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.

Date of Patent:
Jun. 30, 1987

Filed:

Jun. 06, 1986
Applicant:
Inventors:

Dennis A Burgess, Tonka Bay, MN (US);

William J Campbell, Minnetonka, MN (US);

Arvids Saldenais, Champlin, MN (US);

Assignee:

Burgess Industries Inc., Plymouth, MN (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 91 ; 355 73 ;
Abstract

The present invention provides an improved vacuum frame having upper and lower frame members of rectangular shape, the upper one of which supports a plate of glass. Connected to the lower frame is a flexible sheet such as a rubber sheet with a backing member connected to its lower surfae. Resilient members such as springs urge one edge of the sealing sheet upwardly toward the glass plate and the other edge downwardly away from the glass plate to produce a wedge shaped vacuum chamber which upon being evacuated becomes progressively smaller as air is progressively and directionally removed proceeding from one edge of the glass plate to the other.


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