초록 ▼

A PVC film cover is provided including a down and interned marginal portion terminating in a thickened bead, the marginal portion tapering in thickness from the bead toward the central body portion of the cover.The cover is produced through the use of a shape-conforming mold into whose central porti

A PVC film cover is provided including a down and interned marginal portion terminating in a thickened bead, the marginal portion tapering in thickness from the bead toward the central body portion of the cover.The cover is produced through the use of a shape-conforming mold into whose central portion liquid PVC is dispensed while the mold is rotating. The liquid PVC moves over the mold surfaces outward toward the outer marginal portion thereof by centrifugal force and rotation of the mold is terminated and the mold is quickly inverted into a downwardly opening position whereupon the excess liquid PVC at the outer periphery of the mold flows slowly down to a reversely turned edge for forming the bead of the cover. In quick succession, the mold is heated in order to gel and then harden the liquid PVC, mold is cooled and the cover is thereafter removed from the mold.

대표청구항 ▼

1. An object cover including a thin, flexible body of PVC, said body including a central body portion of generally circular plan shape having a first side facing in one direction and an outer peripheral portion directed in said one direction and terminating outwardly in a thickened, non-rolled perip

1. An object cover including a thin, flexible body of PVC, said body including a central body portion of generally circular plan shape having a first side facing in one direction and an outer peripheral portion directed in said one direction and terminating outwardly in a thickened, non-rolled peripheral reinforcement bead, said outer peripheral portion, at least adjacent said bead, gradually thickening toward said bead.