Abstract: A caliber bar for locating the centerline of the bore at the muzzle of a gun including a frame, first and second trunnion housings axially mounted on the frame, each of the trunnion housings pivotally mounting three centering arms circumferentially spaced at 120.degree. from each other for contacting the side of a bore at axially spaced locations, and first and second liquid springs mounted on the first and second trunnion housings, respectively, for biasing the centering arms associated with each trunnion housing simultaneously outwardly equal amounts into engagement with the side of the bore, and detents for removably holding the first and second trunnion housings in the frame.

Abstract: A frictionless hydraulic damper including a cylinder having end walls mounting the opposite ends of a shaft in bushings with a clearance, bellows seals between each end wall and the portions of the shaft extending beyond each end wall, a piston head on the shaft within the cylinder, hydraulic fluid in the cylinder and in both bellows seals, an orifice construction located relative to the piston head for permitting flow of hydraulic fluid past the piston head to produce damping, and a conduit in the shaft for effecting communication between the two bellows. The damper as described above also functions as a snubber by including a valve construction which selectively closes the orifice construction. The damper as described above also includes structure which effectively closes off the clearances at the relevant bushings when the piston head travels above a predetermined velocity, to thereby prevent leakage past the bushings and thus enhance the snubbing action.

Abstract: A snubber with an integral test structure which permits the snubber to be tested for drag, lockup and full load pressure characteristics without disconnecting it from between two external members between which it is mounted including a cylinder with opposite end walls, a piston mounted on a piston rod extending through the end walls and dividing the space between the end walls into first and second chambers which are filled with hydraulic fluid, a first clevis connecting one end of the piston rod to a first external member, a housing mounted for sliding movement on the cylinder and including a second clevis connecting it to a second external member, a plurality of selectively removable pins for fixedly attaching the housing to the cylinder or permitting it, when removed, to slide relative thereto, and ports in communication with the two chambers for conducting hydraulic liquid thereto or exhausting hydraulic liquid therefrom.

Abstract: A frictionless hydraulic damper including a cylinder having end walls mounting the opposite ends of a shaft with a clearance in labyrinth seals, bellows seals between each end wall and the portions of the shaft extending beyond each end wall, a piston head on the shaft within the cylinder, hydraulic fluid in the cylinder and in both bellows seals, an orifice construction located relative to the piston head for permitting flow of hydraulic fluid past the piston head to produce damping, and a conduit in the shaft for effecting communication between the two bellows. The damper as described above also functions as a snubber by including a valve construction which selectively closes the orifice construction.

Abstract: A shock absorber including a casing, a piston rod having a portion in the casing, a piston head mounted on the piston rod for dividing the casing into chambers on opposite sides thereof, a piston head having a central bore therein having an inner peripheral surface which flares outwardly at opposite ends thereof, and a plurality of interspersed grooves and ridges on the piston rod within the bore for permitting flow of liquid between the chambers to thereby provide fluid amplification through the spaces between the inner peripheral surface of the piston head and the outer peripheral surface of the piston rod.

Abstract: A damped liquid spring construction in which high instantaneous pressure rises are damped so as not to be experienced at the seal including a cylinder containing compressible liquid with a piston in the cylinder and a seal located in sealing engagement with the piston, and an annular pressure damping ring mounted in contiguous relationship to the seal, the pressure damping ring including an annular surface spaced from the outside surface of the piston for providing an annular space around the piston for restricting transmission of pressure and shock pulses from the main portion of the cylinder to the portion at which the seal is located, to thereby damp high substantially instantaneous pressure rises before the high pressure can affect the seal.

Abstract: An air cushion vehicle including a body, a flexible outer skirt depending downwardly therefrom, a rigid inner skirt within the outer skirt, air moving structure for creating pressure underneath the vehicle for normal driving and for creating a suction within the rigid skirt for holding the vehicle against the ground to withstand ground motion, spikes mounted on the vehicle in a normally retracted position, and structure for driving the spikes into the ground to stabilize the vehicle against lateral forces resulting from overpressure pulses and high winds.

Abstract: A shock absorber having a casing and a piston with a piston head mounted thereon and located in a chamber within the casing containing fluid, an annular peripheral groove on the shock absorber head for mounting an annular turbulence inducing member having an L-shaped cross section which is slidable on the bottom surface of the groove from a passive position which it occupies when the piston head forces liquid from one side thereof to the other in a fluid amplification mode and which moves to an active position for creating turbulence within the groove during the rebound movement of the piston head.

Abstract: An end cap for a cylinder including a body portion having an outer surface and first and second ends, a bore extending between the first and second ends, an annular sealing lip surrounding the bore, an annular recess surrounding the annular sealing lip, an annular outer body portion surrounding the annular recess, with the annular recess permitting radial flexing of the annular outer body portion both toward and away from the annular sealing lip, and an annular barb on the outer surface extending circumferentially about the annular outer body portion for reception in a mating groove in the cylinder.

Abstract: A liquid energy absorber device including an elongated liquid energy absorber member mounted on a base, an annular elastomeric member also mounted on the base in surrounding relationship to the liquid energy absorber member, a sleeve mounted on the liquid energy absorber member for sliding movement, a plate connected to the sleeve and supported on the end of the annular elastomeric member remote from the base, grooves in the plate and in the portion of the sleeve facing the liquid energy absorber member to conduct atmospheric air to a space which is formed between the sleeve and the elastomeric member as the latter distorts in operation to thereby cool the liquid energy absorber member and the annular elastomeric member, with the annular elastomeric member being longer than the liquid energy absorber member so that there is deflection of the annular elastomeric member prior to the activation of the liquid energy absorber member.

Abstract: A suspension for isolating the operator's seat in the cab of an overhead or gantry crane from various forces to which the cab is subjected including a base for mounting the seat, a plurality of cables for suspending the base from the frame of the cab to substantially isolate the base from the various vibratory, oscillatory and torsional forces applied to the cab, and shock absorbers connected between the base and the frame of the cab to dampen any oscillations of the base and to prevent the base from moving rotationally.

Abstract: A recoil-counter-recoil energy absorber unit including an outer housing for guiding a recoiling mass, an hydraulic energy absorber unit mounted between a portion of the housing and the mass, a recoil spring mounted between the energy absorber unit and the housing, a second housing mounting the hydraulic energy absorber unit and for permitting it to move unrestrictedly in a recoil direction but resisting movement thereof in a counter-recoil direction, whereby the second housing will be stretched after the hydraulic energy absorber moves beyond a predetermined counter-recoil position to thereby absorb counter-recoil energy as a result of being stretched.

Abstract: A simplified but highly efficient fluid-amplified liquid spring shock absorber is provided by incorporating a plurality of DeLaval nozzles in the piston head or dashpot head of a shock absorber.

Abstract: A method of obtaining a low variance in suspension frequency of an object including the steps of establishing the natural frequency which is desired, calculating the varying spring rate required to maintain the desired suspension frequency throughout a predetermined load range, selecting a compressible fluid having a varying rate of compressibility which approaches the desired calculated varying spring rate, and utilizing a spring constructed with said compressible fluid to support said object. A vehicle suspension system comprising in combination a vehicle body for functioning over a predetermined load range and a spring suspension having a low variance in natural frequency over said predetermined load range comprising a housing, a piston in said housing, a compressible fluid having a varying compressibility in said housing with the rate of change of the compressibility of the compressible fluid being matched to a varying spring rate which will produce said low variance.