Patent attributes
A valve arranged to close a flow path extending through it, on the loss of an electrical voltage supplied to a driving motor of an actuation element, the driving motor, which comprises a stator and a rotor, being arranged to, via transmission elements, displace the actuation element between at least a first position, in which the actuation element is arranged at a distance from a spring-loaded, rotatable valve element, and a second position, in which the actuation element holds the spring-loaded, rotatable valve element in an open position, the rotor of the driving motor surrounding and being connected to a roller nut which is provided with a number of supported thread rollers which are distributed around and are threadedly engaged with the actuation element, the actuation element being a flow pipe which forms a flow path and is axially displaceable away from its second position by means of an actuator spring.
