Abstract: A suspension system for a vehicle includes an extendable and retractable actuator disposed at each side of a frame of the vehicle and pivotally attached at one end to a vehicle bracket and at the other end to a suspension bracket. The suspension bracket includes an actuator portion, an axle portion and a suspension arm, with the actuator portion and the suspension arm pivotable relative to an axis of the axle portion. When the actuator is extended or retracted, the actuator portion pivots about the axis of the axle portion and imparts pivotal movement of a suspension arm about the axis to adjust a height of the frame of the vehicle. The actuator includes an elastomeric element disposed between an outer end of a slide rod and an outer end of a ram rod, with the slide rod movable to absorb sudden movements of the frame or wheel.

Abstract: A pile driving system for driving a pile. The pile driving system comprises a housing assembly, a hammer, a helmet member, and a lifting system. The housing assembly defines at least one vent opening is arranged at a first vent location along the drive axis, and at least one vent opening is arranged at a second vent location along the drive axis. When the hammer drops and is above the first vent location, ambient air flows from the main chamber through the vent openings formed at the first and second vent locations. When the hammer is below the first vent location and above the second vent location, ambient air flows from the main chamber through the vent openings formed at the second vent location. When the hammer is below the second vent location, air within the main chamber is compressed to preload the helmet member.

Abstract: A vane type hydraulic rotary actuator incorporates a fail-safe brake for preventing movement of the device's rotor relative to a housing in which the rotor is journaled. The brake has a spring-biased piston that is forced to a locked condition whenever applied hydraulic operating pressure acting on the vane falls below a predefined limit. The rotary actuator also incorporates an improved sealing arrangement that prevents egress of hydraulic fluid from a high pressure chamber on one side of the vane to a low pressure chamber on the opposite side of the vane.

Abstract: A fluid drive system that can be used to drive a vehicle and has energy regeneration and storage capabilities. The fluid drive system includes an electrical energy supply source mounted on the vehicle, at least one electrical motor electrically connected to the electrical supply source, and a hydraulic pump driven that may be of the variable displacement type by the electrical motor. The fluid drive system may also include a low pressure hydraulic fluid supply tank supplying fluid to the hydraulic pump, at least one pneumatically charged accumulator tank for storing pressurized hydraulic fluid, a combination hydraulic motor and pump that may also be of the variable displacement type being alternately driven by the hydraulic pump and the pneumatically charged accumulator tank; and an electrical regeneration system for regenerating the electrical energy supply. The electrical regeneration system may be powered by hydraulic fluid from the combination electrical motor and pump.

Abstract: A hydraulic cylinder comprising a cylinder, a piston which is adjustable in the cylinder, and at least one pressure connection which is disposed in the vicinity of an end position of the piston and through which a pressure fluid can be introduced into the cylinder, is characterized in that the piston is provided with a valve element which can cooperate with the pressure connection, in order to cover the pressure connection when the piston approaches its end position, and in order to uncover the pressure connection when pressure fluid is introduced into the cylinder.

Abstract: A pair of throttle valves are installed to first and second installation holes of a cylinder tube, respectively. The throttle valve comprises a rotatable member, a needle which is engaged with the rotatable member and which controls the flow rate of a pressure fluid flowing through first and second bypass passages formed in each of the first and second installation holes, a covering member which covers each of said first and second installation holes, and a stopper ring which prevents the displacement of the rotatable member.

Abstract: An engine valve actuation system includes an engine valve moveable between first and second positions, a valve actuation assembly connected to move the engine valve between the first and second positions, a fluid actuator configured to selectively modify a timing of the engine valve in moving from the second to the first position, a source of fluid, and a pair of passages in the cylinder that allow fluid to flow from the chamber to the fluid source. The fluid actuator includes a cylinder and a piston at least partly defining a chamber. The piston is slidably movable in the cylinder between a first position and a second position, and blocks at least a portion of one of the passages at an intermediate position between the second position and the first position to reduce fluid flow from the chamber when the piston moves from the second position toward the first position.

Abstract: A pressurized medium activated working cylinder with a piston that can move longitudinally in a cylinder chamber between two end positions has a device for damping the movement of the piston when it approaches each end position. This device comprises, e.g., a damping pin arranged at the cylinder cover, which is inserted into a corresponding receptacle opening in the piston when the piston approaches the end position. The damping pin and the receptacle opening are arranged eccentric to a side of the piston rod, wherein the receptacle opening opens into a part projecting into the cylinder chamber.

Abstract: A hydraulic control device having a hydraulic actuator with a cylinder space, in which a piston is accommodated. In the cylinder space the piston bounds a first chamber and second chamber. The housing is provided with a first and a second connection for the supply and discharge of hydraulic fluid, in communication with the first and the second chamber by way of a first and a second opening. The damping means are achieved by the fact that the piston is provided with shut-off means, which are designed to shut off the second opening of the cylinder space before the piston/piston rod assembly reaches an end position. The hydraulic actuator is further provided with a third connection, which by way of a third opening is in communication with the second chamber in any position of the piston. The hydraulic control device further comprises a throttling facility.

Abstract: At a step of pressurizing a workpiece after reducing a speed of a piston rod at an end of a forward stroke of the piston rod by restrictively allowing compressed air to flow out of an exhaust-side pressure chamber, operation of a rapid exhaust valve is triggered by reduction of internal pressure of the exhaust-side pressure chamber to lower pressure than internal pressure of a pressurizing-side pressure chamber to thereby directly open the exhaust-side pressure chamber into the atmosphere through the rapid exhaust valve and rapidly reduce back pressure of a main piston remaining in the exhaust-side pressure chamber.

Abstract: In a linear actuator in which a slide table on a pedestal is caused to reciprocate linearly by two air cylinder mechanisms mounted in the pedestal, exhaust holes are provided to positions adjacent to ports, flow rate restricting mechanisms for restricting a flow rate of exhaust are provided between the exhaust holes and the ports, and pieces of cushion packing for being positioned over one of through holes of the ports on an exhaust side immediately before the piston reaches a stroke end is provided to an outer peripheral face of the piston to cause compressed air in pressure chambers to be discharged from the exhaust hole through the flow rate restricting mechanism.

Abstract: To facilitate assembling work of a check valve to improve workability at the time of assembling a lift cylinder. In a lift cylinder, a check valve 4 disposed in a shaft center part of a piston 2 has a valve seat member 41, a poppet valve, a bias spring 43 and a spring receiver 44, whereas a cushion ring 21 movably held on the piston 2 is placed in contact with an open end of the valve seat member 41 to thereby prevent it from slipping out of a predetermined position.

Abstract: In a linear actuator in which a slide table on a pedestal is caused to reciprocate linearly by two air cylinder mechanisms mounted in the pedestal, exhaust holes are provided to positions adjacent at ports and, flow rate restricting mechanisms for restricting a flow rate of exhaust are provided between the exhaust holes and the ports, and pieces of cushion packing for being positioned over one of through holes of the ports on an exhaust side immediately before the piston reaches a stroke end are provided at an outer peripheral face of the piston to cause compressed air in pressure chambers of the actuator to be discharged from the exhaust hole through the flow rate restricting mechanism.

Abstract: A cushion hydraulic cylinder is provided with a series of longitudinally separated metering orifices in the wall of the cylinder through which exhausted fluid is expelled. As the piston extends towards these metering orifices a seal sequentially cover and uncovers the metering orifices further restricting the flow of exhausted fluid. In addition the piston is provided with radial bores having one or more longitudinal passages which are in fluid communication with either the piston side of the cylinder or the rod side of the cylinder. The first longitudinal passage is provided with a passage orifice through which exhausted fluid can flow after a circumferential piston seal reopens a previously blocked metering orifice. The second longitudinal passage maybe provided with a check valve which prevents the flow of fluid in one direction.

Abstract: A multi-speed slit valve apparatus and method of actuating a slit valve apparatus at least at two distinct speeds is provided. The slit valve apparatus includes a pneumatic cylinder 210 having a primary channel 254, 266 and auxiliary channel 258, 270 at each end, wherein the auxiliary channels 258, 270 have a cross sectional area smaller than that of the primary channels 254, 266. A piston 226 defining a front volume 240 and a back volume 242 is disposed in the cylinder 210 and is reciprocally actuated by a compressed fluid such as air. At a predetermined stage during the cylinder's out-stroke and in-stroke the primary channels 254, 266 become sealed from the front and back volumes 240, 242, respectively, such that during the remainder of the stroke the fluid is biased to exhaust through the auxiliary channels 258, 270.

Abstract: A fluid pressure cylinder (1) includes two cylinder end walls (6',6"), a cylinder tube (2) and a piston (3), which is axially movable inside the cylinder tube, wherein at least one of the cylinder end walls is provided with an outward housing portion (7;60) and, located therein, an inward insert portion (8;61) which comprises a portion of at least one fluid channel belonging to the cylinder. The cylinder is distinguished in that the housing portion axially contacts the cylinder tube under force transmission, and that the insert portion includes an integral valve seat (12,16,22") of a fluid valve which is located in said fluid channel.

Abstract: The invention concerns a device in an piston cylinder aggregate including a valve element (8) which comprises a valve body (9) for choking the flow in a fluid channel (6) in co-operation with a valve opening (7), wherein the device is arranged in a bore (11) in an end wall (1) of the piston cylinder aggregate and wherein the valve element (8) is provided with a setting means (10) to allow adjustment from the outside of the end wall.

Abstract: A rodless pneumatic cylinder includes main exhaust ports defined by the open ends of a pair of fixed tubular members that extend, respectively, into the cylinder body from its opposed ends. The main piston of the rodless cylinder has an axial bore formed in it in which is slidably mounted a small piston that serves mutually to isolate the working chambers of the cylinder. The bore carries seals adjacent to its opposed ends whereby, during motion of the piston, the bore sealingly receives one or other of the tubular members at a predetermined stage during the motion thereby effectively closing the main exhaust port. During further motion of the piston, air can, therefore, exhaust only through a throttled auxiliary exhaust port and such further motion of the piston is thus cushioned. The arrangement provides for a greater extent of cushioning relative to known arrangements in which the working chambers are mutually isolated by a barrier fixedly secured in the bore.

Abstract: A hydraulically operated piston apparatus including an outer cylinder having an inner telescopically received piston rod. An elongated slot forms a hydraulic fluid outlet through the wall of the cylinder adjacent the closed end of the cylinder. The piston extends from the open end of the cylinder and, in one aspect of the invention, is rigidly secured to an examination chair to provide for vertical adjustment of the chair. One end of the piston is adapted to gradually block the elongated fluid outlet slot to provide for smooth, linear deceleration of the piston to a stop at the end of its stroke.

Abstract: A relief valve 23 serving as cushion pressure adjusting means in a cushion mechanism is provided on a support member 4, and the support member 4 is rotatably mounted on covers 2 and 3 of a pneumatic cylinder in order to facilitate adjustment of relief pressure.

Abstract: Snubbers are useful in dampening inertia loads at the end of stroke movement of a hydraulic motor. The known snubbers usually restrict fluid flow therethrough in the non-snubbing mode thereby slowing the response of the motor in the opposite direction. The subject self-energizing snubber includes a snubber piston which is moved from a first operative position to an intermediate operative position by contact with an end surface and then hydraulically moved to a second position by differential pressure established between an actuating chamber and a fluid passage. The snubber piston defines a variable rate flow path continuously communicating the actuating chamber with the passage. A maximum flow rate is established through the flow path at the first operative position while a minimum flow rate is established through the flow path at the second operative position.

Abstract: An axial piston-type servomotor uses control connections on the working cylinder and corresponding control edges on the working piston, together with selector valve apparatus for controlling the working piston into a central stroke position.

Abstract: An improved cylinder structure for a pneumatically operated tool, which is characterized in the two air tight chambers defined at the front and rear ends of the cylinder so that the air confined therein can produce reaction pressure respectively to reduce the operation speed of the piston when it approaches the dead ends of the cylinder and further to bounce back the same in a rapid manner whereby the impact of the moving piston can be effectively reduced at the dead ends and the noise and vibration generated as a result of high speed impact on the ends of the cylinder can also be minimized; moreover, the piston can be protected from being deformed and damaged due to constant direct impacts.

Abstract: A hydraulic actuator system, for use in an aircraft, and in which the servo fluid supply to the system is used to provide for the operation and cooling of the system. The system comprises a hydraulically operated piston mechanism including at least one hydraulically operated piston, a servo vluid input to the system, which is connected in a ring main to a first side of the hydraulically operated piston, a servo fluid output from the system, which is connected in a ring main to a second side of the hydraulically operated piston, a variable restrictor arrangement which provides an interface between the servo fluid input ring main and the servo fluid output ring main, and a restrictor arrangement positioned in the servo fluid output side of the system. The position of the piston of the hydraulic piston and the adjustment thereof, are controlled by the restriction applied on the system by the variable restrictor arrangement.

Abstract: A hydraulic door opening or closing device comprises a hydraulic fluid pump motor having two ports connected to each end of integral dual manifold and operating cylinder apparatus by way of two branch fluid lines. One branch line is fluidly connected to a particular end of the operating cylinder by way of a directional flow valve. The other branch line to the same end of the cylinder is fluidly connected to the cylinder by way of an associated manifold. Fluid communication with the cylinder through the manifold is accomplished by providing a plurality of valved openings linearly disposed along the end of the cylinder between the manifold and the cylinder. As a piston of the operating cylinder passes these openings, a door coupled to the piston is automatically slowed as fluid on the drive side of the piston is returned through the openings to the hydraulic fluid pump.

Abstract: A railway car hydraulic cushioning unit prevents the mixing of gas and hydraulic fluid in chambers interiorly and exteriorly of a high pressure cylinder unit by strategic placing of metering ports through the cylinder wall at positions below the level of gas in the exterior chamber. The invention is furthermore directed to a method for converting hydraulic cushioning units adapted for connection to an external spring operated restoring mechanism to a self-contained gas return unit.

Abstract: A cushioning system for a fluid power cylinder includes a first passage for the flow of fluid to and from the space between the piston and end cap closure of the cylinder, and a second passage including a throttling valve for throttling the flow of fluid from the space as the piston approaches the end cap closure to cushion the piston. An O-ring seal is centered in the first passage and relative to a seal actuating sleeve on the piston by a plurality of spaced projections extending outwardly from the O-ring. An improved method of forming the valve seat of the throttling valve is also disclosed, wherein the second passage is deformed to substantially conform to the width and shape of the throttling valve and provide substantially zero clearance between the valve and its valve seat.

Abstract: An improved mechanism is provided for controlling the relative pivoting movement of two members about a main pivot axis as effected by two hydraulic motors. Each hydraulic motor is a double-acting piston-cylinder type that is fully extended when its respective line of action intersects the main pivot axis. Each hydraulic motor has an end port at each end. Two spaced-apart intermediate ports are provided within the piston stroke length of each motor. Pilot-actuated top dead center-selector valves are provided for reversing the flow to one of the hydraulic motors in response to a pressure differential between an end port and an intermediate port of the other of the hydraulic motors. Decelerator selector valves are provided to normally direct the return flow from the hydraulic motors so as to bypass a hydraulic cushioning circuit.

Abstract: The moving means is for use in moving an operative member between an out-of-the-way position and an operative position by a movement having a linear component in a vertical direction and a rotary component about a vertical axis. A first shaft on which the operative member is mounted is movable vertically by a first piston and cylinder assembly and is in driving connection with a second shaft relative to which it can move vertically. A second piston and cylinder assembly is operable through a screw-threaded connection to cause its piston to rotate thereby rotating the second shaft and hence the first shaft about the vertical axis.

Abstract: This disclosure is directed to a method and combined apparatus for converting or translating the immense potential energy of the deep sea water into useful work by providing a jointly enclosed environment in a column or mass of a fluid in which a container or vessel is maintained under a pressure which is less than that of the pressure exerted by the deep sea water. The apparatus consists of two, in all respects entirely independent, machines with individual performances and with entirely separated energy consumptions operatively connected to achieve the end result.A fluid activated work producing machine is disposed so as to be actuated by the continuous differential in pressure between the pressure exerted by the continuous deep sea water and the low pressure of the environment in an associated container or vessel.

Abstract: A novel rotary actuator utilizes viscosity of the oil and prevents the oil leakage, without using the sealing member to the vane. The instant device installs the flanges in parallel and fixes the vane therebetween, and sets within the cylinder the rotor keeping the stopper therebetween, not fixing it, and the radial bearings at both sides of the cylinder to support the stopper, whereby a fine clearance is maintained between the flange and the inner wall of the cylinder. The rotor is formed in order of machining into flanges, small diameter portions and a rotary shaft. The vane is formed by cutting the material of doughnut shape into a sector.

Abstract: An hydraulic booster has a housing provided with a bore, an inlet connected to a source of pressure fluid, and an outlet connected to a reservoir for fluid, a boost piston being advanced in the bore in response to pressurization of a boost chamber, the boost chamber being pressurized under the control of a valve mechanism operative in response to a load applied to an input member. Two connections are provided between the source and the boost chamber, both connections being closed when the booster is inoperative, and when the booster is operated the first connection is opened following initial movement of the input member, and the second connection is opened following initial movement of the boost piston in response to pressurization of the boost chamber. Thus the booster is in a closed center mode when inoperative, but operates in an open center mode. The connections are preferably controlled by valves. The input load may be applied in tension or compression.

Abstract: A system for resiliently supporting a load at a reference height includes a hydraulic cylinder for resiliently supporting a load about a reference height and an accumulator which cooperates with the cylinder for flowing hydraulic fluid therebetween in response to varying loads imposed on the cylinder. A valve is provided for dampening the rate of fluid flowing between the cylinder and the accumulator and a metering valve coacts with the cylinder for adjusting the reference height about which the load is supported.

Abstract: Helically splined hydraulic actuator provided with hydraulic cushioning and rapid initiation of movement. The actuator is provided with an elongated cylindrical bearing integral with the shaft of the actuator for increasing radial and moment load-carrying capacity of the actuator without increasing its length.

Abstract: The invention disclosed comprises an air cushion system that utilizes a two-diameter piston and a floating bushing to create an effective air cushion seal which prevents the piston from hitting the barrel bridge.

Abstract: A cushion valve for a hydraulic piston. The valve includes two inlet ports each connected into the same end of the cylinder. One port leads directly to an outlet while the second port feeds to the outlet through a floating, restricted flow orifice to provide a cushioning effect for the 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: A hydraulic cylinder arrangement of the type wherein the opposite ends of a cylinder are connected selectively to either a pump or sump by a control valve. Each end of the cylinder is provided with a pair of oppositely acting, uni-directional check valves, each connected to a port on the control valve by an individual conduit. The four check valves are so arranged that all the fluid discharged from either end of the cylinder in response to the reciprocation of the piston therein is constrained to flow to sump before it is pressurized and returned to the cylinder.

Abstract: A fluid pressure actuated device for use with material splitting machines of the type described, the device comprising a cylinder, a double acting piston movable in the cylinder by pressurized fluid, the piston being operatively connectable to the pressure roller of the machine for, in use, effecting withdrawal of the pressure roller from a cutting plane in response to movement of the piston from a first extreme position towards a second extreme position, said cylinder having first and second ports communicating with opposite ends of the piston and arranged so that in use pressurized fluid applied to the first port while the second port is connected to exhaust will cause the piston to move from said first extreme position to said second extreme position so as to effect maximum withdrawal of the pressure roller to permit cleaning of the scrapers and the cutting region, and a third port between the first and second ports and arranged so that in use pressurized fluid applied to the first port while the third por

Abstract: An automotive type carburetor has a rotatable lever connected to the choke valve and to an actuating link having a pin-slot type connection to an engine vacuum controlled servo, a fast idle cam is connected to the choke lever by a lost motion pin and slot connection and to a second actuating link also connected to the servo by a pin-slot type connection, the servo pin-slot connections to the links are such that when the engine is started with the choke valve closed and the fast idle cam on its high cam step, vacuum applied to the servo during a first stage movement rotates the choke lever to open the choke valve and subsequently during a second stage movement both the choke lever is rotated further and the fast idle cam is rotated off its fast idle step position, to reduce the opening of the throttle valve while opening further the choke valve, the first stage movement of the servo moving a diaphragm and plunger until the plunger blocks a main vacuum feed line to the diaphragm, the second stage movement movin

Abstract: A hydraulic jack suitable for powering a large load such as an elevator or a drawbridge. In a first embodiment the hydraulic jack telescopes at a uniform rate over its entire distance of extension and includes a plunger member telescopingly enclosed within a sleeve member which, in turn, is telescopingly enclosed within a cylinder member, with the cylinder member encircled by an oil jacket within which the cylinder member is capable of limited angular movement. Means are provided for angularly aligning the various members within one another. Means are also provided to restrict the flow of hydraulic fluid as the hydraulic jack reaches a limit of its travel. Hydraulic jacks in accordance with the present invention can be coupled together in systems to lift large loads.

Abstract: Fluid is forced from a reservoir into an evacuated chamber by forcing a plunger into the reservoir. When it is desired accurately to stop the flow of the fluid, the plunger is withdrawn and concurrently the pressure in the reservoir is reduced to that of the evacuated chamber by means of vacuum pump connected to the reservoir.

Abstract: Herein disclosed is a hydraulic actuator which comprises an outer cylinder; an inner cylinder attached at its one end to the axial inner one end of the outer cylinder in coaxial relation with the outer cylinder to define an annular gap between the outer and inner cylinders; a piston having a hollow bore axially extending from its one end to the other end and closed at the other end and slidably received in the annular gap; and a locking mechanism temporarily locking the piston with the outer cylinder upon the farthest movement of the piston to the other end thereof; the locking mechanism including a locking member coupled with one end portion of the piston and which is radially movable, a ram resiliently received in the other end of the inner cylinder and having an inclined stepped portion and a hollow bore axially extending from its one end to the other end and opened at the other end, and an annular locking groove formed at the inner periphery of the other end of the outer cylinder, whereby the locking memb

Abstract: A shock absorber of the kind having an infinitely adjustable damping characteristic comprises a main cylinder containing a piston fixed to a piston rod which extends from the main cylinder and liquid within the cylinder acting on the piston. The main cylinder has openings for the flow from it of the liquid upon movement of the piston in the cylinder and an adjustment device is provided for restricting these openings to provide the adjustment of the damping characteristic. The openings are situated in the peripheral wall of the main cylinder and are axially spaced apart from each other in positions in which they are successively passed over and closed by the piston as the piston approaches the end of its stroke at one end of the main cylinder in a damping movement. Thus the flow of liquid from the main cylinder is progressively further throttled by closure of the openings as the piston approaches the end of its movement.

Abstract: A large bore, long stroke, low friction, hydraulic actuator having dual hydrostatic bearings permitting elastic deformation of the piston rod while inhibiting metal to metal contact between either the piston head or the deformed piston rod and the walls of the hydraulic cylinder. The actuator employs a safe and highly reliable metering orifice cushion decelerating means. Piston displacement is constantly monitored by a completely internal, magnetostrictive, sonic delay line displacement measuring means.

Abstract: A device for accelerating the initial stroke of hydraulic jacks, comprising a cylinder, a piston provided with sealing-rings, said cylinder fluid feed-orifices and orifices for exhausting fluid through a plurality of calibrated ports arranged in rows in the cylinder periphery at both ends thereof, characterized in that at least one piston-ring (S.sub.2, S.sub.4) at one end of piston (P) is mounted in its respective groove (R.sub.1) with a certain amount of axial and lateral clearance, said groove communicating with the bottom of the piston through at least one port (B.sub.1).

Abstract: In a piston/cylinder assembly in which the power strokes of the piston are damped, there is a pressure chamber on one side of the piston and an external pipe which serves for the discharge and supply of pressure medium. A restricted zone is provided in a pipe which connects the external pipe to the pressure chamber for limiting the flow of motive gas therethrough. A return pipe connects the external pipe with the pressure chamber and has a one-way valve which closes the return pipe when the pressure medium is discharged from the pressure chamber and opens it when pressure medium is supplied from the external pipe. A connecting line extends from the external pipe to the pressure chamber, and the piston has a member projecting therefrom engageable in the connecting line when the damping movement begins to close that line.

Abstract: A hammer and more particularly a fluid operable hammer wherein alternating impetus provided by pressurized liquid and gas means actuates a reciprocable hammer piston to generate repetitive impact loads.

Abstract: A shock absorber of the kind having an infinitely adjustable damping characteristic comprises a cylinder containing a piston fixed to a piston rod which extends from the cylinder and liquid within the cylinder acting on the piston. The cylinder has openings for the flow from it of the liquid upon movement of the piston in the cylinder and means are provided for restricting these openings to provide the adjustment of the damping characteristic. The openings are situated in the peripheral wall of the cylinder and are axially spaced apart from each other in positions in which they are successively passed over and closed by the piston as the piston approaches the end of its stroke at one end of the cylinder in a damping movement. Thus the flow of liquid from the cylinder is progressively further throttled by closure of the openings as the piston approaches the end of its movement.

Abstract: In glassware forming apparatus the reciprocation of a transfer carriage between two operating positions is effected by a cylinder and piston device in which the traverse of the piston is progressively cushioned at the ends of the piston stroke. Members, which are slidably mounted in the piston and protrude from it, close exhaust outlets in an end wall of the cylinder when the piston is at different predetermined distances from the end wall, and these members are positioned in the piston by the action of the end wall for similarly co-operating with corresponding exhaust outlets in the opposite end wall of the cylinder.