Abstract: An improvement to a stamping press having a blanking punch and die combination comprising a blanking die defining an opening, a cooperating blanking punch dimensioned closely to mate with the opening wherein the die edge defining the opening is radiused to cause metal flow, a stock engaging shedder displaceable within the die opening to engage and clamp stock, and a stripper encircling the blanking punch and displaceable therealong to remove surplus stock after a blanking operation. The improvement comprises the stripper being disposed to engage and clamp stock being punched by the blanking punch and die.

Abstract: A die stamping system includes opposed die members which clamp a metal workpiece to be shaped, cut or pierced after which the die members are moved away from one another and a part is subsequently ejected wherein the ejector is controlled for a selected delay time by a plurality of cylinder assemblies mounted in a manifold so that they are connected to a source of inert gas such as nitrogen under high pressure and to a source of hydraulic pressure. Each cylinder assembly includes a piston associated with and exposed to the nitrogen in the manifold. The cylinder assemblies are connected to a single hydraulic valve which has associated therewith an accumulator and which is operated simultaneously to actuate the cylinders. The hydraulic lines to the cylinders are provided in the manifold.

Abstract: A single action cylinder is used with a machine. The machine has a first part and a second part having reciprocating motion relative to each other. The single action cylinder affects the reciprocation between the first and second parts. The cylinder includes a base adapted for attachment to one of said parts. The cylinder includes a plurality of open ended longitudinally extendable resilient actuators stacked one above the other. A first actuator of said actuators has one end connected to the base. Each of the actuators is interconnected to an adjacent actuator to allow a fluid to flow between the actuators. A second actuator of the actuators has one end connected to an apparatus for attaching the second actuator to the other of the parts. An elongated guide is connected to one of the actuators to limit movement of that actuator in a direction transverse to the length of the guide.

Abstract: A pneumatic-hydraulic booster type driving device for the cushion-knockout mechanism associated with the slide of a press-machine serves to stably hold down a work plate such as a printed board and the like while performing a cushion operation at the time of a pressing stroke and serves to knock out the work plate after the pressing stroke in the press-machine. In the driving device, a pneumatic-hydraulic booster is connected through a pressure oil supply and discharge means to a hydraulic actuation chamber of a cushion cylinder provided in the slide of the press-machine, and the pressure oil supply and discharge means comprises a valve chamber within a valve casing and a knockout actuator which is fixedly secured to the valve casing so as to perform the valve opening operation of the valve unit.

Abstract: Arrangement for the ejection of a pressed component from a press tool. The arrangement consists of a number of ejection pins distributed over the press surface tool. Each of the ejection pins is so arranged as to lie during the pressing operation with its tip no higher than on a level with the aforementioned press surface, and, in conjunction with the opening of the tool after a pressing operation has been completed, as to eject the component from the tool with its tip. A characteristic feature of the invention is that each ejection pin is operatively connected via a pistion rod to a hydraulic piston. The piston is capable of axial displacement in a hydraulic cylinder, which is filled with an incompressible fluid in space between the piston and an end wall of the cylinder. The space communicates via a duct with a drive unit for the ejection pin.

Abstract: A power press used for metal working is provided with a cushioning system. During the operation of a press, abrupt changes in the velocity of certain moving parts of the press may damage or cause rapid wear to parts. The present invention utilizes pneumatic bellows actuators. A hydraulic snubber and snubber-intensifier having closed systems are in combination with a pneumatic bellows actuated die cushion. The snubber has a piston within a cylinder assembly. During the upward stroke of the ram of the press, the movable plate of the die cushion is held back by the piston so as to prevent a damaging impact on the movable die parts and workpiece supported by an air cushion. Fluid is allowed to flow from the top of the piston through a flow valve to return to a reservoir within the die cushion or to the bottom of the cylinder.

Abstract: A pneumatic shock absorber used primarily as a die spring includes a piston formed with a base and an upstanding cylindrical body provided with an internal fluid reservoir. An outer housing is mounted on the base and extends about the cylindrical body. An inner housing is axially telescopically mounted for sliding movements within the outer housing. A flexible sleeve is enclosed at one end by a sealing cap and is sealingly connected at its outer end to the exterior of the piston body forming a fluid chamber therein which communicates with the fluid reservoir of the piston. An opening is formed in the piston body to fill the reservoir and chamber with a high pressure fluid which places the inner housing in an expanded position by the end cap pressing against an end wall of the inner housing upon axial expansion of the sleeve. Rolled end flanges formed on the housings engage each other to stop the movement of the inner housing at the expanded position.

Abstract: A drawing apparatus in a press for holding the sheet metal part during the drawing and for the ejection thereof. Additionally, blocking devices are provided which prevent the ejection of the sheet metal draw part at the same time with the upward movement of the press ram. Each blocking device is thereby to be rendered selectively operable or inoperable. A continuous flow of the hydraulic liquid is to be precluded during the inoperative condition of the blocking device. The blocking device consists of a pressure cylinder, of a pressure piston which is displaceably movable on the piston rod displaceable by the draw cushion, and of a compression spring for the displacement of the pressure piston in the ejection direction. The pressure space formed above the pressure piston is selectively pressureless for the inoperative condition, respectively, adapted to be acted upon with controlled pressure for the operative condition of the blocking device.

Abstract: A gas spring with a piston rod slidably received in a cylinder which defines a chamber in which a gas is compressed when the rod is forced into the cylinder. The gas spring can be operated with either an external source of gas or as a precharged and self-contained unit by changing first and second valves assemblies either of which can be installed in the same cavity in the cylinder. If desired, a check valve can control the bleeding of gas under pressure in the cylinder back to the entrance of the cavity containing one of the valve assemblies through which the cylinder is filled with gas.

Abstract: The present invention relates to a pneumatic press counterbalance and cushion construction. The press counterbalance holds certain parts of a press in the same relative engagement during the return stroke of a ram of the press as during the power stroke of that ram. The counterbalance includes a fixed plate adapted for connection to a part of the press. A pneumatic bellows has one end connected to the fixed plate. A movable plate is connected to the opposite end of the pneumatic bellows. A connector rod is connected to the movable plate and to another part of the press which part is movable relative to the part to which the fixed plate is connected. The pneumatic cushion includes a resilient bellows having one end connected to the fixed plate. A bellows connector is connected to the other end of the bellows. A second bellows has one end connected to the bellows and the other end connected to the movable plate.

Abstract: A drawing installation for a press which must produce the holding force during the drawing operation. The drawing ram displaces the sheet metal part and the sheet metal holder against the holding force and additionally must overcome at the beginning of the sheet metal deformation the inertia forces of the accelerated parts of the drawing installation. In order to avoid the forces which occur thereby in an impact-like manner, the piston rods transmitting the holding force and the ejector piston rods are pre-accelerated prior to the drawing ram. The piston rods each include an operating surface adapted to be acted upon in the drawing direction. The pressure spaces coordinated thereto are connected with a pressure quantity space each of a pre-acceleration cylinder and by way of a refill control with a pressure source. The control of the pre-acceleration cylinder and of the refill from the pressure source takes place in dependence on the movement of the drawing ram.

Abstract: A self-lubricating die cylinder assembly is provided containing a cylinder, piston, expansion reservoir and working chamber. A lubricating oil recirculation means is provided to transport oil between the working chamber and the expansion reservoir during each of the piston strokes. A flow restrictor is provided to create a pressure differential between the two chambers during movement of the piston thus creating a jet mixture of compressible working fluid and lubricating oil spraying onto the walls of the cylinder.

Abstract: A gas spring unit having a housing, and a piston assembly slidably supported within and projecting outwardly of the housing. The housing and piston assembly cooperate to define therebetween a pressure chamber which is precharged with a high pressure gas, specifically nitrogen, for absorbing external shock forces as imposed on the piston assembly. A first passage, containing a one-way check valve, extends through the end cap of the housing to permit charging of the pressure chamber with high-pressure gas, and to additionally permit make up gas to be supplied to the chamber. A second passage permits relieving of pressure within the pressure chamber, such as due to overload or when relief of pressure is desired.

Abstract: An accumulator system for establishing a clamping force on dies in a closed die forging device. The accumulator system includes an accumulator having a differential piston and a free piston. The small end of the differential piston forms a wall of the accumulator oil chamber hydraulically connected to variable volume oil chambers behind the dies. The big end of the differential piston and one side of the free piston form a low pressure gas chamber of the accumulator. The other side of the free piston forms a wall of a high pressure gas chamber of the accumulator. As the dies of the forging apparatus close, oil in the chambers behind the dies moves the differential piston against only the gas pressure in the low pressure gas chamber so that closure is essentially without impact.

Abstract: A die cushion construction for use in a press is the subject matter of the present invention. The instant die cushion construction includes a fixed plate connected to the press. A resilient cushion actuator has one end sealingly connected to the fixed plate. The resilient cushion actuator has an opposite end sealingly connected to a movable plate. The movable plate is adapted for connection to a portion of a die mounted in the press. A resilient snubber actuator has one end fixed relative to the fixed plate. The snubber actuator has an opposite movable end connected to the movable plate for affecting the rate of movement of the movable plate and a portion of the die. The snubber actuator is connected to means for allowing fluid to flow into the snubber actuator when the movable plate moves toward the snubber actuator.

Abstract: A die stamping system for use in a fine blanking apparatus that includes opposed die members which clamp a metal workpiece to be cut and pierced after which the die members are moved away from one another and the slugs pierced from the blank and the cut blanks are subsequently ejected wherein the ejector is controlled for a selected delay time by a plurality of cylinder assemblies mounted in a manifold so that they are connected to a source of inert gas such as nitrogen under high pressure. Each cylinder assembly includes a first piston associated with and exposed to the nitrogen in the manifold and a second piston engaged by the first piston and urged outwardly into engagement with a punch base.

Abstract: A die cylinder assembly is designed for use in an environment which has contaminants outside the assembly. The die cylinder assembly includes a piston disposed in a cylinder and having an outer end surface. The piston is moved in one direction by forces applied to the outer end surface of the piston. The piston is moved in an opposite direction by a working fluid pressure in a head end chamber of the cylinder. The cylinder includes a rod end variable volume chamber which is connected in fluid communication, through a first passage in the piston rod, with a third chamber located in the piston rod. The fluid pressure in the rod end chamber is always maintained at least as great as ambient fluid pressure to prevent contaminants from entering the rod end chamber. A check valve in a second passage admits outside air to the third chamber when fluid pressure in the third chamber drops below ambient pressure. A relief valve vents the third chamber if fluid pressure therein becomes too high.

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: For use in a system comprising a source of pressurized fluid and a plurality of lines extending to a plurality of gas springs, a gas spring comprising a cylindrical body with a bore, a piston rod positioned in the body and having an end projecting beyond one end of the body, a base closing the other end of the body, the cylindrical body and piston rod interengaging one another to limit relative outward movement of the piston rod with respect to the body. The gas spring includes a radial inlet through the wall of the cylindrical body into the base. A one-way valve is positioned in the base within the inlet and an axial inlet pressure passage extends from the outlet end of the valve to the interior of the cylinder. A radial bore is provided in the base and communicates at one end through an axial pressure relief passage to the interior of the cylinder.

Abstract: A self contained gas spring interchangeable with a coil spring comprising a cylindrical body having a constant diameter external cylindrical surface, the cylindrical body having open ends and a piston within said cylindrical body and having one end projecting through one of the openings of the cylindrical body. The piston and the cylindrical body have interengaging flanges that limit the outward movement of the piston relative to the cylindrical body. A plug is positioned in the other end of the cylindrical body to close the opening of the cylindrical body. A charging valve is positioned in the plug for charging the interior of the gas spring. The piston has a hollow inner end with an inner surface tapering outwardly and axially toward the plug. The plug has a generally complementary surface such that the piston can move downwardly about a portion of the plug thereby substantially reducing the height of the gas spring.

Abstract: The present invention relates to a pneumatic press counterbalance which holds selected parts of a press in the same relative engagement during the return stroke of a ram as during the power stroke of that ram. The counterbalance includes a base plate adapted for connection to a first part of a press. An elongated cylindrical base tube having an open end is mounted on the base plate and has a center axis substantially perpendicular to the base plate. A resilient unconfined tubular bellows for holding air has a pair of opposed ends. The bellows has an elongated tubular resilient sleeve connecting the open ends and formed integral therewith. One of the open ends of the bellows is sealingly connected to the base tube. A first portion of the tubular sleeve surrounds a portion of the base tube. A second portion of the tubular sleeve is connected to the first portion by a fold in the sleeve and has a part surrounding the first portion. A movable plate is connected to the other end of the bellows.

Abstract: A pneumatic die cushion for use in a power press is the subject matter of this invention. The die cushion includes a pair of spaced substantially parallel plates with resilient bellows for resiliently spacing apart the plates. A plurality of limiter pins are releasably secured to one of said spaced plates. Each of said limiter pins has an end threadedly mounted in one of said plates. Each of said limiter pins is movable relative to the other of said plates. A stop mechanism is mounted on the other end of each limiter pin for limiting movement of the first mentioned plate away from the other plate. A limit sleeve is mounted on each of the limiter pins to control the minimum spacing between the plates. A quick change adaptor plate is fixed to one end of the bellows. The quick change adaptor plate has a pair of opposed ears. A mechanism is provided to releasably secure the ears of the quick change adaptor plate to said one of said plates to secure said one end of the bellows to said one of said plates.

Abstract: The mechanical press, particularly a toggle press, comprises a hydraulic member connected between the force transmitting and force receiving components, such as a toggle joint, carriage, anvil, and platen. The anvil is mounted on a hydraulic member which is located in a hydraulic chamber. The hydraulic member acts as a press cushion which is continuously connected with a large volume fluid reservoir which is maintained constantly under a gas pressure. The hydraulic member has a maximum filling volume which is at most 1% of the volume of the fluid reservoir.

Abstract: A drawing apparatus, by means of which the different individual functions such as control of the sheet metal holder pressure, control of the sheet metal holder upward movement, control of the ejector movement and of the end position abutment are adjustable, respectively, controllable independently of one another.

Abstract: A self-lubricating die cylinder assembly is provided containing a cylinder, piston, expansion reservoir and working chamber. A lubricating oil recirculation means is provided to transport oil between the working chamber and the expansion reservoir during each of the piston strokes. A flow restrictor is provided to create a pressure differential between the two chambers during movement of the piston thus creating a jet mixture of compressible working fluid and lubricating oil spraying onto the walls of the cylinder.

Abstract: A press cushion assembly includes a variable volume chamber which is expanded during operation of the press to an open condition and is contracted during operation of the press to a closed condition. During expansion of the variable volume chamber, a flow of lubricating liquid is conducted to the variable volume chamber from a reservoir. At the same time, a flow of gas is also conducted from the reservoir to the variable volume chamber. Upon closing of the press and contraction of the variable volume chamber, a flow of lubricating fluid and gas is conducted from the variable volume chamber back to the reservoir. The cushion assembly may include a manifold plate in which a plurality of piston and cylinder assemblies are mounted. A reservoir disposed in the manifold plate is connected in fluid communication with the piston and cylinder assemblies by a plurality of passages. Check valves may be provided in the passages so that the lubricating fluid can flow in only one direction.

Abstract: An impact force shaping head includes an elongated casing having an interior wall, an open end and a closed end and contains a liquid. A piston is slidingly mounted within the casing and extends longitudinally beyond the open end of the casing. The piston sealingly engages the interior wall of the casing to define a liquid-filled first chamber between the piston and the closed end of the casing. A reservoir contains liquid and a conduit connects the first chamber with the reservoir. A control valve controls the flow of liquid through the conduit. The control valve is operative in response to changes in the pressure of the liquid contained in the first chamber.

Abstract: A press comprises a bed affixed to a frame, a slide vertically movably provided above the bed, a lower cushion mounted to the underside of the bed and having chambers, an upper cushion mounted to the slide and having chambers, a pneumatic hydraulic control circuit for a pressure source of each of the cushions, and a control for controlling individually the pressure within the chambers, wherein a complicated workpiece can be formed in one stroke of the slide.

Abstract: A gas spring unit with an improved packing structure for providing a lubricated guide and seal with the piston rod for containing a high-pressure gas while enabling the spring unit to function for a large number of operational cycles. The packing structure includes a pair of lubricating-type bushings disposed for slidable engagement with the piston rod, which bushings are axially spaced and confine a seal ring therebetween, the latter preferably being of polyurethane. The bushings are preferably impregnated with a lubricant such as graphite. The innermost bushing abuts against a shoulder on the housing to avoid imposition of excessive compressive forces on the seal ring.

Abstract: In a die cushion apparatus, a die cushion mechanism for achieving a die cushioning capability as relying upon a preset pneumatic pressure is provided with a hydraulic pressure chamber into which a piston connected to a die cushion pad is fitted, the hydraulic pressure chamber is provided with a hydraulic pressure feed circuit and an exhaust circuit, a relief valve whose relief pressure is controllable is disposed in the exhaust circuit, and relief pressure control means is coupled to the relief valve.

Abstract: A nitrogen die piston-cylinder unit has a central post threaded at one end into a nitrogen manifold. The piston has an axial bore therethrough. A sleeve closed at one end is telescoped over the free end of the post and is vertically slideable thereon. The upper end of the post has an annular seal thereon in sliding sealed engagement with the bore of the sleeve. A key and keyway formed on the inside of the sleeve and the outside of the post are arranged to interengage when the sleeve is fully telescoped over the post to prevent relative rotation therebetween. The exposed end face of the sleeve is formed with recesses adapted to be engaged by a spanner wrench to enable the unit to be removed from the threaded port of the manifold when the key is engaged with the keyway.

Abstract: Method and apparatus for controlling the spacing between a metal forming punch and a die pad in which the method includes supporting the work-piece on a fluid supported pad and the periphery of the work-piece on a fluid supported sleeve, engaging the workpiece with a forming punch and, during a portion of the travel of the forming punch, moving the pressure sleeve and the support pad for the central portion of the workpiece simultaneously while maintaining the spacing between the top of the pad and the bottom of the punch. The apparatus includes a die pad riser attached to the pad and to a pressure sleeve, both of which are movable in response to movement of the punch during a portion of the travel of the punch. The pressure sleeve is secured to the die pad riser so that the spacing between the punch and the die pad is maintained during such movement.

Abstract: An apparatus, for controlling dynamic characteristics of a press load, facilitates changing the balance between a hydraulic pressure and a pneumatic pressure in a hydroblank holder, wherein a first pneumatic device which supplies a standard pneumatic pressure with which a predetermined dynamic load can be obtained and a second pneumatic device which supplies a pneumatic pressure higher or lower than the standard pneumatic pressure are provided in parallel in a pneumatic device which supplies pneumatic pressure to the hydroblank holder and the first and second pneumatic devices are switched in accordance with a press stroke and, when the switching is made to low pressure, an accumulator is depressurized by the operation of a depressurizing device.

Abstract: There is disclosed a piston-cylinder assembly for use as a die spring wherein one end of the cylinder is connected to the source of nitrogen at high pressure to bias the piston outwardly through the opposite open end of the cylinder. The open end of the cylinder is provided with a high pressure seal and the opposite end of the piston is likewise provided with a high pressure seal. An annular chamber of relatively small cross sectional area is provided between the piston and the cylinder. A valve stem on the piston controls a passageway communicating with the annular chamber. Axial pressure is applied to the seal on the cylinder to produce firm sealing engagement with the piston by pressurizing the annular chamber or by arranging a compression spring between the seal and a shoulder on the cylinder.

Abstract: A piston-cylinder unit for use in a die is threaded into a port of a nitrogen manifold. The piston has a seal thereon slideably engaging the cylinder bore and has a rod projecting out one end of the cylinder, the rod being biased by the gas pressure at the threaded end of the cylinder into engagement with a die member reciprocated in response to reciprocation of the ram of the press in which the die is mounted. The portion of the cylinder threaded into the manifold has a bleed passageway therethrough which communicates with the interior of the cylinder below the seal on the rod when the press ram is at bottom dead center position and with the interior of the cylinder above the seal on the piston when the piston rod is fully retracted.

Abstract: A pneumatic spring for use in absorbing an external force by compressing gaseous fluid trapped therein. The pneumatic spring includes internal valves for recharging and for relieving excessive pressure. In one form, the pneumatic spring comprises an outer housing defining an open-ended outer cylinder and an inner cylinder slidingly and sealingly positioned in the outer cylinder. The inner cylinder has a cylindrical side wall and end walls and a rod extends from the inner end wall of the outer cylinder through the inner end wall of the inner cylinder. A piston is fixed on the rod within the inner cylinder, thereby defining a first chamber between the inner end of the outer cylinder and the inner end wall on the inner cylinder and a second chamber between the piston on the rod and the outer end wall of the inner cylinder. The chambers are isolated from one another.

Abstract: A fluid die spring comprises a cylinder connected at one end to a reservoir of gas at high pressure. A piston in the cylinder has a smaller diameter rod projecting out the other end of the cylinder for engagement with a movable die member. The rod end of the cylinder has a high pressure seal engaging the rod and arranged to prevent leakage of liquid die lubricant into the cylinder.

Abstract: The disclosure describes a new type of pressure cylinder to provide clamping force while fabricating deep drawn metal parts. The piston is a hollow cylinder connected to the clamping pad. The drawing tools are connected to the draw ram by a rod passing through the hollow piston. This arrangement provides a smaller overall press height and an axisymmetric clamping force. In addition, the symmetry of the parts described means that the wear parts can be reversed to double their useful lives.

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 cylinder structure and method for rapidly evacuating a cylinder without contamination thereof. The structure comprises a hollow cylinder, a piston mounted in the cylinder for axial reciprocation, a hollow piston rod secured to the piston for movement therewith extending out of one end of the cylinder, a seal between the one end of the cylinder and the piston rod, and a radial opening through the hollow piston rod between the piston and seal for evacuating the space between the cylinder, piston, piston rod and seal during reciprocation of the piston within the cylinder. The method includes the step of evacuating the space between the cylinder, piston, piston rod and seal through the piston rod during reciprocation of the piston within the cylinder.

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: An impact damper for use, for example, between the stationary and reciprocating parts of a stamping machine to reduce the noise produced at the end of each stamping operation, consists of a two-stage telescopic gas pressure cylinder 10. A base 3 of the cylinder is fixed on the stationary part of the machine and the head 33 of an internal piston 14 is in permanent engagement with the reciprocating part 6. As the part 6 moves downwards, the piston 14 is retracted, but at first an external piston 13 remains stationary. There is therefore a small resistance to movement of the part 6. As the part 6 approaches the end of its downward movement at which noise is generated at the end of a stamping operation, the head 33 engages a ring 34 at the upper end of the external piston 3 so that the external piston also then starts to be retracted.

Abstract: This disclosure relates to a dampener particularly adapted to be connected to a load beam of a forming press wherein at an initial forming stage there is to be a higher than normal resistance to movement of the load beam. The dampener includes suitable lever arrangements which are coupled to fluid motors which resist the movement of the lever arrangements. The lever arrangements are actuated by a cam member carried by a movable press component which is coupled to the supporting pad of the press tooling.

Abstract: A gas-operated piston cylinder assembly arranged between upper and lower die members of a press. The lower end of the cylinder communicates with a source of high pressure gas and also communicates through a passageway with the upper rod end of the cylinder which is sealed from the surrounding atmosphere. The piston rod has a cross sectional area only slightly smaller than the piston. The passageway between the lower and the upper ends of the cylinder contains a lubricant impregnated member and a by-pass controlled by a check valve which allows gas flowing from the rod end of the cylinder to the lower end thereof to bypass the lubricant impregnated member.

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: 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: There is disclosed a hydraulic circuit of a press for the hydromechanical drawing of pressings or workpieces in a pressure chamber forming the drawing die which includes at least two spaces for the fluid separated from each other by at least one piston transmitter. At least one of the spaces for the fluid in the pressure chamber separated from the pressure fluid for the forming of the pressing by the piston transmitter is connected by means of a connection branch with a controlled throttle valve with the hydraulic unit of the main working cylinder of the press which drives the drawing punch of the press. To the space for the fluid in the pressure chamber, which is separated by the piston transmitter from the pressure fluid for forming the pressing, is connected a filling branch with a return valve incorporated by means of a hydraulic distributor in the circuit of a hydrogenerator for driving the main working cylinder of the press.

Abstract: Pressure regulating equipment for an air cushion, which has a check valve, an outlet of which is connected with a large capacity air cushion such as a balancer, diecushion, etc. of a press.