(under subclass 661) Subject matter wherein the platen* is formed of a plurality of convolutions of material about the axis of the platen.
(1) Note. The convolutions may be wound spirally (i.e., increasing in diameter as the convolutions are wound around the axis) or helically (i.e., having the same diameter but progressing along the axis as the convolutions are wound around the axis), or be a combination of both forms of convolutions.
