for measuring both the continuity and a potential ground fault condition between the circuit trace and pumping liquid. The circuit trace is formed in a configuration which resists the effects of strain induced by continuous flexing of the diaphragm.

Abstract: A pneumatic-hydraulic booster for vehicle includes a master cylinder part; a pneumatic cylinder part combined with the master cylinder part which includes a power piston slidable fitted to a cylindrical casing and an output rod fixed to the power piston, extending to the master cylinder part; a partition wall body fitted to the cylindrical casing; and a relay valve part arranged at the opposite side of the partition wall body from the power piston in the cylindrical casing. The relay valve supplies compressed air into an air pressure chamber formed between the partition wall body and the power piston and discharges the compressed air from the air pressure chamber to the atmosphere. When compressed air is suppplied into the air pressure chamber through the relay valve part the power piston and the output rod are moved forwards to generate hydraulic pressure in the master cylinder. The hydraulic pressure is applied to a wheel cylinder for braking.

Abstract: A pneumatic-hydraulic booster for vehicles includes a master cylinder part; a pneumatic cylinder part combined with the master cylinder part including a power piston slidably fitted to a cylindrical casing and an output rod fixed to the power piston, extending to the master cylinder part; a partition wall body fitted to the cylindrical casing; and a relay valve part being arranged at the opposite side of the partition wall body to the power piston in the cylindrical casing. The relay valve supplies compressed air into an air pressure chamber formed between the partition wall body and the power piston and discharges the compressed air from the air pressure chamber to the atmosphere. When compressed air is supplied into the air pressure chamber through the relay valve part, the power piston and the output rod are moved forwards to generate hydraulic pressure in the master cylinder part. The hydraulic pressure is applied to a wheel cylinder.

Abstract: A shock absorber includes a piston slidably mounted in a fluid cylinder for decelerating the motion of an object acting on the shock absorber. A metering mechanism adjusts the rate at which fluid escapes from the cylinder upon displacement of the piston caused by impact of the object. A proximity sensor disposed in the end of the cylinder provides an indication of when the piston reaches a displacement position corresponding to a stroke length in which maximum energy is transferred from the object to the fluid. The proximity sensor includes an electrical probe extending through the end wall of the cylinder and possesses an electrical property whose magnitude varies in accordance with the distance between the piston and the probe.

Abstract: A modular transmitter has an outer housing with a wall forming an interior cavity in which a control module is inserted. The wall has one or more ports therein that are connected to pressure conduits. When the control module is fully seated, the ports align with internal passageways in the control module that lead to control components in the control module. The control module further has an electrical circuit supported on an end thereof that is toward the inner end of the cavity when the control module is inserted and the circuit has components that removably mate with further elements mounted on the end wall of the cavity. These connections may include electrical contacts, and also rotationally adjustable components that have set points and which are coupled to set point adjustment and control shafts that are accessible from the opposite side of the end wall from the cavity.

Abstract: An electrohydraulic servo system which includes an actuator having a cylinder and a piston variably positioned therewithin, a servo valve responsive to valve control signals for coupling the actuator to a source of hydraulic fluid, and control electronics responsive to piston position for generating the valve control signals. A variable frequency rf generator is coupled through associated directional couplers to a pair of antennas which are positioned within the actuator cylinder and physically spaced from each other in the direction of piston motion by an odd multiple of quarter-wavelengths at a nominal generator output frequency.

Abstract: A linear actuator (42) includes a housing (44), and a linearly displaceable piston (46) having a shaft (48) with a gradated position scale (60) and a gradated direction scale (62) disposed by ion implantation on a casing (50) of the shaft, in axial alignment (49) with the shaft stroke. Proximity sensors (64, 66) mounted in the housing sense movement in the position of the scales to provide sensed shaft position signals (68) and sense shaft direction signals (70).

Abstract: A fluid pressure operated device comprises a body adapted for moving an article and carrying magnets coupled to other magnets on a piston movable by fluid pressure in a cylinder. The body also carries spaced magnets and another piston carries spaced magnets. In a start position, one of said body magnets and one of said piston magnets are coupled. During normal operation the body and pistons move to another position in which the one body magnet operates a return sensor to return the device to start position. If an obstacle is encountered, the piston moves to release another sensor to reverse the device for a short stroke where a timer again reverses the fluid pressure to complete the stroke. Engagement with a second obstacle or a repeat engagement with the first obstacle returns the device to the start position and a warning alerts an operator to remove the obstruction.