the mandrel are encircled by an elastic band 87 which resides in the channels 124 of the several shoes by this means the shoes hence the distal ends of the linkages are all biased radially inwardly toward the housing of the mandrel thereby biasing each of the piston members in a direction which minimizes the volume of the space within a given chamber which is to be pressurized for actuation of the piston further the elastic band restricts rotational movement of the shoes to a few degrees of rotation thereby maintaining the orientation of the outer surface of each shoe generally concentric with respect to the outer circumference of the mandrel but allowing a relatively small degree of freedom of rotation to provide for alignment of each shoe such that its distal edge 130 properly engages the inner circumference of a tire carcass adjacent a respective bead ring when employed in a shaping drum this elastic band is not shown in most of the drawings for purposes of clarity in one example the mandrel of the present invention may be employed in a shaping drum as an aid to alignment of a green vehicle tire carcass on the shaping drum in this example for a carcass having a diameter of about 14 inches the outer diameter of the housing 14 is 10 5 inches and has a cross sectional area of about 0 27 in 2 the overall length of each linkage is 5 5 inches as measured along the intersecting longitudinal dimensions of the proximal and distal body portions.