Abstract: A position-sensing potentiometer arrangement for sensing the position of a movable piston and piston rod configuration within a linear actuator includes a first support member extending longitudinally within an open-ended recess formed in the rod and a sliding contact mounted thereon. A tubular support is mounted to a stationary closed end of the linear actuator and extends into the recess to surround a portion of the first support member and a center support member which is also mounted on the closed end of the a actuator. A longitudinally-extending resistance element and a parallel conductor element are mounted on and supported by the center support member. As the first support member moves through the tubular support, the sliding contacts couple the resistance element to the conductor element to provide a resistance value variable as a function of the position of the piston rod.

Abstract: An automatic depth control system is disclosed. The system includes a floating piston hydraulic cylinder in which the floating piston is adjusted as a stop for limiting the travel of the main piston in the cylinder. A depth sensing system is provided to sense the actual depth of a implement tool on which the cylinder is mounted to provide a depth signal indicative of the depth penetration of the tool. A circuit system is provided to receive the depth signal and to control a hydraulic valve system to move the stop piston within the cylinder to adjust the working position of the implement tool. The control system includes an instrument panel having a first display indicating the actual depth of the implement tool and a second display indicating the depth limit settings predetermined by the operator. Further means are provided to monitor the actual depth and compare it to the selected depth setting and thereby correct the position of the floating piston.

Abstract: There is disclosed herein an apparatus forming a part of an actuator for providing a constant visual display of the position of a valve. Such apparatus comprises an indicator shaft rotatably disposed in a bore which is oriented perpendicularly of and offset from an actuator stem, a rack means on the actuator stem, a pinion means on the indicator shaft, and an indicating means engraved on the end face of the indicator shaft and visible from the exterior of the actuator. The apparatus is sealingly enclosed and immersed in a fluid medium. Linear motion of the actuator stem generates angular motion of the indicator shaft, causing the indicating means to provide a visual display of valve position.

Abstract: Electrohydraulic regulating device, particularly for aircraft controls, iuding a regulating cylinder having a regulating piston therein capable of being loaded at either end thereof for the positioning of which necessary volumes of operating fluid can be supplied separately to either end space of the cylinder by means of magnetically-operable valves; a computer by which switch pulses of variable duration to be fed to the magnetically-operable valves are determined in dependence on the specified adjustment distance of the regulating piston; restrictors which determine the throughput of operating fluid through the magnetically-operable valves and sensors which after the switching of a respective magnetically-operable valve generate electrical signals which are fed back to the computer purely as a confirmation of operation. The restrictors are so arranged in an operating fluid circuit that, on movement of the piston, operating fluid flows through only one of the restrictors.

Abstract: An apparatus for the exact position feedback of a double-acting power piston in a hydraulic power cylinder subjected to extreme environmental conditions, especially high temperatures, comprising a double-acting detecting (measuring), or follower cylinder, having a volume corresponding to that of said power cylinder and including a detecting piston the position of which is sensed by an electrical detector, wherein a pair of working spaces of power and detecting cylinders are in fluid communication with each other via a connecting pipe, while the respective other working spaces are adapted to be connected to a (pressursized) fluid pump or a reservoir through a control valve.

Abstract: A positioning device capable of positioning a rod with a first piston fixed thereto into one of four positions selectively by means of a second piston disposed within a chamber A formed in a large-diameter cylinder portion and first, third and fourth pistons disposed within chambers B and C formed in a small-diameter cylinder portion. It is convenient to apply this positioning device to a select mechanism of a transmission or the like having four select positions.

Abstract: A pushbutton control system for raising and lowering the dump body of a dump vehicle. Included are "up", "hold" and "down/float" switches which are connected in circuit with "up", "down" and "float" solenoid valves. These valves on energization direct pressurized air into the "up", "down" and "float" chambers of two air cylinders included in an actuating mechanism for a hoist valve controlling the telescopic hoist cylinders of the vehicle. The dump body is raised upon depression of the "up" switch with the consequent opening of the "up" valve. The depression of the "down/float" switch, resulting in the opening of the "down" valve, causes the dump body to lower by the forced contraction of the hoist cylinders. Upon subsequent release of the "down/float" switch the "float" valve opens to allow the dump body to lower under its own weight. The depression of the "hold" switch, with the consequent closure of all the solenoid valves, makes it possible to hold the dump body against movement in any desired position.

Abstract: A fluid pressure actuator is disclosed of the piston and cylinder type, in which an internally mounted transducer is incorporated for providing an electrical output signal corresponding to the position of the piston in the cylinder. The transducer is disclosed as a rotary potentiometer having a disc or drum element provided with conductive plastic tracks and a rotary wiper element rotated in correspondence with the linear travel of the piston in the cylinder by a connected cam rod slidably mounted within the piston rod and caused to rotate in one embodiment by means of a cam bushing engaging the cam rod, and in other embodiments by three converging spring biased plungers carried in the piston engaging respective sides of a hexagonal shaped cam rod.

Abstract: A hydraulic ram for use as an advance ram in mining operations has a plurality of permanent magnets embedded in its piston rod. At least one sensor is associated with a guide bush fixed to the piston rod end of the cylinder of the ram. The or each sensor is accommodated within a respective pocket formed in the guide bush. The pocket(s) can be closed off by a detachable closure member.

Abstract: Disclosed is a method and apparatus for indicating the position of a hydraulically actuated device by measuring the volume of hydraulic fluid flow in and out of the hydraulic actuator together with separate measurement corrections to compensate for the hydraulic system elasticity and transient flows and for the mechanical clearance or slop in the linkage between the actuator and the device. In a preferred embodiment of the method, the compensation for hydraulic system elasticity and transient flows is preferably made by measuring the relaxation reverse flow when the actuator is depressurized and using this measurement to offset an equal amount of the measured forward flow when the actuator is repressurized in the same direction. Further, the compensation for mechanical clearance in the linkage between the actuator and the device is applied only when the actuator direction is reversed; the amount of such compensation is empirically determined and may increase with wear and tear on the linkage.

Abstract: A hydrostatic transmission including a pump and motor unit wherein the pump unit is displaceable effectuated by an operative member integral to the pump unit. A neutral start switch communicating with a carrying machine is mounted in the pump unit to contact the operative member in a manner causing the neutral start switch to become operative only when the operative member is assuming a neutral position.

Abstract: A position-sensing cylinder includes a hollow housing within which reciprocates a piston fixed to a hollow rod. A hollow fitting is threadably attached to one end of the housing. a hollow metallic insert is press fitted into the hollow fitting. An elongated potentiometer support is received by and welded to the insert and is reciprocally received by the hollow rod. The support includes curved edges which slidably engage the wiper wall of the hollow rod and includes a planar support surface upon which are mounted resistive and conductive potentiometer strips. A hollow wiper carrier is mounted for movement with the piston and rod so that the support reciprocates within the carrier and so that conductive wipers are maintained in contact with the potentiometer strips. The wiper carrier cooperates with the rod and the support to substantially prevent fluid flow in the vicinity of the wipers.

Abstract: A work-clamp pallet of the exchangeable type for facilitating changing of works and intended for use with a machine tool of either the vertical or horizontal type with its base block provided with a plurality of hydraulic clamping devices and also with a special shut-off valve for shutting down its oil path. It is so arranged that its oil path may be shut down after supplying the hydraulic clamping devices with a set level of hydraulic pressure. This hydraulic pressure is maintained for a long time without any supplementary feeding of hydraulic pressure for the clamping devices to be kept in the clamping condition. When this work-clamp pallet is used, it is possible to change workpieces on the work-clamp pallet at a work-changing station outside the work table of the machine tool. The work-clamp pallet with workpieces clamped in position can then be transferred onto the machine tool to carry out the machining operations.

Abstract: A chuck actuator has a cylinder extending along a main axis and a piston axially displaceable in the cylinder, forming therein two compartments, and having an axially backwardly extending stem also centered on the axis and formed with two respective intake passages each having one end opening into the respective compartment and another end opening at a respective location on the stem. A connector rotatable about the axis on the stem is provided with respective fittings communicating with the locations. First and second axially spaced bearings prevent the connector from moving axially on the stem. Fluid is fed under pressure alternately to the fittings to pressurize and depressurize the respective compartments and thereby axially displace the piston in the cylinder. Normally the cylinder is connected to a chuck body and the piston to a chuck-actuating member for fluid actuation of the member.

Abstract: A pneumatic throttle control configuration provides synchronized start-up and independent shut-off of multiple pneumatic tools. Each tool includes a throttle control assembly having a manually operable throttle valve which selectively admits air to the vane motor of the tool and a spring-biased piston operably coupled to the throttle valve which maintains it in an open position in response to air pressure in a control line which interconnects the tools. The vane motor includes a governor controlled valve which opens at a predetermined motor speed and provides air to the control line and the pistons of each tool of the multiple tool arrangement, thereby opening every throttle valve. Each pneumatic tool may then operate and stall independently. When the last tool stalls, the control air flow to all tools is terminated and the throttle valves close.

Abstract: The invention relates to an apparatus for the exact position feedback of a double-acting power piston in a hydraulic power cylinder subjected to extreme environmental conditions, especially high temperatures, comprising a likewise double-acting detecting (measuring) or follower cylinder having a volume equivalent to that of said power cylinder and including a detecting piston the position of which can be sensed by electric means, wherein a pair of working spaces of power and detecting cylinders are in fluid communication with each other via a connecting pipe, while the respective other working spaces are adapted to be connected to a (pressurized) fluid pump or a reservoir through a control valve.

Abstract: The operator of a lift truck or other load supporting vehicle (11) having a tiltable mast (12, 12a) is alerted as the mast (12, 12a) tilts beyond a predetermined orientation by a temporarily slowing of the rate of tilting movement. Return motion of the mast (12, 12a) may be unimpeded. The operator is reliably made aware when the mast (12, 12a) reaches a predetermined limit but may continue the tilting motion when that is necessary for such purposes as traveling the vehicle (11) under overhead obstructions. In systems where the mast (12, 12a) is tilted by fluid motors (20, 20a), the automatic tilt speed reduction may be realized with a valve (33, 33a) which temporarily introduces a one way flow restriction (49) into the fluid flow path (28, 28a) between the motors (20, 20a) and pressurized fluid source (27, 27a), the valve (33, 33a) being actuated by inclination sensing mechanism (23, 23a).

Abstract: In this fluid powered positioning system, a sliding assembly includes a slide plate that moves linearly with respect to a frame. A plurality of "working" linear cylinder actuators are mounted to the frame. Each includes a piston and a rod which extends through an opening in the slide plate and terminates at a stop flange. A set of adjustable stop members are mounted to the frame and each is positioned to limit the travel of a respective actuator rod. Appropriate control means applies to a selectable one of the actuators a pressurized fluid, that causes the piston and rod to be moved in a first direction until it is stopped by the associated stop member. In this movement, the stop flange can pull the slide plate to the new location. A "balance" linear actuator cylinder includes a ram that exerts a continuous force in the opposite direction against the slide plate. This "balance" actuator damps and effectively prevents overshoot of the slide plate as it is positioned to each new location.

Abstract: A hydraulic adjustment apparatus as is for instance used to adjust a roller of a rolling mill has a cylinder forming a first cylinder chamber and having a first cylinder surface directed backwardly in a predetermined direction in the first chamber. A first piston is displaceable forwardly and backwardly in the direction in the first chamber relative to the cylinder and has in this chamber a forwardly directed first piston face of a predetermined first piston area. The first piston is formed with at least one second chamber receiving a forwardly and backwardly displaceable second piston having a forwardly directed end engageable with the first chamber surface. This second piston in turn has a second piston face of a predetermined second piston area substantially smaller than the first piston area and directed backwardly in the second chamber.

Abstract: A remotely controllable adjustable-stroke fluid cylinder system is described in various embodiments. The system includes a floating stop piston (48) and a main piston (24,224) which is controlled by a valving system (70) and which has visual indicator means having a graduated scale (69,169).

Abstract: Method and apparatus for hydraulically controlling subsea well equipment, such as valve operators, connectors, and other hydraulically actuated devices, with a significantly smaller number of hydraulic pressure source lines from the surface to the subsea location of said well equipment and for providing return signals to indicate the state of operation of said well equipment using the same hydraulic lines. The apparatus includes a plurality of hydraulic AND-gate logic elements and a plurality of hydraulic valves mounted near the well equipment. A pair of hydraulic lines between the hydraulic valves and a surface vessel or other surface facility provides control for the various valve operators, connectors and other hydraulically actuated devices, while a third hydraulic line provides power to operate the various devices. The same pair of control lines can be used to transmit signal information from the various devices on the sea floor to the surface vessel to indicate the operating status of these devices.

Abstract: A power assist device for a control system to amplify force to assist in movement of control apparatus. Device has signal input device and directional valve which are both responsive to a control signal, and a fluid power cylinder assembly which is connectable to an input of the control apparatus to apply an amplified control signal thereto. The directional valve means controls fluid flow between first and second chambers on opposite sides of a piston of the power cylinder assembly so as to determine the direction of movement of the assembly in response to valve position. The signal input device has an indicator to indicate a particular control setting or datum for a control signal which can be felt by operator, which contrasts with prior art power assist device where feel of a particular setting location is lost.

Abstract: A fluid pressure actuator is disclosed of the piston and cylinder type, in which an internally mounted transducer is incorporated for providing an electrical output signal corresponding to the position of the piston in the cylinder. The transducer is disclosed as a rotary potentiometer having a disc or drum element provided with conductive plastic tracks and a rotary wiper element rotated in correspondence with the linear travel of the piston in the cylinder by a connected cam rod slidably mounted within the piston rod and caused to rotate in one embodiment by means of a cam bushing engaging the cam rod, and in other embodiments by three converging spring biased plungers carried in the piston engaging respective sides of a hexagonal shaped cam rod.

Abstract: A vacuum operable differential servo-motor adapted for use on motor vehicles to operate, for example, an anti-skid brake control system, a brake booster and the like, including a housing, a power piston movable therein and dividing the interior of the housing into two chambers one on each side of the power piston, a conduit member fluidly connecting one of the chambers to an engine intake manifold, a solenoid valve for controlling a pressure differential between the chambers in response to an input signal and a failure sensing switch member having a casing outside of the housing and a plunger operatively connected to the power piston and a diaphragm seal member with its peripheral bead clamped between the casing and the housing with a central portion being sealed to the plunger.

Abstract: A multiple-section, multiple-position switching valve and a hydraulic powered valve actuator for controlling subsea well equipment, such as valve operators, connectors and other hydraulically actuated devices, with only two hydraulic pressure source lines from the surface to the subsea location of such well equipment. The switching valve includes a plurality of readily removable and replaceable valve sections, each having a unique combination of valve portings, which sections can be connected end to end to obtain a switching system having a predetermined matrix of switching control. The valve actuator moves the switching valve in a first direction through a sequence of distinct positions, and then reverses and moves the switching valve in the opposite direction through the same distinct positions.

Abstract: Disclosed is a method of and apparatus to facilitate the operation of two servoactuators with a two/one (2/1) fail operational capability. In preferred embodiments, four signal processing channels are provided, two of which are active and directly control hydraulic servovalves which in turn controls the rate of operation of the servoactuators. Two other modeling channels produce an electrical output similar to the output expected from the servoactuator when supplied with the input to the active channel. The two actual rate indicative outputs and the two modeled rate indicative outputs are compared and deviations in one channel from the other three cause that channel to be declared a "failed" channel. Through a logical switching system, if an active channel has failed, the output of its associated model channel is connected to the servoactuator to continue operation of that actuator.

Abstract: A servo valve for controlling an actuator comprising a housing, a first slide movable in the housing for controlling the flow of fluid to and from the actuator and a second slide mounted for movement in the housing. Both of the slides are movable in the housing during normal operation of the servo valve. Each of the slides is movable in the housing when the other of the slides jams. A jam sensor responds to either of the slides jamming for providing a corrective function for the servo valve.

Abstract: An actuator for a power chuck has a hollow actuator housing having a rearwardly extending housing tube that is centered on an axis and that has a closed rear end. This tube is formed with a pair of axially spaced and radially inwardly open grooves both having axial lengths equal at least to a predetermined axial distance, and the tube is further formed at these grooves with respective radially throughgoing apertures. A piston subdivides the interior of the housing into a pair of compartments and has a stem extending axially rearwardly in the tube. This piston is axially displaceable in the housing through an axial stroke at most as long as the distance corresponding to the axial lengths of the grooves. The piston is formed with a pair of throughgoing passages each having one end opening at the stem into a respective one of the grooves and another end opening into a respective one of the compartments.

Abstract: A protective fluid system having a fluid pump and a fluid control valve and a fluid protective valve and a fluid motor all connected together. The protective valve is responsive to a loss of pressure in a fluid line, such as when the line breaks, and the valve then closes to avoid the reaction of the fluid motor which may be a powered cylinder assembly under the influence of a load, and thus the load does not fall or otherwise move when the pressure is lost in the cylinder assembly.

Abstract: An electro-hydraulic actuator is disclosed, particularly for use with control surfaces in aircraft. The actuator includes a regulating piston and cylinders an rapidly-operable switching valves for the positioning of the piston in the cylinder that are operated by the supplying of discrete volumes of operating fluid thereto. Switching pulses are applied to the valves by a computer, and a sensor that is responsive to each activation of the switching valves applies an answering pulse to the computer wherein a valve breakdown can immediately be recognized. The sensor may be responsive to changes in pressure and/or flow between the valves and the cylinder located at the valve body.

Abstract: A method for testing steam turbine admission valve assemblies for determining the operational force margins present therein which are used to diagnose the likelihood of valve inoperativeness due to the build-up of frictional forces in the valve assembly is disclosed.

Abstract: The present invention relates to a rotary hydraulic jack device. This jack device comprises a rotary hydraulic joint whose rotary part is formed by a tubular extension of a first end cover of the jack cylinder. Two check valves and the rotary joint are respectively inserted in two main pipes which alternately connect the two compartments of the jack cylinder to a source of pressurized hydraulic fluid and to a tank at atmospheric pressure. Each check valve is controlled by an auxiliary pipe connected to one of the main pipes upstream of the other check valve. The two check valves are respectively located in tight chambers arranged in the first end cover of the jack cylinder. This jack device may be used to control the part of clamping chuck of a machine tool.

Abstract: A relief valve assembly particularly in combination with yieldable pit posts is provided having an elongate housing, a first load chamber at one end of said housing, an inlet aperture into said housing, a non-return valve in said inlet aperture for admitting fluid non-returnably into said load chamber, a first valve seat in said housing communicating with said load chamber, a spring loaded relief valve movable lengthwise of the housing and normally engaging said seat to close the load chamber, a second valve seat in said housing spaced lengthwise from said first valve seat and relief valve and forming therebetween a balancing load chamber, a spring loaded pilot relief valve movable lengthwise of the housing and normally engaging said second seat to close the same, and a regulated orifice means in said relief valve connecting the first load chamber and the balancing load chamber whereby said balancing load chamber is normally pressurized to the pressure of the load chamber.

Abstract: An electromagnetic motor is provided with a samarium cobalt permanent magnet comprising a plurality of radially abutting segments. A combination of linear and non-linear springs with a force gradient larger than the magnetic force gradient facilitate motor operation in proportion to currents in electrical coils positioned on each side of the permanent magnet. Servoamplifiers independently control the current in each electrical coil in response to an input command signal, a motor position feedback signal and an actuator position feedback signal. A failure detection circuit detects coil failure by comparing current in each coil on one side of the magnet with the current in a corresponding coil on the opposite side of the permanent magnet. The circuit produces output signals to disconnect a defective coil and initiate an alarm. The circuit also detects power supply and motor position transducer failures by comparing their respective output voltage signals against predetermined reference voltages.

Abstract: A failure detection apparatus useful with a hydraulic system for maintaining fluid pressure signals present in the system to detect predetermined disparity therebetween. The apparatus includes a movable sleeve mounted within a housing and defining a central bore as well as transverse fluid flow passageways therethrough. A piston is mounted within the bore in the sleeve and normally blocks the fluid flow passageways defined within the sleeve. Fluid pressure signals to be monitored for detection of disparity therbetween are applied to opposite ends of the movable sleeve. Upon movement of the sleeve, fluid under pressure is applied through the passageways and through bores provided in the pistons thereby to cause movement of the piston to apply the fluid under pressure to a shut-off valve and a failure indicator mechanism. The piston latches in a limit position to retain the detection device and the shut-off valve in the actuated position.

Abstract: A method of temporarily maintaining the position of a hydraulically, pneumatically or electrically driven drive apparatus by sensing the movement of the drive apparatus and then supporting the drive apparatus by the components to be controlled.

Abstract: The specification discloses an automatic programmable valve sequencer employing a rotatable cam cylinder operating adjacent cam valves by means of cam segments mounted thereon to directly operate air cylinders or other air-operated tools.While the cam cylinder is manually advanced between steps where such cylinders or other tools are to be actuated, if a particular program doesn't utilize all the steps available, by virtue of one cam cylinder in combination with several control valves being able to automatically advance the cam cylinder when programmed to do so, the valve programmer will advance past vacant steps to the start of the next programmed cycle immediately on completion of the previous one.

Abstract: Plural servo actuators are coupled to provide a redundant system for operating a common output device. Each servo actuator has plural servo valves each having one active output that causes controlled opposite operation of the output device and one passive output. A fault detector coupled to each servo actuator compares the sum of the passive output pressures with the pressures of two other fluid signals, in one case the supply and return fluid signals and in another case the two active output signals of the servo valves, to detect the condition thereof. A convenient checkout system and a fluid by-pass mechanism also are provided in the fault detector.

Abstract: Primary switches in bus cab, for instance, activate contacts in secondary switch group in rear transmission compartment to energize solenoids selectively pressurizing opposed cylinders to drive transmission shift operation to various positions.

Abstract: Apparatus for remotely operating self-advancing supports or the like at a long-walled pit face of a coal mine comprises a receiver attached to every group of the supports which are arranged in front of and along the long-walled pit face, each of the receivers having a specific frequency, hydraulic cylinders attached to the support for causing the support to be operated, electromagnetic valves connected to the receiver to control the hydraulic cylinders, and a portable operating means including keys for specifying the groups of the supports, key switches for specifying the supports to be operated, and a transmitting circuit having operating switches, wherein operating signals are applied from the operating means via the radio system to the receivers.

Abstract: A vacuum augmentation device for use with a vehicle braking system and of the type having a body, a diaphragm-piston mechanism providing a pair of fluid chambers in the body, valving for isolating or communicating the chambers, a push rod actuated plunger assembly for operating the valving, an output rod shiftably mounted in the body and carrying a fulcrum plate, and a number of reaction levers for effecting a lever type coupling between the diaphragm-piston mechanism, the shiftable plunger assembly and the fulcrum plate on the output rod is provided with improved structure for coupling the reaction levers with the diaphragm-piston mechanism, which structure employs a mounting plate member engaged with the mechanism and carrying on the opposite side thereof an elongate fulcrum pin for each reaction lever which is longitudinally engageable with the latter in line contacting relationship to provide a radially fixed fulcrum for each of the reaction levers.

Abstract: In a diaphragm type gas meter, one crank plate pivotally mounting a pair of diaphragm movement transmission levers and the other crank plate pivotally mounting a pair of valve actuating levers overlap each other rockably around the central axis of a crank shaft. The relative angular position of the two plates is controlled e.g. by an eccentric cam. On a diaphragm control wall member for restricting the stroke end of the reciprocation of each measuring diaphragm of said gas meter are formed two inclined diaphragm control surfaces with different angles of inclination. Further, on a lower casing of the gas meter is integrally die-cast a partition wall with triangular section flush with the top surface of the lower casing and defining a discharge-side valve chamber and a discharge passage.

Abstract: A hydraulic system for opening and closing hopper barge comprises at least one and preferably two fluid pressure cylinders which are adapted to be positioned on one of the barge parts and a piston which is slidable in the cylinder which is adapted to be connected through its piston rod to the other barge part. The cylinder is connected by a first conduit at its piston rod end and by a second conduit at the opposite end, and a pump and a return line are connected to the respective first and second conduits. A pilot valve is located in the first and second conduits and includes three separate positions. In one position a pump discharge is connected to one end of the cylinder and the other end is connected to the return, and in another position, the opposite is true. In a third position, the first conduit is connected to a check valve and the pump discharge is connected to a return line in order to short circuit the pump.

Abstract: System and equipment for operating self-advancing supports comprising electromagnetic valves being provided in each of the self-advancing supports which support the roof of a long-walled pit face in a coal mine and rendering operative the hydraulic cylinders for causing the roof plates of the supports to be lowered and lifted and for causing the supports to move toward the pit face, and operating devices being connected to the electromagnetic valves through a cable wherein the electromagnetic valves can be opened and closed through the operating devices from a desired position remote from the supports so as to operate the supports.

Abstract: An electronic system to monitor the performance of a pneumatic impact forming tool is disclosed. A signal is generated in real time representing the actuating pressure of the pneumatic tool. Electronic functions operate on the real time pressure signal over a predetermined time portion of each work cycle of the pneumatic tool to generate signals representative of the energy and friction developed in the pneumatic tool during the predetermined time portions of one or more work cycles. The electronic system additionally provides a count of the number of work cycles generated by the pneumatic tool during operation thereof.

Abstract: A stop mechanism for a bending press, plate shear or the like machine, provided with a work-table and with a work-piece stop which is horizontally adjustable along the work table thereby defining the position of the work-piece relative to the machinery, the work-piece stop being coupled with a position control-unit which is provided with an indicator of the momentary position of the work-piece stop and can be programmed with the desired position, the stop being displaceable by means of a hydraulic piston-cylinder unit and a pump drive means controlled by the position control-unit.

Abstract: A fluid supply distributor communicates fluid from a stationary fluid source to a rotating hydraulic motor. The distributor includes a housing with main ports for connection to high and low pressure at the source. A shaft rotating in the housing is attached to the motor and includes motor ports for connection to the rotating motor. A sleeve in the housing surrounds the shaft, and the sleeve and shaft define interfacing sealing surfaces. The housing, the sleeve, and the shaft include passages for communicating fluid between the main ports and the motor ports. The sleeve is normally retained in a stationary position, but is released to rotate within the housing should the shaft seize within the housing. The passages include spaced supply grooves at the sealing surfaces connected to the main ports and thus maintained at different pressures.

Abstract: An electro hydraulic system for controlling a hydraulic function includes a pump and a reservoir connected to the function through a manually operable, electro-hydraulic control valve. The valve is positionable to either side of a neutral ports blocked position and may be held to one side by the engaging of a spring loaded detent. The detent is disengaged by an electrical signal produced by a comparator when a preset, operator-controlled, limiting signal is equalled by a feed back sensor signal proportional to the output of the function. The system will allow initial activation of the valve to provide continuous operation of the function until the limiting input is reached at which time the function will be stopped. The system further provides manual override of the electrical control system to permit operation of the valve when the feedback signal is greater than the limiting input signal.

Abstract: Apparatus and method for indicating whether friction forces within a position modulating valve are approaching a predetermined friction value. The invention includes pressure detectors which monitor the pressure forces required by the valve actuator to move the valve plug predetermined distances toward open and seated positions. Means are provided which generate signal proportional to the difference between opening and seating actuating pressures and which is functionally related to the friction force within the valve. Means for comparing the generated signal to a predetermined reference signal, and for indicating if the generated signal exceeds the reference, are also provided.

Abstract: A tool including a fastener rotating output member and mechanism for indicating if a fastener rotated by said output member has been tightened to a prescribed torque and/or for providing an indication of the length of time for which the fastener was tightened.