(under subclass 600) Subject matter wherein the spool is provided with significant surface voids between structural portions.
(1) Note. The voids may be created in the surface of a spool hub or flange by skeletal or grid construction of rods, wire, dowels, slats, lath, netting, or perforated material provided with significant openings or spacing frequently used to facilitate fluid flow about wound material for washing, drying, dyeing, etc., or to create a large, lightweight spool.
SEE OR SEARCH THIS CLASS, SUBCLASS:
118.1, and 118.11, for an openwork strand spool.
407.1+, for a spool used with a drive to form a reel.
577+, for a spoke-type skein holder.
602+, for a spool with convolution separators or a spoke-type spool.