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:
Mar. 01, 1994
Filed:
Jul. 07, 1992
Herman F Nied, Clifton Park, NY (US);
Alexander T Chen, Schenectady, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A method and apparatus for thermoforming 3-dimensional articles of chosen wall thickness dimensions from a polar polymer sheet. The polymer sheet is dielectrically heated, the heating being controlled to impress a predetermined thermal pattern on the sheet. The thermal pattern is selected in accordance with the amount of stretching to which each area of the sheet is subjected during the subsequent work-forming step, the areas subjected to greater stretching being heated to a lower temperature and vice versa. Thus, the stretching action is balanced and results in accurate control of the wall thickness of the final article.