Abstract: An interrupt for an automatic traction control system includes a park brake control valve for controlling a park brake of a vehicle as a function of a park brake control pressure signal. A service brake control valve controls a service brake as a function of a service brake control pressure signal. A traction control valve communicates the service brake control pressure signal to the service brake control valve as a function of the park brake control pressure signal.

Abstract: An automatic air suspension control system for a tractor trailer includes a system for allowing suspension air pressure to be dumped for the suspension system during a necessary and required loading/unloading of the tractor trailer. The control system includes a transmission device and an receiving device for activating a valve for exhausting the air pressure from a suspension unit.

Abstract: A bus door/service brake interlock system having a warning system is provided to inform a driver that the service brake pressure is insufficient or not being applied at all, as well as indicating if a system malfunction occurs, precluding a service brake application. The system is based on a sequential operation of the driver activating the caution lights and opening the door. Once these events have occurred, the autobrake system including an alarm is activated. On the other hand, applying the park brake deactivates the autobrake system. The autobrake assembly energizes a solenoid that receives regulated pressure from a pressure reducing valve. This pressure is supplied to one side of a double check valve, while the other side receives a delivery from the foot valve to assure delivery for normal service braking.

Abstract: A continuous flow dryer system for compressed air includes first and second air dryers for receiving and alternately drying compressed air from a source. The dried air from the first dryer is transmitted to the second dryer. First and second reservoirs store the dried compressed air. A plurality of control valves in the second air dryer are used for distributing the dried air to the respective reservoirs.

Abstract: A cargo or bulk product off-load system includes a compressor (10) that pressurizes air. The air is dried by a dryer (12, 14) and routed to a supply tank (16). From the supply tank, the air is either used to pressurize service reservoirs (24, 26) or to assist the off-load system. Air stored in the service reservoirs (24, 26) is used to pressurize purge volumes associated with the dryers (12, 14). The compressor (10) operates at a lower pressure when supplying air to assist the off-load system than when pressurizing the service reservoirs (24, 26). Controllers (30, 40) coordinate switching of airflow, and alternating purging and drying of the dryers.

Abstract: A continuous flow dryer system for compressed air includes first and second air dryers for receiving and alternately drying compressed air from a source. The dried air from the first dryer is transmitted to the second dryer. First and second reservoirs store the dried compressed air. A plurality of control valves in the second air dryer are used for distributing the dried air to the respective reservoirs.

Abstract: A control system for a container chassis latching assembly of a trailer provides for initial pressurization of the latching assembly via the trailer supply line. Once a trailer reservoir is sufficiently charged, pressure is maintained for the latch assembly by the trailer reservoir. A preferred control valve interconnects the supply line with a supply port of the valve to provide the desired pressure at a delivery port. A control port of the valve is connected with the trailer reservoir and shuts off this flow once the trailer reservoir has reached a predetermined pressure. Thereafter, the latch assembly is maintained via air supplied from the trailer reservoir.

Abstract: A parking brake control circuit engages the parking brake of a vehicle when the transmission of the vehicle is in the “park” position and the engine of the vehicle is turned off, without requiring the constant application of electrical power. The parking brake control circuit utilizes latching solenoid technology that eliminates the need for a constant voltage source. A time-delay relay is used to change the state of the latching solenoid. The time-delay relay is preferably activated through a circuit containing an engine oil pressure switch, a transmission park switch and a vehicle speed switch. Activation of the relay latches the solenoid in a position that allows the parking brake to be applied, without requiring the application of a constant voltage to the solenoid. Accordingly, the possibility of inadvertent brake application due to electrical failure is avoided.

Abstract: A system and method for improving the traction of a vehicle uses weight distribution control to improve wheel to driving surface friction. A driven axle and a non-driven axle support a vehicle load through adjustable suspension members. The suspension members are, for example, air bags. Actuators and controllers adjust the suspension members in a selectable predetermined manner. The selection can be based on operator preference, vehicle operating mode, or a sensed loss of traction. The driven axle carries a drive axle maximum rated load in order to maximize drive wheel traction at all times.

Abstract: A bus door/service brake interlock system having a warning system is provided. The interlock system includes a foot valve assembly to effect a service brake application when warning lights are activated, a vehicle door is open, and minimum speed conditions are met. An auxiliary line is positioned between a source of pressure and the foot valve assembly and includes a valve and a low pressure indicator. Should the operator leave the driver seat with the interlock system engaged, the parking brake is automatically applied.

Abstract: A parking brake control circuit engages the parking brake of a vehicle when the transmission of the vehicle is in the “park” position and the engine of the vehicle is turned off, without requiring the constant application of electrical power. The parking brake control circuit utilizes latching solenoid technology that eliminates the need for a constant voltage source. A time-delay relay is used to change the state of the latching solenoid. The time-delay relay is preferably activated through a circuit containing an engine oil pressure switch, a transmission park switch and a vehicle speed switch. Activation of the relay latches the solenoid in a position that allows the parking brake to be applied, without requiring the application of a constant voltage to the solenoid. Accordingly, the possibility of inadvertent brake application due to electrical failure is avoided.

Abstract: A control system for a container chassis latching assembly of a trailer provides for initial pressurization of the latching assembly via the trailer supply line. Once a trailer reservoir is sufficiently charged, pressure is maintained for the latch assembly by the trailer reservoir. A preferred control valve interconnects the supply line with a supply port of the valve to provide the desired pressure at a delivery port. A control port of the valve is connected with the trailer reservoir and shuts off this flow once the trailer reservoir has reached a predetermined pressure. Thereafter, the latch assembly is maintained via air supplied from the trailer reservoir.

Abstract: An air dryer system for a trailer braking assembly is modified to provide a purge flow when the park brakes are actuated. An air reservoir, either the main air tank or a separate reservoir, is in operative communication with the trailer air dryer. A valve disposed at a supply end of the trailer air dryer selectively vents a purge flow to atmosphere in response to a park brake application. A restricting orifice limits the purge flow through the trailer air dryer to extend the purge time and maximize the removal of moisture from the air dryer.

Abstract: A system and method for improving the traction of a vehicle uses weight distribution control to improve wheel to driving surface friction. A driven axle and a non-driven axle support a vehicle load through adjustable suspension members. The suspension members are, for example, air bags. Actuators and controllers adjust the suspension members in a selectable predetermined manner. The selection can be based on operator preference, vehicle operating mode, or a sensed loss of traction. The driven axle carries a drive axle maximum rated load in order to maximize drive wheel traction at all times.

Abstract: A proportional load transfer valve is disclosed to shift a predetermined ratio of approximately fifty percent (50%) of the weight on a tag axle to the drive axle. The load transfer valve acts in response to a pneumatic signal indicative of a traction event. The valve alters the ratio of supply port pressure associated with the air suspension bags of the drive axle that is forwarded to the delivery port associated with the air bag suspension assembly of the tag axle. As the weight imposed on the drive axle approaches a predetermined maximum, the load transfer valve transfers less weight so that the drive axle is not overloaded.

Abstract: An electric control valve for a heavy duty vehicle air parking brake system. The system uses latching electrically controlled solenoid air valves to control the parking brake systems of the tractor and trailer. The system allows electric control devices to be placed in the vehicle's instrument panel. The system maintains a previously set state of the system even in the event of a loss of electrical power to the controller. Indicator lamps provide park status information to the vehicle driver.

Abstract: A proportional load transfer valve is disclosed to shift a predetermined ratio of approximately fifty percent (50%) of the weight on a tag axle to the drive axle. The load transfer valve acts in response to a pneumatic signal indicative of a traction event. The valve alters the ratio of supply port pressure associated with the air suspension bags of the drive axle that is forwarded to the delivery port associated with the air bag suspension assembly of the tag axle. As the weight imposed on the drive axle approaches a predetermined maximum, the load transfer valve transfers less weight so that the drive axle is not overloaded.

Abstract: A double check valve is integrally located in a spring brake chamber to reduce plumbing associated with a pneumatic brake system. Anti-compounding is provided by virtue of a bias pressure of approximately twenty to thirty psi between a pressure chamber of a service actuator and an operating chamber of a parking/emergency actuator. Likewise, vehicle roll-back is addressed since the transition from a service application to a park application assures that the service brakes are sufficiently applied until the spring brake becomes operative.

Abstract: A braking system is able to meet emergency stopping distance requirements associated with a failed rear axle service control line by modifying the service relay valve. The service relay valve incorporates a biased double check valve so that an additional or secondary control line from the foot control valve communicates with the service port of the relay valve. If the primary circuit is operational, a biasing force imposed on the double check valve permits normal operation via the primary service line. On the other hand, if the primary service line is lost, the biasing force is overcome and communication between the secondary service line and the service port of the relay valve is established.

Abstract: An pneumatic system (10) for a tractor trailer truck (6) which increases compressed air flow to the trailer reservoir (52) whenever the tractor (7) is parked. This decreases the time it takes to charge the trailer reservoir (52) to a sufficient pressure to release the trailer brakes allowing the truck (6) to move. In normal over the road operation the trailer reservoir (52) is charged through a tractor protection control valve (14) which is mounted on the tractor dash. However when the tractor (7) is parked and a tractor park valve (12) which is mounted on the tractor dash is pulled out compressed air from the tractor secondary reservoir (42) is delivered with an increased flow rate to the trailer supply line (50). When the tractor park control valve (12) is pushed in releasing the tractor parking brake the trailer charging reverts back to charging through the dash mounted tractor protection control valve (14).