Abstract: A control unit for pneumatic actuation of a cylinder, in particular an active creel of a textile-processing machine or a cabling machine, having a compressed air inlet for connecting a compressed air supply, a working air outlet for operating the cylinder, which acts at least on one side, a valve unit arranged between the compressed air inlet and the working air outlet, and an operating element for opening the valve unit to trigger a lifting movement of the cylinder.

Abstract: The invention relates to a press for extruding metal material. The press comprises a hydraulic oil circuit for controlling one or more extrusion pistons movable within corresponding cylinders. Such a circuit comprises a fixed displacement, circulation pump operated by an electric motor with variable rotation speed. The hydraulic circuit comprises a main line and a branch line, along which a shutoff element is arranged. The hydraulic circuit comprises a hydraulic control unit comprising a pilot valve arranged along a pilot line provided with a first segment communicating with the main line and a second discharging segment. Said hydraulic unit is provided to move the shutoff element between an opening position and a closing position of the branch line according to the difference between the oil pressure upstream of the shutoff element and that in the first segment of said pilot line.

Abstract: A lifting column includes a first column element and at least one second column element, the at least one second column element being movable relative to the first column element, and at least one damping unit. The damping unit is deformable by a force that acts on an upper side of the lifting column in at least one operating configuration of the lifting column such that the force is at least partly transmitted through the damping unit to a drive of the lifting column.

Abstract: The present invention concerns an air motor comprising a piston and a housing, the piston being received in the housing and dividing the housing into two primary chambers of variable volume. Said motor comprises a first direct supply valve for supplying a first primary chamber of the two primary chambers and a second direct supply valve for supplying the other primary chamber, said two valves each being movable relative to at least one respective seat. The first valve and the second valve are mounted on a same stem movable relative to the housing in a direction parallel to the direction of movement of the piston, and the stem is configured to be moved between a first position and a second position by moving means activated by the piston.

Abstract: An electrohydraulic control valve comprising a valve element that is displaceable in a first direction by a pressure in a first pressure chamber and in a second direction by a pressure in a second pressure chamber. The first pressure chamber is connectable to a high pressure supply and a low pressure supply. The second pressure chamber is connectable to the high pressure supply and the low pressure supply. A first magnetic valve is connected to the first pressure chamber and a second magnetic valve is connected to the second pressure chamber. A third magnetic valve is connected to the high pressure supply and to the first magnetic valve and to the second magnetic valve. It is intended to provide an electrohydraulic control valve that is both reliable and less complex than previous valve arrangements. To this end the first magnetic valve and the second magnetic valve are three-way valves.

Abstract: A method is provided for testing the tightness of an electric machine stator core includes: introducing a test instrument that is connected to a movable support into an air gap between a stator core and a rotor, locally placing the test instrument and locally testing defined zones of the generator stator core. A device for carrying out the method is also provided.

Abstract: A fluid working machine has at least one working chamber of cyclically varying volume and low and high pressure valves to regulate the flow of working fluid into and out of the working chamber, from low and high pressure manifolds. The low and high pressure valves are actuated by electronically controlled valve actuation means which, when actuated, applies forces to the low and high pressure valve members to open and/or close the respective valves. The low and high pressure valve members are independently moveable and, although the low pressure valve member typically begins to move quickly in response to a shared valve control signal, the high pressure valve member typically moves only after a change in the pressure within the working chamber.

Abstract: A full fluid-linked steering system, especially for use in on-highway steering, in which the system includes a fluid controller (21) including a fluid meter (65) operable to provide follow-up movement to controller valving (87,89), in response to the flow of fluid through the meter. The controller (21) includes a centering or biasing spring assembly (75) which provides sufficient torque that, upon rotation of the steering wheel (W), fluid is communicated to the steering actuator (19) without relative displacement of the valving, thus providing driver with the desired road feel. The system includes an EHC valve assembly (23) which controls flow to or from the actuator (19) in response to appropriate input signals (113,115) to maintain steered wheel to steering wheel registry.

Abstract: The invention relates to a system for powering the driving actuator of an aircraft undercarriage, the system including a hydraulic generator capable of delivering fluid under pressure to one or the other of two chambers of the driving actuator. According to the invention, the power supply system includes a safety device enabling any overloading of the actuator rod under the effect of pressure peaks to be avoided: said device comprises two pressure relief valves, the first valve limiting the pressure delivered to the annular chamber and being under the control of the pressure in the full-section chamber, and the second pressure relief valve being of the differential type and continuously controlling the pressure difference between the two chambers of the actuator. The invention is applicable to providing very safe power supply systems for aircraft undercarriages.

Abstract: Apparatus for controlling fluid communication with a fluid pressure system includes parallel flow paths connected to the system. A first flow path includes first valve apparatus for selectively closing the flow path. The second flow path includes relief valve apparatus responsive to fluid pressure in the second flow path to move from a closed configuration to an open configuration. Switching apparatus, including sensors for detecting the condition of the system, operate to close the first valve apparatus in response to pre-determined threshold values of such condition. Fluid communication from the system may thereafter occur along the second flow path at the relief valve apparatus opens in response to pressure buildup in the flow path. A third flow path, parallel to the first two flow paths, may be provided with throttling apparatus for controlled communication of fluid along such third flow path.

Abstract: The invention relates to piston and cylinder unit with a regulating valve for controlling the speed of the piston. The regulating valve has an open position in which it allows free passage of a fluid to the piston and a choking position in which it reduces the rate of such flow for influencing the speed of the piston. Furthermore there is at least one sensor responding to a given position of the piston and designed to change over the setting of the regulating valve. The sensor is an inductive, electrical or magnetic contactless sensor. The regulating valve has a setting unit electrically operated by the regulating valve so that the regulating valve is switched between its open and choked positions.

Abstract: An actuator system is disclosed which modulates a linear output shaft associated with a working control valve or the like in response to a control signal input. The system includes a feedback control link, a pneumatic positioner, a pneumatically controlled hydraulic valving system and a hydraulic cylinder and piston assembly controlled by the hydraulic valving system. The hydraulic valving system includes a three-position, four-way valve actuated by pneumatic binary output signals from a signal conditioner which is in turn controlled by the positioner. Hydraulic flow to the three-position, four-way valve may also be controlled from the signal conditioner in response to positioner output for most effective actuation of the hydraulic cylinder and piston assembly. Failure modes are also disclosed with the present system. The resulting system exhibits extremely rapid response times and high accuracy with dynamic stability.

Abstract: An apparatus for controlling a hydraulic turbine is disclosed comprising a hydraulic circuit to control the positioning of turbine runner blades and a hydraulic circuit to control the positioning of turbine wicket gates. The runner blade hydraulic circuit comprises a solenoid valve for normal operation of the blades and a slow rate servovalve for moving the blades when the actual blade position differs from a desired position by less than a predetermined tolerance. The wicket gate circuit comprises a solenoid valve for normal control of the gates. A diverter directs flow from the solenoid valve to a flow rate control valve when the difference between the actual and desired position of the gates is less than a second predetermined tolerance.

Abstract: A control system for controlling the movement of the slide of a hydraulic press of the type having a main cylinder containing a piston mounting the slide. The control system comprises an electronic processor, a pressure transducer to measure the pressure of hydraulic fluid applied to the piston to move the slide downwardly, a position encoder coupled to the slide to determine the vertical position of the slide, and a hydraulic circuit to supply hydraulic fluid under pressure to the cylinder to move the piston and slide upwardly and downwardly. The hydraulic circuit comprises a plurality of cartridge valves having controls actuable by outputs from the processor.

Abstract: For supplying a compressible driving fluid, preferably air, under pressure from a source to a motor of the kind comprising a housing, in which a body is reciprocable between predetermined end positions while dividing the interior of the housing into two chambers alternatingly serving as fluid receiving chambers, a drive system composed of conventional valves and other circuit components is provided, which assures that the driving fluid is supplied to the pressure chamber at a reduced pressure during the finishing phase of each operating stroke of the motor. The source is presupposed to deliver the compressible fluid under a pressure substantially exceeding the fluid pressure required for driving the motor under its anticipated maximum load.

Abstract: The disclosure is directed to a hydraulic cylinder with an improved cushion device thereon to enhance the operational characteristics thereof. A cushion pin is affixed to the cylinder piston by a cap screw in such a manner that the cushion pin can float about the screw relative to the piston. Optional orifices in the cushion pin provide an additional fluid flow passage whereby the metering action between the pin and a fluid flow port to the cylinder is different for retraction and extension of the piston.

Abstract: A hydraulic system in which pressurized fluid fed from a hydraulic pump is distributed through a distributor valve, on one part to a hydraulic booster for a brake and on the other part to a power steering unit or other hydraulic device. The distributor valve has a spool valve slidably fitted in a casing, the spool being displaced according to a fluid pressure differential acting at opposite ends thereof to increase the discharge pressure of the hydraulic pump in response to an increase in the fluid pressure at a first outlet port of the casing leading to the hydraulic booster or in the fluid pressure at a second outlet port leading to the power steering unit. Upon application of brake, a fluid passage which drains the first outlet port through a power piston is closed by movement of an input piston which is associated with a brake pedal, thereby slidingly displacing a valve piston.

Abstract: A vacuum actuator for connection to a vacuum source, the actuator utilizing a diaphragm combination having three stable positions. An annular diaphragm, having its outer periphery fixed in a housing, has its inner periphery secured between two movable annular members, the diaphragm and the annular members forming a combination dividing the housing into upper and lower chambers. Two inlet ports individually supply a vacuum force or atmospheric pressure to the upper chamber, the first one of the ports including a projection extending toward a space formed by the movable members. A poppet valve normally closes an opening at the top of the space, the bottom of the space normally having access to the atmosphere. When vacuum is applied to the first port, the diaphragm combination is raised from a biased first position to the position where the poppet valve interrupts the vacuum through the projection, determining the second position.

Abstract: An absolute-control numerical hydraulic actuating device with display of the output position, comprising a hydraulic jack, a distributor formed with orifices and a selector connected to the orifices in order to make the required hydraulic connections for hydraulic locking in the desired output position.According to the invention, the orifices of the distributor can be selectively connected by the selector to the active chamber of the jack in order hydraulically to lock the output positions in accordance with numerical orders supplied to the selector, and additional intermediate locking positions are created by the provision of additional rows of orifices which can be selectively connected to the high-pressure source, to the low-pressure source, or to the active chamber of the jack through a further selector.

Abstract: A self-driven pneumatically operated ram borer for boring holes in the ground includes a casing containing a percussion piston and a control sleeve for controlling the supply of compressed air through a hose to cause the piston to reciprocate, is provided with a control tube which is rotatable to vary the porting of the borer to cause it to move either forwards or rearwards. The tube is rotated into either a forward position or a reverse position by means of a flexible shaft which extends from the casing within the hose. By enclosing the shaft within the hose, the shaft is protected and is not subject to friction against the wall of the hole bored by the borer or to jamming if the hole collapses. The borer can thus easily be controlled even when it has passed through a very long bore hole.

Abstract: An impact mechanism operated with gaseous fluid under pressure fed from a source of fluid having a casing with an inner cylindrical space. A piston is accommodated for reciprocation within the cylindrical space of the casing to divide the space into a work stroke chamber and an idle stroke chamber. The chambers are in communication with the source of gaseous fluid through a distribution means for reciprocation of the piston under the action of fluid. A valve is provided over the inlet port of at least one chamber to admit gaseous fluid under pressure thereto. The valve comprises biasing means in the form of a helical compression spring mounted coaxially with the inlet port of the chamber. One end of the spring is tightly sealed and the other end is fixed over the inlet port of the casing. Gaseous fluids under pressure is admitted to the chamber through gaps between the turns of the spring when the spring is expanded, and the admission is interrupted when the spring is compressed.

Abstract: A pneumatic-hydraulic proportional valve actuator system is provided having a relatively simple and adjustable means of achieving two stroking speeds by the hydraulic actuator, high speed in normal operation and low speed for small position adjustments and for the final part of any large position adjustments. This prevents overshoot and instability of the actuator.

Abstract: A device for controlling both the displacement of, and the transmittal of force by, a longitudinally movable driving apparatus comprising a piston rod which is hydraulically movable inside a cylinder, an emitter and receiver for ultrasonic waves, which are transmitted between a movable and a fixed part of the driving apparatus, a logic circuit and a controllable source of force, said receiver being electronically connected to said controllable source of force via said logic circuit.

Abstract: A novel electropneumatic servoactuator utilizing a fluid pressure control signal chamber and a duty-cycle control valve alternating between a fluid supply pressure port means and port means venting the chamber to the atmosphere and controlling fluid pressure in the chamber. The control valve is driven by electromagnetic means comprising a coil responsive to an electrical input signal. Pressure responsive actuator means moves in response to the chamber pressure level for providing a mechanical position output. Feedback means senses movement of the actuator means and throttles the fluid flow in one of said port means. In another aspect of the invention, an auxiliary dump release valve armature means is also driven by the coil in preferably magnetic series circuit arrangement with the control valve and coil for rapidly porting the control chamber to the atmosphere for emergency release.

Abstract: A step-by-step controlled servomechanism of the type comprising a drive element movable provided with a plurality of receiver ports, and a fixed distributor to supply said receiver ports and having a number of transmitter ports capable of being connected, in pairs, respectively to the low pressure and to the high pressure, a fixed manifold having a plurality of manifold ports capable of communicating with the chamber of the drive element, all the receiver ports being capable of being made to open in succession into one of said manifold ports, selecting means capable of connecting, in succession by permutation and simultaneously, at least one pair of transmitter ports to the high pressure and to the low pressure, respectively, and at least one manifold port to the chamber of the drive element.

Abstract: A non-impacting nut running pneumatic tool in which torque pulses are transmitted by an oscillating air motor through a one-way clutch and reduction gearing to the work. A torque responsive cam clutch member responds to a predetermined delivered torque to cause stalling of the motor by blocking off escape of exhaust air and to cause discontinuance of further torque transmission to the work by disabling the drive connection. Manually operable adjusting means is provided to regulate the value of torque delivered.

Abstract: A stroke limiting mechanism is connected with the movable member of a hydraulically operated machine to precisely position the movable member. The flow circuit for the stroke limiting mechanism is connected in such a manner that even if an equipment failure occurs, the movable member will be retained in a pressure-balanced condition, thus creating a fail-safe situation.

Abstract: There is disclosed a hydraulic control system including body automatic and manual control for controlling the position of a grader blade for a motor grader. The hydraulic system is supplied fluid from a single pump and is provided with means to isolate the fluid supply from the automatic portion of the system when the manual portion of the system is activated.

Abstract: Step by step controlled servomechanism of the cylinder-type comprising a drive element movable in a case which it divides into two chambers and provided with a plurality of receiver ports, a distributor adapted to be put in communication with the high pressure and the low pressure and to supply said receiver ports, wherein said distributor is fixed and provided with a number of supply or transmitter ports at least equal to three but independent of the number of receiver ports, the transmitter ports being capable of being connected by permutation, in succession and in pairs, respectively to the low pressure and to the high pressure, the distance between the receiver ports and their length, on the one hand, the distance between the transmitter ports and their length, on the other hand, being such that, by the step by step displacement in one direction of the drive element, on one hand, it is possible to bring each time at least one receiver port between the two transmitter ports of a pair in such position that

Abstract: A pneumatic-hydraulic proportional valve actuator system is provided having a relatively simple and adjustable means of achieving two stroking speeds by the hydraulic actuator, high speed in normal operation and low speed for small position adjustments and for the final part of any large position adjustments. This prevents overshoot and instability of the actuator.