In a tire inflating device having a machine frame (2), a tire filling bell (4) arranged on the machine frame (2) and a supporting and sealing device (5) for sealing a filling chamber. The tire filling bell (4) is comprised of a filling plate (10) and a separate filling ring (11). A magazine (3) has a magazine rack (20) and magazine guides (21) lying in a plurality of parallel planes, each of said guides being able to hold a filling ring (11, 11′) mounted so that it can move. The magazine rack (20) and the filling plate (10) can be moved with respect to each other into a plurality of transfer positions in the direction of the axis of rotation. The magazine guide (21) in each case is connected to a filling plate guide (18) arranged on the filling plate (10) in said transfer positions. A filling ring (11) which is located in the magazine guide (21) arranged in the transfer position can be conveyed by a conveying device (40) into a filling plate guide and a centered position on the filling plate (10).