Abstract: A lase diode light source (21) is arranged to emit light of a desired intensity (I1), which is transmitted via an optical conductor (22). Light exiting the fiber has an intensity (I.sub.2), and falls incident on the receiver surface of a photodiode (23). Such transmitted light provides both the power and control for operating a load (24). The load has a maximum impedance such that the maximum load input voltage required to produce the maximum desired load current does not exceed the forward conductive breakdown voltage of the photodiode.

Abstract: A fluid coupling device has a male section (20) and a female section (21). Each of the sections has two rotatable ball valve elements (30,31). A docking member (23,24) is mounted on each section to accomodate a misalignment of the flow passageways when the sections are brought together. When the sections are brought together, the ball valves automatically rotate sequentially from flow-preventing positions to flow-permitting positions.

Abstract: A device and method for modulating light intensity in response to a varying electrical signal which is particularly useful with optical fiber information sensing systems. The device includes a number of components positioned in seriatim in an elongated cavity in an insulating body. Means for receiving a light signal, such as from an optical fiber, is positioned at one end of the cavity. A lens receives the light and collimates it into a narrow collimated beam directed through the cavity. The beam is polarized, retarded by a wave plate to circular polarization and passed through a modulator material which is capable of rotating beam polarization in response to varying voltage signals imposed on the modulator through electrodes thereon. A mirror at the end of the modulator reflects the beam back through the system.

Abstract: A fluid coupling device has a male section (20) and a female section (21). Each of the sections has two rotatable ball-valve elements (30,31). A docking member (23,24) is mounted on each section to accommodate a misalignment of the flow passageways when the sections are brought together. When the sections are joined together, the ball valves automatically rotate sequentially from flow-preventing positions to flow-permitting positions.

Abstract: An improved energy-conserving servoactuator has at least one valve operatively associated with a double-acting fluid-powered actuator. When a load is applied to the actuator, the pressure in one actuator chamber will be greater than in the other. If the load is "opposing" with respect to the desired direction of actuator movement, fluid is supplied to the higher pressure chamber and is permitted to flow from the lower pressure chamber. However, if the load is "aiding" with respect to the desired direction of actuator movement, fluid in the higher pressure chamber is permitted to flow into the lower pressure chamber without drawing fresh fluid from the source.

Abstract: The second stage (10) of a fail-fixed flow-control servovalve has a five-lobed valve spool (12) slidably mounted in a body bore (19). At null, the end lobes (41,45) are substantially zero-lapped with respect to supply pressure slots (22,26), the middle lobe (43) is substantially zero-lapped with respect to a pair of return slots (23,24), and the intermediate control lobes (42,45) are both symmetrically underlapped with respect to their associated control slots (29,30). Stops (34,35) limit movement of the spool in either axial direction. When the spool is at null or in either hard-over position, deliberate flow with respect to the control slots is blocked, and relative leakage flows are controlled. Such leakage flows may be balanced such that there is substantially-zero net leakage flow with respect to each control slots. Alternatively, such leakage flows may be deliberately mismatched to provide for desired net leakage flows with respect to control slots.

Abstract: A piezoelectric torque motor (10) includes a body (11), a pair of opposed nozzle assemblies (12,13) mounted on the body, a pair of piezoelectric actuators (14,15) extending upwardly away from the body, and a lever assembly (16) having an upper portion (95) engaging the upper ends of the actuators and having depending leg portions (96,98). A foot plate (94) is mounted on the lower marginal end portions of the lever legs, and is positioned between the nozzles. The piezoelectric actuators are supplied with differential voltages to cause swinging movement of the lever assembly between the nozzles. The improved torque motor may be used in the first- or pilot-stage of a two-stage electrohydraulic servovalve.

Abstract: A fluid-powered actuator has a piston slidably mounted in a cylinder. The piston subdivides the cylinder into first and second end chambers. A plurality of solenoid valves are arranged to selectively inject fuel and oxidizer into either chamber, or to inject liquid oxidizer to react with a solid fuel. Upon contact with one another, the fuel and oxidizer undergo a hypergolic reaction, and the products of this reaction create a pressure sufficient to displace the piston. Alternatively, a mono-propellant fluid fuel may be injected into such chamber. Upon contact with a catalyst in the chamber, the fuel undergoes a disassociation reaction, and the products thereof may be used to displace the piston.

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.