Abstract: A piston is slidably fitted in a cylinder for dividing the interior of the cylinder into upper and lower cylinder chambers. A reservoir is connected to the piston. A primary passage communicates between the upper cylinder chamber and the reservoir. The primary passage includes a primary damping valve. A secondary passage is connected to the primary passage to bypass the primary damping valve. A constant orifice, a filter, and a damping force adjusting valve are provided in the secondary passage. The primary damping valve includes a pilot line. The pilot line is connected downstream of the filter. The flow resistance of the damping force adjusting valve is directly adjusted by changing the cross sectional flow area of the damping force adjusting valve. The valve opening pressure of the primary damping valve is adjusted by changing the pilot pressure introduced from the pilot line. When the filter becomes clogged, the primary passage ensures the flow of the hydraulic fluid.

Abstract: A rotary damper includes a housing and a vane. There is an indentation in the housing which permits fluid to flow readily from one side of the vane to the other during part of the rotary stroke. At the end of the rotary stroke, there is an alternative path for fluid to take from one side of the vane to the other, and this path preferably includes an adjustable aperture so the amount of damping at the end of the stroke can be adjusted.

Abstract: A device for providing a rigid mechanical link with frequency cut-off between two structures, the device comprising a rigid tie-rod (14) the ends of which are secured to the two structures (10, 12) and a cylinder and piston assembly (16, 18) in parallel with the tie-rod (14), the two ends of the cylinder (16) being interconnected by a duct (22) which, together with the cylinder (16), is filled with a liquid of very low viscosity, the device providing filtering of a low excitation frequency applied to one of the structures and preventing the transmission of this frequency to other structures.

Abstract: A vibration damping device comprises two cylindrical and flexible membrane members, a restricted passage constituting member connected at both end portions to these membrane members, two face plates connected at their end portion to the membrane members, a closed chamber defined by these members and face plates, a rigid member connecting both the face plates to each other at inside or outside of the closed chamber, a fluid filled in the closed chamber, and a fastening member disposed at each side of the restricted passage constituting member and the face plate.

Abstract: An enclosed hydraulic cylinder which may be used as a tension buffer, mainly consists of a body casing having an integrally formed sealed inner passage and a piston stem. The body casing is internally divided into a pressure chamber, a buffer chamber, and a regulation chamber between the pressure chamber and the buffer chamber. When the body casing and the piston stem are subjected to external pulling force in reverse direction, fluid filled in the pressure chamber, being compressed by air coming from an air intake chamber communicable with the pressure chamber and by the piston stem, flows through a flow-limit disposed near outer end of the pressure chamber and into the sealed inner passage before it enters the regulation chamber and thereby adjusts the inner pressure of the cylinder. The buffer chamber adjoins the regulation chamber and the room thereof can automatically adjust to relieve the hydraulic pressure in the regulation chamber and prevent the body casing from excess hydraulic pressure.

Abstract: A vehicular suspension system incorporates, at each wheel, a liquid spring which internally utilizes a compressible liquid to generate spring and damping forces that yieldingly resist vertical wheel deflection relative to the vehicle frame. The liquid spring includes a dual piston assembly which divides a main cylinder into bounce and rebound chambers. A rotary metering valve is interposed between the bounce and rebound chambers for controlling the flow of compressible liquid from one chamber to the other during bounce and rebound. The dual piston assembly includes a tubular piston having a modulation chamber coupled in flow communication with the bounce chamber. The spring and damping characteristics of each liquid spring are computer adjusted during vehicle operation by modulating the bounce chamber pressure in response to sensed variations in various liquid spring and vehicle operating parameters.

Abstract: A hydraulically-operated piston device installed between the frame of a structure and a vibration-resisting element provided separately from the frame varies the rigidity of the frame by changing the condition of connection between the frame and the vibration-resisting element. A valve controls the operation of the piston device and can be adjusted to change the coefficient of damping of the piston device. To obtain maximum rigidity of the frame, the piston is hydraulically locked in place. For maximum flexiblity of the frame, the piston can be hydraulically released from a locked position to move freely. Hydraulic resistance to movement of the piston can be graduated by metering the flow of oil into and out of the piston device. The coefficient of damping is a function of the metered flow of hydraulic fluid in the piston device.

Abstract: An actuator (1) in particular for proportionally influencing the fluid flow in hydraulic and/or pneumatic devices, including a cylindrical housing (2) with an elongated actuating element (3) movably supported therein, elements (11, 12, 13) of memory metal, engaging said actuating element (3), the housing (2) and the actuating element (3) movable relative to one another by activation of the elements (11, 12, 13) of memory metal, if necessary against the force exerted by an element (15) of permanent resilient material. The housing (2) is provided at one end (8) with an opening (9) through which the actuating element (3) protrudes longitudinally upon relative movement. Bringing about the intended proportional operation, the actuator (1) includes locking means (16, 17, 19), engaging the actuating element (3), for mutually locking the actuating element (3) and their housing (2) in one or more positions.

Abstract: The device serves to convert rotary motion to hydraulic pressure and vice versa. A piston assembly is entirely located within a cylinder, including a piston head and a piston stem fixed to the piston head. The piston assembly divides the cylinder into two distinct variable volume chambers to be filled with a fluid. The piston assembly is prevented from rotating relative to the cylinder. A rotary shaft extends through one closed end of the cylinder and has an inner portion in telescopic and threaded engagement with the piston stem. Two fluid ports communicate with the respective chambers for allowing a fluid to alternatively exit from and enter into the chambers. Rotation of the shaft causes longitudinal displacement of the piston assembly relative to the cylinder or vice versa. The device can have different applications: for instance, if a throttle valve is connected across the two ports, controlled braking of the shaft rotated by an external torque, is obtained.

Abstract: The shock absorber is mounted on a vehicle chassis. It comprises an outer guiding housing and a supporting member movable axially and rotatable relative to it. A hydraulic chamber is located between the guiding housing and the supporting member. This hydraulic chamber is formed by a hydraulic cylinder in this supporting member and is closed by a piston connected axially and nonrotatably with the guiding housing. The hydraulic cylinder may comprise the supporting member alone or may be a separate unit within the supporting member.

Abstract: An adjustable vibration damper is for a motor vehicle or the like. The vibration damper includes a cylinder containing a damping medium. A piston is disposed within the cylinder for movement of the damping medium. A valve device is connected to the cylinder for flow of the damping medium therethrough. The valve device has at least a first damping element and a second damping element. The first damping element includes a first compression valve assembly and a first decompression valve assembly. The second damping element includes a second compression valve assembly and a second decompression valve assembly. The first compression valve assembly, the first decompression valve assembly, the second compression valve assembly, and the second decompression valve assembly have respective damping characteristics. There is included switching apparatus for selectively switching to at least one of the first and the second damping elements to select the respective damping characteristics thereof.

Abstract: The technical field of the present invention is that of sealing devices between a piston rod and a cylinder of an artillery recoil brake. The piston divides the chamber into a high-pressure chamber and a low-pressure chamber. The volumes of the chambers vary according to the position of the piston relative to the cylinder. The sealing device according to the invention includes a "medium-pressure" chamber through which the piston rod passes, and which communicates with the high pressure chamber by means of a roughly annular channel surrounding the piston rod. The medium-pressure chamber is connected to the low pressure chamber by a pipe having a cross sectional area greater than that of the annular channel. The device is intended for applications to artillery material.

Abstract: An apparatus for damping movement courses of two bodies, in particular in a vehicle wheel/vehicle suspension system, having a piston sliding in a cylinder and dividing it into two work chambers, the two work chambers arranged to communicate with one another via respective oppositely acting check valves and via a variably asymmetrical damper valve adjustable in such a manner that upon a valve member movement the opening cross section for one flow direction decreases to the extent that it increases for the other flow direction, such that whenever in comparison with an active damper system energy would have to be supplied from outside, the damper force is substantially reduced to the value of zero.

Abstract: For preventing very small amplitude vibrations of the rod in a tensioner during high speed movement of a belt to be tensioned by the tensioner, a tube which is connected to a plunger which moves together with the rod is overlapped with a stationary member so as to define an annular clearance therebetween in an operating chamber of the tensioner. By filling an operating fluid in the clearance, shear strain is generated upon high speed movement of the plunger, which resists movement of the plunger.

Abstract: A composite hydraulic cylinder apparatus which has a pneumatic cylinder mechanism, a braking oil hydraulic cylinder mechanism associated concentrically with the pneumatic cylinder mechanism, an oil passage for communicating between the front chamber and the rear chamber of the oil hydraulic cylinder mechanism, and a control valve provided in the oil passage for controlling the flow of the oil. Thus, the apparatus provides high positioning accuracy, a large holding force, economy and small size as a movable element control system, and can be applied as a buffer for the movable element.

Abstract: Operation of a continuously variable semiactive damper of the system is modified so as to reduce generation in the system of undesirable shocks and noise. The modifications include delaying some or all of the changes in the on/off states of the damper, and/or limiting the rate and/or extent of changes in the damping coefficient of the damper at certain of the times when the damper is in an on state.

Abstract: The shock absorbing jack of the invention includes essentially a rod in which a sliding piston defines an extension chamber and which itself slides in a body by means of a piston defining a retraction chamber, the body including a throttling device and, on the side opposite the rod, two high and low pressure gas chambers, these chambers being separated by a membrane bearing, at rest, on a support with hemispherical perforated bottom.

Abstract: A shock isolator apparatus of the pressurized air type having a plurality of cylinder chambers and a piston positioned for movement in the cylinder chambers. An air passage tube axially located in the piston permits air to flow between one end of the piston extending into a first end chamber in the cylinder and a chamber formed in the piston at an end opposite the one end. Air communication between the end chamber, the chamber formed in the piston, and a second end chamber in the cylinder is accomplished by air bypass ports extending between the air passage tube and the second chamber. Unidirectional pressurized valves positioned between chambers of the cylinder operate to equalize the pressure distribution throughout the cylinder.

Abstract: Conventional piston-cylinder hydraulic actuators require external pressure sources. The hydraulic actuator disclosed utilizes the centrifugal head developed in its chambers. The piston (36) is attached to shaft extension (24) which is splined to the actuator cylinder (20). The cylinder (20) rotates with the shaft (16) to develop a centrifugal fluid head which is selectively directed from the outlet port (40a, 40b) of a contracting chamber through a servo valve (46) to the return passageway (46b, 46a) of an expanding chamber to axially displace piston (36) and shaft (16). An accumulator in the fluid circuit retains fluid displaced from the cylinder (20).

Abstract: An exercise rowing machine has a frame and a swing arm pivotally connected thereto which is manually pushed and pulled in opposition to an adjustable hydraulic load-resisting mechanism pivotally connected between the frame and the arm. This mechanism has a pair of spring-loaded, independently adjustable flow control valves at opposite ends for controlling flow to and from opposite ends of a cylinder which a double-acting piston reciprocates responsive to movement of the swing arm. The range of adjustment of the spring pressure on the valves is preset.

Abstract: A fluid energy absorber device, such as a fluid spring or shock absorber, or combination of both, having a composite casing, compressible fluid in the composite casing, and a piston in the composite casing, the composite casing including an inner plastic cylinder having an outer surface, and an outer high strength plastic cylinder on the outer surface for reinforcing the inner plastic cylinder, the outer high strength plastic cylinder including fibers of metal or plastic extending longitudinally of the inner cylinder and plastic stretchable fibers extending circumferentially of the inner cylinder so as to permit radial expansion of the inner cylinder to provide a high spring rate as compared to a fluid energy absorber device, such as a fluid spring, having a simple plastic casing, the fibers of the outer cylinder being encased in a resin.

Abstract: Snubbers and methods and apparatus for the in-place testing thereof are disclosed. The snubbers include a manifold between the hydraulic cylinder and each of the two control valves fastened thereto whereby for test purposes the control valves and hydraulic cylinder may be isolated from each other and coupled to a test machine for the independent testing thereof. Isolation of the control valves from the hydraulic cylinder allows separate testing of the control valves for lockup and bleed, and isolation of the hydraulic cylinder allows the testing of the cylinder for leakage and breakaway. Various embodiments are disclosed.

Abstract: A vibration damping system for vehicles, with a damping element in a cylinder. The cylinder holds a damping medium and is divided into two chambers by a piston. A damping valve, located in a bypass, is connected parallel to the work cylinder. The damping valve variably controls damping to any desired damping in the decompression and compression stages of operation of the vibration damping system. The damping valve has an axially-movable, controllable valve being disposable in an opening. The controllable valve is connected in a series fluid flow relationship with at least one pressure-controlled, spring-loaded valve within the same valve body. The damping valve can be installed in numerous variations in vibration damping systems of vehicles.

Abstract: A pressure regulator mechanism for use in a hydraulic device having a cylinder and a piston slidably movable therein, includes a casing housing the cylinder therein, a first restriction on the cylinder for forming a portion of a passage of working oil between the cylinder and the casing, a valve member angularly movable around an axis of movement of the piston for closing the first restriction, and a second restriction on the valve member for forming a remaining portion of the passage when brought into confronting relation to the first restriction in response to angular movement of the valve member. One of the first and second restrictions has different cross-sectional areas selectable for communication therethrough between the first and second restrictions, so that the rate of flow of the working oil through the passage can be varied.

Abstract: A rate controller for use in outer space is provided where motion damping occurs by forcing damping fluid from one side of an actuator piston to the other side of the piston through an external line. The damping fluid is totally contained in a sealed system of metallic bellows with no seals required between moving parts and the external environment.

Abstract: This disclosure pertains to protection apparatus for liquid-filled submergible equipment such as downhole electric motors used in oil wells and the like. The protection apparatus provides a positive bias force on the filling liquid so that any liquid leakage through motor seals and the like takes place from the inside out. The positive bias pressure is created by a piston having a substantially constant biasing pressure applied thereto by constant force springs. The piston operates in a cylinder which communicates at its head-end with the equipment being protected. The base-end of the cylinder communicates with a conventional labyrinth-type protector for maintaining an interface between the protecting liquid and well fluid externally of the cylinder.

Abstract: An overload coupling member is used as a strut to interconnect the upper link of a tractor lift device with an implement, such as a cultivator. The member includes two portions that are moved towards one another upon overload to allow the implement to pivot upwardly on the other two links. One portion has an inner end sleeve pivoted to a further sleeve on the other portion's inner end and relative movement between the two portions is prevented by a shear pin that extends into an opening of the sleeves. Upon overload, the pin shears and the portions jack-knife until the lift raises the implement past the obstacle and the implement is then lowered. The inner opening end is normally closed by an abutment member, but when the portions are pivoted, the opening is exposed and a severed pin portion falls out. The shear pin can have a number of severable portions and be spring biased to slide in a holder and establish rigid connection between the two portions a number of times.

Abstract: An elongated coupling member is connectable to the upper link of a three point tractor lift and to an implement carried by the lift, such as a spreader. The member includes a piston slideably mounted in a cylinder and a hydraulic circuit between a space at each side of the piston. The piston can be adjusted to a set position in which the relative positions of the piston and cylinder are maintained by hydraulic fluid within the circuit and spaces. An overload device, such as a spring biased, one-way valve, is included in the circuit so that upon overload, the piston moves, usually to lengthen the coupling member and allow fluid to flow from one space to the other. In one version, an overflow space or reservoir is in the circuit to accomodate excess fluid when the piston is shifted and one space is larger than the other.

Abstract: The hydraulic knee control for a prosthetic leg has a cylinder and piston assembly. In addition, within the cylinder is disposed a free floating plug so that the space between the free plug and the head end is filled with air or a compressible fluid, and the spaces between the free plug and the crank end is filled with a liquid or hydraulic fluid. The piston is disposed within this liquid and has sealing means which prevents the liquid from bypassing therearound. Disposed outside of the cylinder are two bypass passageways wherein one end of each passageway communicates with the cylinder in the region between the piston and crank end and the other end of each passageway communicates with the cylinder in the region between the piston and the floating plug.

Abstract: A mechanical link member is provided which is easily variable in length for ease of connection yet rigid in operation by the use of hydraulic valve and screw-type adjustments. In addition to an interrupted flow position which prevents relative axial movement of the ends of the link member, the hydraulic valve has full flow and restricted flow positions to control the rate of length adjustment. A spring positions the mechanical link to a midrange position when the hydraulic valve is opened and the link ends are not attached to a load.

Abstract: An apparatus for limiting the tension to which a suspended member can be subjected is disclosed. The apparatus responds to excessive tensile stress by increasing in length at a rate to keep such stress from exceeding a predetermined level. The present invention includes a closed cylinder with a piston disposed therein. Connected to the piston is a piston rod which extends through an opening in one end of the cylinder. The cylinder and piston rod are adapted to connect with a suspended member and a hoisting means. A bypass conduit connects the cylinder chambers by extending from one side of the piston to the other. In the conduit, there is a flow control regulator which actuates when the pressure on one side of the piston reaches a predetermined level, corresponding to a proportional tensile stress, permitting fluid to flow through the conduit in such a volume that the pressure on that side of the piston is maintained at the predetermined level.

Abstract: An electrically-controlled damping device for use in a vehicle suspension includes a cylinder, a piston slidable in the cylinder and a damping control valve controlling the interconnection of the two ends of the cylinder. The valve is servo-operated by means of an electrical pilot valve and hydraulic working fluid for the servo-system is supplied from the cylinder itself through the intermediary of a bridge rectifier arrangement of one-way valves.

Abstract: Apparatus having an operating cylinder and piston rod combined with a shock-absorbing cylinder and piston. The two hydraulic devices are connected by a conduit which allows the piston rod of the operating cylinder to yield under shock loads which are absorbed by the second cylinder and piston and immediately return to an original adjusted position when any imposed load returns to normal.

Abstract: A brake for a fluid-powered sprinkler system is provided for preventing the drive towers from rolling down inclines and for preventing the wind from rolling the drive towers. The fluid power may either be compressed air or water under pressure. An overhead water supply pipe extends outwardly from the center pivot point and is supported by a plurality of spaced-apart wheeled drive towers. In the preferred embodiment, an air-powered drive is provided on each of the towers to propel the towers and water supply pipe around the center pivot point. A control is provided on each of the towers for selectively operating the drive associated therewith to maintain the pipe and towers in an aligned condition as the water supply pipe is pivoted around the central pivot point. The control comprises a rotary cam plate having an alignment rod secured thereto which extends to the gimbal ring on a flexible joint positioned on the water supply pipe adjacent the tower.

Abstract: A hydraulic dashpot having a pressure tube with a port defining a metering orifice through which fluid is metered upon application of impact forces to a piston assembly slidable in the pressure tube, and wherein the pressure tube is rotatable for adjusting the position of the orifice relative to a spiral valve edge for varying the effective area of the orifice.

Abstract: A safety means in an engine for providing a measured rate of clutch engagement in the event of clutch cable rupture or in the event an operator abuses his machine and initiates an almost instant engagement.

Abstract: A liquid-operated tubular shock-absorber capable of exerting an adjustable force, comprises two concentric tubes fixed one inside the other with a narrow annular spacing between their walls, and a piston provided with a spindle sliding in sealing-tight relationship in the inner tube to define two chambers therein; in the end regions the spacing between the tubes communicates with both chambers inside the inner tube to form a closed circuit which is filled with liquid. A needle valve for regulating the flow of liquid are provided. The shock-absorber is particularly useful in physical training as a very reliable exerciser which operates in both compression and traction.