Tire building drum

Claim 1

A TIRE BUILDING DRUM FOR USE IN BUILDING VEHICLE TIRES BY SUPERPOSING PLY STOCK IN ANNULAR BAND FORM AND TURNING THE EDGE PORTIONS THEREOF ABOUT ANNULAR BEAD CORES, THE SAID DRUM COMPRISING A PAIR OF GENERALLY DISKLIKE RIGID SIDE MEMBERS, A FLEXIBLE GENERALLY ANNULAR AIRIMPERVIOUS BLADDER CONNECTED AT ITS EDGE TO SAID SIDE MEMBERS, MEANS SUPPORTING SAID SIDE MEMBERS IN COAXIAL RELATIONSHIP IN A MANNER PERMITTING RELATIVE AXIAL MOVEMENT THEREOF FROM AN INITIAL POSITION WHEREIN THE SAID BLADDER IS GENERALLY CYLINDRICAL AND THE SIDE MEMBERS ARE SPACED APART THEIR MAXIMUM AMOUNT TO A POSITION IN WHICH THE SAID SIDE MEMBERS ARE ADJACENT EACH OTHER AND THE CENTRAL PORTION OF SAID BLADDER IS COLLAPSED RADIALLY INWARDLY BETWEEN THE SAID SIDE MEMBERS, THE SAID SIDE MEMBERS INCLUDING RIGID FLANGE PORTIONS EXTENDING AXIALLY OUTWARDLY FROM THE SIDE MEMBERS WITH THE RADIAL OUTER SURFACE OF THE FLANGE PORTIONS FORMING SMOOTH CONTINUATIONS OF THE SURFACE OF THE BLADDER AND CURVING THEREFROM AS SEGMENTS OF A SPHERE HAVING ITS CENTER ON THE AXIS OF THE DRUM, THE OUTER END FACES OF SAID FLANGE PORTION FORMING SURFACES FOR POSITIONING OF BED CORES DURING BUILDING OF A TIRE BAND ON THE DRUM AND THE FLANGE PORTIONS HAVING A WIDTH AND THICKNESS SUCH AS TO PROVIDE AN UNOBSTSRUCTED REGION RADIALLY INWARDLY THEREOF ADJACENT THE END FACES, WHEREBY THE PERIPHERAL OUTER SURFACES OF THE FLANGE PORTIONS PROVIDE RIGID SUPPORT FOR THE MARGINAL PARTS OF AN ANNULAR TIRE BAND DURING BUILDING THEREOF ON THE DRUM, THE UNOBSTRUCTED REGION BENEATH THE FLANGE PORTIONS PERMITS TURNING OF THE TIRE BAND PLY STOCK ABOUT BEAD CORES PLACED ON THE END FACES OF THE FLANGE PORTIONS, AND THE SEGMENTAL SURFACES OF THE FLANGE PORTIONS FACILITATE REMOVAL OF THE TIRE BAND FROM THE DRUM WHEN BUILDING OF THE BAND IS COMPLETED AND THE SIDE MEMBERS HAVE BEEN MOVED ADJACENT EACH OTHER.