Patent ID: 7513762

Claim:
Mold apparatus for molding a tread belt component of a two-piece tire, comprising: a mold constructed of a generally planar, generally circular base plate having an inner surface and an outer surface; and a cup-shaped top plate having a generally planar base portion and a generally cylindrical sidewall portion extending downward from a periphery of the base portion, the top plate having an inner surface and an outer surface; wherein: the mold has a centerline, the base plate is concentric with the centerline, and the top plate is concentric with the centerline; and a chamber is formed under the top plate when mold is in a closed position; a plurality of inner segments disposed in the mold, each inner segment comprising a generally elongate element comprising a top surface, a bottom surface, an inner surface and an outer surface, and two opposite side edges, the plurality of inner segments including follower segments alternating with leader segments; means for controlling radial movement of the inner segments; and wherein the means for controlling radial movement of the inner segments comprises: a driving shaft having a nominal diameter, a strike plate disposed at a top end of the driving shaft and having a diameter greater than the nominal diameter of the drive shaft; a catch plate disposed below the top end of the driving shaft and having a diameter greater than the nominal diameter of the driving shaft; a first coil spring disposed about the driving shaft below the catch plate and having a first spring constant; a collar disposed about the driving shaft, below the first coil spring having a diameter greater than the nominal diameter of the driving shaft and being free to move axially on the driving shaft; a second coil spring disposed about the driving shaft below the collar and having a second spring constant which is greater than the first spring constant; a first set of linkage beams extending from between the strike plate and the catch plate of the driving shaft to the follower segments, and forming an angle theta (θ) with respect to horizontal; and a second set of linkage beams extending from the collar of the driving shaft to the leader segments and forming an angle omega (Ω) with respect to horizontal.