Abstract: A two-axis force motor (10) has an armature (12) mounted within a body (11) for omni-directional pivotal movement relative to the body. The motor has an electrical section for causing the armature to pivot selectively in either or both of two mutually-perpendicular intersecting planes (x-x,y-y). The motor also has a fluidic section, which includes a plurality of valve members (64) spaced about the armature. These valve members are biased to engage the armature and are closed when the armature is in a null position. When the armature is pivoted off-null, some of the valve members will be opened, while others will remain closed.

Abstract: A vehicle suspension system (10) has a spring (11) operatively arranged to act between sprung (15) and unsprung (13) masses. The coil (24) of an LVDT (22) is mounted on the sprung mass. The core (23) of the LVDT is connected to an intermediate portion (25) of the spring. Thus, displacement of the core relative to the coil will be a proportional fraction of the relative displacement between the masses. This arrangement allows the use of a short-stroke position-sensing transducer to measure the relative displacement between the two masses.

Abstract: An improved clamping mechanism is used to mount a transducer (11) on a motor housing (12). The motor housing has an inclined surface (18). The clamp (13) has one portion (32) engaging the inclined housing surface, and has another portion (30) engaging the transducer. A fastener (33) is used to move the clamp relative to the motor housing. The radial force exerted by the clamp on the transducer is greater than the axial force exerted by the clamp on the transducer.

Abstract: The invention provides an improved method of operating a pulse-width-modulated solenoid valve so as to improve the proportionality of the flow-to-command pulse width characteristics of the valve. A train of command pulses (P.sub.1, P.sub.2, . . . P.sub.n), having widths corresponding to the desired flow through the valve, is superimposed on another train of pre-pulses (p.sub.1, p.sub.2, . . . p.sub.n). Each pre-pulse is timed to appear immediately ahead of an associated command pulse so that their widths will be effectively summed. The pre-pulses have widths necessary to substantially eliminate the "deadzone" in the flow-to-pulse width characteristics of the valve. Hence, the proportionality of the flow-to-command pulse width characteristics of the valve will be substantially improved.

Abstract: A pulse-width-modulated solenoid valve has a body provided with an elongated chamber. The body has inlet and outlet openings communicating with the chamber, and has a seat surrounding the inlet opening and arranged to face into the chamber. An armature is mounted in the chamber for movement therealong toward and away from the seat. A coil is mounted on the body, and is adapted to be selectively energized to move the armature in one direction relative to the body. A return spring is arranged to urge the armature to move in the opposite direction relative to the body. The improvement provides a valve element which is mounted for movement with the armature toward and away from the seat, but also mounted for movement relative to the armature when the element engages the seat, such that the mass of the armature will not exert a substantial force against the seat. According to the improvement, the operating life of the valve may be greatly extended.

Abstract: A pulse-width-modulated solenoid valve has a body provided with an elongated chamber. The body has inlet and outlet openings communicating with the chamber, and has a seat surrounding the inlet opening and arranged to face into the chamber. An armature is mounted in the chamber for movement therealong toward and away from the seat. A coil is mounted on the body, and is adapted to be selectively energized to move the armature in one direction relative to the body. A return spring is arranged to urge the armature to move in the opposite direction relative to the body. The improvement provides a valve element which is mounted for movement with the armature toward and away from the seat, but also mounted for movement relative to the armature when the element engages the seat, such that the mass of the armature will not exert a substantial force against the seat. According to the improvement, the operating life of the valve may be greatly extended.

Abstract: An improved piston-and-cylinder arrangement has a pressure-balanced piston head mounted on an actuator rod. The piston head is mounted for axial movement with the rod, and for radial movement relative thereto. Three annular ring-type seals are provided between facing cylindrical surfaces of the piston head and rod. The frictional impediment to radial movement of the piston head relative to the rod is minimized, and the improved device exhibits a reduction in the average maximum longitudinal frictional force per stroke.

Abstract: A hydrostatic bearing is provided between two relatively movable members. Opposing sensing and bearing pads extend into either member and face the other member. These pads communicate with one another. An inlet orifice is defined between the members and extends from a fluid source to the sensing pad. An outlet orifice is defined between the members and extends from the bearing pad to the fluid return. The areas of the inlet and outlet orifices vary reciprocally in the sense that as one area increases, the other area decreases. The bearing exhibits reduced flow characteristics when one member moves axially and/or radially relative to the other member.

Abstract: A time-delay valve is adapted to be used in association with a source of pressurized first fluid, such as CO.sub.2. When CO.sub.2 is admitted to the inlet of the time-delay valve, an entrapped liquid is pressurized to a known level. Such pressurized liquid is constrained to flow through a restricted orifice, to enter an expanding chamber having a movable piston. The piston is thereafter displaced from a first position to a second position, between which the CO.sub.2 is not permitted to pass from the inlet to the outlet. However, after the piston passes beyond the second position, pilot and main valve elements are moved off their respective seats, and first fluid is permitted to flow directly from the inlet to the outlet.

Abstract: An improved transfer chamber for a space vehicle has an enclosure mounted on the hull of a spacecraft, and is provided with inner and outer doors. Two bladders are placed within this transfer chamber, and are selectively movable toward and away from one another. Conduits communicate these bladders with an outer reservoir exposed to space pressure, and with an inner reservoir exposed to cabin pressure. The conduits, bladders and reservoirs are all filled with liquid. When it is desired to egress an object from the cabin to space, liquid is pumped into the bladders, which move toward one another and deform about the object. This reduces the volume of air which is lost to space when the outer door is opened.

Abstract: An electro-mechanical actuator has a ferrous alloy armature movably mounted within a body chamber. Two axially-spaced permanent magnets are arranged radially inwardly of the chamber and partially define the chamber at the ends thereof. A coil surrounds the chamber. The body is formed of a magnetically-permeable material. Because of the high reluctance of the magnets, each magnet forms a short magnetic loop which passes through the adjacent air gap, and forms a long magnetic loop which encircles the coil and passes through the distant air gap. The armature has a bistable toggle-like movement, and may be latched proximate either end wall. If springs are added between the armature and the body, the improved actuator may be used as a proportional position of force transducer within an operating range of armature movement.

Abstract: A linear force motor has an elongated body provided with an annular chamber therewithin. An armature is arranged within the chamber for axial movement relative thereto. Two axially-spaced permanent magnets, with their like poles arranged to face one another, are arranged within the body radially inwardly of the chamber, and are separated by a common polepiece. The force motor has four axially-spaced active air gaps, arranged in various reciprocal pairs and various parallel pairs. When the armature is shifted one direction relative to the body, the majority of each magnet's static flux passes through one parallel pair of air gaps. When the armature is shifted in the other direction relative to the body, the majority of each magnet static flux passes through the other parallel pair of air gaps. The motor has one or more coils operatively arranged to generate control flux in a path which passes through at least one reciprocal pair of air gaps.

Abstract: A seal assembly is arranged to contain leakage of hydraulic fluid passing between a wall opening and a penetrant rod portion passing through the opening. The seal assembly includes a sliding-seal member mounted on a portion of the rod for sliding movement toward and away from an abutment surface and a non-sliding flexible-seal member arranged between the body and the sliding-seal member. The body, flexible-seal member, sliding-seal member and rod define a sealed chamber into which such fluid will leak. The chamber communicates with a fluid reservoir through a oneway check valve. The sliding-seal and flexible-seal members are arranged in parallel with one another. In one embodiment, a spring urges the sliding-seal member to move toward an abutment surface provided on the rod. In another embodiment, movement of the sliding-seal member relative to the body is limited by facing abutment steps.

Abstract: An equalizer is arranged to continuously sense the control pressures of two valves. In the event of a differential between the control pressures, the equalizer operates to selectively adjust one valve so that the control pressures of both valves will thereafter be substantially equal.

Abstract: A single-stage servovalve has a movable member operatively arranged to selectively divide a continuously-discharged fluid jet between two receiver passages. The hydraulic output of the valve is the differential between the conditions in the receivers. In the event of a hard-over failure of the control system of which the servovalve is a part, a jet deflector surface becomes operative to create a substantially balanced hydraulic condition in the receiver passages, thus terminating control.

Abstract: An improved electrohydraulic servovalve has first and second valve spools mounted for independent sliding movement relative to a body in response to a common command signal. The valve has a first drive mechanism operatively arranged to cause a desired motion of one valve spool in response to the command signal, and has a second drive mechanism operatively arranged to cause a desired simultaneous similar motion of the other valve spool in response to the command signal. The improvement comprises a differential position sensing mechanism arranged to sense the relative positions of the two valve spools and operative to produce an output related to the difference therebetween, and an indicating device supplied with such output and operative to indicate substantially dissimilar relative positions of the spools.

Abstract: A high response servovalve has an improved valve spool slidably mounted within the bore at a sleeve or body. The bearing surfaces on the spool are formed of a relatively soft material. The balance of the surfaces of the spool and the sleeve or body are relatively hard. The soft bearing material tends to absorb contaminants between the bearing lands and the sleeve, is self-healing, and is not prone to weld to the facing sleeve or body surface.

Abstract: A slide mount is adapted to selectively move a plunger assembly of a ski binding relative to a detent recess component. The slide mount includes a rail mounted on the ski and having a channel aligned with the recess, a slide carrying the plunger assembly and mounted on the rail for sliding movement along the channel both toward and away from the recess, and an actuator arranged to act between the rail and slide to cause the slide to move between a first position closer to the detent recess and a second position farther from the detent recess. The actuator includes a lever pivotally mounted on the rail, and a link pivotally connected to the lever and the slide, so that pivotal movement of the lever will produce corresponding linear motion of the slide.

Abstract: Apparatus is provided for sensing the actual position of an armature in an electromagnetic driver, such as a torque motor, a solenoid, or the like. An oscillator generates a relatively high frequency carrier signal, which is superimposed on a relatively low frequency command signal supplied to a drive coil. Detector coils are positioned in a magnetic circuit, and are arranged to have induced therein, signals identical in frequency to the superimposed signals. The amplitude of the induced signals varies with armature position. The high frequency induced signal is separated and demodulated to provide an output signal indicating the actual position of the armature.

Abstract: Mechanical feedback through an articulated mechanism is provided between the swashplate of a variable displacement hydraulic device and the output stage of an electrohydraulic servovalve for controlling such swashplate.