Abstract: The invention relates to a device for retaining a boot on a gliding board. The device includes especially a dorsal support element and a base, the dorsal support element being journalled on the base along a substantially transverse Y-Y' axis of the device, wherein at least one braking mechanism opposes a journal movement of the dorsal support element with respect to the base along the Y-Y' axis, in at least one journal direction, and wherein a return mechanism maintains the dorsal support element substantially in contact with the lower part of the leg.

Abstract: An air spring has a piston having an upper end and a lower end. A roll bellows having a first end connected to the upper end of the piston is provided. A cover is connected to the second end of the roll bellows. The lower end of the piston is open and has a connecting device for directly connecting the air spring to a pull rod of an air spring axle arrangement.

Abstract: A piston-cylinder unit includes a cylinder having an axis and an inner surface and a piston assembly attached to a piston rod and received in the cylinder for axial movement. The piston assembly includes a piston body, which has a plurality of radially resiliently deformable wall portions at its perimeter, the wall portions being spaced apart circumferentially from each other. Each wall portion has opposite ends that are joined integrally with the piston body and is defined by an opening in the body. Each wall portion engages the inner surface of the cylinder and deforms resiliently radially with respect to the axis of the cylinder to compensate for tolerance variations in the inner surface of the cylinder. The piston assembly may include a piston ring, which is received on the piston body with centering surfaces to restrict its radial movement and which functions to block and unblock a fluid bypass between sections of the cylinder on opposite sides of the piston assembly.

Abstract: An adjustable-length gas spring comprises a housing and a piston rod led out of the latter, on which a piston is disposed, dividing the housing into two partial housing chambers. Provision is made for a valve for the partial housing chambers to be connected with each other, the valve comprising a valve-operating lever, which is arranged pivotably at right angles to its longitudinal direction and a valve seat of which, when the lever is pivoted out of a position of rest into a position of opening of the valve, can be lifted off a seal, while forming a gap that connects the partial housing chambers with each other.

Abstract: A gas compression spring comprises a gas-filled cylinder in which a piston carrying a hollow piston rod is slidable and divides the interior of the cylinder into first and second chambers. Over part of the length of the cylinder, a groove is provided in the cylinder wall. Gas pressure within the cylinder causes the piston to drive the piston rod outwards of the cylinder, this being permitted by the groove which allows transfer of gas pressure between the two chambers. When the piston reaches the end of the groove, such gas pressure transfer ceases and movement of the piston rod stops. External manual force applied to a control rod, extending through the hollow interior of the piston rod, unseals an opening at the end of the piston rod which brings the two chambers into communication again. Gas pressure transfer can now take place between the two chambers via the interior of the piston rod.

Abstract: An air or gas sprung and dampened shock absorber for a bicycle is set forth comprising a cylinder having a closed end and an open end forming a compression chamber, a shaft having a closed end and an open end, the open end of the shaft being reciprocally received within the cylinder through the open end of the cylinder, a piston sealingly positioned in the open end of the shaft and slidably and sealingly positioned adjacent an inner surface of the cylinder forming a rebound chamber in the shaft and a gas spring chamber formed between an outer surface of the shaft and an inner surface of the cylinder wherein the gas spring chamber communicates with the rebound chamber during at least a portion of the compression and rebound stroke of the shock absorber. The shock absorber further includes a compression plate sealingly received in the shaft with an axial position of the compression plate being selectively moveable within the shaft for varying a total volume of the shock absorber.

Abstract: A swing phase control for an artificial knee joint is provided with a cylinder (1) having one end closed by a head member (2) and the other end closed by a base member (3), a piston reciprocally movable within the cylinder in axial direction thereof and having a piston rod (6) passing outwards through a bore provided in the head member (2) for connection with the thigh part of a prosthesis. The head member (2) comprises a channel (12) with a check valve (13) providing a communication of the ambient with a head side first chamber (9) defined by the piston (7). The first chamber (9) communicates through a throttle passage with the base side second chamber (10) defined by the piston (7). The base member (3) comprises a vent bore (23) connecting the second chamber (10) with the ambient and a first spring (22) biasing the piston (7) towards the head member (2). Thus the swing phase control has good damping properties for movement of different speed.

Abstract: A gas spring includes a piston assembly or pack having an additional seal, pressure relief valve, and check valve that increases the output force of the gas spring. Various temperature compensation structures, also added to the piston pack, permits this increase to vary from zero at higher ambient temperatures to a maximum value at very cold temperatures thus achieving a temperature compensation, which varies, in an analog manner, inversely in response to the temperature changes.

Abstract: A gas spring for the hatchback or other closure member of a motor vehicle body automatically stops at an intermediate position between the fully closed and fully opened positions. A piston carrying a piston rod separates the interior of a cylindrical body into first and second chambers. Gas under pressure forces the piston and piston rod towards the extended position to open the closure member, a restricted gas path through a groove in the cylinder wall allowing gas to flow from the second chamber to the first chamber. A third chamber is also defined within the cylinder and has an uninterrupted wall portion and a wall portion incorporating a groove. The third chamber is on the opposite side of the second chamber to the first chamber and has a smaller diameter than the first and second chambers.

Abstract: A pneumatic counterbalance spring includes a hollow cylinder defining a first internal chamber divided into a compression compartment and an extension compartment by a piston movably mounted in the chamber. The compression compartment contains pressurized gas and a seal assembly mounted on the piston prevents the gas from escaping into the extension compartmint. A piston rod is slibably mounted in the open end of the cylinder and has its inner end connected to the piston. The piston rod includes a hollow portion defining a second internal chamber which is fluidly connected to the compression compartment by a flow passage. As a result, the compression compartment has an effective volume of A+B, where A represents the volume of the compression compartment and B represents the volume of the piston rod internal chamber. This design is advantageous in applications where a low spring rate is desired and where the length of the spring needs to be minimized.

Abstract: A swing phase control device for an artificial knee joint which is provided with different first and second throttle controls to permit more natural flexing and stretching of the knee joint.

Abstract: A self contained gas spring which is interchangeable with a coil spring that is constructed such that it is not adversely affected by the deleterious effects of oil and other contaminants. The gas spring comprises a one-piece cylindrical upper body having a base wall and a peripheral wall and a rod extending upwardly into the cylindrical body such that the upper body completely encircles and encloses the upper end of the rod. The rod has a base and the outer diameter of the peripheral wall of the cylinder and the outer diameter of the base have substantially the same diameter such that the cylinder can be positioned in a recess of a press or die in place of a coil spring. The cylindrical body and rod include interengaging portions limiting axially outwardly movement of the cylinder relative to the rod.

Abstract: A gas spring comprises a first bypass with a one-way valve that allows fluid to bypass the piston when the piston moves outward, a second bypass with a spring-biassed valve that allows fluid to bypass the piston when the piston is pushed inward with a force exceeding the combined gas-spring and spring-biased valve forces, and a third bypass having a temperature-responsive valve that allows fluid to bypass the piston when the rod is pushed in but only when the temperature of the gas exceeds a selected level.

Abstract: A longitudinally controllable adjustment device, in particular a gas spring partially filled with a fluid has a piston disposed on a piston rod. In order to achieve simple manufacture and assembly and high operational safety, a valve housing for receiving a valve is provided on the piston rod. Further, the piston axially covers to total valve. The piston is secured to the piston rod by deformation, which simultaneously results in a pre-stressing of a seal sealing in four directions. The piston rod with the valve is compressed against a seal in the piston, which seal sealingly abuts on an annular bottom of a receptacle, on the receptacle, on the valve and on the valve body.

Abstract: According to an illustrative example of the invention a cylinder is subdivided by a stationary partition wall into two pressure chambers. A first piston rod is sealingly introduced from atmosphere through one end wall of the cylinder into a first pressure chamber provided on one side of the partition wall. A second piston rod sealingly extends through said partition wall from the first pressure chamber on one side of the partition wall to a second pressure chamber on the other side of the partition wall. A lower gas pressure is provided in the first pressure chamber and a higher gas pressure is provided in the second pressure chamber. Abutment faces are allocated to the first and to the second piston rod. On inward movement of the first piston rod with respect to the cylinder the abutment faces enter into engagement after a predetermined path of inward movement of the first piston rod.

Abstract: A piston for a piston cylinder unit, particularly a gas spring, is to be provided with a piston ring and comprises a portion extending at least from the piston ring groove to a free end and consisting of a plurality of segments separated from one another by longitudinal slots. This portion is provided with a bore the diameter of which is at the free end smaller than the diameter of the related portion of the piston rod. It is the purpose of these measures to enable simple assembly of the piston ring in the piston ring groove and at the same time to ensure reliable seating of the piston ring.

Abstract: A fluid-filled piston-cylinder unit with a tubular fluid-filled housing closed at one end and with a piston rod emerging from the other end comprising, for guiding the said piston rod, a guide bush which is sealed on the one hand against the inside wall of the housing and on the other against the piston rod by the use of seals. Provided at the inner end of the piston rod there is a guide piston. In order on the one hand to avoid surface pressure between the piston rod and the guide bush and on the other to achieve an adequate length of guidance for the piston rod itself, the guide bush is provided with at least one spacer extending in axially parallel manner beyond the seals and in the direction of the guide piston and the cross-section of which is substantially smaller than the cross-section of the guide bush.

Abstract: The invention discloses a lifting telescoping tube which comprises a first tube receiving a pressure liquid, a second tube filled with a pressure gas, a first piston affixed to one open end of the second tube having a first through-passage and a second through-passage intercommunicating the first and second tubes, a check valve disposed in the second through-passage for preventing the pressure liquid from flowing into the first tube from the second tube, a second piston provided in the second tube dividing the second tube into a variable-volume liquid chamber and a variable-volume gas chamber.

Abstract: A vibration isolating apparatus has a pair of small liquid chambers which are communicated with each other through an orifice. A partition which divides the small liquid chambers is provided with a vibrating plate in order to suppress rise in liquid pressure within the small liquid chambers. When a vibration of extremely low frequency is input, a part of a flexible membrane which defines a part of the liquid chamber is pressed against the vibrating plate by the action of a restraining means to prevent vibration of the vibrating plate. Accordingly, the occurrence of resonance of the liquid within the orifice is ensured, and the vibration is thereby effectively absorbed.

Abstract: In the illustrative embodiment of the invention as described an engine bonnet is articulated to the framework of a motor car. A gas spring is articulated to both the framework and the bonnet. The gas spring balances part of the weight of the bonnet when the bonnet is to be opened by hand. In case of an accident the framework and/or the bonnet may be crushed in longitudinal direction of the car. In such case the piston rod of the gas spring is pushed inward of the cylinder beyond the normal innermost operational position and a retaining device becomes effective so as to prevent the piston rod from returning towards its outermost operational position.

Abstract: Apparatus for generating seismic waves including an upstanding hollow cylindrical housing within which an impact piston latched in a cocked position is adapted to be propelled downwardly by high pressure expanding gas in the confined chamber above it within the housing so as to strike a target plate resting on the ground adjacent the lower end of the housing. After each blow against the target, the piston is retracted upwardly by means of hydraulic cylinders which recompress the gas in the chamber to its original pressure. Since there is no need for recharging the pressure chamber after each shot, economical rapid cycle operation is facilitated.

Abstract: In construction of a key musical instrument such as a piano, a swingable element such as a hammer is accompanied with a pneumatic damper having an air vent so that, when impulsive load is applied by motion of the swingable element, fluid viscous resistance caused by flow of air in the pneumatic damper well absorbs shock, thereby greatly suppressing undesirable bound of said swingable element on return to its initial rest position.

Abstract: A height control valve with a spring return actuator for use in an air spring suspension has a damping chamber, an air control chamber and an actuator controlled spring return housing with mutually perpendicular lateral and axial bores. An actuator shaft extends into the damping chamber, the air control chamber and the lateral bore of the spring return housing. The spring return housing is rotatably mounted to the actuator shaft. A spring cup is reciprocably guided in the axial bore and is biased in contact with a flattened portion of the actuator shaft. The spring cup has two axially spaced cylindrical exterior surfaces of essentially zero draft angle and of slightly different diameter. The axial bore cylindrical surfaces are in registry with the spring cup cylindrical surface. The registering cylindrical surfaces of the spring cup and axial bore have dimensions of close correspondence to ensure a snug fit of the spring cup within the axial bore.

Abstract: A pneumatic spring counterbalance extensible link including a closed end cylinder with an end connector a piston and rod assembly within the cylinder and maintained therein by the crimped over end portion of the cylinder retaining a rod bushing and rod to cylinder seal. The cylinder is pressurized prior to assembly of the complete piston and rod into the cylinder. The piston assembly includes orifice by-pass arrangements either in the piston periphery or in a piston ring, and the piston may include a fail-safe provision in the event the orifice is clogged. A crimping die assembly is used in assembling and completing final assembly of the counterbalance components while simultaneously maintaining the link in a pressurized environment, utilizing sealed arrangement between the crimping dies to maintain pressurization of the interior of the dies and the counterbalance components prior to assembly of the components.

Abstract: In the speed reducer disclosed, the gear ring (12) of the planetary gear train is connected via a pair of diametrically-opposed appendages (13) with a corresponding pair of vertically disposed and parallel double-acting hydraulic cylinders (14) suspended via ball-and-socket joints beween the gear unit and a fixed structure. Each cylinder shows a low pressure (31) and a high pressure (32) oil chamber connected to low and high pressure hydraulic accumulators (33, 34) respectively by means of respective throttle valves (35, 36) in parallel with respective ball check valves (37, 38). There are no bearings between the gear case (18, 19)and the shaft instead, the output shaft hub is fitted with an assembly which incorporates thrust rings and a rotary seal (20) featuring diametrial-flow lubrication to ensure freedom from foreign matter.

Abstract: A pneumatic spring-loaded damping or shock absorbing apparatus provided with a venting port and a seal activated by a piston for automatically sealing the port when the apparatus approaches its fully expanded position for maintaining residual pressure within the apparatus.

Abstract: A pneumatic spring counterbalance extensible link including a closed end cylinder with an end connector a piston and rod assembly within the cylinder and maintained therein by the crimped over end portion of the cylinder retaining a rod bushing and rod to cylinder seal. The cylinder is pressurized prior to assembly of the complete piston and rod into the cylinder. The piston assembly includes orifice by-pass arrangements either in the piston periphery or in a piston ring, and the piston may include a fail-safe provision in the event the orifice is clogged. A crimping die assembly is used in assembling and completing final assembly of the counterbalance components while simultaneously maintaining the link in a pressurized environment, utilizing sealed arrangement between the crimping dies to maintain pressurization of the interior of the dies and the counterbalance components prior to assembly of the components.

Abstract: A novel spring-loaded damping unit having a piston mounted for sliding movement within an enclosed cylindrical housing, the piston being provided with a throttle for a controlled exchange of pressure between chambers on opposite sides of the piston wherein the throttle comprises one or more steel washers biased against seats engaging outer and inner peripheral positions on opposite surfaces of the washer. In the case of more than one washer a resilient layer may be provided between them.

Abstract: A hydraulic accumulator for providing pressurized fluid for a hydraulic system, includes a cylinder, a piston movably disposed in the cylinder defining a space in the cylinder on one side of the piston for pressurized fluid, and a mechanical spring device connected to the piston for generating pressure in the pressurized fluid.

Abstract: A rubber plastic composite cylinder that has a cylindrical hollow elastomeric body bonded internally to a shaft and its external surface bonded to a cylindrical sleeve of ultra high molecular weight polyethylene which includes the bonding as by vulcanization two outer shells of ultra-high molecular weight polyethylene to the elastomeric cylinder to place the elastomeric cylinder in compression. Such composite cylinder may be spaced along a shaft or utilized effectively as a coaxial shear spring or as conveyor rollers.

Abstract: A fluid cushioning apparatus acting as a pivoting medium of two objects having a pivoting feature includes a sleeve, a shaft and a partitioning piece. The shaft has two radially enlarged annulations being closely and rotatably mounted in the sleeve and a dividing wall being axially and radially extended between the two annulations to closely engage with the interior wall of the sleeve. The sleeve is mounted on a first object and the shaft is mounted on a second object which is always to have a pivoting relationship with the first object. The partitioning piece is capable of being closely fitted among the sleeve, the shaft and the two annulations and is secured on the sleeve so that the space formed between the shaft and the sleeve is divided into two compartments.

Abstract: A pneumatic spring counterbalance extensible link including a closed end cylinder with an end connector, a piston and rod assembly within the cylinder and maintained therein by the crimped over end portion of the cylinder retaining a rod bushing and rod to cylinder seal assembly. The cylinder is pressurized preferably prior to assembly of the bushing and seal assembly into the cylinder. The piston assembly includes an effective check valve and orifice by-pass structure for metered gas flow past the piston in one direction and free flow past the piston in the other direction of piston movement. A small predetermined amount of oil is contained in the cylinder and provides lubrication for the seals and piston and provides a damping effect at the end of the extension stroke. A standpipe sleeve is secured on the piston extending toward the seal assembly around the piston rod and controls disposition of the oil to assure damping at the end of the extension stroke.

Abstract: A hydropneumatic suspension unit includes a large diameter flanged road arm spindle which is bolted to the vehicle hull; a road arm has one end rotatably mounted on the road arm spindle and another end mounting a road wheel; a barrier fluid sealed piston is reciprocated relative to a road arm bore to seal an in-arm mechanically operated pneumatic spring which has a gas volume trapped by the barrier fluid sealed piston to support the sprung mass of the vehicle; the sealed piston is defined by a pair of spaced seals and an oil chamber which has an oil charge therein pressurized by preload spring on the piston to displace the oil barrier to both lubricate and preload the pair of spaced seals as the piston is dynamically operated to vary gas compression and produce a resultant pressure on the piston to counteract vertical forces on the road wheel.

Abstract: A seal between a piston rod and a housing in which the piston reciprocates for preventing the escape of compressed fluid from the housing. A fixed sealing member engages the piston rod adjacent the housing wall, and a floating sealing member engages the piston rod at a location spaced from the fixed sealing member. A liquid is in the space between the sealing members.

Abstract: A nitrogen die cylinder is disclosed having an upright post threaded at its lower end into the wall of a manifold containing nitrogen at high pressure. The post has a central vertical passageway extending therethrough and communicating with the manifold. A cylindrical sleeve having a top wall is telescoped over the post. A seal at the upper end of the post engages the bore of the sleeve to form a chamber between the seal and the top wall of the sleeve which, when pressurized, urges the sleeve upwardly on the post. The top wall of the post has a noncircular socket therein which is accessible through an opening in the top wall of the sleeve which is normally closed and sealed by means of a threaded plug.

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: The invention pertains to motion compensators and compensator systems, particularly adapted for disposition between an offshore platform and a riser or conductor pipe. Each compensator includes a cylinder with a piston reciprocably mounted therein, the piston rod protruding from one end of the cylinder. That one end of the cylinder is directed toward and connected to either the platform or the riser pipe, with its other end being directed toward the other of those two bodies. Link rods are independently connected to the protruding part of the piston rod and extend longitudinally toward said other end of the cylinder for connection to said other of the two bodies. A compressible fluid is disposed between the piston and said other end of the cylinder to resist movement of the piston toward said other end and thereby resist movement of the platform and the riser pipe away from each other.

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: A kicking strap for sailing-boats comprises a tackle with two multifold blocks (8, 9) connected and supported by means of two telescopic pipes (15, 16). The pipes are connected by a spring counteracting their joining, e.g. a pneumatic spring (21) secured both to one block (8) and the inner pipe (15), its piston being rigidly connected to the outer pipe (16) through a pin (31) extending through the head of the piston (22). The outer pipe is welded to the second block (9). The pin (31) is guided in an extension of the inner pipe (15). At for instance booming, the kicking strap located between the mast-foot and the boom exerts by means of the spring an upward pressure on the boom so that the boom in the central position during the booming is still raised and may thereby safely pass above the crew.

Abstract: In the illustrative embodiments of the invention described, a main gas spring unit used to raise and lower a movable leg rest member of a bed construction includes a further gas spring device axially connected end-to-end to the main gas spring unit. The addition of the gas spring device allows the leg rest member to be raised, with only a small manual effort, to a higher level than is possible with the main gas spring unit alone. Preferably the internal force exerted on the piston rod of the main gas spring unit is greater than the internal force exerted on the piston rod of the gas spring device. The cylinder members of the main gas spring unit and the gas spring device may be formed by a common tubular member, with the two units being separated by a common movable wall. Alternatively, the cylinder members can be separate self-contained members that are rigidly attached at adjoining end walls thereof.

Abstract: A small-sized differential piston unit is disclosed. The piston unit has a cylinder filled with liquid medium and a piston slideably mounted in the cylinder. An operation rod is operatively connected to said piston. An improved sealing member consisting of a membrane is used to completely seal the liquid medium in the cylinder. Control means is provided for imparting fluid resistance caused by the liquid medium to the piston differently between its forward movement and backward movement in the cylinder.

Abstract: A gas spring of the piston-and-cylinder type in which the two compartments of the cylinder cavity, separated by a piston assembly, are connected by a first passage. A valve arrangement on the piston assembly defines a second passage between the compartments and closes in response to movement of the piston assembly away from a terminal position in the cylinder while opening in response to movement of the piston assembly towards the terminal position. Releasable locking structure carried in part by the cylinder and in part by the piston assembly cooperates to close the first passage when the piston assembly approaches the terminal position, thereby to hold the piston assembly in such terminal position.

Abstract: In a shock absorber device, a piston rod unit is axially displaceable through a cylindrical member from one end toward the other end thereof. The cylindrical member forms a variable volume working chamber containing a first fluid. A spring chamber is in communication with the working chamber so that the first fluid can flow between the two chambers. A pressurized second fluid is contained within the spring chamber separate from the first fluid and it acts on the first fluid for biasing the piston rod unit out of the working chamber. When the piston rod unit is moved into the working chamber and approaches an inner end position, it forms at least in part a damping chamber which decelerates the movement of the piston rod unit.

Abstract: In the illustrative embodiments of the invention described, a pneumatic cylinder-and-piston device includes a unitary piston structure for providing two different damping rates in dependency on the direction of movement of the piston within the cylinder. Fluid flow across the piston is preferably controlled, to effect the different damping rates, by use of an elastic sleeve which at one end is carried by the piston and which at the other end engages, suitably under fluid pressure, the inner surface of the cylinder.

Abstract: In the illustrative embodiments described, a pneumatic spring includes selectively releasable structure, located in part at the outer end of the piston rod and in part at the corresponding end of the cylinder, for retaining the piston rod at or near its innermost position within the cylinder. The retaining structure carried by the cylinder preferably constitutes a sleeve surrounding the piston rod, and the structure carried by the piston rod may include projections for coacting with shoulders on the sleeve. Alternatively, the sleeve and piston rod may be formed with cooperating recesses for receipt of an external pin-like securing bracket.

Abstract: In the illustrative embodiments described, the two compartments of the cylinder cavity of a gas spring of the piston-and-cylinder type, separated by a piston assembly, are connected by first and second passages extending across the piston. A valve arrangement on the piston assembly opens the second passage in response to movement of the piston assembly towards a terminal position in the cylinder and closes the second passage in response to movement of the piston assembly away from the terminal position. The first passage is open at all positions of the piston assembly remote from the terminal position. Releasable locking structure in the cylinder is operable to close the first passage as the piston assembly approaches the terminal position, thereby to hold the piston assembly in such terminal position until the locking force is manually overridden.

Abstract: In the illustrative embodiments described, a cylinder-piston device such as a gas spring includes a novel piston rod-piston unit assembly which embodies a snap-on type construction for facilitating the connection and disconnection of the piston unit to and from the piston rod. Resilient tongue members carried by the piston unit are formed with detent-like abutment members at their free ends, which abutment members snap behind an engagement shoulder, formed for example by a disc or groove, on the piston rod to hold the piston unit on the rod. The free ends of the tongue members are also formed with bevelled surfaces which coact with the piston rod to cam the tongue members radially outward as the piston unit is urged onto the piston rod, so that the abutment members are first displaced away from and then snap behind the abutment shoulder.

Abstract: A gas spring includes a cylinder having two axial portions of different cross section and two pistons mounted on a common piston rod and respectively matching the cross sections of the cylinder portions. The pistons are spaced on the piston rod so that they are either both in the wider cylinder portion or respectively received in the two portions. A first throttling passage permits flow of fluid between the two cylinder compartments separated by the larger piston, and a second throttling passage by-passes the smaller piston only during movement inward of the smaller cylinder portion to permit flow of fluid out of that cylinder portion. A valve arrangement is biased for sealing the two parts of the cylinder cavity separated by the smaller piston when the latter is in the smaller cylinder portion, but does not move inward of that portion. The valve arrangement responds to a sufficient, axially applied force for connecting the two cavity parts.

Abstract: A gas spring comprising a cylinder having a closed end and an open end with the rod of a piston projecting into the cylinder through the open end and a sealing assembly surrounding the rod adjacent the open end of the cylinder and normally sealing the interior of the cylinder from the surrounding atmosphere. The sealing assembly includes an annular resilient sealing member having surfaces which are in sealing engagement with the rod and the inner wall of the cylinder and a plurality of protuberances are formed on the inner wall of the cylinder and are located inwardly of the normal position of the sealing member. When the open end of the cylinder is placed in communication with a gas under pressure, the gas moves the sealing member into engagement with the protuberances so that openings are formed between the member and the inner wall of the cylinder and the gas flows into the cylinder through these openings.

Abstract: A combined hydraulic cylinder and shock absorber used in combination with a cantilever supported boom having a plurality of longitudinally spaced discharge nozzles thereon for flowable material with one end of the boom being pivotally supported from a vehicle, or the like, for vertical adjustment in a vertical plane with the hydraulic cylinder enabling angular adjustment of the boom about a horizontal axis and including a structure which provides a shock absorber to dampen and cushion vertical oscillation or bouncing movement about a horizontal axis as the boom and vehicle traverse uneven terrain such as when applying liquid fertilizer or other flowable material agent to the soil.