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US 3,996,330 AGranted
Method of making a molded brush back
AssigneeVistron Corporation
InventorsKenneth B. Jones, Walter C. Gorenflo
Life of this patent
Estimating the term…
Abstract
A finished plastic-handled brush is prepared by a single molding step involving gateless molding of the brush back by a tunnel-gating and novel punch-pin finishing apparatus and process which eliminates the usual gate stud, and removing the finished brush back and securing tufts of bristles in the face of the brush back to complete the brush construction.
Claims3
The process of making a finished brush back, comprising:
- injecting a plastified thermoplastic material into a cavity of a mold through a tunnel gate communicating with said cavity, moving a punch pin into said gate until an end of said pin is flush with an inner surface of a wall of said mold defining said cavity, to force thermoplastic material from said gate into said cavity, accomplishing said moving by moving horizontally one wedge of a pair of cooperating wedges to actuate a second wedge of said pair causing it to move transversely to the direction of movement of said first wedge, said second wedge actuating said pin, while preventing movement of said second wedge, in a direction parallel to the direction of movement of said first wedge, by movably receiving a guide pin in an aperture therein.
Dependencies are inferred from the claim text.