Abstract: A signaling device includes an electrical circuit which discharges an electrical energy storage device through an electrically powered alert mechanism via a biased open transition switch upon disruption of electrical power in an electrical system of a work machine. A work machine is further provided having an alert device coupled with a normally closed electrical power circuit, the alert device being activated upon opening of the normally closed electrical circuit via a transistor switch. An associated method includes using the signaling device to alert a work machine operator to a predetermined condition by closing a normally open electrically switch to connect an electrical energy storage device with an electrically powered alert mechanism, via an electronic controller or via interruption of electrical power in a normally closed electrical circuit of a work machine.

Abstract: An audible signal device which includes a DC to DC converter is provided. A group of work machines is further provided, including at least two work machines having electrical systems with different operating voltages. First and second audible signal devices are coupled with the first and second electrical systems respectively, wherein the second audible signal device is interchangeable with the first audible signal device and at least one of the devices includes a DC to DC converter. A method of assembling a plurality of dissimilar machines, each including an interchangeable audible signal device is further provided.

Abstract: A method and apparatus for providing an audible alarm signal. The method and apparatus includes creating a rectangular pulse signal having a desired period and a desired first amplitude, adding a shaped modulation component to the rectangular pulse signal from the desired first amplitude to a desired second amplitude to create a modulating waveform, creating a carrier signal, and combining the carrier signal and the modulating waveform to create the audible alarm signal.

Abstract: A dual airflow control system for an environment having a first air zone and a second air zone. The system includes a first input device operable to generate a first input signal indicative of a desired airflow to the first zone and a second input device operable to generate a second input signal indicative of a desired airflow to the second zone. First and second flow regulators are configured to regulate airflow to the first and second zones, respectively, such that the first and second regulators selectively provide the airflow to each of the first and second zones based on the first and second input signals. A single actuator is associated with the first and second flow regulators. The actuator is operable to simultaneously actuate the first and second flow regulators based on an input from the first and second input devices to allow the desired airflows to the first and the second zones.

Abstract: A device for latching a rotatable shaft. A lever arm is coupled with the shaft and rotates the shaft between a first and second positions when the lever arm rotates between respective first and second positions. A latching device latches the lever arm, in response to receiving an activation signal, when the lever arm is in the first position. The latching device holds the lever arm in the first position. A biasing device is coupled with the lever arm and exerts a biasing force on the lever arm that biases the lever arm towards the second position.

Abstract: A variable displacement hydraulic piston unit with electrically operated variable displacement control and timing control is disclosed, the displacement control utilizing an electric motor such as a stepper motor and cam arrangement operable for changing the tilt angle of a swash plate of the unit, and the timing control including an electric motor, such as a stepper motor operable for rotating the swash plate relative to the pistons of the unit for effecting timing changes, the unit being operable as a pump, motor, or the like.

Abstract: An apparatus and method of restricting flow of exhaust gas in an exhaust gas duct of a machine having an internal combustion engine is disclosed. The apparatus includes a closure member pivotably mounted relative to the exhaust gas duct within the exhaust gas duct interior. The closure member is pivotable between a first position wherein the exhaust gas duct is substantially unblocked by the closure member and a second position wherein the exhaust gas duct is substantially blocked by the closure member. An actuator is operatively connected to the closure member, moving the closure member between the first and second positions. A machine speed sensor and a throttle position sensor are provided, as is a manually operable switch.

Abstract: An electromagnetic actuator for an electromagnetically actuated valve is disclosed. The actuator includes an electromagnet and an armature, the armature having a normally biased initial spaced apart first position distal from the electromagnet when the electromagnet is off and a second fixed stop position in abutment with the electromagnet when the electromagnet is on. In addition, the actuator includes a resilient member adapted to bias the armature in the normally biased initial spaced apart first position, and a compliant member operably connected to the armature. The armature approaches the electromagnet when the electromagnet is on and compresses the compliant member until the armature reaches the fixed stop position.

Abstract: The locking force of an electromagnetic joystick lock with flux having a flux canceling driver circuit is controlled in order to maintain the control lever of a joystick in a desired position. In one embodiment, the locking force may be in either an activated or deactivated state, and one of a forward or reverse current is applied to the coils of the lock in response to the state, in order to eliminate the residual magnetism when the locking force is deactivated.

Abstract: An apparatus for generating a audible tone is disclosed. The apparatus includes a ferromagnetic container 105, a ferromagnetic pole 110, a coil 115, a first stationary lead wire 175, a second stationary lead wire 180, and a flexible ferromagnetic diaphragm 120. The ferromagnetic pole 110 is disposed within the ferromagnetic container 105. The coil 115 is encircling a portion of the ferromagnetic pole 110. The coil 115 has an input end 165 connected to a first stationary lead wire 175, configured to receive an electrical signal, and an output end 170 connected to a second stationary lead wire 180. The flexible ferromagnetic diaphragm 120 is disposed along the top edge 135 of the ferromagnetic container 105. The flexible ferromagnetic diaphragm 120 is configured to flex when magnetically attracted toward the ferromagnetic pole 110. As the flexible ferromagnetic diaphragm 120 flexes the first stationary lead wire 175 and the second stationary lead wire 180 will remain stationary.

Abstract: An apparatus for generating a audible tone is disclosed. The apparatus includes a non-ferromagnetic container 105, a ferromagnetic member 110, a coil 115, a first stationary lead wire 175, a second stationary lead wire 180, and a flexible ferromagnetic diaphragm 120. The ferromagnetic member 110 is essentially disposed within the nonferromagnetic container 105. The coil 115 is encircling a portion of the ferromagnetic member 110. The coil 115 has an input end 165 connected to a first stationary lead wire 175, configured to receive an electrical signal, and an output end 170 connected to a second stationary lead wire 180. The flexible ferromagnetic diaphragm 120 is disposed along the top edge 135 of the non-ferromagnetic container 105. The flexible ferromagnetic diaphragm 120 is configured to flex when magnetically attracted toward the ferromagnetic member 110. As the flexible ferromagnetic diaphragm 120 flexes the first stationary lead wire 175 and the second stationary lead wire 180 will remain stationary.

Abstract: In one aspect of the present invention, an electromagnetic actuator is disclosed. The electromagnetic actuator includes a plunger adapted to move between first and second positions, a pull coil adapted to receive electrical energy and responsively produce a high electromagnetic force causing the plunger to move from the first position to the second position, and a hold coil adapted to receive electrical energy and responsively produce a low electromagnetic force for maintaining the plunger at the second position. A sensing device is included to detect the magnetic flux density produced by the coils and responsively produce a position signal having a magnitude responsive to the position of the plunger. Advantageously, signal conditioning circuitry receives the position signal, and de-energizes the pull coil in response to the position signal indicating that the plunger is at the second position.

Abstract: In one aspect of the present invention, an apparatus detects a shorted winding condition of a solenoid coil. The apparatus includes a reference solenoid that is connected to a test solenoid. A sine generator drives the reference solenoid with a sinusoidal waveform to cause an induced voltage across the test solenoid. A meter determines the voltage difference between the solenoids and compares the voltage difference to a predetermined value.

Abstract: Centering spring devices are useful in hydraulic control valves for returning the valve to the neutral position under both normal and abnormal operating conditions. Since the actuator moving the valve spool must work against the spring centering device, electrically actuated hydraulic valves have been limited to small sizes. The subject hydraulic control valve incorporates a centering spring device that can be controllably disabled so that the valve spool can be freely moved between the neutral and operating positions. In one embodiment, a centering spring is disabled by hydraulically moving the spring retainers toward each other to compress the spring with hydraulic fluid controlled by a solenoid valve. Maintaining the spring in a compressed condition permits the valve spool to be moved with a smaller actuator thereby making it feasible to control the valve position with an electrical actuator.

Abstract: An electromagnetic actuator is disclosed. The actuator includes a core, and a cylindrical shell disposed around the core defining an annular space therebetween. A signal device produces a desired position signal. A direct current amplifier transmits an energization signal in response to the desired position signal. A coil disposed in the annular space has a plurality of windings. The coil is adapted to receive the energization signal and responsively produce a magnetic field about the coil proportional to the magnitude of the energization signal causing one of the coil and the core to move relative to the other. A sensing device is adapted to detect the magnetic field produced by the energized coil. The sensing device responsively produces a sensed position signal correlative to the magnitude of the magnetic field.

Abstract: An electromagnetic actuator is disclosed. The acutator includes a core, a cylindrical shell disposed around the core which defines an annular space therebetween, and a magnetic assembly disposed about the core. The magnetic assembly including a pair of permanent magnets having opposite polarity. Also included is a coil which has first and second ends, first and second end portions, and an intermediate portion disposed between the first and second end portion. The first end is connected to the second end, and the coil is disposed in the annular space. Additionally, the coil has a plurality of windings wound in a common direction. The coil has electrically connectable leads at the end connection and the intermediate portion. An amplifier delivers an energization signal to the leads of the coil.

Abstract: A joystick is disclosed which comprises an operator member mounted to a pivotal member, the operator member for moving the pivotal member, a position sensor associated with the pivotal member, a linear solenoid having a pair of plunger members each being positioned within the solenoid on opposite sides of the solenoid, and a cable member connected to the operator member and the plunger members with the cable member for centering the operator member when the solenoid is energized.