The invention relates to a transmission mechanism (20) of a progressive gear (1), especially a steering gear for a vehicle, comprising a seating for each of an input shaft (10) and an output shaft (30). The transmission mechanism (20) according to the invention consists of a movable coupler (21) which is in articulated connection with the input shaft (10) and the output shaft (30) so that transmission from the input shaft (10) to the output shaft (30) with a progressive characteristic is achieved in the range −180° to +180°. The advantage of such a gear (1) lies in the simple and therefore economical production of the apparatus and in its low space requirement. The absence of play in the mechanism and the direct transmission of forces by virtue of the individual components having suitable angles with respect to one another are further advantages.