Tire building machine having axially adjustable bead seats

Claim 1

A TIRE BUILDING DRUM COMPRISING A MAIN SHAFT HAVING TWO SHAFT PORTIONS TELESCOPICALLY SLIDABLE WITH RESPECT TO EACH OTHER, A SLEEVE FIXED ON THE OUTER END OF EACH SHAFT PORTION, EACH SLEEVE HAVING AN UPSTANDING ANNULAR FLANGE, A TUBULAR DIAPHRAGM HAVING ITS ENDS ANCHORED IN FLUID TIGHT RELATION TO THE OUTER FACES OF SAID FLANGES, A RIGID RING COAXIALLY AND SLIDABLY MOUNTED ON EACH SLEEVE AND DISPOSED INWARDLY OF AND IN CLOSE PROXIMITY TO AN ADJACENT FLANGE, SAID RIGID RING BEING PROVIDED WITH A SEAT RECEIVING AN ANNULAR INFLATABLE AIR TUBE AND AN ELASTIC RING SURROUNDING SAID AIR TUBE, EACH ELASTIC RING HAVING ON ITS OUTER PERIPHERAL SURFACE A CIRCUMFERENTIAL GROOVE, SAID ELASTIC RING BEING EXPANSIBLE FROM A DIAMETER LESS THAN THAT OF THE RIGID RING TO A DIAMETER GREATER THAN THE DIAMETER OF THE RIGID RING, AND MEANS FOR DISPLACING EACH RIGID RING ALONG ITS CORRESPONDING SLEEVE IN DIRECTIONS TOWARDS AND AWAY FROM THE ADJACENT FLANGE, THE DISPLACEMENT OF SAID RINGS BEING INDEPENDENT OF ANY MOVEMENT OF SAID ADJACENT FLANGE.