Abstract: A hydraulic system for steering an aircraft while taxiing selectively applies pressurized fluid to different ports of a hydraulic motor to turn a landing gear wheel either left or right. Shimmy of the landing gear attached to the wheel is dampened by a device that is coupled across the hydraulic lines that are connected to the motor. That device has a piston in a bore with one hydraulic line connected via an orifice to a first chamber on one side of the piston and the other hydraulic line connected via a different orifice to a second chamber on the other side of the piston. The piston stroke is limited to control the effective oscillation damping amplitude. The shimmy produces an oscillating pressure differential in the two hydraulic lines which is dampened by the device.

Abstract: A circuit breaker includes a molded housing, separable contacts, an operating mechanism adapted to open and close the separable contacts, and a trip circuit cooperating with the operating mechanism to trip open the separable contacts. The molded housing includes two molded halves. The trip circuit includes a pair of arc fault printed circuit boards which cooperate with the corresponding molded halves to form an external composite structure. That external composite structure includes the printed circuit boards and an over-molding material, such as, for example, a thermally conductive epoxy coating disposed thereon.

Abstract: An apparatus controls fluid flow to an actuator. A feedback mechanism responds to a pressure differential that occurs across the actuator by altering the fluid flow. That pressure differential indicates acceleration of the actuator that can occur when the load acting thereon varies. Thus as the actuator accelerates, the apparatus reduces the flow of fluid which counteracts the acceleration and maintains the actuator speed relatively constant. A unique directional control valve incorporates the feedback mechanism that functions regardless of the direction in which the actuator moves.

Abstract: A detection module and remote load voltage sensor determine a location of a parallel arc for a power circuit between a power source and a load in real time. The detection module provides a value of voltage from the power source. A current sensor measures a value of current flowing in the power circuit to or from the power source. The remote load voltage sensor measures a value of voltage at the load. A microprocessor determines the parallel arc location from the value of voltage from the power source, the value of current, the value of voltage at the load, and a wire resistance or conductance per unit length of the power circuit. In one case, connector resistance is accounted for. In another case, the load voltage is encoded at a predetermined frequency using a switched precision resistor near the load, thereby providing a power line carrier type communication.

Abstract: A miniature circuit breaker comprising a non-conductive housing assembly; a pair of separable contacts including a first, fixed contact coupled to said housing assembly and having a terminal extending outside said housing assembly, and a second, movable contact having a terminal extending outside said housing assembly; an operating mechanism coupled to, and structured to move, said movable contact between a first position, wherein said movable contact engages said fixed contact, and a second position, wherein said movable contact is spaced from said fixed contact; a trip device coupled to said operating mechanism and structured to actuate said operating mechanism to separate said separable contacts upon the occurrence of a trip condition; an arc fault trip mechanism having an arc fault detector and a shape memory alloy element; said arc fault detector structured to detect an arc fault on the load side of said separable contacts and to provide an electrical pulse; said shape memory alloy element structured to

Abstract: The continuity of the coil of the actuating solenoid of an electric power switch is detected through utilization of a signaling device, such as a light emitting diode (LED) that monitors energization of a dc power supply fed from the source side of the coil. A circuit energized from the other side of the coil generates a dc voltage V2 that is applied to the gate electrode of an electronic switch shunting the LED. The voltage V2 is greater than the dc supply voltage to bias the electronic switch off so that the LED is illuminated when there is continuity through the coil. If the coil fails, V2 will be zero and the electronic switch is turned on to short circuit the LED to signal the failure of the coil.

Abstract: A valve assembly includes a valve stem which is connected with a valve. A drive member is disposed in engagement with the valve stem. A gear assembly is operable to rotate the drive member to effect axial movement of the valve stem. The gear assembly is driven by an electrical motor. In the event of a power failure, the valve may be moved to a closed condition by either a return spring or an auxiliary source of electrical energy. To facilitate movement of the valve between the open and closed conditions, the valve is pressure balanced.

Abstract: A roller thrust bearing assembly is effective to transmit force along a path extending between two members. The roller thrust bearing assembly includes a circular disc with an annular array of spaced apart slots. Each of the slots has a longitudinal central axis which is skewed at the same angle relative to disc radii. A plurality of roller bearings are disposed in each of the slots.

Abstract: A valve for controlling an emergency brake system on an aircraft. The valve has separate poppets for controlling the flow of fluid from a supply line to the brake cylinders and from the brake cylinders to a tank return line. The poppets act on each other. A dampening orifice restricts fluid flow around one of the poppets thereby limiting the rate at which that poppet opens and closes. An actuator applies an externally generated control force to the poppets to activate and de-active the emergency brake system.

Abstract: A proximity sensor has a resonant circuit which when stimulated by a pulse produces a signal with decaying oscillations. The number of such oscillations above a signal threshold varies in relation to the distance between a metal object and the proximity sensor. The sensor operation is configured by deriving a function that defines how the performance of a given proximity sensor deviates from performance reference data. The function is employed to normalize the count of oscillations produced by the given proximity sensor and the normalized count is used to determine presence of an object. By normalizing sensor performance, common configuration data can be used to setup a given proximity sensor without having to take into account specific performance variations of that sensor.

Abstract: A subminiature circuit breaker is equipped with an arc fault auxiliary switch actuated by the arc fault trip motor through an indicator actuator that also deploys a pop-up arc fault indicator. An additional auxiliary switch actuated by the drive link on the toggle mechanism provides an indication of the open/closed state of the circuit breaker separable contacts. Both the arc fault auxiliary switch and the contact state auxiliary switch are mounted on the outside of the subminiature circuit breaker housing and are operated by an operating member and a pivoted member, respectively, extending through openings in the housing.

Abstract: A circuit breaker includes a housing; separable contacts mounted in the housing; and an operating mechanism for opening and closing the separable contacts. An overcurrent assembly is responsive to selected conditions of current flowing through the separable contacts and actuates the operating mechanism to trip open the separable contacts. A bonnet forms a U-shape which surrounds the separable contacts and which cools and splits an arc when the operating mechanism trips open the separable contacts. A first bonnet piece forms a first leg of the bonnet, and a second bonnet piece forms a second leg and a base of the bonnet.

Abstract: The present invention provides a rolling seal that is disposed between the handle and the housing. The subminiature circuit breaker has a housing and a handle assembly as noted above. The housing has a handle opening bushing that includes at least one through opening. The handle assembly has a handle member disposed in the handle opening which is structured to move between a first position and a second position. The handle member further has an attachment ring. The rolling seal includes a flexible tubular member having a first end and a second end, and a lip. Said lip extends inwardly toward the axis of the tubular member. The lip is disposed at the first end of the tubular member and the second end is disposed at the second end of the tubular member. The lip is structured to engage the handle opening at least one through opening and the second end is structured to engage the attachment ring.

Abstract: A circuit breaker includes separable contacts, a latchable operating mechanism having a latch member, a bimetal and an arc fault trip assembly. The trip assembly includes a thermistor responsive to bimetal temperature, an amplifier having first and second inputs and an output, a first resistor electrically connected between a second bimetal terminal and the first amplifier input, a second resistor electrically connected in parallel with the thermistor, a third resistor electrically connected in series with that parallel combination, with that series combination being electrically connected between the first amplifier input and the amplifier output. The second amplifier input is referenced to the first bimetal terminal. The amplifier output has a voltage, which is compensated for the bimetal temperature coefficient. The trip assembly provides a trip signal as a function of compensated voltage. A solenoid responds to the trip signal and releases the latch member to trip the separable contacts open.

Abstract: A tester for in situ testing of a plurality of circuit breakers having a range of rated currents and multiple trip functions, includes a plurality of power resistors of known impedance, an electronic switch associated with each power resistor connecting the resistor in series with the load terminal of the circuit breaker under test, and a controller that turns on a number of the switches selected to collectively draw through the associated power resistors a test current that is a function of the rated current and sufficient to trip the circuit breaker within a selected time window. Turn on of the electronic switches is also controlled to generate a current waveform appropriate for the trip function being tested. In a self test mode, the value of each of the power resistors is verified as being within limits.

Abstract: A circuit breaker includes a housing; separable contacts mounted in the housing; and an operating mechanism for opening and closing the separable contacts. An overcurrent assembly is responsive to selected conditions of current flowing through the separable contacts and actuates the operating mechanism to trip open the separable contacts. A bonnet forms a U-shape which surrounds the separable contacts and which cools and splits an arc when the operating mechanism trips open the separable contacts. A first bonnet piece forms a first leg of the bonnet, and a second bonnet piece forms a second leg and a base of the bonnet.

Abstract: A circuit breaker includes separable contacts, an operating mechanism, a power supply, and a trip mechanism powered from a first power supply output. A power supply monitor circuit includes a terminal adapted for electrical connection to a ground, a first resistor electrically connected in series with a power supply regulator, a first transistor having an output and two inputs electrically connected in parallel with the first resistor, a first capacitor electrically connected between the first power supply output and the first transistor output, a second resistor electrically connected in series with the first capacitor between power supply outputs, a second transistor having a first input electrically interconnected with the first transistor output, a second input and an output, a diode electrically connected between the terminal and the second transistor second input, and an interface between the second transistor output and a trip mechanism input for disabling the tripping.

Abstract: An indicator reset tool is for a movable arc fault indicator of a circuit breaker. The circuit breaker further includes a housing enclosing separable contacts, an operating mechanism for opening and closing the separable contacts, and an operating handle protruding through an opening in the housing. An actuator actuates the movable indicator arc fault indicator and actuates the operating mechanism to trip the separable contacts open. The indicator reset tool includes a reset member having a first end with an indicator engaging portion structured to depress and reset the movable arc fault indicator. The second end of the reset member includes a handle portion for gripping by a user.

Abstract: A scraper assembly for use with a disc brake including a scraper blade which continually engages with the braking surface of the disc brake to remove dirt, oil and other extraneous materials from the braking surface to increase the coefficient of friction of the braking surface. A weight is provided for biasing the scraper blade with a substantially constant force into engagement with the braking surface. The scraper blade and weight are disposed in a channel which guides and supports the scraper blade into a position in which the blade is engaged with the braking surface.

Abstract: An aircraft circuit breaker includes a housing; separable contacts mounted in the housing; a latchable operating mechanism including a latch member which when unlatched opens the separable contacts; and an overcurrent assembly responsive to selected conditions of current flowing through the separable contacts for unlatching the latch member to trip the separable contacts open. A movable and illuminable arc fault indicator has a first ring portion and second leg portions internal to the housing. An arc fault actuator which when energized moves one of the second leg portions. An arc fault current assembly responds to selected arc fault conditions of current flowing through the separable contacts to energize the arc fault actuator to move the second leg portions internal to the housing and the first ring portion external to the housing. The arc fault current assembly includes a light for illuminating the first ring portion.