Abstract: A torque motor (20) has a base (21), four polepieces (22A, 22B, 22C, 22D) extending away from the base, the polepieces being separated from one another and being arranged at the corners of an imaginary polygon (27), each polepiece terminating in a pole (23A, 23B, 23C, 23D); a coil (24A, 24B, 24C, 24D) surrounding each of the polepieces; an armature (26) pivotally mounted on the base, the armature having a portion arranged to move toward and away from an associated one of the poles, respectively, to define a variable-reluctance air gap (gA, gB, gC, gD) therebetween; a permanent magnet (29) mounted on one of the base and armature and polarized in a direction parallel to the pivotal axis of the armature; and wherein at least a portion of the torque motor is formed by a MEMS technique; whereby the coil may be selectively energized to cause the armature to pivot about its axis.

Abstract: A servoactuator (20) is operatively arranged to control the movement of an output member (21) in either of two directions in response to a command signal. The servoactuator includes an electric motor (25); a motor controller (24); a first transmission mechanism (34); a hydrostatic second transmission mechanism (35); a transfer mechanism (36) operatively arranged to selectively couple the motor output shaft to the output member either through the first transmission mechanism to impart a high-speed low-force drive to the output member, or through the second transmission mechanism to impart a low-speed high-force drive to the output member; at least one feed-back transducer (29, 32); and a servo control loop (30, 33) closed about the motor, controller, transmission mechanisms, transfer mechanism, feedback transducer and output member for selectively controlling at least one of the position, velocity or force of the output member as a function of the command signal.

Abstract: A skewed roller brake assembly (20) has a main axis of rotation (x—x), has a first plate (21) adapted to be rotated about the main axis, has a second plate (22) adapted to be rotated relative to the first plate about the main axis, and has an intermediate plate (23) positioned between the first and second plates. The first and second plates are adapted to be axially loaded with respect to one another. The intermediate plate has a plurality of slots (25). Each slot is bounded by a first wall (26) that is arranged at a first angle (&thgr;1) with respect to a radius from the main axis. A cylindrical roller (25) is arranged in each slot for rolling engagement with the first and second plates about the axis of the roller such that the roller axis (y—y) is parallel to the first wall when the first and second plates are rotated relative to one another in one angular direction.

Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.

Abstract: A servoactuator (20) is operatively arranged to control the movement of an output member (21) in either of two directions in response to a command signal.

Abstract: A compound differential planetary gear assembly (50) includes a sun gear (52), a plurality of planet gears (53) engaging the sun gear, a plurality of first ring gears (54), and a plurality of second ring gears (55). Each of the second ring gears has a number of teeth that is different from the number of teeth of the first ring gears. The first and second ring gears are arranged alternately in an axial stack. Each planet gear has a constant gear-tooth cross-section along the length of the stack, with its gear teeth in meshing engagement with the teeth of the first and second ring gears. Loads transmitted between the first and second ring gears and the planets act in alternate directions along the length of the stack.

Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.

Abstract: A torque motor (20) has a base (21), four polepieces (22A, 22B, 22C, 22D) extending away from the base, the polepieces being separated from one another and being arranged at the corners of an imaginary polygon (27), each polepiece terminating in a pole (23A, 23B, 23C, 23D); a coil (24A, 24B, 24C, 24D) surrounding each of the polepieces; an armature (26) pivotally mounted on the base, the armature having a portion arranged to move toward and away from an associated one of the poles, respectively, to define a variable-reluctance air gap (gA, gB, gC, gD) therebetween; a permanent magnet (29) mounted on one of the base and armature and polarized in a direction parallel to the pivotal axis of the armature; and wherein at least a portion of the torque motor is formed by a MEMS technique; whereby the coil may be selectively energized to cause the armature to pivot about its axis.

Abstract: A bidirectional self-contained end-of stroke snubbing device (20) includes a housing (21), a rod (22) movable relative to the housing, a single fluid-filled variable-volume chamber (23) communicating with a fluid sump (24) through an orifice (65), and a lost-motion mechanism for selectively reducing the volume of the chamber proximate either end of the stroke of the rod-like member. The mechanism will force fluid from the chamber through the orifice to decelerate and cushion movement of the rod-like member relative to the housing proximate either end of its stroke.

Abstract: The improved multi-function actuator (20) broadly includes; a first mechanism (21) capable of bi-directional displacement; a motor (22) operatively arranged to selectively displace the first mechanism through a first displacement range; a second mechanism (24) capable of uni-directional displacement from a first position to a second position; a spring (25) operatively arranged to urge the second mechanism to move from the first position to the second position; a release mechanism (26) operatively arranged to release the spring when the first mechanism is moved beyond the first displacement range; a third mechanism (27) capable of bi-directional displacement; and a clutch (28) operated by the release of the spring to selectively disconnect the motor from the first mechanism and to selectively connect the motor to the third mechanism; whereby the motor may be operated to selectively control either the first mechanism or the third mechanism.

Abstract: A force-limiting rotary lock (20) for a shaft (21) mounted on a housing (22) for rotational and axial movement relative thereto, broadly includes a lug member (28) provided on the shaft, and a pawl (51) mounted on the housing. The pawl is movable relative to the housing between first and second positions. The pawl is operatively arranged to engage the lug when the pawl is in its first position (shown in FIG. 3) to prevent further rotation of the shaft in one angular direction, and to be disengaged from the lug when the pawl is in its second position (shown in FIG. 2) to permit rotation of the shaft in either angular direction. A cam (25) is mounted on the shaft, and a follower (49) is mounted on the housing for selectively moving the pawl between the first and second positions when the shaft is axially displaced from its predetermined position.

Abstract: A force-limiting rotary lock (20) for a shaft (21) mounted on a housing (22) for rotational and axial movement relative thereto, broadly includes a lug member (28) provided on the shaft, and a pawl (51) mounted on the housing. The pawl is movable relative to the housing between first and second positions. The pawl is operatively arranged to engage the lug when the pawl is in its first position (shown in FIG. 3) to prevent further rotation of the shaft in one angular direction, and to be disengaged from the lug when the pawl is in its second position (shown in FIG. 2) to permit rotation of the shaft in either angular direction. A cam (25) is mounted on the shaft, and a follower (49) is mounted on the housing for selectively moving the pawl between the first and second positions when the shaft is axially displaced from its predetermined position.

Abstract: A compound differential planetary gear assembly (50) includes a sun gear (52), a plurality of planet gears (53) engaging the sun gear, a plurality of first ring gears (54), and a plurality of second ring gears (55). Each of the second ring gears has a number of teeth that is different from the number of teeth of the first ring gears. The first and second ring gears are arranged alternately in an axial stack. Each planet gear has a constant gear-tooth cross-section along the length of the stack, with its gear teeth in meshing engagement with the teeth of the first and second ring gears. Loads transmitted between the first and second ring gears and the planets act in alternate directions along the length of the stack.

Abstract: A differential coupling (20) has a body (21), a rotary input member (22), and two rotary output shafts (23, 24). The algebraic sum of the angular displacements of the output shafts is proportional to the rotation of the input member. The improvement includes mechanical means (39), such as a planetary gear (42), for sensing a torque differential between the output shafts, and a brake (38) mounted on the body and operatively arranged to selectively brake rotation of the input member, or both output members, when the difference between the torques on the outputs exceeds a predetermined first value.

Abstract: Apparatus (20) for testing the extent of contaminants in a fluid during a test period, comprises: a source (Ps) of pressurized fluid to be tested; a fluid sump (R); a first flow restriction (R1) adapted to be supplied with fluid flow from the source, the first flow restriction being configured as an annular clearance between a first land (24) and a first bore (22) and being sized and arranged so as to be progressively occluded by contaminants in the fluid flow during said test period; a second flow restriction (R2) arranged between the first flow restriction and said sump, the second flow restriction being configured as an annular clearance between a second land (25) and a second bore (22), the second flow restriction being substantially the same dimensionally as the first flow restriction so that the second flow restriction will not be occluded by contaminants passing through the first flow restriction and the pressure drops across each of the flow restrictions will be substantially equal at the beginning of

Abstract: A bidirectional self-contained end-of stroke snubbing device (20) includes a housing (21), a rod (22) movable relative to the housing, a single fluid-filled variable-volume chamber (23) communicating with a fluid sump (24) through an orifice (65), and a lost-motion mechanism for selectively reducing the volume of the chamber proximate either end of the stroke of the rod-like member. The mechanism will force fluid from the chamber through the orifice to decelerate and cushion movement of the rod-like member relative to the housing proximate either end of its stroke.

Abstract: A propellant supply device (10) is provided for a vehicle (11) having a main propulsion motor (12) and having an attitude control system (11) including a plurality of thrusters (14A, 14B, 14C, . . . , 14F). The improved device comprises: a pressure vessel (15); first and second movable walls (20, 21) operatively arranged within the pressure vessel and dividing the interior space therewithin into three separate sealed chambers (22, 23, 24) from each of which fluid may be supplied; a first fluid (e.g., a first bipropellant)in one of the chambers; a second fluid (e.g., a second bipropellant) in a second of the chambers; and a third fluid (e.g., ammonia) in a third of the chambers, the third fluid being a volatile liquid having a liquid phase and a gaseous phase, and wherein all three chambers are pressurized to the vapor pressure of the third fluid.

Abstract: A mechanism (16) for controlling independently the pitch of a plurality of blades (15A, 15B, 15C) of a wind turbine (10) includes: a hub (11) rotatable about an axis (x-x) relative to a nacelle (12); a plurality of blades mounted on the hub for rotation therewith about the hub axis, each blade having a shaft (21) and being mounted on the hub for rotation about its axis of elongation; a plurality of motors (34) mounted on the nacelle, each motor having an output shaft (35) and being associated with a respective one of the blades; and a coupling mechanism (37) operatively interposed between each motor and its associated blade for selectively rotating such blade about its axis to vary the pitch of the associated blade relative to the hub axis. The pitch of each blade may be controlled independently of the pitch of the others.

Abstract: A differential coupling (20) has a body (21), a rotary input member (22), and two rotary output shafts (23, 24). The algebraic sum of the angular displacements of the output shafts is proportional to the rotation of the input member. The improvement includes mechanical means (39), such as a planetary gear (42), for sensing a torque differential between the output shafts, and a brake (38) mounted on the body and operatively arranged to selectively brake rotation of the input member, or both output members, when the difference between the torques on the outputs exceeds a predetermined first value.

Abstract: The invention provides an improvement in apparatus (20) for testing the level of contaminants in a fluid during a test period. The apparatus has a source of pressurized fluid (Ps) to be tested; a fluid sump (R); and a test passage (48) which is substantially free of occluding contaminants at the beginning of the test period and which is adapted to be supplied with a flow of fluid from the source. The passage is so configured and arranged as to be progressively occluded by contaminants in the fluid flow. The apparatus also includes a device (23) defining a variable-volume chamber (47). The volume of said chamber is variable between a minimum value and a maximum value.