Abstract: A fluid pressure cylinder and a clamp device that, when an output member arrives at a prescribed position such as, in particular, an advance limit position or a retraction limit position, are capable of detecting the position of the output member on the basis of change of air pressure as, due to an opening/closing valve mechanism, the communication state of an air passage within the clamp main body is changed over together with the operation of the output member.

Abstract: In a method for slicing food products, a cutting blade carries out a primary movement defining a cutting plane and a product to be sliced is supplied to the cutting blade by means of a conveying device to bring the product into engagement with the cutting blade. The cutting blade moved is from time to time at a speed different from the speed of the primary movement while it is in engagement with the product.

Abstract: A method, and an apparatus, for operating a hydraulic shearing machine. For cutting a shearing-movement of at least one shear blade which is curved, starting from a starting-position under application of an overall actuating-force and for resetting of the shear blades which were moved for cutting to their starting-position after accomplishment of the shearing-movement, a reset-movement under application of an overall reset-force. The shearing-movement and the reset-movement are accomplished by a hydraulic actuating-mechanism comprising hydraulic cylinders, wherein the overall actuating-force and the overall reset-force being applied to the moved shear blades by at least one hydraulic cylinder of the actuating-mechanism. The magnitude of the overall actuating-force is adjustable by switching one or several hydraulic cylinders of the actuating-mechanism in and out of operation-mode.

Abstract: A fluid distributor apparatus includes a body having distribution ports; a spool adapted for controlling the distribution ports and mounted slidingly in a first sliding seat obtained in the body and communicating with the distribution ports; a copying-member mounted slidingly and sealed in a second seat obtained in the spool; and a supply system for a controlled supply of the fluid to the second seat, so that the copying-member slides in a controlled way. The supply system includes also a chamber containing the fluid and communicating with said the seat, and a pushing device of the fluid mounted slidingly and sealed in the chamber.

Abstract: A wire processing machine having a cutting system, comprising a knife holder which carries a knife cooperating during a cut with a stationary counter-blade tool and is connected for performing a reciprocating motion by connecting means to an eccentric pin or a cam disk of a crankshaft, which on its part is driven by an electric motor, with the knife holder sliding in a guide during its reciprocating movement, which guide is arranged in a stationary manner or can be pivoted freely about an axis parallel to the rotational axis of the crankshaft in the case of a rigid connection of connecting means and knife holder, the crankshaft is driven directly by an asynchronous motor to which a gyrating mass is connected whose kinetic energy is released as a cutting force upon impingement of the knife on the wire, with the asynchronous motor performing precisely one rotation per cutting cycle and being controlled in such a way that it is accelerated up to the start of the cut and is braked after the cut has been performed

Abstract: A fluid distributor apparatus includes a body having distribution ports (35, 37, 39, 62, 63); a spool adapted for controlling said distribution ports and mounted sliding in a first sliding seat obtained in said body and communicating with said distribution ports; a copying-member mounted sliding and sealed in a second seat obtained in said spool; and supply means for a controlled supply of said fluid to said second seat, so that said copying-member slides in a controlled way. Said supply means include also chamber means containing said fluid and communicating with said second seat, and pushing means of said fluid mounted sliding and sealed in said chamber means.

Abstract: A cutting system that includes a rotary blade cartridge that can be interchangeably used with a variety of cutting tools is disclosed. The cartridge houses a rotary blade assembly that is maintained in a secure and safe retracted state and that can be activated when the cartridge is inserted into a cutting tool. Activating a plunger of any of the cutting tools causes a piston of the rotary blade assembly to move the blade to an operative cutting position protruding from an aperture provided in the cartridge housing. Deactivating the plunger causes the blade to be return to its retracted and inoperative position within the housing. Cutting tools of the invention include rail cutters such as a primary workstation and a compact workstation, circle cutters, elliptical cutters, and freeform cutters. Each cutting tool is capable of receiving a rotary blade cartridge. Cartridges are freely interchangeable between the cutting tools.

Abstract: The invention relates to a cutting machine, in particular a tread cutting machine, having at least one cutting blade (8) linearly traversable on a blade carriage (1) for achieving a feed movement and rotationally driven by a motor (2), the motor (2) for the drive of the cutting blade (8) being arranged outside the blade carriage (1), and a torque-transmission means, which comprises a means for transmitting tensile forces, being provided between the motor (2) and the cutting blade (8), and that part of the torque-transmission means which is traversable with the blade carriage (1) having a markedly lower mass than the motor (2). In this case, the motor (2) is provided with a device which is designed as a closed-loop control or an open-loop control and is intended for keeping the rotational speed of the cutting blade (8) at least approximately constant during a feed movement of the cutting blade (8).

Abstract: An apparatus for cutting a material having prevalently two-dimensional extension into appropriately shaped portions, in particular for cutting a fabric or the like into shaped portions for the manufacture of clothing items or other items, comprising a support frame (12), means (22) for supporting said material (16), means for supporting cutting means (20). Said cutting means (20) are movable, relative to said material (16) according to trajectories suited for effecting longitudinal, transverse, or otherwise oriented cuts into said material (16).

Abstract: Disclosed is a punch pressing machine requiring no turret, having punch units and die units as die sets, the number of which is not inferior to a turret punch pressing machine, and exhibiting a working accuracy superior to the turret punch pressing machine. A plurality of punch units and die units are disposed in two or more lines on a mounting plate member. A hammer member confronting the respective punch and die units is positioned in X-and-Y axis directions, whereby a workpiece can undergo necessary punch press working.

Abstract: A punching press according to the present invention employs a servo motor as the driving source of the punching operation to achieve fine control, and exhibits a performance which is equivalent to or higher than that of a conventional punching press which employs a hydraulic cylinder. A hammer member which performs the punching operation is coupled to a stroke member which performs a stroke motion. The stroke member is coupled to a motion converting unit which converts the rotational motion of a servo motor into a stroke motion.

Abstract: A control apparatus and method for progressively fracturing a workpiece from a material sheet in a press in which a ram is progressively advanced through the thickness of the material sheet in discrete steps, each of the discrete steps including an advance of the ram into the material sheet a predetermined distance less than the total thickness of the sheet, a stopping of the advance of the ram, a relief of the pressure built up in the press due to the pressurized advance of the ram and a subsequent advance of the ram through the material sheet. A distance measuring transducer generates an output indicative of the position of the piston of the cylinder and the ram during movement of the ram. A controller, in response to a stored control program and the output of the distance measuring transducer, controls the operation of fluid valves to supply pressurized fluid to the cylinder to reciprocate the ram.

Abstract: Hydraulic sawing cycle control system for an undercut swing saw. Hydromotor 5 with crankshaft 7 fitted thereon without play drives the sawing lever arm 2 via a connecting rod 3. One revolution of the hydromotor corresponds to one saw cut. The hydromotor 5 is thereby controlled via a proportional valve. The path of movement of the sawing cycle can advantageously be regulated.

Abstract: A control apparatus and method for progressively fracturing a workpiece from a material sheet in a press in which a ram is progressively advanced through the thickness of the material sheet in discrete steps, each of the discrete steps including an advance of the ram into the material sheet a predetermined distance less than the total thickness of the sheet, a stopping of the advance of the ram, a relief of the pressure built up in the press due to the pressurized advance of the ram and a subsequent advance of the ram through the material sheet. A distance measuring transducer generates an output indicative of the position of the piston of the cylinder and the ram during movement of the ram. A controller, in response to a stored control program and the output of the distance measuring transducer, controls the operation of fluid valves to supply pressurized fluid to the cylinder to reciprocate the ram.

Abstract: A servicer is described for supplying two cut-to-length strips of sidewall simultaneously to a tire building drum without handling by the tire builder, thereby eliminating any stretching of the sidewalls or distortion of the shape of the sidewalls which can happen when the sidewalls are physically handled by the tire builder. The servicer employs twin cassettes which contain two spools of spirally wound sidewall which is separated by a comparatively rigid, U-shaped protective liner.The servicer has an indexing table for moving twin cassettes from a standby position to a let-off position to a take-up position and, lastly, to a removal position where the cassette is removed for rewinding with new material.

Abstract: There is disclosed a pressure-drop sensor valve system for controlling the movement of a fluid operated, ram-type device, such as that used to drive a panel punch. The valve-like device includes a main passage having an inlet for pressurized fluid and an outlet connectable to the ram-type device. Disposed intermediate said inlet and outlet is a fluid chamber. A poppet valve is positioned between said fluid chamber and an accumulator chamber in the body of the device. A fluid by-pass is connected to the fluid passage and a reservoir, and is blocked when the poppet valve is closed and opened when said valve is opened. A piston member is provided with its stem in the accumulator chamber opposite the poppet valve, both said member and valve being slightably movable by separate compression springs. A check valve is positioned in an axial passage of the poppet valve.

Abstract: An improved punch assembly (10) for a punch press comprises a main piston (13) driving a punching tool (11) and an auxiliary piston (17) which can be selectively enabled to cooperate with the main pisto1 (13) in a high force, slow speed mode or disabled to allow the main pisto1 (13) to operate alone in a low force high speed mode. The punch assembly (10) also comprises a pressure transducer (41) and position transducer (25) whose respective outputs are connected to a microprocessor controller for the punch assembly. Operation of the punch press is microprocessor controlled to reduce noise and punch cycle time. A stripper assembly (42-48) is also provided and operates in conjunction with the punching tool (11) under microprocessor control to facilitate tool stripping. The stripper assembly (42-48) can also be used for automatic measuring of work sheet thickness.

Abstract: A pneumatic drive for punching, cutting and stamping devices, which have two tool parts which can be moved toward one another, and of which preferably one, at least in the operating position, is fixedly connected to the machine frame, is constructed such that an opening gap, which is as large as possible, is created. Furthermore, when the tool parts are moved together, the pneumatic drive is operated at a low pressure, so that additional safety devices are not needed. A pneumatic cylinder is secured on the movable tool part for this purpose, the piston rod of the pneumatic cylinder being constructed lockably in at least one end position. The piston rod of a pressure clamping element is secured on the piston rod exiting from the pneumatic cylinder. The cylinder of the pressure clamping element is arranged or fixably stationarily and consists of at least two piston cylinder units with one common piston rod, which piston cylinder units are connected one behind the other.

Abstract: An improved snubber apparatus for an air cushion within a forming press is provided. A floating piston is mounted within the air cushion and defines a snubbing chamber. As the air cushion returns to its top stroke position after yieldably deforming to cushion a member within the forming press, a movable piston within the air cushion contacts the floating piston, forcing it to move in the direction reducing the volume of the snubbing chamber. A check valve is provided between a cushion chamber and the snubbing chamber which maintains the pressure in the snubbing chamber at a minimum equivalent to the pressure in the cushion chamber. As the volume of the snubbing chamber is reduced, the air trapped within is rapidly compressed to a value snubbing the motion of the air cushion. The snubber valve is provided communicating with the snubbing chamber and maintained in a closed position by the air pressure within the cushion chamber.

Abstract: The present invention relates generally to bandsaw machines having a flexible bandsaw blade trained around a plurality of wheels to perform cutting operations and, more particularly, pertains to a method and apparatus for controlling the feeding of the bandsaw blade into a workpiece such that the bandsaw blade is fed intermittently into the workpiece so as to prevent the blade from deflecting off the workpiece and causing work hardening of the workpiece. An alternative embodiment of the invention provides feeding the workpiece into the bandsaw blade in an intermittent fashion.

Abstract: A new breed of die cylinders operating at 1000-5000 psig. working fluid pressures and adaptable for use individually or by manifolding with punch presses to cushion dies can be operated with maximum rated pressure force against a force which a ram develops in one direction and in the opposite direction with partial pressure force which the die cylinders exert when force balanced. The following is accomplished by loading a piston underside by the same working fluid pressure when the piston bottoms inside a cylinder housing at the end of the ram induced stroke enabling an instant high pressure surge of fluid, be it Nitrogen gas or other working fluid, to enter the piston underside provided with a piston rod and exert a resistance force proportional to the net free area exposed thereto thereby providing force balanced cylinder operation.

Abstract: A shock absorbing device in a press is formed by having a telescopically sliding member fastened to the punch plate of the press and a stopper member fastened to the die plate of the press and placing an oil of high viscosity between the post and the outer cylinder of the telescopically sliding member. This shock absorbing device damps the unloading impact produced when the punch of the press collides with a workpiece and fractures it and, thereby, abates the noise generated from the press, the tool and the workpiece.

Abstract: A method for cutting off a steel plate, wherein the steel plate is heated to a temperature within the range of from 950.degree. to 1,400.degree. C. at the time of cutting off the steel plate; the heated steel plate is placed on a roller table extending horizontally and positioned at a desired position so that a side edge of the heated steel plate is in contact with the cutting edge of at least one cutting knife on the roller table. The cutting edge angle of the cutting knife is within the range of from 10.degree. to 45.degree.. The cutting knife is then moved horizontally relative to the heated steel plate, in the width direction or the length direction of the steel plate, at a cutting speed of from 10 to 1000 cm/minute, thereby cutting off the steel plate by the cutting knife in the horizontal direction.

Abstract: A resilient stop block for gradually loading the ram of a press for scoring easy open can ends to assure an accurately controlled residual and reduce press noise. The resilient stop block replaces the conventional solid stop block and comprises a metallic member having a longitudinal bore and vertically spaced overlying pairs of diametrically opposed angularly oriented segmental slots extending inwardly through the sides of the block into the bore. The resilient stop block is compressable by the overlying solid stop block as the ram approaches the press bed.

Abstract: A pneumatic press assembly 10 uses air pressure to power a piston 70 in a cylinder 52 through a power stroke. Springs 76, 78, 80, 82, 84, and 86 oppose the motion of the piston 70. A set of return springs (76 and 78) is effective over the entire stroke of the piston. The return springs are compactly mounted within the cylinder 52 between the bottom of the piston 70 and a shoulder 56 which extends radially inwardly from the cylinder wall. The shoulder also cooperates with a central portion 110 of the piston 70 to prevent rotation of the piston. A second set of springs (80, 82, 84, and 86) is effective only when the piston 70 is within a predetermined distance from the bottom of the power stroke. The second set of springs 80, 82, 84 and 86 is disposed between the bottom 230 of the cylinder 52 and a preload member 234. When the piston 70 approaches the bottom of its stroke, it contacts the preload member 234 which in turn compresses the springs 80, 82, 84, and 86 bringing the piston to a halt.

Abstract: An improved hydraulic fluid shock dampening system is disclosed for a shearing press to minimize shock loading vibration, and the level of noise emanating upon breakthrough of the material being sheared. The system includes cylinder and piston units interposed between the press bed and slide, each providing a variable volume fluid receiving chamber from which fluid under pressure is expelled during movement of the slide toward the bed to achieve a shearing operation. A flow sensitive valve in communication with the chambers has a first fixed flow rate thereacross during the shearing operation, and prior to breakthrough, and is responsive to accelerated movement of the slide upon breakthrough to provide a second and substantially lower fixed flow rate thereacross during completion of the movement of the slide toward the press bed.

Abstract: Apparatus is provided for damping a billet shears assembly and includes a damping cylinder and piston mounted to the stationary portion of the assembly opposite the moving shear blade. The damping piston defines a control cylinder and the base of the damping cylinder carries a control piston adjustably fixed in the control cylinder in axial alignment with the damping piston over the entire stroke distance. A pneumatic fluid supply line in the control piston connects the damping cylinder with the control cylinder and is provided with a non-return valve.

Abstract: A system for damping abrupt movement of a punch press ram at the moment of cut-breakthrough with the use of at least two damping pistons disposed within cylinders and arranged to engage the press ram before and during cut-breakthrough. The cylinders within which the damping pistons are carried are connected to a hydraulic control system which permits the pistons to yield with the ram until the instant of cut-breakthrough, whereupon the damping pistons act as rigid bodies and prevent abrupt breakthrough movement of the ram.

Abstract: A trim press employs a hammer assembly to deliver a hammer blow to the punch of the press at the moment the punch begins to apply shearing pressure to material being trimmed. A spring system applies a steadily increasing spring loading to the hammer as the punch carrying platen moves downwardly in its operating stroke toward the die. A latch assembly, triggered by an abutment on the die, unlatches the hammer at the time the punch engages the material so that the downward velocity of the punch due to the downward movement of the platen is increased by a hammer blow as the punch moves through the material being trimmed. The spring system is operable to restore the hammer to its latched position during the upward stroke of the platen.

Abstract: Fast head operating device for flag type die-cutting machines, comprising a hydraulic circuit with one end connected to a feed pump and the other to two cylindrical chambers defined at the base of a column supporting the head of the die-cutting machine, the hydraulic circuit comprising a control valve, equipped with a seal which slides into and is engaged in the body of the same valve to form a fluid communication between a feed conduit and a first inlet conduit, which flows into one of said cylindrical chambers for the rise of the column and with a second inlet conduit which flows into the other cylindrical chamber for the downstroke of the abovementioned column. Interposed on said first inlet conduit, a sequence valve is provided while a further fluid conduit branching from the second inlet conduit, flows into a cylindrical chamber into which a small piston slides and is engaged, carrying, at the opposite end, the mobile contact of a pressure switch connected to the electric operating device.

Abstract: A straight line shearing mechanism which includes a unique pneumatic control system to cause the operation of the shears. One feature involves the cushioning of the piston member of the pneumatic cylinder assembly on the return stroke. Another feature is the provision of an automatic retract to open the shears in the event that the shear blades do not complete their cutting stroke. Also, one blade of a set of shear blades may tilt in the event of excess tension between the blades. Additionally, one shear blade is pivotally adjustable about a pin member having an axis extending in the direction of travel of the blades. Further, the drop guides are horizontally adjustable relative to its associated shear blade in the direction of travel of the shear blade and also adjustable about a vertical axis.

Abstract: There is provided a hydraulic shock absorption cutting and/or punching system which may be applied to a pre-existing press with said system having at least one damping cylinder that is under preset pressure supplied by a pump with the pressure chamber of the cylinder being connected with a damping valve. The damping valve has a piston-type displacing element including a throttle member, the construction and design of which provides for pressure-dependent adjustment of said throttle member in a housing on axial movement of said throttle member so that the cross section of a throttle gap is finely controlled and pressure-dependent adjustment of said gap is attained while also providing for practically constant flow through said throttle gap.

Abstract: A hydraulic fluid shock dampening system is disclosed for a shearing press to minimize shock and vibration imposed on the press following breakthrough of the material being sheared by cutting die components carried by the press bed and slide. The system includes cylinder and piston units interposed between the press bed and slide each providing a variable volume fluid receiving chamber from which fluid under pressure is expelled during movement of the slide toward the bed to achieve a shearing operation. A flow sensitive shutoff valve is responsive to accelerated movement of the slide upon breakthrough to block fluid flow from the chambers and thus restrain further slide movement toward the press bed. In preferred structural embodiments of the system, the cylinder and piston units, shutoff valve and fluid pressure accumulator components are structurally associated with a bolster plate mountable on a press, or with die components mountable on a bolster plate.

Abstract: A control system for a hydraulic punch press is adapted to dissipate the energy stored in a hydraulic actuator so that the punch will exit the workpiece without substantial release impact. The control system includes a signal generator for producing a progressively increasing command signal while the punch penetrates the workpiece, a position transducer for producing a negative feedback signal indicating the actual punch position during such penetration, and a summing point for supplying the difference between the command and actual signals as an error signal to a servovalve used to control operation of the actuator.

Abstract: An arrangement for protecting tools in a hydraulic press against overloading if a foreign object or body is present in a tool space of the hydraulic press. A displacement or travel switch monitors at least a portion of a path of movement of a press ram with a control member providing an output signal during a predetermined movement of the press ram. A control circuit evaluates a sequence of the output signals of the displacement or travel switch and the control member in such a manner that a fault signal is formed when the additional switching device provides an output signal prior to an output signal of the displacement or travel switch. The control member is arranged in a path of force of at least one component of the hydraulic press and is constructed as a signal transducer operating virtually stationarily as a function of pressure.

Abstract: An arrangement for protecting tools in a hydraulic press against overloading if an object is present in a tool space of the hydraulic press. A displacement switch monitors at least a portion of a path of movement of a press ram with an additional switching device providing an output signal during a predetermined movement of the press ram. A control circuit evaluates a sequence of the output signals of the displacement switch and additional switching device in such a manner that a fault signal is formed when the additional switching device provides an output signal prior to an output signal from the displacement switch. The additional switching device may be constructed as a switch element which provides an output signal in dependence upon a pressure or a speed of flow of a pressure medium in a hydraulic circuit.

Abstract: The specification discloses a hydraulic pressure operated hand tool of the type in which the manual pressure exerted on a small-area pump piston creates a hydraulic pressure which is communicated to a power cylinder for activating a hand tool jaw member, such as a cutter blade. Preliminary take-up movement of the cutter blade into contact with the object to be severed, such as cables, pipe etc., is effected by manual pressure applied to a second pump piston of relatively large area, which causes rapid displacement of the hydraulic medium from a reservoir to the power cylinder before exertion of manual pressure to the small-area pump piston. A release valve provides instant return displacement of hydraulic medium via a by-pass communication from the cylinder to the reservoir to relieve the activating pressure on the cutter blade and restore it promptly to normal position. Interchangeable cutters are provided.

Abstract: A straight line shearing mechanism which includes a unique pneumatic control system to cause the operation of the shears. One feature involves the cushioning of the piston member of the pneumatic cylinder assembly on the return stroke. Another feature is the provision of an automatic retract to open the shears in the event that the shear blades do not complete their cutting stroke. Also, one blade of a set of shear blades may tilt in the event of excess tension between the blades. Additionally, one shear blade is pivotally adjustable about a pin member having an axis extending in the direction of travel of the blades. Further, the drop guides are horizontally adjustable relative to its associated shear blade in the direction of travel of the shear blade and also adjustable about a vertical axis.

Abstract: A machine for clipping strip material including a blade operated in a cyclic manner having a cutting stroke and a return stroke. A toggle linkage including a toggle bar effecting one blade cycle by moving in a lengthwise direction with the blade being reciprocated by toggle linkages moving through an upright position to a position oppositely inclined to their starting position. The toggle bar is coupled to an actuating piston rod of a pneumatic cylinder. End caps of the cylinder are recessed to receive piston extensions during final stages of piston travel for cushioning purposes. Seal means engage each piston extension during the later stage of piston travel to trap air between the advancing piston and the end cap. Accordingly, blade and toggle assembly inertia is dissipated in the compression of trapped cylinder air. Exhaust means within each of said end caps is valve controlled to release cylinder pressure at a desired pressure braking the latter stages of piston travel.

Abstract: A method and apparatus for splitting logs, comprising an engine or prime mover actuating a reciprocating trolley through mechanical linkages along a fixed bed such that the trolley may urge a log to be split against a blade or wedge with mechanically amplified force sufficient to accomplish the splitting but may be instantly reversed and withdrawn to starting position at a rate of speed substantially higher than the speed of the splitting stroke as a result of differing mechanical advantages of the forward and reverse mechanical linkages.

Abstract: An anvil roll has a steel core and an outer portion of polyurethane. The roll is slightly rotated after a number of veneer clipping operations by a clutch which drives the roll after the roll is pushed by a knife down away from arcuate braking surfaces. An airbag normally urges the roll into engagement with the braking surfaces and is collapsed during adjustment of the roll. Operation of the clutch is prevented during the clipping operation. A double-acting cylinder drives the knife through a toggle joint linkage, and cushioning cylinder means aid in overcoming inertia of the knife at the start of a clipping cycle and also cushion the return of the knife. The cylinder has poppet check valves to rapidly admit air thereto.

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

Abstract: A fluid cylinder assembly includes a cylinder and a piston slidably disposed in the cylinder, the cylinder having a cylinder bore closed at both ends by end caps. One of the end caps is provided therein with a flow control valve assembly for controlling the fluid flow from the cylinder bore during a working stroke of the fluid cylinder assembly. The flow control valve assembly comprises a poppet valve having a pair of poppets on a valve rod and a spool valve movable in response to the operation of the poppet valve. The poppet valve is shiftable by a solenoid alternately energized and de-energized by an electric control circuit which is closed just before contact of a cutter on the piston rod with a workpiece.

Abstract: A motor driven by a pressurized fluid medium for operating an impact tool in a linear direction adapted for metal stamping and high velocity milling comprising a housing and a piston unit. The latter comprises a drive piston, a piston rod and a tool. In addition, the motor includes a kinetic energy absorbing device comprising a hydraulic fluid chamber and a retard piston which is rigidly connected to said piston unit and arranged to reciprocate in said fluid chamber. The retard piston retards the piston unit at the end of the strokes only and is freely passed by hydraulic fluid during the working stroke. Cup-shaped means are provided to restrict said by-pass flow of hydraulic fluid at the end of the strokes and thereby protect the motor from excessive stresses during no-load conditions.

Abstract: Hydraulic press for performing shearing, cutting and bloom-compression operations comprising a pressure-fluid accumulator operatively connected to the working chamber of the main piston having its rod rigid with a slide member coupled via linkage means and a bell-crank lever to the longitudinal stem of a spool valve movable in a spool valve chamber communicating via a first port to the fluid reservoir, via a second port to the accumulator and via a third port to the pressure chamber of the main piston.

Abstract: A pneumatic impact device comprising a housing, a drive piston and a piston rod. At the forward end of the piston rod there is attached a tool intended for metal working like punching, cropping or forging. The housing contains a drive chamber, an air charge chamber, a reverse chamber and a retard chamber. The piston rod is provided with two forward-facing, annular shoulders one of which constitutes a reverse piston for working in the reverse chamber and the other a retard piston for working in the retard chamber. For being protected from impact strains, the drive piston is longitudinally displaceable relative to the piston rod. During the working strokes, the drive piston cooperates with a backwardly facing shoulder on the piston rod, but just before the latter reaches the point where the tool hits the billet to be worked, the drive piston is stopped in the drive chamber and is thereby separated from the piston rod shoulder.