Abstract: This specification discloses an improved means for adjusting the movement of a gyratory head fan comprising a turntable driven by the fan motor and supporting an adjusting mechanism which changes the position of a socket member for the ball of a gyratory linkage with respect to the axis of rotation of the turntable. The adjusting mechanism comprises a rim which may be held against rotation relative to the turntable, lugs on the rim which engages lugs on a rotatably mounted member incorporating the socket such that the member is rotated to change position of the socket. The rim may be held against rotation by means of a plunger which engages projections on the rim. Spring loaded pawl means may be provided to hold the member in several predetermined positions to provide different modes of operation.