The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 23, 1984
Filed:
May. 27, 1983
John J Prusak, Indianapolis, IN (US);
Bhupendra P Patel, Indianapolis, IN (US);
RCA Corporation, New York, NY (US);
Abstract
An apparatus for molding an article, such as a preform, used in making information recorded discs, includes top and bottom mold members having recesses in their approved surfaces. The top mold member is mounted on the end of the piston rod of a pneumatic cylinder which is adapted to move the top mold member into mating relation with the bottom mold member so that the mold recesses form a mold cavity. The bottom mold member includes means for injecting a plastic mold material into the mold cavity. To mold a preform, the top mold member is moved by the pneumatic cylinder toward the bottom mold member to a collapsed position of the mold members where the mold cavity is of a volume less than the desired volume of the preform being molded. Plastic mold material is injected into the mold cavity until it is filled and additional mold material is injected into the mold forcing the top mold member away from the bottom mold member until the cavity is of the desired volume of the preform. The pneumatic cylinder is connected to an air reservoir so that when the top mold member is moved against the pressure of the pneumatic cylinder the air therein is forced into the air reservoir so as to maintain a substantially uniform, and preferably relatively low, pressure on the article being molded.