Abstract: In one aspect of the present invention, it is contemplated that a valve includes a passage. A first sealing element is biased to restrict flow of a fluid in a first direction through the passage when an upstream volumetric flow rate of the fluid in the first direction is less than a first predetermined threshold. A second sealing element is biased to unrestrict flow of the fluid to a baseline unrestricted flow rate in a second direction through the passage when an upstream volumetric flow rate of the fluid in the second direction is less than a second predetermined threshold.

Abstract: A latching valve includes a housing, a supply port, defined in the housing, which receives supply pressure, a delivery port defined in the housing, an exhaust port, defined in the housing, and an apply port defined in the housing. A housing bore fluidly communicates with the supply port, the delivery port, the exhaust port, and the apply port fluidly. A shuttle is sealingly and movably secured in the housing bore. The shuttle is alternately set to one of an apply position and a release position as a function of sequential pilot pressures at the apply port acting on the shuttle, and as a function of the supply pressure acting on one of an apply pair of sealed seats with different diameters in the housing bore and a release pair of sealed seats with different diameters in the housing bore. The delivery port fluidly communicates with the supply port while the shuttle is in the apply position. The delivery port fluidly communicates with the exhaust port while the shuttle is in the release position.

Abstract: A latching valve system includes a housing, a supply port defined in the housing, a delivery port defined in the housing, an exhaust port defined in the housing, an apply port defined in the housing, and a release port defined in the housing. The apply port is sealingly fluidly isolated from the supply port, the delivery port, and the exhaust port. The release port is sealingly fluidly isolated from the supply port, the delivery port, and the exhaust port. An apply valve supplies an apply pilot pressure to the apply port as a function of a state of the apply valve. A release valve supplies a release pilot pressure to the release port as a function of a state of the release valve. A bore, defined in the housing, fluidly communicates with the supply port, the delivery port, the exhaust port, the apply port, and the release port.

Abstract: A valve includes a valve housing. A bore is in the valve housing. An inlet supply port fluidly communicates a pressurized supply fluid to the bore. A piston is movably positioned in the bore based on the pressure of the supply fluid. A portion of the piston extends into a frusto-conically shaped portion of the bore. A sealing member is associated with the portion of the piston sealingly engaging a surface of the frusto-conically shaped portion of the bore based on the pressure of the supply fluid. An inlet valve, movably positioned in the bore, is biased to sealingly engage a wall of the bore based on the pressure of the supply fluid. A control pressure supply port fluidly communicates a pressurized control fluid to the bore through the valve housing. A control pressure delivery port fluidly communicates with the control pressure supply port, via the bore, based on the pressure of the supply fluid.

Abstract: A service brake/traction control valve includes a service brake control port, a traction control port, an exhaust port, and a control chamber. The control chamber fluidly communicates with the service brake control port and the traction control port as a function of a service brake event and as a function of a traction control event. The control chamber fluidly communicates with the exhaust port when the service brake event is released. The control chamber fluidly also communicates with the exhaust port when the traction control event is released.

Abstract: In one embodiment, a solenoid valve includes a supply port that fluidly communicates with a source of compressed air, a delivery port, a bore that selectively fluidly communicates with the supply and delivery ports, an armature in the bore, a pole piece in the bore, and a coil that is selectively energized with electrical power. The coil is around the armature and pole piece. The armature and pole piece selectively sealingly engage and move as an armature/pole piece single unit as a function of the electrical power in the coil. A position of the armature/pole piece within the bore controls fluid communication between the supply port and the delivery port.

Abstract: One embodiment provides a system for decrypting data frames in an Ethernet passive optical network (EPON). During operation, the system maintains a local cipher counter at a local node, and receives from a remote node a data frame which is encrypted based on a remote input block and a session key. The remote input block is constructed based on the remote cipher counter and a remote block counter. The system updates the local cipher counter based on a received field located in a preamble of the data frame, truncates the local cipher counter by discarding a number of least significant bits, and constructs for the received data frame a local input block based on the truncated local cipher counter, the received field, and a local block counter. The system then decrypts the data frame based on the local input block and the session key.

Abstract: A flow control device having a first port, a second port, a third port and the movable member. In a first mode, the movable member seals the second port while allowing fluid flow between the first and third ports, wherein the differential pressure between the first port and third port, during the first mode, is about zero. In the second mode, the movable member seals the first port while allowing fluid flow between the third port and second port, wherein the movable member is adapted to transition from the first mode to the second mode in response to a small change in differential pressure.

Abstract: A service brake/traction control valve includes a service brake control port, a traction control port, an exhaust port, and a control chamber. The control chamber fluidly communicates with the service brake control port and the traction control port as a function of a service brake event and as a function of a traction control event. The control chamber fluidly communicates with the exhaust port when the service brake event is released. The control chamber fluidly also communicates with the exhaust port when the traction control event is released.

Abstract: In one aspect of the present invention, it is contemplated that a valve includes a passage. A first sealing element is biased to restrict flow of a fluid in a first direction through the passage when an upstream volumetric flow rate of the fluid in the first direction is less than a first predetermined threshold. A second sealing element is biased to unrestrict flow of the fluid to a baseline unrestricted flow rate in a second direction through the passage when an upstream volumetric flow rate of the fluid in the second direction is less than a second predetermined threshold.

Abstract: An improved valve for use in a heavy vehicle pneumatic braking and parking system is disclosed. The valve includes a solenoid coil assembly, a valve seat, an armature, and a spring. The solenoid coil includes a pole piece and produces a magnetic field when energized. The valve seat has a valve seat surface and defines a flow passage. The armature has a first end and a second end and includes a spherical shaped elastomeric seal sized to engage the valve seat to block air flow through the flow passage. The spring is engaged around an exterior of the armature and resiliently biases the armature toward the valve seat. When energized, the solenoid coil displaces the armature to an open position away from the valve seat and toward the pole piece to allow air flow through the flow passage.

Abstract: A flow control device having a first port, a second port, a third port and the movable member. In a first mode, the movable member seals the second port while allowing fluid flow between the first and third ports, wherein the differential pressure between the first port and third port, during the first mode, is about zero. In the second mode, the movable member seals the first port while allowing fluid flow between the third port and second port, wherein the movable member is adapted to transition from the first mode to the second mode in response to a small change in differential pressure.

Abstract: A valve for use in a pneumatic fluid system, such as an air brake system, is disclosed. The valve provides for fast release of pneumatic fluid from the delivery cavity through the exhaust port upon cessation of flow from the pneumatic fluid reservoir through the supply cavity. The valve includes a flow diverter that restricts fluid flow from the delivery cavity to the supply cavity when pneumatic fluid pressure in the supply cavity is less than that in the delivery cavity with minimal restriction of flow from the supply cavity to the delivery cavity when pressure in the supply cavity is greater than in the delivery cavity.

Abstract: An improved valve for use in a heavy vehicle pneumatic braking and parking system is disclosed. The valve includes a solenoid coil assembly, a valve seat, an armature, and a spring. The solenoid coil includes a pole piece and produces a magnetic field when energized. The valve seat has a valve seat surface and defines a flow passage. The armature has a first end and a second end and includes a spherical shaped elastomeric seal sized to engage the valve seat to block air flow through the flow passage. The spring is engaged around an exterior of the armature and resiliently biases the armature toward the valve seat. When energized, the solenoid coil displaces the armature to an open position away from the valve seat and toward the pole piece to allow air flow through the flow passage.

Abstract: A valve for use in a pneumatic fluid system, such as an air brake system, is disclosed. The valve provides for fast release of pneumatic fluid from the delivery cavity through the exhaust port upon cessation of flow from the pneumatic fluid reservoir through the supply cavity. The valve includes a flow diverter that restricts fluid flow from the delivery cavity to the supply cavity when pneumatic fluid pressure in the supply cavity is less than that in the delivery cavity with minimal restriction of flow from the supply cavity to the delivery cavity when pressure in the supply cavity is greater than in the delivery cavity.

Abstract: An apparatus and method for compensating actuator arm oscillation induced by resonance mode excitation during a seek in a disc drive data handling system. The actuator arm supports a head adjacent a recording surface, and a servo loop controls the position of the actuator arm. A frequency of actuator arm oscillation is identified, after which a seek is initiated to move the head from an initial track to a destination track on the recording surface. A position error signal (PES) is generated to indicate position of the head relative to the destination track, and a compensation signal is generated by a filter based on the PES and the frequency of oscillation of the actuator arm. The compensation signal is adapted to remove a component of the PES arising from the actuator arm oscillation, and is applied to the servo loop as the head is settled onto the destination track.

Abstract: A digital sine/cosine wave generator generates discrete values representative of either a sine wave or a cosine wave. The digital sine/cosine wave generator generates sine and/or cosine waves by implementing a difference equation of the form y(n)=b*y(n?2)?y(n?1). One of the initial conditions of the difference equation is selected from a series of values generated by a coefficient generator. The frequency of the sine and/or cosine wave generated by the sine/cosine wave generator is dependent on, and may be selected according to, which of the series of values generated by a coefficient generator is chosen as an initial condition of the difference equation.

Abstract: Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A “measured” subset of the tracks is selected so as to be interspersed with an “unmeasured” subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

Abstract: Autonomous retransmission of data packets onto a network from a Network Interface Card level upon command from a host processor is support. Efficient FIFO buffering in an ASIC is retained. Uses for autonomous retransmission include hardware and software testing and in network management.

Abstract: A valve for use in a pneumatic fluid system, such as an air brake system, is disclosed. The valve provides for fast release of pneumatic fluid from the delivery cavity through the exhaust port upon cessation of flow from the pneumatic fluid reservoir through the supply cavity. The valve includes a flow diverter that restricts fluid flow from the delivery cavity to the supply cavity when pneumatic fluid pressure in the supply cavity is less than that in the delivery cavity with minimal restriction of flow from the supply cavity to the delivery cavity when pressure in the supply cavity is greater than in the delivery cavity.