Abstract: An in-arm suspension (12) is provided for actively controlling a suspension arm (20) mounted to a vehicle frame (14). The suspension arm (20) has a housing (60) in which the a compressible fluid strut (32) and a fluid control section (90) are enclosed. The compressible fluid strut (32) includes a cylinder (134) and a piston rod (136) which is urged to extend from within the cylinder (134) in response to fluid pressure applied to compressible fluid disposed within the cylinder (134). A damper piston (174) is mounted to an interior portion of the piston rod (136), and moves with the piston rod (136) to pass the compressible fluid through the damper piston 174 and attenuate bounce and rebound of the piston rod (136) within the cylinder (134). A damper lock (210) is mounted to the piston rod (136) for selectively preventing the flow of compressible fluid through the damper piston (174).

Abstract: A strut (12) is configured for an active suspension system (142) which provides electronic control for both the force applied by the strut (12) and the dampening characteristics of the strut (12). A compressible fluid (18) is used within the strut (12), and preferably includes a compressible base fluid and electromagnetic field responsive particles (132) which are suspended in the compressible base fluid. The electromagnetic field responsive particles (132) are preferably closely matched in density and modulas of elasticity to that of the compressible base fluid to prevent sedimentation of the particles (132) and to maintain the elasticity of the compressible fluid (18). The amount compressible fluid (18) within the strut (12) is electronically controlled to determine the force applied by the strut (12) and a field strength applied to the compressible fluid in a fluid flow passage is electronically controlled to determine the dampening characteristics of the strut (12).

Abstract: An active, independent suspension system has dual piston, compressible fluid struts (22). Each of the dual piston struts (22) has an outer cylinder (24) and an outer piston rod (30), which each respectively define exterior peripheries for an outer pressure chamber (32) and an inner pressure chamber (54). Pressures applied to a compressible fluid (56) in respective ones of the outer and inner pressure chambers (32, 54) urge the outer piston to extend from within the outer cylinder (24). A control system (240) is provided for actively controlling an amount of compressible fluid (56) disposed within each of the outer and inner chambers (32, 54).

Abstract: A strut (12) is configured for an active suspension system (142) which provides electronic control for both the force applied by the strut (12) and the dampening characteristics of the strut (12). A compressible fluid (18) is used within the strut (12), and preferably includes a compressible base fluid and electromagnetic field responsive particles (132) which are suspended in the compressible base fluid. The electromagnetic field responsive particles (132) are preferably closely matched in density and modulas of elasticity to that of the compressible base fluid to prevent sedimentation of the particles (132) and to maintain the elasticity of the compressible fluid (18). The amount compressible fluid (18) within the strut (12) is electronically controlled to determine the force applied by the strut (12) and a field strength applied to the compressible fluid in a fluid flow passage is electronically controlled to determine the dampening characteristics of the strut (12).

Abstract: A suspension system (20) controls the amount of compressible fluid (42) within struts (28) to determine spring rate coefficients (Ks) and dampening coefficients (Bs) for the struts (28). The spring rate and dampening coefficients (Ks, Bs) are selected to provide forces (F) which are a sum of several components, which include a desired target static force (Fd) for balancing various forces acting upon a vehicle chassis, comparison of the target strut force (Fd) to the actual force (F) applied by the respective struts (28), comparison of velocity ({dot over (z)}5) of the chassis relative to a selected reference datum, and a ride height error (erh). Frequency dependant filtering decreases the spring rate coefficients (Ks) when changes in position (Zs) are detected at frequencies (&ohgr;) beneath a threshold level (&ohgr;K), and decreases the dampening coefficients (Bs) when changes in velocity ({dot over (z)}s) are detected at frequencies (&ohgr;) above a threshold level (&ohgr;B).

Abstract: A hydraulic system for exercise equipment and a method of providing resistance to piston motion in exercise equipment.

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 spring and damping characteristics of each liquid spring are computer adjusted during vehicle operation in response to sensed variations in various liquid spring and vehicle operating parameters.

Abstract: A vehicular suspension system includes a liquid spring operatively interconnected between a vehicle frame and an associated wheel assembly to provide resistive spring and damping forces in response to relative vertical displacement between the frame and wheel assembly. The liquid spring includes a cylinder secured to the vehicle frame and having a compressible liquid-filled internal chamber in which a piston structure is reciprocally disposed and divides the chamber into bounce and rebound chambers. A rod is slidably and sealinqly carried by the cylinder for axial movement into and out of the chamber, the rod having an inner end anchored to the piston structure, and an outer end portion extending outwardly from the cylinder and secured to the wheel assembly. A flow passage extends through the piston and intercommunicates the bounce and rebound subchambers.

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 vibration isolating and damping suspension strut for vehicle undercarriages comprising an elongated cylinder and piston structure wherein the cylinder is divided into opposed chambers which are in communication with each other by flow restrictive passages formed in the piston or in the cylinder wall. When the strut undergoes a retraction stroke of the piston to absorb loads silicone fluid is compressed in the opposed chambers and transferred from the chamber opposite the piston rod to the rod side chamber through the restrictive passages resulting in heating of the fluid. When the strut rebounds or extends its piston rod fluid is forced to flow through the restrictive passages preferably at a more restricted rate.

Abstract: A vehicle with a suspension system having a compressible liquid confined in a cylinder and compressed to a predetermined static pressure. A damping piston is disposed on a double ended rod where the rod ends have different cross sectional areas to provide a differential area which is acted on by the liquid to spring support the weight of the vehicle. The end of the larger rod is connected to the vehicle chassis and bearings in each end of the cylinder transfer high bending moments due to wheel loads. Friction is reduced by eliminating contact between the large diameter piston and cylinder, and limiting frictional contact to the relatively small diameter of the bearings and seals. Total fluid volume is increased to provide a lower spring rate by a fluid chamber within the rod, and an apparatus is provided to control ride height by changes in liquid pressure and/or volume which also changes spring rate.

Abstract: A vibration isolating and damping suspension strut for vehicle undercarriages comprising an elongated cylinder and piston structure wherein the cylinder is divided into opposed chambers which are in communication with each other by passages formed in the piston and in a flow restricting shuttle valve mounted on the piston rod. When the strut undergoes a retraction stroke of the piston to absorb loads silicone fluid is compressed in the opposed chambers and transferred from the chamber opposite the piston rod to the rod side chamber through passages in the piston only. When the strut rebounds or extends its piston rod fluid is forced to flow through passages in the shuttle valve member and the piston flow passages at a more restricted rate. The piston flow passages and the shuttle valve are arranged to direct fluid flow toward the outer cylinder borewall to improve heat transfer to the exterior of the strut and minimize heating of the fluid contained in the cylinder chambers.

Abstract: A compressible fluid type suspension strut is interconnected between a vehicle frame and a steerable wheel spindle support providing spring and shock absorbing functions and serving as a steering bearing support assembly. An arrangement of spherical bearing members and bearing support plates are disposed around the piston rod of the suspension strut and interconnect the rod with a frame support member for transmitting bearing loads during normal operation of the strut and in the event of collapse of the strut whereby the spindle supported by the strut may be steered. The lower end of the suspension strut cylinder is connected to the spindle support body by a self aligning bearing assembly to alleviate bending loads on the strut cylinder. An outer bearing sleeve extends between the spindle body and a frame support member for carrying bending loads imposed on the strut assembly.

Abstract: A vehicle for traversing rough terrain, such as is commonly found in open mining operations and highway construction work. The vehicle is characterized by a movable frame structure. The frame includes a pair of elongated side members which are joined in a spaced apart relationship near the rear of the frame members by a first crossmember which is provided with a pivotal joint to permit the side members to rotate or pivot relative to each other. The front ends of the side members are connected by second and third crossmembers, each of which is pivotally connected at both ends to the side members to provide lateral restraint to the side members while the vehicle is traversing rough terrain. The second and third crossmembers are vertically displaced to prevent relative rotation of the side members about their longitudinal axes while permitting up and down movement of the forward ends of the side members as the side members rotate about the pivot point in the first crossmember.