Patent ID: 7819332

Claim:
A bypass valve ( 1 ) for uncoupling oil flow through a radiator at low oil temperatures, with an oil supply ( 6 ) from the radiator ( 7 ), a supply ( 4 ) via a bypass line ( 5 ), an oil outlet ( 8 ), and a valve unit being displaceable inside a valve housing ( 10 ) against a force of a compression spring ( 11 ) that is connected in series, the bypass valve ( 1 ) comprising a heat sensitive element ( 2 ) that moves inside the valve housing ( 10 ) subject to an oil temperature such that, at oil temperatures below a threshold value, the oil supply ( 6 ) from the radiator ( 7 ) is closed and the supply ( 4 ), via a bypass line ( 5 ), is opened as a result of which, at temperatures above the threshold value, the oil supply ( 6 ) from the radiator ( 7 ) is opened and the supply ( 4 ), via the bypass line ( 5 ), is closed resulting in that, once a predefined oil pressure is reached, the entire valve unit is displaced axially against the force of the compression spring ( 11 ), as a result of which the supply ( 4 ), via the bypass line ( 5 ), is opened, the heat sensitive element is a spring ( 2 ) made of a memory metal alloy, where respective ends of the spring ( 2 ) are operationally connected to a piston ( 3 , 11 ), resulting in that at a temperature above a predefined threshold value, both pistons ( 3 , 11 ) are displaced by the spring ( 2 ), which closes the supply ( 4 ), via the bypass line ( 5 ), and opens the oil supply ( 6 ) from the radiator ( 7 ), and at a temperature below the threshold value the spring ( 2 ) is in a relaxed state, so that when the supply ( 6 ) from the radiator ( 7 ) is closed, and the oil flow is conducted past the radiator ( 7 ) via the bypass line ( 5 ).