Abstract: A fluid vibration damper, such as, a shock absorber includes a cylinder and piston combination in which the piston head travels through a fluid-filled cylinder and has fluid bypass openings in its external surface forming one or more recesses of predetermined cross-sectional configurations and sizes whereby to regulate fluid flow past the piston head according to a performance curve. The bypass openings can be formed in interchangeable elements so as to permit selective variations in the fluid flow characteristics of each particular size or design of shock absorber according to a specific force performance curve.

Abstract: A shock absorber for a vehicle suspension and the like in which an oil deflector is mounted between the piston rod guide and a single lip low pressure seal to divert streams of high pressure oil from impingement on the seal to thereby prevent the escape of oil from the shock absorber on rebound stroke.

Abstract: An exercising device comprising a frame, actuating means, and a double acting hydraulic cylinder used therewith. The hydraulic cylinder includes a container having first and second chambers and passageways for placing the chambers in fluid communication with one another. A piston is slideably mounted within the first chamber and valve means are mounted with the container for preventing fluid communication into the first chamber when the piston is moved in a first direction and for preventing fluid communication around the piston when the piston is moved in a second direction. A piston rod extends into the container for moving the piston in response to movement of the actuating means. A control means governs the fluid flow through a selected passageway from the first to the second chamber to regulate the amount of force necessary to move the actuating means during exercise of a portion of the body.

Abstract: A piston slides in a fluid-filled piston chamber for damping or snubbing the movement of an object connected thereto. Attached to the piston is a piston rod which is disposed in the main fluid supply reservoir located below the piston chamber, at the lowest point in the apparatus. As the piston moves, the associated movement of this rod in the reservoir varies its displacement therein, thereby displacing fluid into a vented secondary reservoir which is located above the piston chamber, at the highest point in the damper apparatus. Any leakage from the piston chamber collects in the reservoirs. Both reservoirs are in fluid supply connection with the piston chamber so that piston movement causes fluid to flow into the chamber from the reservoirs so as to keep the chamber completely filled with fluid at all times. Both reservoirs supply fluid to the piston rod seals, which are thereby always immersed in fluid.

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

Abstract: A hydraulic damper of the type having a cylinder defining an actuating chamber receiving hydraulic oil therein, a piston working in the actuating chamber, a piston rod with one end thereof secured to the piston and the other end thereof projecting from one end of the cylinder, a resisting force generating device mounted on the piston for controlling oil flow across the piston when the piston reciprocates in the actuating chamber, and a volume compensating chamber disposed adjacent to the actuating chamber and receiving gas and hydraulic oil therein. The hydraulic oil is caused to flow between the actuating chamber and the volume compensating chamber through a small hole.

Abstract: A spool valve is positioned within the reservoir of a hydraulic shock absorber. The valve body is secured to the pressure tube of the hydraulic cylinder and has openings aligned with ports therein. The spool has threads engaging threads on the valve body so that as the spool is rotated the spool is moved axially to cause the lands on the spool to cover more or less of the openings in the valve body. A rotatable shaft device extends radially through the external housing and into the reservoir. At its inner end the shaft device has a gear which engages a gear on the spool so that as the shaft device is rotated the spool also is rotated.

Abstract: A heavy duty hydraulic shock absorber having an inner tube in which is slidably mounted an impact receiving piston assembly. Upon application of an impact force on the piston assembly, the piston assembly is moved inwardly of the inner tube and fluid from the inner tube is metered through a plurality of exponentially disposed metering orifices into an accumulator chamber formed between the inner tube and an outer tube which encloses the inner tube. An adjustable, slidable metering spool is operatively mounted in the accumulator chamber, over the metering orifices, for regulating the flow of fluid through the metering orifices into the accumulator chamber.

Abstract: A spring device including a piston slidably disposed in an inner cylinder of a dual inner and outer cylinder with a piston rod secured thereto and extending to the outside of the cylinder through a rod guide closing one end of the inner cylinder, an oil passage formed in the rod guide and connecting an annular chamber between the inner and outer cylinders with the interior of the inner cylinder, and a device for supplying a force on the piston to project the piston rod outwardly, in which a guide member is supported on the piston rod with a coil spring interposed between the guide member and the piston, and the guide member is adapted to contact the rod guide to control the oil flowing through the oil passage when the piston rod moves outward by a predetermined amount.

Abstract: A buffer includes an actuation cylinder filled with oil, a piston rod extending through the upper end of the cylinder for vertical movement in the cylinder, a piston provided at the lower end of the piston rod in sliding contact with the inner wall of the cylinder and having a damping action producing mechanism. The piston divides the interior of the cylinder into upper and lower chambers. An outer cylinder is disposed about the cylinder in a peripherally spaced relationship therewith to define a reservoir chamber therebetween, the upper portion of the reservoir chamber being filled with gas and the lower portion of the reservoir chamber being filled with oil. A passage communicates the lower oil filled portion of the reservoir chamber with the lower chamber of the cylinder. A passage communicates the upper gas filled portion of the reservoir chamber with the upper chamber of the cylinder through the outer periphery of the piston rod.

Abstract: A cylinder-and-piston type hydraulic damper has spaced dual seals on its piston rods to provide annular cavities between seals. A fluid leakage line connects said cavities to the closed reservoir of a fluid leakage indicator which consists of a cylinder closed by a spring biased diaphragm which carries the indicating member of the indicator. The damper chambers on opposite sides of the piston are alternately supplied with fluid from the reservoir during operation of the damper by means of a shuttle valve, thus providing a closed and sealed fluid system including redundant seals with means for indicating that the damper needs servicing upon a predetermined loss of fluid from the reservoir.

Abstract: A vehicle shock absorber of the hydraulic cylinder and piston type which includes a control valve for limiting pressure of the hydraulic fluid during compression movement to control the damping force of the device in accordance with rate of compression movement above a predetermined rate. The damping force is limited during expansion movement to provide good road-holding ability for the vehicle.

Abstract: An apparatus for automatically sensing trailer sway and applying trailer brakes, thereby minimizing or eliminating the sway is provided. A hydraulic device, similar to a shock absorber with the addition of a pressure operated switch at each end of the cylinder, is mounted between the trailer A frame and the hitch head assembly. A sudden sway in either direction causes one of the switches to close and apply power to the electric trailer brakes thus minimizing or eliminating the sway and causing the car and trailer to "line up". The hydraulic device has an orifice in the piston or at each end of the cylinder so that normal turns made by the car and trailer do not cause sufficient pressure build up to cause either switch to operate. Similar automatic performance can be realized by the use of a gas filled bellows device.

Abstract: A shock absorber having a pressure tube with metering bores defining metering orifices through which fluid is metered upon application of impact forces to a piston assembly slidable in the pressure tube, and an adjustable metering sleeve with ports adjacent the metering orifices for regulating the flow of fluid through the orifices.

Abstract: A shock absorber having passageways through which fluid is metered from a primary chamber upon application of an impact force to a piston assembly slidable in the chamber, and an adjustable flow control member for regulating the flow of fluid through the passageways to an accumulator chamber within the flow control member.

Abstract: A shock absorber having a piston movable against a head of fluid under externally applied loads transmitted through a hollow piston rod. The piston has a valve surrounding a hollow metering pin defining a primary orifice and an auxiliary orifice, adjustable in size, is formed in the housing for augmenting the primary orifice area. The hollow metering pin provides a passage establishing communication between the auxiliary orifice and an accumulating reservoir located within the hollow piston rod. A fluid circulating system is provided for returning displaced fluid and for dissipating the heat generated in such fluid.

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 check assembly using compressible fluid for linearly dampening the closing movement of a door includes a cylindrical, hollow housing having a cavity defined therein with first and second ends. Slidably mounted within the cavity and attached to the door is a piston of substantially the same cross-sectional area as the cavity. The piston has flap-type, relief check valves allowing free passage of compressible fluid through the piston only during motion of the piston in the door opening mode. The check assembly further includes longitudinal grooves fabricated circumferentially around the cavity and of a dimension such that the seal of the piston against the cavity wall is broken at different points during movement of the piston allowing compressible fluid to flow from one side of the piston to the other. Finally, the check assembly includes a fluid bypass continuously communicating compressible fluid from one end of the cavity to the other thereby defining a closed loop system.

Abstract: A seismic damper device is provided between the supporting plate adjacent the bottom of an upstanding piece of electrical apparatus and the lower main frame support members, supporting said upstanding electrical equipment, so that any relative motion between the upstanding column structure and the main lower-disposed frame support structure is restricted. Preferably, a liquid-filled dash-pot assembly, or energy-absorbing device, is utilized at one or more locations extending between the lower supporting plate member of each upstanding column structure and the lower-disposed main supporting framework.In one form of the invention there are provided three equally-spaced radially-extending support arms extending outwardly from the main supporting plate disposed adjacent and fixed to the lower end of each upstanding column structure.

Abstract: A hydraulic damper for controlling the lag-lead movements of a helicopter rotor blade has dual oil seals on its piston rods. A fluid conduit connects the area between the seals to the area beneath the piston of a cylinder-and-piston type indicator and also through a fluid restriction back into an open fluid system. A bypass conduit is extended from the fluid conduit on the downstream side of the restriction to the area above the indicator piston so that any back pressure in the fluid system which creates a pressure rise of the other side of the restriction also acts on the upper end of the indicator piston.

Abstract: A liquid damper comprises a piston head which slides within a cylinder and which is carried by a piston rod which slides within an annular gland at one end of the cylinder. A passage which includes a damping valve connects the annular cylinder space to a liquid reservoir so that liquid displaced from the annular cylinder space by movement of the piston in either direction is fed through the damping valve to the liquid reservoir. The liquid reservoir is connected to the other cylinder space through a non-return valve. A groove which varies in area along its length, extends partway along the piston rod.

Abstract: A vehicle shock absorber of the hydraulic cylinder and piston type, including a control valve which, during compressive movement, limits pressure of the hydraulic fluid and thereby the damping force of the device in accordance with the rate of compressive movement above a predetermined rate. Operation of the valve may be controlled by pressure generated by obstructing the flow back to the reservoir of fluid displaced by the piston rod entering the cylinder on compressive movement, which pressure will vary in accordance with the rate of compression and consequently the rate of entry of the rod into the cylinder. A pressure control device is provided to limit the damping force during expansion of the shock absorber to thereby permit better road holding ability of the vehicle, with the relative strong damping force at the beginning of the following compressive movement acting to control oscillation of the suspended mass of the vehicle.

Abstract: A shock absorber is provided for automotive vehicles in which the damping force is dependent upon the position of the piston in a cylinder and therefore dependent upon the load. The damping forces in both directions of movement of the piston in a cylinder are higher in a more compressed portion than in a more expanded position of the shock absorber. The damping action for different portions of the stroke can be adjusted readily from the outside and independently for both directions of movement.

Abstract: The improved hydraulically actuated percussion drill described hereinafter is designed to reciprocate a striker piston contained therein regardless of whether or not the striker piston engages the drill steel whereby vibration can be imparted to the drill. The drill includes an overtravel portion that cooperates with the striker piston to prevent metal-to-metal contact of the striker piston with the housing during operation. Means are provided to prevent the loss of fluid from the overtravel chamber whereby the striker piston will be returned to the upper end of its stroke and will not become stalled in the overtravel chamber.