Abstract: A position-sensitive shock absorber 1 comprising an internal fluid space 3, a piston 5 and fluid system 7. The piston divides the internal fluid space into a compression side 3a and a rebound side 3b. The fluid system fluidly connects the compression side to the rebound side. The fluid system comprises a chain 9 of three or more external fluid spaces 9a, 9b, 9c, 9d external to the internal fluid space, space flow-control-arrangements 27i, 27ii, 27iii, and passage arrangements 25a, 25b, 25c, 25d mutually spaced along the internal fluid space. Each of the space flow-control-arrangements is configured to mutually fluidly connect a respective adjacent two of the external fluid spaces. Each of the external fluid spaces has a respective one of the passage arrangements. Each of the passage arrangements comprises one or more passages opening to the internal fluid space.

Abstract: In one embodiment, a gas spring having a travel control includes positive and negative chambers and a valve mechanism that controls the fluid communication between the chambers. The valve mechanism includes a valve bore that while only moving a small amount, allows for large changes in gas spring travel length.

Abstract: A hydraulic buffer assembly for use in a paint gun includes a sealed housing having first and second ends and an interior including a chamber containing a hydraulic fluid. A piston assembly including at least one piston rod and a piston head is axially movable through the interior of the housing, wherein the piston head includes at least one orifice through which hydraulic fluid flows when the piston assembly is moved under load. The buffer assembly is configured to decrease or slow the firing rate of an automatic paint gun.

Abstract: An aircraft landing gear assembly includes a mechanical structural linkage having a shock absorber and a linkage abutment which are biased apart by a mechanical spring. The force required to deform the spring sufficiently to place the linkage abutment at a predefined distance with respect to the shock absorber abutment is less than the breakout force of the shock absorber.

Abstract: The patent was disclosed a telescopic mechanism in a telescopic hitch buffer device for use in high speed electric multiple unit (EMU) trains. The telescopic mechanism comprises a compression rod (2) located inside a movable housing (1) of said hitch buffer device, one end of said compression rod (2) being connected to the movable housing (1), and a bearing connector (3) encasing the compression rod (2). A guiding barrel (4) is fixedly mounted outside the bearing connector (3). An extension/retraction driving mechanism (9) is provided between the guiding barrel (4) and the movable housing (1). A locking mechanism comprises protrusions (6) distributed at the other end of the compression rod (2), and grooves (7) in engagement with protrusions (6) on the inner wall of the bearing connector (3).

Abstract: A railcar cushioning device has a hydraulic cylinder holding pressurized fluid. The cylinder has a cylinder body with an inner chamber and a reservoir chamber. A piston is movably positioned in the inner chamber. The cylinder body has a bleed opening allowing bleed flow from the inner chamber to the reservoir chamber. A bleed orifice valve in the bleed opening has a valve housing and a poppet received in the valve housing that moves to allow and restrict fluid flow through a bleed flow path based on the pressure of the fluid. The poppet has an orifice channel allowing a restricted fluid flow through the valve housing when the pressure in the inner chamber is greater than the pressure in the reservoir chamber.

Abstract: The invention relates to a device for damping tractive and compressive forces which damps forces acting in both the tractive and compressive directions over a wide range, the device operating to be free of wear and having small overall length. The device has a damping system held in a housing and which has a resilient unit and a hydraulic damping arrangement, and a piston rod which is displaceable in the longitudinal direction relative to the housing of the damping system. Formed in an end region of the piston rod is a piston head which is held in a first hydraulic chamber of the hydraulic damping arrangement to be displaceable. If there is longitudinal movement of the piston head relative to the first hydraulic chamber, hydraulic fluid flows in a throttled manner, via a transfer-flow system, to a second hydraulic chamber of the hydraulic damping arrangement.

Abstract: The invention relates to a device for damping tractive and compressive forces which damps forces acting in both the tractive and compressive directions over a wide range, the device operating to be free of wear and having small overall length. The device has a damping system held in a housing and which has a resilient unit and a hydraulic damping arrangement, and a piston rod which is displaceable in the longitudinal direction relative to the housing of the damping system. Formed in an end region of the piston rod is a piston head which is held in a first hydraulic chamber of the hydraulic damping arrangement to be displaceable. If there is longitudinal movement of the piston head relative to the first hydraulic chamber, hydraulic fluid flows in a throttled manner, via a transfer-flow system, to a second hydraulic chamber of the hydraulic damping arrangement.

Abstract: A plate for a compressible elastomeric spring is formed from a predetermined material and has each of a first substantially flat surface, an opposed second substantially flat surface, a predetermined thickness and a predetermined shape. Prongs are provided on at least one surface of the plate and extend outwardly at a predetermined angle relative thereto for mechanically interlocking the plate with an axial end an abutting elastomeric pad. Prongs may have trapezoidal shape. An axial aperture may be also provided with the prongs located on or in close proximity to a peripheral edge of the apertures. Prongs may be also provided on the opposed surface of the plate for mechanically interlocking the plate with an axial end of another abutting elastomeric pad. Annular ring-like projections are also provided for mechanically interlocking the plate to at least one elastomeric pad.

Abstract: A compressible resilient elastomeric pad includes a body defining a central axis, the body formed from a predetermined material and having each of a peripheral side surface, a first axial end and a second axial end, each of the first and second axial ends having a flat surface thereof disposed normal to such central axis. A first raised projection is centrally formed on the flat surface of the first axial end and a second raised projection is centrally formed on the flat surface of the second axial end. A first groove is formed in the flat surface of the first axial end in abutting relationship with a peripheral side surface of the first projection and a second groove is formed in the flat surface of the second axial end in abutting relationship with a peripheral side surface of the second projection.

Abstract: A draft gear assembly including a housing having an open front and closed rear portions. A compressible cushioning element is positioned within the rear portion with a seating arrangement abutting one end thereof adjacent the open front portion. A friction cushioning element is provided in the open front portion of the housing. A spring release mechanism continuously urges the friction cushioning element outwardly from the compressible cushioning element thereby releasing such friction cushioning element after compression of such draft gear assembly. A compressible cushioning element includes a hydraulic cylinder having a slidable piston to define a high pressure chamber and a low pressure chamber.

Abstract: A rail car cushioning1 device is provided for connecting to a coupler. The rail car cushioning device includes an arrangement of a hydraulic cylinder, a piston assembly, and at least a valve assembly, which are configured with cooperating features to allow the device to be switchable between a locked mode and a cushioning mode.

Abstract: A friction-type draft gear assembly includes a housing having an open front and closed rear portions. A compressible cushioning element is positioned within the rear portion with a seating arrangement abutting one end thereof adjacent the open front portion. A friction cushioning element is provided in the open front portion of the housing. A spring release mechanism is adapted for continuously urging the friction cushioning element outwardly from the compressible cushioning element thereby releasing such friction cushioning element after compression of such draft gear assembly. A compressible cushioning element includes a hydraulic cylinder having a slidable piston to define a high pressure chamber and a low pressure chamber. A metering pin disposed within the piston has aworking portion of a decreased diameter for increasing shock absorbing capacity of such draft gear assembly.

Abstract: A traction/compression buffer for coupling devices on rail and wheel-mounted vehicles comprises a housing (1) and a piston element (3), which projects out of said housing on one side and which can be moved out of a zero position in two directions against the resistance of a spring device and a damping device. A hydraulic damping device is provided for damping the return movement of the piston element (3) out of the position in which it is drawn out of the housing (1) in the direction of the zero position. Said hydraulic damping device comprises a ring-shaped hydraulic working chamber (32) that surrounds the piston element (3) and that is connected to an overflow chamber (29) by at least one overflow channel (31).

Abstract: The gas-hydraulic shock absorber assembly comprises a sleeve member and a ram member movable relative to the sleeve member. In the interior of the ram member, a gas chamber is provided that is pressurized by means of a gas. In the interior of the sleeve member, an oil chamber is provided that is filled with a hydraulic medium and which decreases in volume the more the ram member is moved relative to the sleeve member. Between the two chambers, a gas-hydraulic control assembly is provided. Upstream of the control assembly, there is a bleeding assembly, comprising a transfer channel opening into a portion of the oil chamber remote from the control assembly. Further provided is a bleeding channel, opening into an upper portion of the oil chamber and connecting the transfer channel to the control assembly when the shock absorber assembly is at rest. The bleeding assembly comprises several channels connecting the oil chamber to the control assembly and comprising each a V-shaped valve flap to close the channels.

Abstract: A self-positioning cushioning device adapted to be mounted in the end of a rail car sill includes a hydraulic cylinder and yoke. A piston rod extends from the cylinder and is joined to one end of a yoke. The other end of the yoke is joined to a rail car coupler through a drawbar. A preloaded stack of elastomer pads is confined in a pocket in the yoke between a pair of stop plates which extend laterally of the yoke to engage stops during movement of the yoke, rod and piston in response to buff and draft impacts. The cylinder is filled with pressurized hydraulic fluid which maintains the piston in a central neutral position with the stop plate adjacent to coupler held against stops on the rail car sill. Buff impacts are cushioned first by the cylinder and at the end of the stroke by both the cylinder and the spring. Draft impacts are cushioned by both the cylinder and the spring.

Abstract: A railcar cushioning device with a gas charged cylinder and a piston contained in the cylinder for cushioning buff and draft impacts. A spring assembly is contained in the cylinder between the piston and an end of the cylinder to locate the piston in a neutral position.

Abstract: A railcar cushioning device with a gas charged cylinder and a piston contained in the cylinder for cushioning buff and draft impacts. An elastomer spring is contained in the cylinder between the piston and an end of the cylinder to locate the piston in a neutral position.

Abstract: A pressure relief valving system for a rail car cushion device including several preload valves mounted in the cylinder wall of the cushion device each having both spring biasing and hydraulic biasing applied to retain a valve piston against a seat until a preload pressure is reached, and each preload valve capable of transitioning from a closed mode to an open mode at a preset preload pressure.

Abstract: A railcar cushioning device includes an elastomeric spring and a hydraulic shock absorber member. The fluid accumulator is located outside of and above the fluid chambers. The accumulator is in communication with the fluid chamber in a non-stroked position, causing entrapped air to be displaced by the fluid, into the accumulator. Free of air, the shock absorber immediately responds to impact forces. The elastomeric spring reduces peak impact forces and returns the piston of the shock absorber to its non-stroked position. The elastomeric spring also absorbs draft forces.

Abstract: A valving system for a rail car cushion device including several pressure control relief sequence valves (PCRS) mounted in the cylinder wall of the cushion device each having hydraulic biasing applied to retain a valve piston against a seat until a preload pressure is reached, with one or more optional spike control (SC) valves mounted in a cushion device piston head.

Abstract: A shock absorber for a railcar locates within a center sill of the railcar. The shock absorber has a housing that moves relative to the center sill. A backstop is welded to the center sill for retaining the piston shaft. The backstop has a top, a bottom and two parallel sides. The height of the backstop from the bottom to the top is substantially less than the center sill. The sides of the backstop are welded to the sidewalls of the center sill in a position which provides an upper clearance between the top of the backstop and the top wall of the center sill and a lower clearance between the bottom of the backstop and the bottom of the center sill.

Abstract: A double acting center-of-car cushioning device mounted in the sliding sill of a rail car includes two pistons and rods, two pressure cylinders and mirror image sets of flow orifices in the pressure cylinders. The piston rods extend out from ends of the pressure cylinders and engage a fixed sill of the rail car. Movement of the pistons within the pressure cylinders forces fluid through the flow orifices resulting in efficient dampening.

Abstract: A railcar cushioning device includes an elastomeric spring and a hydraulic shock absorber member. The fluid accumulator is located outside of and above the fluid chambers. The accumulator is in communication with the fluid chamber in a non-stroked position, causing entrapped air to be displaced by the fluid, into the accumulator. Free of air, the shock absorber immediately responds to impact forces. The elastomeric spring reduces peak impact forces and returns the piston of the shock absorber to its non-stroked position. The elastomeric spring also absorbs draft forces.

Abstract: A railway buffer capsule comprising a hollow cylindrical plunger slidably mounted in a cylinder. The cylinder is closed at one end. The plunger is closed at its outer end, and in its inner end is formed a fixed area orifice of flow restricting dimensions. A floating piston slides in the bore of the plunger and separates a liquid reservoir from the remainder of the interior of the plunger which comprises a gas containing space. A stepped piston has its larger diameter exposed to pressure in the reservoir and its smaller diameter end adapted to seat and close the orifice and be exposed to compression chamber pressure. The combination of the stepped piston and the orifice is a multiplier valve which multiplies the resistance of the compressed gas to lengthwise compression of the buffer.

Abstract: A railcar shock absorber has neutral position in which the piston is spaced between buff and draft ends of the cylinder. An external spring is mounted to the shock absorber. A slider rod has one end mounted to the coupling to move relative to the frame of the railcar. The spring has retainers on each end, and the slider rod passes through the retainers. One of the retainers is stationary relative to the frame. The other retainer floats relative to the frame and will abut a neutral stop of the frame when the spring is in the maximum length position. An engagement member on the slider rod will further compress the spring if a draft shock occurs from the neutral position. If a buff shock occurs from the neutral position, the engagement member moves away from the floating retainer.

Abstract: A railcar cushioning device for absorbing impact between railcars is provided having a hydraulic cylinder containing hydraulic fluid. A piston locates within the cylinder and is movable relative to the cylinder between an extended position and a contracted position in response to draft and buff forces. First and second sensors are provided with the piston and cylinder for detecting movement of the piston and cylinder substantially between the contracted and extended positions. By means of a suitable logic circuit or microprocessor, the period of time that it takes for the piston and cylinder to move between the contracted and extended positions can be monitored to determine if the period of time is less than a preselected amount thus indicating that the cushioning unit has failed. A counter may also be provided to count the number of times that the cushioning unit has failed.

Abstract: A rail car has a sliding sill located within a fixed frame and a shock absorber for absorbing shock. The shock absorber has a housing with inner and outer chambers containing oil and gas. A piston extends from the housing. The housing has an end plate on its end which engages a frame stop. The housing has a base end which engages another frame stop. Limiting stops formed on the housing limit the amount of buff movement allowed.

Abstract: An end-of-car coupler includes a hydro-pneumatic cushioning device. The latter has a ported tube separating the hydraulic cylinder chamber from an outer annular chamber containing gas. Each port is fitted with a valve, the obturating member of each valve being a differential area piston. The valves are all closed until subjected to a certain threshold force by movement of the plunger in the cylinder when all those valves between the plunger and the end of the cylinder chamber open to allow liquid flow between the two chambers.

Abstract: A railway car cushioning device is provided for minimizing slack between railway cars. The cushioning device is provided with a piston and piston rod disposed within the cylinder. The cylinder is filled with an oil and gas mixture. A housing surrounds the cylinder providing a fluid recovery reservoir defined by the space between the outer wall of the cylinder and the housing. At one end of the cylinder is a bulkhead and at the other end is a cylinder head. The piston rod extends through a hole formed in the cylinder head and is joined to the sill of a railcar. A coupler is joined to the cushioning device for coupling to another railway car. A series of pressure relief valves are provided and engaged with egress ports formed in the cylinder wall between the bulk head and the piston when the piston is in an extended position. The pressure relief valves are constructed so that fluid may flow in only one direction, from the interior of the cylinder to the fluid reservoir.

Abstract: A shock absorber for use with a sliding center sill rail car utilizes an internal gas type spring. The shock absorber has a housing and a cylinder located in the housing that moves with the center sill. An annular outer chamber surrounds the cylinder within the housing. Two pistons are slidably carried in the cylinder for independent movement relative to each other. Each has a shaft that extends in opposite directions. The shafts engage stationary stops mounted stationarily to the frame of the rail car. Ports are located in the side wall of the cylinder for the outflow and inflow of a gas and liquid fluid combination. The ports are symmetrical measured either from the rearward end or the forward end.

Abstract: A shock absorber in a compound trolley conveyor, including two cylinders disposed between a foremost trolley and a front trolley of the compound trolley conveyor and connected together face to face with each other, and two pistons inserted into the cylinders respectively and interconnected. When an impact force is applied to a carrier member at the time of connection or disconnection between the trolley connected to the carrier member and a drive chain, one piston moves in a direction to compress the air in the associated cylinder, while the other piston moves in a direction to withdraw or exhaust air from the associated cylinder. By such air compressing and withdrawing actions, the impact energy is absorbed to buffer the impact force. The compressed air in one cylinder slowly flows out to the exterior from a piston-cylinder gap, while the outside air slowly flows into the other cylinder through a piston-cylinder gap.

Abstract: A hydraulic cushioning unit includes a high pressure cylinder having a piston therein and a piston rod extended through the rod end of the cylinder. The cylinder is contained within an outer housing. A head casting closes the head ends of the cylinder and housing and an end cap closes the rod ends thereof. The end cap includes a ball stop sleeve protruding interiorly of the cylinder for cooperating with a ball valve port through the cylinder adjacent the rod end thereof to accomplish returned valving of fluid into the high pressure cylinder behind the piston. The same ball stop sleeve supports a resilient bumper for limiting the extent of movement of the cylinder in response to draft forces.

Abstract: A rail car cushion apparatus comprises concentric cylinder and housing members mounted at one end to a seat of a cushion apparatus body and at the other end to a cylinder head. The cylinder head includes a flow chamber and flow passages. A sleeve valve chamber is also included in the cylinder head adjacent to the flow chamber. A sleeve valve is provided in the sleeve valve chamber and is slidably mounted to slide along a piston rod telescopically received in the concentric cylinder and housing members. The sleeve valve is confined for limited movement by a sleeve retainer lip provided in the cylinder head. The retainer lip is discontinous to provide space for the sleeve valve to be inserted into the sleeve valve chamber. The sleeve valve retainer lip alternatively may be formed by a flexible retainer member retained in a groove formed in the cylinder head.

Abstract: This invention concerns an end-of-car hydraulic cushioning device for use on rail cars and a method of repairing such devices. The cushioning device has a piston and shaft assembly which is subject to train action forces. The piston and shaft are connected by means of a threaded engagement which prevents relative axial movements between the two parts. Rotational movement of the piston on the shaft is prevented by a hardened steel pin disposed in aligned, radial holes formed in the piston and shaft. The pin and holes are sized to provide clearance between the piston and pin. This permits piston metal deformation to occur during high speed impacts without catastrophically stressing the steel pin. A filler rod retains the pin in the radial holes.

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 apparatus for a railway car includes a housing having a cylinder bore disposed therein with an end plate closing one end of the cylinder bore. A piston assembly includes a shaft extending through the end plate and a piston disposed on the shaft and slidably received within the cylinder bore. The piston is slidable between an axially innermost position furthest from the end plate and an axially outermost position closest to the end plate. A limit pin has an interference fit within a pin bore of the end plate and extends outward therefrom toward the piston for initially limiting axially outward movement of the piston short of its axially outermost position to thereby limit a length of the cushioning apparatus prior to installation of the cushioning apparatus in a railway car.

Abstract: A railroad vehicle end-of-car center coupler includes a telescopic energy absorber comprising a hollow cylindrical plunger in a cylinder having one closed end. The plunger has an aperture in its inner end wall. A perforated metering tube is fixed in the closed end wall by a special fixing arrangement. It projects through the aperture and carries an annular piston head which slides in the bore of the plunger. A floating piston divides the interior of the plunger into a gas space and a liquid chamber. Four direct acting pressure relief valves are mounted in the piston head. Conduits through the tube connect their inlets to respective ones of four axially-spaced ports in the outer surface of the tube so that they all communicate with the annular chamber that surrounds the tube within the plunger when the absorber is compressed and so that they are progressively cut-off from such communication during the final stages of extension of the absorber.

Abstract: A lading protection device in the form of a shock absorber for a railway car including a cylinder containing a piston and a body of hydraulic fluid normally captive between the front face of the piston and the closed end of the cylinder. A flow control valve assembly, centered in the piston, mounts an orifice bushing defining a constricted circular orifice. The assembly includes a valve stem slidable in the piston with a spring at its inner end for pressing the stem in a direction to seal the orifice. The piston has a fluid passage extending therethrough and an annular separator piston defines, with the main piston, a receiving space into which the fluid flows upon impact. The space in back of the separator piston is filled with a charge of gas under high pressure so that when the impact has been dissipated the gas pressure acting upon the separator piston restores the fluid to its normal position in readiness for a succeeding impact.

Abstract: A backstop assembly for use with a cushioning device in the sill of a railway car. The cushioning device has a body, or cylinder, slidable endwise in the sill and carrying a car coupler at its outer end. The cylinder has a piston centered on the sill axis and a piston rod projecting from its inner end terminating in an enlarged end collar of circular cross section which is received in a backstop. The backstop is of rectangular box shape secured in the sill and having an inner end wall, outer end wall, top wall and parallel side walls, the end walls being axially spaced to form a chamber for loose, axially captive accommodation of the collar. The outer end wall has an arch-shaped clearance opening for loose accommodation of the piston rod.

Abstract: A lock-out apparatus for shock absorbing draft gear on a railway car which draft gear has a housing adapted to be fixed to one end of the railway car, a shock absorber is provided in the housing to cushion shock on the coupler of a railway car at the one end. The shock absorber includes at least one movable shock absorbing member operatively connected to the coupler and a cushion cooperating with the movable member to cushion shock. The lock-out apparatus has a locking member slidably mounted in the housing for movement between a locking and an unlocking position. There is a fluid motor for moving the locking member, and a conduit connecting the fluid motor to a brake line on the railway car whereby a change in the pressure of the fluid in the brake line will operate the fluid motor to move the locking member to a locking position to prevent movement of the movable shock absorbing member and to thus lock out the draw gear.

Abstract: A high capacity plate-type friction draft gear is disclosed for utilization with railroad cars. The draft gear has a friction clutch mechanism with a special two-piece split spring seat, so that two individual spring forces can be exerted separately against the friction shoes to maintain operability of the friction clutch mechanism when the various plates become worn to the point of normal replacement.

Abstract: A cushion assembly having an outer cylinder and a metering cylinder extending between end caps and defining an annular reservoir therebetween with communication being provided by metering orifices distributed along the length of the metering cylinder. A piston is slideable in the metering cylinder having a first piston rod connected to one side and a second piston rod of hollow construction connected to the other side, the first piston rod having a head at its outer end. The head and the first end cap define a gap between them when the first piston rod is in its contracted state. Stop members on the slideable sill and frame of the car occupy normal side by side positions in register with one another in the gap, so that a shock applied to the sill in either direction causes the stop members to shift out of register with one another elongating the gap so as to tension and extend the first piston rod.

Abstract: A fabricated backstop for an end-of car cushioning unit in a railway car. The backstop is composed of two plate members or pieces which are welded separately to the inside of a center sill. One backstop piece is a generally U-shaped vertical plate member which is welded about its entire outer circumference to the inside of the center sill and provides an over-solid stop. The second backstop piece is a horizontal plate member positioned in contact with the rear face of the vertical plate member and having a cutout portion to receive an end collar of an end-of-car cushioning device. The horizontal plate member is welded at its front face to the vertical plate member and at its outer sides to the center sill to provide a rear buff stop and a rear draft stop.

Abstract: A coupler arrangement for rapid transit passenger cars includes a self-centering coupler shank having limited horizontal and vertical swinging movement about a spherical bearing structure. The arrangement includes first and second shock absorbing mechanisms sequentially effective. A pin type coupler includes a locking arrangement on the coupler structure engageable with the coupler pin.

Abstract: A hydraulic buffer for a vehicle, the buffer including a piston and cylinder arrangement in which the piston is displaced by the pressure of hydraulic fluid, the hydraulic fluid being contained in a chamber defined by the piston and cylinder, the chamber being in flow communication with a reservoir for the hydraulic fluid, a valve being provided for permitting flow from the chamber to the reservoir, the valve comprising a perforated resilient sleeve in flow communication with the interior of the chamber and a resilient bush mounted on the periphery of the sleeve, an increase in pressure within the chamber causing deformation of the sleeve and bush, the deformation constituting the opening of the valve.

Abstract: An end-of-car railway car cushioning unit has a cylinder and a cylindrical piston mounted in the cylinder with the piston rod secured to the piston extending through an opening in the rear end of the cylinder with the piston forming a high pressure fluid chamber on the front face thereof and a low pressure fluid chamber on the rear face thereof. The piston has a plurality of openings therethrough and a metering valve is mounted in each of the openings to meter fluid flow between the low pressure chamber and the high pressure chamber. Each metering valve has a buff flow passage and a restricted draft flow passage. At least one selected metering valve has a cylindrical extension thereon projecting from the front face of the piston and adapted to engage an end wall of the high pressure chamber as the piston approaches the end of its buff stroke to block the flow of fluid from the high pressure chamber to the associated metering valve adjacent the end of the buff stroke.

Abstract: A method and apparatus for cushioning motion and dissipating impact energy, preferably in a marine environment, including a piston and cylinder assembly, impedance means associated with the piston and cylinder for impeding translation of the piston within the cylinder assembly and an isolation and restoring assembly protectively surrounding the piston and cylinder assembly and continuously biasing the piston and cylinder assembly in a normally extended position operable to dissipate impact energy. The method includes the steps of isolating the piston and cylinder assembly from an ambient environment, cushioning impact forces imparted to the piston and cylinder assembly and restoring the assembly in an extended posture operable to dissipate subsequent impact energy imparted thereto.

Abstract: An end-of-car hydraulic pneumatic cushioning device for connecting to the coupler of a railway car having a piston mounted within a cylinder and a piston rod secured to the piston extending rearwardly from the cylinder. The piston divides the cylinder into a front high pressure chamber and a rear low pressure chamber, and a gaseous and liquid fluid mixture is provided in both the high and low pressure chambers. The piston carries normally closed metering valves which open in buff travel a buff flow passage between the low and high pressure chambers after around two inches or more of buff travel from neutral extended position, and open upon return draft travel after buff travel a restricted draft flow passage between the low and high pressure chambers. The gas in the fluid mixture particularly upon high velocity impact loads is dispersed throughout the liquid and thus has a large contact area with the liquid to minimize the increase in temperature of the gas upon being compressed.

Abstract: This disclosure deals with a hydraulic cushioning unit for a railway car, including a gas return. The unit includes a main reservoir which is precharged with a hydraulic oil and an inert gas. At least one reservoir extension is also provided at the upper side of the unit, the extension enabling the unit to be charged with relatively large amounts of oil and gas. The oil volume when the unit is in its neutral position is approximately 76 percent of the total reservoir volume, and the reduction in the gas volume during impact conditions is not more than approximately 40 percent. The unit includes a tube and two separate charging passages for precharging the unit to the desired oil and gas volumes.