System for preventing a trailer's overrun brakes from being activated during reversing
AssigneeSvela Solutions AS
InventorSverre Egil Larsen
Life of this patent
Estimating the term…
Abstract
A overrun brake system includes a gas spring with a gas-tight cylinder and a piston with holes allowing gas to slip through so that the pressure is the same on both sides. Since the free end of the piston has a larger area than the side where the piston rod is located, the gas spring will act as a compression spring. To prevent the overrun brakes from being activated during reversing, the gas spring has a solenoid controlled valve receiving current from the reverse light circuit and closing the flow of gas through the piston when the towing unit's gear is set into reverse. When the gear is set into forward position the solenoid loses its current and a mechanical return spring opens the valve, so that the overrun brakes may act normally again.
Claims10
An overrun brake system for a trailer, the system comprising:
- a coupling device adapted to connect the trailer to a towbar of a vehicle,
- a slide providing a first connection connecting the coupling device to a drawbar of the trailer and transferring retardation forces to brakes of the trailer,
- a gas spring providing a second connection connecting the slide to the drawbar in parallel with the first connection, the gas spring including a cylinder and a piston, the piston including two sides and at least one channel connecting the two sides, and
- a solenoid valve, the solenoid valve being electrically connected to and operated by an electric source, the solenoid valve being activated only when the vehicle is set in reverse, the solenoid valve being open and connecting the two sides of the piston so that gas passes from one of the two sides to another of the two sides via the at least one channel when the solenoid valve is non-energized, and the solenoid valve being closed and preventing gas from passing between the two sides of the piston when the solenoid valve is energized by the electric source.
Dependencies are inferred from the claim text.