Patent Number: 7,028,979

Title: Servo assisted butterfly valve provided with a flat leaf spring and a spiral spring to establish the limp-home position

Abstract: A servo-assisted butterfly valve comprising a valve body, a valve seat formed in the valve body, a butterfly disc adapted to engage the valve seat, a shaft on which the butterfly disc is keyed, an electric motor coupled to the shaft by means of at least one toothed wheel provided with a projection, a spiral return spring adapted to rotate the butterfly disc towards the closed position, and an opposing spring adapted to rotate the butterfly disc towards a limp-home position defined by an abutment body against the action of the return spring; the opposing spring is a flat leaf spring and is mounted on a moving member which is mounted coaxially and idly on the shaft and comprises a projection adapted to engage in abutment against the abutment body, a first end of the opposing spring being free and adapted to come into contact with the projection of the toothed wheel during the rotation of this toothed wheel.

Inventors: Fauni; Claudio (Bologna, IT)

Assignee: Magneti Marelli Powertrain S.p.A.

International Classification: F16K 31/04 (20060101)

Expiration Date: 4/18/02018