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:
Sep. 24, 1996
Filed:
Jun. 01, 1995
Applicant:
Inventors:
Jorgen O Bernt, Oakville, CA;
Kevin B Langille, Burlington, CA;
Assignee:
J.O. Bernt & Associates Limited, Mississauga, CA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C04B / ;
U.S. Cl.
CPC ...
106677 ; 106680 ; 106772 ; 106778 ; 106820 ; 428703 ; 428920 ; 524-8 ;
Abstract
A core for fire doors comprises hydrated gypsum occupying about 40% to 46% of the core volume and bubbles occupying almost all the core volume which is not gypsum. The bubbles preferably comprise about 31% to 38% by volume of larger bubbles of between 1 and 4 mm and about 17% to 25% of smaller bubbles between 0.01 mm and 0.25 mm. The larger bubbles are formed using styrene spheroids.