Abstract: The present disclosure relates to a system including an anchor configured to be disposed within a foundation, wherein an upper side of the anchor is configured to be exposed at a surface of the foundation and a wedge-style anti-ram security barrier configured to mechanically couple to the anchor and mount to the surface of the foundation.

Abstract: A combined d.c. brushless motor and drive control assembly for a rotary mower includes a hollow motor housing, a cover removably attached to an open rear end of the housing, and an end shield mounted to an internal shelf of the housing adjacent its rear end. The end shield and a front wall of the housing define rotary bearing seats for a motor drive shaft. An electronic circuit board including motor drive electronics and feedback sensors is mounted to the housing or to the cover, and is positioned at an axial location between the internal shelf of the housing and the rear wall of the cover. The housing is configured for mounting on a shroud of the rotary mower such that at least the removable cover is above the shroud and easily accessible, whereby repair or replacement of the electronic circuit board is facilitated.

Abstract: A true north heading is determined by using gyroscopes of differing accuracy and orienting a gyroscope of a higher accuracy to a direction that is more sensitive to azimuth change (e.g., an east/west direction). A gyroscope with a lower accuracy is placed perpendicular to the gyroscope with a higher accuracy and can be oriented towards a north or south direction. The gyroscopes may be placed on a rotatable platform to properly orient the gyroscopes. The higher-accuracy gyroscope may be implemented by using multiple gyroscopes oriented in the same direction.

Abstract: This invention provides a fiber optic rotary joint (20) for enabling the transmission of digital optical signals across the interface between facing surfaces (26, 29) of a rotor and a stator (21, 22), comprising: a plurality of light sources (42A, 42B, 42C, . . .

Abstract: A load-sensing strut has a main body (26) having a longitudinal loading axis (A) along which an applied load is transmitted, and a load sensing member (38) arranged to carry at least a portion of the applied load when the load is within a predetermined range, wherein the load sensing member (38) includes at least one load sensor (46) generating a load signal. The strut also has a load alleviation member (36) arranged to reduce the portion of the applied load carried by the load sensing member (38) when the applied load is outside the predetermined loading range. Consequently, the load sensors exhibit greater sensitivity to incremental changes in the applied load within the predetermined range, yet the strut provides high strength and is capable of reacting to very high loads outside of the predetermined range. The strut may be used in actuating aircraft control surfaces in a high-lift system.

Abstract: A tuned mass damper may be formed using one or more rotary magnetic dampers (108) coupled to a pendulous mass (102). The tuned mass damper thus formed may be used to suppress the motion of a man-made structure. The mass (308) of the tuned mass damper may be adjusted by adjusting the magnitude of the pendulous mass. The natural frequency of the tuned mass damper may be tuned by adjusting the distance from the mass center of the pendulous mass to the pivot point of the pendulum. The motion being suppressed may be generated by environmental factors such as waves, earthquakes, or wind, for example.

Abstract: This invention provides a fiber optic rotary joint (20) for enabling the transmission of digital optical signals across the interface between facing surfaces (26, 29) of a rotor and a stator (21, 22), comprising: a plurality of light sources (42A, 42B, 42C, . . .

Abstract: A system and method for acoustic quieting and reduction of vibration of an electromechanical actuator (“EMA”) accomplished by using closed loop control techniques using vibration feedback from an EMA mounted sensor to modify the current command in the motor drive electronics to minimize the resultant motor torque ripple.

Abstract: A power supply (20) for providing a desired current to an electric load (23) broadly comprises: a current limiter (21) for providing a desired current; a current sensor (28) for determining the actual current supplied by the current limiter and providing a feedback signal (30, 31) to the current limiter for causing the current limiter to reduce the error between the desired and the actual currents; and a test circuit (24) for temporarily changing the actual current sensed by the current sensor to a level different from the desired current for causing the current limiter to adjust the magnitude of the current provided thereby; whereby the operation of the power supply may be tested. The invention also provides an improved method of operating such a power supply.

Abstract: An actuator system having a controlled element configured for rotary movement about a first axis relative to a reference structure; a linkage system between the element and reference structure; a first actuator and a second actuator configured to power a first degree of freedom and an independent second degree of freedom of the linkage system, respectively; the linkage system having a first link configured for rotary movement about a second axis not coincident to the first axis and second link configured for rotary movement about a third axis; the linkage system configured such that a first angle of rotation may be driven independently of a second angle of rotation between said first link and said reference structure; wherein one of the first or second actuators is configured and arranged to drive rotation of the element about the first axis when the other is operatively locked.

Abstract: A power-off brake for stopping a rotating shaft comprises a solenoid including a coil and armature, an opposing plate axially spaced from the armature, and a ball carrier rotor between the armature and opposing plate. The ball carrier rotor rotates with the shaft and carries spherical balls in recesses angularly space about the shaft. The armature and opposing plate have respective braking surfaces. In one embodiment, at least one braking surface is ramped to urge the plurality of balls radially outward against an internal surface of a surrounding outer race as the armature is forced toward the opposing plate under spring loading when current to the solenoid coil is shut off. In another embodiment, the braking surfaces are not ramped, such that the balls are merely clamped between the braking surfaces upon solenoid deactivation. Increased rolling friction stops rotation of the ball carrier rotor and the shaft without problematic wear.

Abstract: A ball-detent torque-limiting assembly has breakout means for maintaining an axial separation distance between opposing pocketed surfaces of the assembly once the primary balls of the assembly have rolled out of their pockets, wherein the axial separation distance maintained by the breakout means is at least as great as the diameter of the balls. The breakout means may include a plurality of secondary balls deployed in a breakout event. The breakout means assumes the axially directed spring load that urges the opposing pocketed surfaces together, thereby preventing the primary balls from entering and exiting the pockets in quick and violent succession following breakout and avoiding damage to the torque-limiting assembly. The torque-limiting assembly is resettable by counter-rotation following a breakout event.

Abstract: A ball-detent torque-limiting assembly has breakout means for maintaining an axial separation distance between opposing pocketed surfaces of the assembly once the primary balls of the assembly have rolled out of their pockets, wherein the axial separation distance maintained by the breakout means is at least as great as the diameter of the balls. The breakout means may include a plurality of secondary balls deployed in a breakout event. The breakout means assumes the axially directed spring load that urges the opposing pocketed surfaces together, thereby preventing the primary balls from entering and exiting the pockets in quick and violent succession following breakout and avoiding damage to the torque-limiting assembly. The torque-limiting assembly is resettable by counter-rotation following a breakout event.

Abstract: A permanent magnet-type stepping motor broadly includes: a movable member (e.g., a rotor) having a number of magnetic poles on a surface thereof, with adjacent poles being of opposite polarity, the number of poles being a function of a constant, the number of phases and a desired step interval; and a stationary member (e.g., a stator) having a number of equally-spaced teeth arranged to face toward said movable member surface, each of said teeth having a plurality of fingers arranged to face toward said movable member surface, the number of said teeth being a whole integer that is a function of a constant, the number of said poles, the number of said fingers on each stator tooth, and the number of phases.

Abstract: A navigation system repeatedly determines a GNSS heading for the vehicle based on GNSS data received from the GNSS receiver, and repeatedly determines an inertial heading for the vehicle based on data received from an inertial measurement unit. The navigation system repeatedly sets the inertial heading to a verified GNSS heading and then provides the set inertial heading as input to a recursive feedback algorithm. The recursive feedback algorithm receives additional inputs indicating the vehicle's angular displacement or acceleration and outputs an updated inertial heading. The navigation system compares the subsequently determined GNSS headings with the updated inertial heading. If the two headings are different, the navigation system sets the GNSS heading to the updated inertial or 180 degree reverse of the GNSS heading.

Abstract: A rotary valve comprises a bushing and a cylindrical spool rotatably received by the bushing. The rotary valve avoids redundant control edge pairs by having exactly one first supply edge pair (P-C1) for controlling a first fluid supply path, exactly one second supply edge pair (P-C2) for controlling a second fluid supply path, exactly one first return edge pair (C2-R1) for controlling a first fluid return path, and exactly one second return edge pair (C1-R2) for controlling a second fluid return path. A first angle between the first supply edge pair and the first return edge pair, and a second angle between the second supply edge pair and the second return edge pair, are each greater than or equal to 120 degrees and less than 180 degrees. Geometric simplicity is achieved by tolerating a limited degree of force imbalance in valve operation.

Abstract: An actuator system comprising a shared link (121) arranged to pivot about a first axis (131) relative to a reference structure, a controlled element (125) arranged to pivot about a second axis (126) relative to the reference structure, a first member (146, 152) arranged to pivot about a third axis (134) relative to the shard link and a fourth axis (136) relative to the controlled member, a first actuator arranged to control a first variable distance (LI) between the third axis and fourth axis, a second member (147, 153) arranged to pivot about a fifth axis (133) relative to the shared link and a sixth axis (135) relative to the controlled element, a second actuator (141) arranged to control a second variable distance between the fifth axis and the sixth axis, the system configured such that a change in the first variable distance causes rotation of the controlled element about the second axis when the second variable distance is constant and vice versa.

Abstract: Embodiments of the invention provide a pump assembly and a method for assembly the pump assembly. The pump assembly includes a stator assembly, a lower pump housing, an upper pump housing, a rotor assembly, and an isolation cup. The method includes coupling the stator assembly to the lower pump housing, overmolding an overmold material over the stator assembly and the lower pump housing, positioning the isolation cup over the overmold, and positioning the rotor assembly inside the isolation cup. The method further includes placing the upper pump housing over the rotor assembly and coupling the upper pump housing to the lower pump housing.

Abstract: A valve (210) comprising a motor (221) having an output shaft (231) orientated about a motor axis (230), a hydraulic valve having a drive spool (224) configured to move from a first position to a second position, a mechanical linkage (222) between the output shaft (231) and the drive spool (224) having a sleeve (232) mechanically coupled to the output shaft (231), a pole shaft (233) configured for sliding engagement in a direction generally perpendicular to the motor axis, a link (235) connected to the pole shaft (233) by a pivot joint (234), a drive shaft (252) coupled to the link (235) and rotatable about a drive axis, the drive shaft (252) having an end portion to engage and apply a force to the spool (224), and a spring (223) to provide a bias between the pole shaft (233) and the sleeve (232), such that a distance between the motor axis and the pivot joint multiplied by a distance between the drive axis and the applied force is less than a distance between the drive axis and the pivot joint.

Abstract: An improved motor (90) broadly including a first member (30) and a second member (20) mounted for movement relative to one another. The first member has a plurality of poles (32) spaced substantially equidistantly. The second member has a plurality of arms (22). Each arm includes a plurality of fingers (27), a permanent magnet (29), and a coil (25). The fingers are arranged such that their distal end generally faces toward the poles on the first member. Each permanent magnet has a width that is greater than the pole spacing. Each arm is associated with one of a number of phases. The fingers of the arms within a particular phase are arranged such that they simultaneously align with respective poles when the first and second members are in one position relative to one another.