Convoluted hose constructions made of one or more strips of helically wound elastomeric material are well known in the art. However, many of such hose constructions have comparatively poor structural properties, others of such hose constructions are expensive to produce, still others of such hose constructions have poor flexibility, and yet others of such hose constructions have gaps or irregularities defining their inside surfaces and thereby producing poor air flow characteristics and areas for trapping and accumulating material flowing therethrough.
USPTO Backgrounds
USPTO Backgrounds