System and Method for Failsafe Operation of a Tractor Protection Control Module
AssigneeBendix Commercial Vehicle Systems LLC
InventorsRyan S. Hurley, Randy J. Salvatora, Subashish Sasmal, Edward F. Hoban
Life of this patent
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Abstract
An electronically-controlled tractor protection control module in a tractor prevents air flow from an air reservoir to a gladhand when a signal is received that indicates a trailer is not coupled with the gladhand. This prevents air from being vented out the gladhand when the tractor's service brakes are applied. However, a failure can occur that prevents this signal from being received or acted upon, which would result in air being vented out the gladhand. To address this problem, an air flow restrictor is used to limit the amount of air that is vented in such a situation.
Claims20
A tractor protection system comprising:
- an electronically-controlled tractor protection controller comprising:
- an output port configured to be coupled with a braking system of a trailer;
- at least one input port configured to receive air from at least one reservoir;
- a relay comprising a control port, a source port that receives air from the at least one reservoir, and a drain port coupled with the output port, wherein the relay is configured to selectively allow air to flow between the source port and the drain port in response to a pneumatic signal received at the control port;
- and
- a solenoid valve configured to selectively prevent pneumatic signal from being applied to the control port in response to an electrical signal received by the electronically-controlled tractor protection controller indicating that the tractor is not coupled with the trailer;
- and
- a flow rate restrictor positioned between one of the at least one reservoir and the source port of the relay, wherein the flow rate restrictor is configured to restrict a flow rate of air supplied from the one of the at least one reservoir to the source port of the relay to no greater than a rate at which a compressor of the tractor is able to refill the one of the at least one reservoir with air.
A method comprising:
- supplying air from a first reservoir in a tractor to a relay that controls air flow to a braking system of a trailer in response to the first reservoir being at or above a first pressure;
- supplying air from a second reservoir in the tractor to the relay in response to the first reservoir not being at or above the first pressure;
- and
- restricting a rate at which air is supplied from the second reservoir to the relay to prevent a pressure in the second reservoir from dropping below a second pressure that would cause the tractor to automatically park.
A system comprising:
- an electronic tractor protection module configured to prevent air flow to a trailer gladhand in response to a signal indicating that a trailer is not coupled with the trailer gladhand;
- and
- means for limiting an amount of air supplied from a reservoir in the tractor to the trailer gladhand after a failure prevents the electronic tractor protection module from preventing air flow to the trailer gladhand even though the trailer is not coupled with the trailer gladhand.
Dependencies are inferred from the claim text.