Abstract: A shock absorber includes a housing and an end wall slidably disposed within the housing. The end wall and the housing cooperate to define at least a portion of a cavity within the housing. The cavity is filled with a fluid, and a piston is slidably disposed within the cavity. Movement of the piston within the cavity compresses the fluid to provide a spring force. The shock absorber further includes a compensator coupled to the end wall. The compensator positions the end wall within the housing to change a volume of the cavity in response to a change in a temperature of a first element of the compensator.

Abstract: An improved switch point machine is provided which can seal out water, even if the machine itself becomes submerged. The operating rod and the point indicating rod that extend out of the switch box housing should be ground round and have a smooth surface for an improved seal. Those rods are preferably chrome plated. Dynamic hydraulic seals can be used to seal out moisture. Internal components, within the switch box housing, should also be sealed to be water resistant in the event water does enter the housing.

Abstract: A damping device includes a housing defining a pressure chamber, containing a magnetorheological fluid. A rod is slideably coupled to the housing to adjust a length of the housing. A piston is attached to the rod and disposed within the pressure chamber. The piston is immersed within the magnetorheological fluid, and separates the pressure chamber into a first half and a second half. An electromagnet is disposed in magnetic contact with the magnetorheological fluid, and is operable to apply a magnetic field to the magnetorheological fluid to increase viscosity of the magnetorheological fluid to prevent movement of the rod relative to the housing. The magnetorheological fluid is free to flow through a fluid port in the piston, between a first half and a second half of the pressure chamber, in the absence of the magnetic field from the magnetic source to allow adjustment of the length.

Abstract: The present invention provides a suspension and vibration isolation system having cable isolators. The cable isolators employ low-friction air-bearing pneumatic cylinders and cables to isolate a suspended payload from vibrations of a carrier or to isolate the carrier from vibrations of the payload. Using such air-lubricated cylinder to piston interfaces virtually eliminates static friction and so improves the effectiveness of the isolation for small forces and displacement. The use of pneumatic cylinders also permits the system to be tuned to the required resonance frequency to isolate the payload from vibrations in a desired frequency band.

Abstract: The invention relates to a device comprising a suspension system, which suspension system comprises a first part to which a mass is applied, a second part and an air spring arranged between said first part and said second part, at least one additional volume means for air being provided, the volume of which can be connected in a controlled manner, and a control means for connecting the volume of the additional volume means, wherein, via the control means, a pressure accumulator and the additional volume means are in fluid communication with the air spring such that a force/displacement characteristic line of the air spring can itself be modified depending on a deflection displacement and/or rebound displacement and/or speed and/or acceleration of the first part in a presettable manner, by connecting the additional volume and/or the pressure accumulator by means of the control means during the deflection and/or rebound of the first part.

Abstract: A method and apparatus for a vehicle shock absorber comprising a main damper cylinder, a first reservoir and a second reservoir. One embodiment includes a first operational mode where both reservoirs are in fluid communication with the cylinder. In a second operational mode, only one reservoir communicates with the cylinder during fluid evacuation from the cylinder. In each mode, rebound from either or both reservoirs may travel through a single, user-adjustable metering device.

Abstract: This invention concerns a gas spring having a working cylinder and therein a slidably arranged piston, whereas the working gas is, in order to provide for springing and dampening, optionally transferable between the working cylinder and the reservoir, characterized in that the reservoir is arranged in the piston rod. The gas or air spring according to this invention is self-dampening in both directions, i.e. at compression as well as at the extension. At compression it behaves as an air spring with dampening and at the extension it also behaves as an air spring with dampening, whereas both these damping effects can be, as regards the magnitude of the dampening, controlled independently from each other.

Abstract: A gas spring for forming equipment, including a piston received at least partially in a cylinder for reciprocation between extended and retracted positions, and including a throttling passage disposed between the piston and the cylinder in fluid communication between first and second pressure chambers during at least a portion of the reciprocation of the piston. The throttling passage is of variable cross-sectional area, which varies with a length of the passage to at least partially restrict gas flow therethrough in a manner varying with return of the piston toward its extended position to decelerate the piston at a predetermined rate.

Abstract: A gas spring is described, which comprises a first part which defines a cylinder, which comprises a longitudinal axis and which is closed at a first end along the longitudinal axis. The gas spring further comprises a piston, which is arranged to be movable along the longitudinal axis in the cylinder, a piston rod which is connected to the piston and which projects out through a second end of the cylinder, a separating piston which is arranged to be movable in the cylinder along the longitudinal axis between the piston and the first, gas which is contained in the cylinder between the separating piston and the first, and liquid which is contained between the separating piston and the piston.

Abstract: A pneumatic spring consists of a hollow working cylinder (1) with a first end (2) being adapted for fixing to one suspended object and with a second end (12) being closed, a sealed piston rod (60) going through this second end (12), one free end of the sealed piston rod (60) going out of the working cylinder (1) is adapted for fixing to a second suspended object and the second free end interfering into a working space (10) of the working cylinder (1), wherein the working space (10) being closed with the bottom (3) of the working cylinder (1) first end (2) or with a piston (61) connected with the second free end of the piston rod (60) and interconnected through interconnection holes (35) of the working cylinder (1) with an outer storage space (33) of a work medium, wherein according to the invention a cylindrical gear pivot (20) is seated coaxially with the piston rod (60) in the second end (12) of the working cylinder (1), the end of the gear pivot (20) going out of the working cylinder (1) is fitted with act

Abstract: A suspension system between two bodies, the suspension system including: a first pressure chamber provided between the bodies; and at least one other pressure chamber provided between the bodies such that the at least one other pressure chamber opposes the action of the first pressure chamber; and a control system to control the pressure and volume in the first pressure chamber and the at least one other pressure chamber to adjust the stiffness value of the suspension system independently of adjusting a distance between the bodies.

Abstract: The present disclosure generally provides systems for adjusting tension and positioning of a harrowing chain. Systems may include a tension adjustment assembly, and the tension adjustment assembly may include a pivot assembly and/or a cylinder hydraulic assembly. Modifications also may be made to the frame of an agricultural implement to address transport issues related to harrowing chains. Further modifications to exterior harrowing chains may be made to reduce the number of small ditches formed in a field due to digging by harrow disks of the chains.

Abstract: A tunable pneumatic suspension includes a piston and two opposed pneumatic chambers. The two champers apply opposed pneumatic pressures to opposite faces of the piston. The tunable pneumatic suspension also includes a pneumatic controller that independently controls the pressure in each of the chambers. The independent control of the two chambers allows the suspension to change the relative positions of the piston and the chambers by differing the pressures in each chamber, and allows the suspension to change its stiffness by increasing or decreasing the pressures in each of the chambers by equal amounts. If used in a vehicle, changing the relative positions of the piston and the chambers can change the ride height of the vehicle, and changing the stiffness of the suspension can change the stiffness of the vehicle's ride.

Abstract: A shock absorber system for use with a vehicle having a shield to reduce the effects of a shock event.

Abstract: A suspension fork of a bicycle includes at least one stanchion tube and a slider tube interacting therewith and a wheel receiving space adjacent thereto, and a damper system. The damper system includes a shut-off valve to adjust a lockout in the rebound stage and a shut-off valve to adjust a lockout in the compression stage, and one joint adjusting element. Using the joint adjusting element, the locking of the rebound stage and locking of the compression stage can be adjusted.

Abstract: A hydraulic shock absorber enables its piston rod to be locked near its minimum length position and allows the locked condition to be visually confirmed easily. A cap member is secured to a distal end portion of a piston rod extending from a cylinder part, and a dust cover is secured to the cap member. A lock member is secured to an end of the cylinder part from which the piston rod extends to the outside. The lock member is cut and bent upward to form engaging portions. The cap member is cut and bent downward to form engaging pieces and windows. With the piston rod contracted to near its minimum length position, the cap member is rotated to engage the engaging portions and the engaging pieces with each other, thereby locking the piston rod. The engaged condition of the engaging portions and the engaging pieces can be visually confirmed through the windows.

Abstract: Presented is a piston-cylinder unit. The piston-cylinder unit includes an outer tube defining a cavity, a working cylinder disposed in the cavity of the outer tube and filling only a portion of the cavity. The unfilled portion of the cavity is a compensating space. The compensating space is divided into an area filled with a damping medium and an area filed with a gas. The piston-cylinder unit further includes a piston rod that includes a damping piston. The piston rod is disposed in the working cylinder and has freedom of axial movement, and is configured to displace the gas. The piston-cylinder unit further includes a reservoir that has a variable volume configured for actuating the compensating space.

Abstract: An impact damper for deceleration of a vehicle impacting on all obstacle by hydraulic damping forces and gas spring forces includes at least inner and outer pipes telescopically displaceable one inside the other and defining an annular space therebetween with a base closing one end of the inner pipe. A dividing piston is sealingly guided in the inner pipe. The inner pipe, the base, and the dividing piston define a gas space which holds gas under pressure. The inner pipe further defines a first liquid space separated from the gas space by the dividing piston. An intermediate wall is fastened to the inner pipe and includes a throttle opening therethrough connecting a second liquid space to the first liquid space. The annular space between the first and second pipes has one end sealed to the atmosphere and another end sealed by the intermediate wall. The annular space is connected to the second liquid space by a flow connection having a valve.

Abstract: The active vibration-isolating device of the invention is used for preventing vibrations due to ground motions or running of an automobile from being propagated to a platform which is disposed in, for example, a semiconductor device factory or a laser device factory, and on which various kinds of equipment are to be mounted, and also from causing the platform to vibrate. The device has: an air spring which elastically supports a platform; a piston-like member which abuts against and supports the platform; plural piezoelectric actuators which can be externally controlled; a working fluid such as an aqueous solution of ethylene glycol which transmits driving displacements of the piezoelectric actuators to the piston-like member via piston members which are respectively fixed to ends of the piezoelectric actuators in a driving direction x; and a fluid path in which the working fluid is hermetically filled.

Abstract: A pneumatic spring for damping movement of a machine part having a guide shaft for performing a stroke. The spring includes a housing containing gas. The housing is formed as a stationary body with a central opening adapted to accommodate the guide shaft. Several cylindrical bores are formed within the stationary body. A piston is peripherally guided within each cylindrical bore. Each piston has a center point located on a circle which is concentrically oriented with the central opening. The pistons contact the machine part with an upper support end so that all the pistons jointly perform a stroke with the machine part. Alternatively, the cylindrical bores are. selectively equipped with sealing disks instead of pistons, to adjust the resistance force characteristic of the spring.

Abstract: An erector holds a leaf-flap in various opening settings relative to its frame, in particular for holding a motor-car hood. The erector has a continuously length-variable dynamic unit, which comprises, supported against the leaf-flap and frame, a hollow cylinder and a piston which is slidably guided in the hollow cylinder. The hollow-cylinder space is divided by the piston moved via a piston rod, into a two pressure-medium chambers which are overflow-connected, with a flow regulator being interposed therebetween. A control valve is disposed in one of two overflow ducts of the flow-regulator so that the assigned overflow duct, when the control valve is closed, is flow-blocked in both directions.

Abstract: A shock-absorbing strut in which fluid passages extend through the strut to communicate with a hydraulic wheel drive of the wheel assembly to which a movable part of the strut is affixed. Telescoping connectors are provided between the outer guide housing affixed to the vehicle frame and a revolving joint in the axially movable support element and compensating cylinders are provided to balance the hydraulic pressure on the revolving joint resulting from the pressure in the telescoping connectors of the oil feed to the wheel drive.

Abstract: A shock absorber includes an extruded reservoir housing and a sleeve with position valving therein. The shock absorber coordinates the position valving and valving in the piston assembly in a manner such that the position of the piston assembly relative to the position valving becomes a factor in determining changes in valving.

Abstract: A closed type cylinder unit, instead of the open-to-atmosphere type cylinder unit of conventional equipment forms part of the die cushion apparatus. Based on the principle that the die cushion capability by the closed type cylinder unit is determined by the differential pressure between the lower chamber pressure and the upper chamber pressure, the differential pressure is controlled in such manner that the lower chamber and the upper chamber communicate with each other through a check valve, which is opened when the differential pressure exceeds a preset differential pressure value. As the upper and lower chambers communicate through a shut-off valve, which hinders the excessive increase of the upper chamber pressure when the piston goes up. Further, the form of the check valve is changed for conveniently changing and adjusting the die cushion apparatus during press fabrication.

Abstract: A tensioner unit (12) comprising an inner cylinder (22), filled partially with hydraulic fluid, with a piston (26) and piston rod (28) reciprocal therein (sometimes referred to as a hydraulic cylinder) surrounded by a cylindrical chamber (40) (sometimes referred to as an accumulator) for hydraulic fluid and gas. The gas in accumulator (40) is pressurized to maintain the hydraulic fluid under pressure against the piston (26) placing the piston rod (28) under tension to provide the necessary tension force on a marine riser (14) and to compensate for the rise and fall of a floating platform. This is a self-contained integral unit with one end of the piston rod (28) connected to the riser (14), and the other end connected to a frame (16) supported on a platform of a TLP. A plurality of such tensioner units (12) on this frame (16) and connected to said riser (14) form a complete riser tensioner (10) without external accumulators.

Abstract: A gas spring with end positions damping has a cylindrical housing filled with a fluid under pressure, in which a piston rod, sealingly extending from one end of the housing, is disposed to be coaxially slideable and on the inner end of which a piston is attached. To create an end position damping that is simple in structure, and which can be used purely pneumatic, purely hydraulic or hydropneumatic, an auxiliary piston in the form of a throttle piston is slidingly disposed on the piston rod, which is supported via an energy accumulator towards the end of the housing where the piston rod exits. The piston abuts against this auxiliary piston at the end of the extension movement of the piston rod. Its throttle effect is larger during movement in the direction toward the end where the piston rod exits than in the opposite direction.

Abstract: A liquid spring unit operable in both tension and compression including a cylinder, compressible liquid in the cylinder, a piston and a seal for the piston, a first sleeve mounted for telescopic movement with respect to the cylinder, a collapsible housing consisting of a second sleeve mounted about the first sleeve and a third sleeve mounted on the second sleeve, a first attachment member mounted relative to the first sleeve for attachment to a first external member, a second attachment member on the third sleeve for attachment to a second external member, a stop for preventing the second and third sleeves from extending beyond a predetermined length when tension forces are applied to the first and second attachment members, a slidable connection between the second and third sleeves for permitting the housing to collapse when compressive forces are applied to the first and second attachment members, and a connection between the piston and the housing for driving the piston into the cylinder when both tension

Abstract: A liquid spring unit operable in both tension and compression includes a liquid spring having a cylinder, a piston, a seal between the cylinder and piston, and compressible liquid in the cylinder. A cylinder extension has diametrically opposed slots therein. A sleeve slidably mounts the cylinder and has diametrically opposed slots in alignment with the slots in the cylinder extension. A link is attached to the piston and has pintles received in the pairs of aligned slots. A first load-receiving member is attached to the sleeve and a second load-receiving member bears on the link to force the piston into the cylinder when the load-receiving members are moved toward each other and causes the cylinder to be moved onto the piston when the load-receiving members are pulled away from each other.

Abstract: A suspension strut for a vehicle comprises a cylinder in which works a piston, and the piston is carried by a piston-rod which passes through an axial extension depending from a closure for one end of the cylinder. An annular chamber defined between the cylinder and the extension accommodates the whole of a volume of gas or air and a portion of a volume of hydraulic fluid which fills the remaining space in the cylinder and against which the piston works. A seal through which the piston-rod works is carried by the extension at a position which is always below the level of hydraulic fluid in the cylinder so that the gas or air is prevented from escaping past the seal by the presence of the hydraulic fluid.

Abstract: An improved shock absorbing snubber for derrick hooks is shown which includes a stationary hydraulic plunger and a telescoping barrel arrangement. A spring loaded check valve mounted on the plunger allows generally free fluid flow as the barrel is moved in one direction relative to the plunger but restricts the flow of fluid as the barrel is moved in the opposite direction.

Abstract: A hydraulic damper includes a dual-tube type housing consisting of inner and outer tubes, a piston slidably disposed in the inner tube and dividing the interior thereof into two oil chambers, a piston rod secured to the piston and extending to the outside of the housing, a reservoir chamber defined between the inner and outer tubes and containing therein oil and gas, a passage connecting one of the oil chambers through which the piston rod extends with the gas containing portion of the reservoir chamber, and a valve member formed of a resilient material and having a lip portion acting as one-way valve for allowing fluid flow in the passage only in the direction from the one oil chamber to the reservoir chamber. A substantial portion of the radially inner surface of the lip portion is supported by a rigid annular retaining member.

Abstract: A recoil system and method for supporting a marine riser which is extended from offshore well head equipment to a floating platform are disclosed. The purpose of the recoil system is to prevent a violent collisin of the riser with the platform when the riser becomes separated from the well head equipment during a planned or an emergency disconnect operation. Upon disconnection of the riser from the well head equipment, the lifting force applied to the riser is reduced to a predetermined lower level and the riser is retracted to an elevated position above the well head equipment to permit unobstructed excursions of the riser. A variable lifting force is applied to the riser to maintain the riser substantially in equilibrium in the retracted position as the floating platform heaves relative to the riser in response to wave action.

Abstract: A hydraulic shock absorber of the type including a tubular main body having of an inner tube containing oil and slidably receiving a piston and an outer tube surrounding the inner tube to define around the inner tube an annular reservoir chamber containing therein pressurized gas in the upper portion and oil in the lower portion. A rod guide closes the upper end of the inner tube, and a piston rod is secured to the piston and slidably extends through the rod guide and through a seal member closing the upper end of the main body.

Abstract: A shock absorber of the hydraulic-pneumatic type includes a cylindrical casing closed at both ends and partially filled with a liquid damping medium. A piston is reciprocable in the casing, has valve controlled passages and a piston rod thereon extending outwardly through a packed opening in one of the ends. A quantity of gaseous fluid under super-atmospheric pressure occupies the space above the level of the liquid, and a perforated partition forming an anti-splash device is disposed slightly below the liquid level. The partition is stationary in the casing and is frictionally held in place against the inner surface of the casing but is displaceable under the effect of a force greater than that applied to it by the movement of the shock absorber as a whole or of the liquid damping medium upon reciprocation of the piston.

Abstract: A gas spring includes a cylinder, filled with compressed gas, a piston rod movable axially inward and outward of the cylinder cavity, and a piston axially movable on the end of the piston rod in the cavity and resiliently biased into engagement with an abutment on the free end of the piston rod. One of two passages bounded by the piston and connecting the two compartments into which the cylinder cavity is divided by the piston is blocked when the piston engages the abutment and opened when the piston is moved away from the abutment against the resilient bias. The other passage is opened during outward movement of the piston rod from the cylinder cavity.

Abstract: A riser tensioner cylinder is provided with a hollow piston rod which forms a second cylinder in which a ram is reciprocated. The free end of the ram is connected to a link which in turn is connected to the end of the riser for providing tension on the riser. The ram reciprocates in the second cylinder under constant pressure to compensate for wave action on the floating platform and the second cylinder is automatically positioned within the first cylinder for adjustment for tide, vessel offset or other infrequent but variable factors.

Abstract: A hydraulic seat cushioning device comprising a cylinder body and a piston has a concentric post-like upward projection in the cylinder body with a cylindrical surface in which there are a pressure fluid port and a vent port. An annular valving element closely slidably surrounding the post-like portion covers those ports when in a normal position but uncovers the vent port when above that position and uncovers the pressure fluid port when below it. The piston is so connected with the valving element as to move independently thereof in a lower portion of its stroke, but through the remainder of the piston stroke the valving element is constrained to move with the piston.

Abstract: The hydraulic spring comprises a fixed part innerly provided with an axial bore communicating with a reservoir of liquid and having an outlet aperture, a moving part filled with liquid, surrounding the fixed part and provided with an inside recess. The inside recess of the moving part is substantially in front of the outlet aperture of the fixed part at position of outer dead center and substantially in front of the free end of the fixed part at position of inner dead center.

Abstract: With the purpose of attaining effective reduction of vertical vibrations, there is arranged in vertical direction between the vibrating mass and the excitation source one or more little-damped springing systems which include compressed-air springing elements provided with a connecting pipe for the inlet or outlet of compressed air, whereby active intervention in the functioning of base springing systems is made possible. The active intervention concerns the vibrating of the mass in the resonance of the systems, and consequently, these systems may be provided only with the dampers which enable low damping or may be even without dampers at all. Moreover, between the vibrating mass and one or more springing systems, or between the springing systems and the excitation source, there is arranged one or more acceleration transformers in vertical direction.

Abstract: A snubber cartridge assembly is mounted to the nozzle of a control rod drive mechanism to insure that the snubber assembly will be located within the liquid filled section of a nuclear reactor vessel whenever the control rod drive is assembled thereto. The snubber assembly includes a piston mounted proximate to the control rod connecting end of the control rod drive leadscrew to allow the piston to travel within the liquid filled snubber cartridge and controllably exhaust liquid therefrom during a "scram" condition. The snubber cartridge provides three separate areas of increasing resistance to piston travel to insure a speedy but safe "scram" of the control rod into the reactor.

Abstract: Cushioning apparatus for cushioning a hydraulic jack is disclosed which includes a plunger reciprocably mounted within a blind bore. The plunger sequentially closes off a plurality of axially spaced orifices provided through the wall of the bore as the plunger moves from a first position adjacent the open end of the bore to a second position adjacent its closed end, thereby progressively restricting the escape of fluid from the bore so as to slow the movement of one of the telescopic members of the jack toward another.

Abstract: A ship in which a string of heavy pipe is raised or lowered vertically beneath the ship at a substantially constant velocity in spite of heaving movement of the ship. The equipment for raising and lowering the pipe string is supported by the vessel through a heave compensation mechanism that permits vertical movement of the ship relative to the pipe raising and lowering mechanism. The heave compensation mechanism is a passive damped pneumatic-hydraulic spring system for isolating the vertical movement of the ship from the pipe raising and lowering equipment. The spring system operates over a very wide range of load imposed by the raising, lowering and supporting of a very long heavy pipe string.

Abstract: A linear spring system using pneumatic cylinders arranged to give a substantially linear force versus displacement curve across a wide range of displacement and which is capable of providing large forces with mechanism.

Abstract: A riser is tensioned from a floating platform by the use of one or more active hydraulic heave compensator units, each having an in-line backup unit coupled thereto so that the backup unit will automatically take over the load if there is loss of pressure in the active unit.

Abstract: A direction reversal device including a housing and an abutment rod passing through, and movable relative to, the housing, one of the housing and the rod being stationary and the other being arranged to be impacted by a moving unit whose direction of travel is to be reversed, the device also including a resilient connection disposed between the rod and the housing and arranged to have a potential energy storage capacity corresponding to the kinetic energy possessed by the moving unit, and control elements for adjusting the storage capacity and the location of the point of direction reversal of the device.

Abstract: A ship in which a string of heavy pipe is raised or lowered vertically beneath the ship at a substantially constant velocity in spite of heaving movement of the ship. The equipment for raising and lowering the pipe string is supported by the vessel through heave compensation means that permits vertical movement of the ship relative to the pipe raising and lowering mechanism. The heave compensation means is a passive damped pneumatic-hydraulic spring system for isolating the vertical movement of the ship from the pipe raising and lowering equipment. The spring system operates over a very wide range of load imposed by the raising, lowering and supporting of a very long heavy pipe string.