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:
Dec. 31, 1991
Filed:
May. 04, 1990
Applicant:
Inventor:
Jerry E Frease, Lexington, KY (US);
Assignee:
Jennmar Corporation, Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21D / ;
U.S. Cl.
CPC ...
4052591 ; 4052596 ;
Abstract
A mechanical expansion shell assembly has an expansion shell with a plurality of leaves and a plug with a plurality of sloped surfaces. The inner surfaces of the leaves are positioned in overlying relation with the sloped surfaces of the plug. A friction reducing material is positioned between the overlying surfaces and is arranged to reduce the torque applied to the roof bolt connected to the expansion shell assembly to obtain a preselected lateral force on the expansion shell leaves. In another embodiment, a friction reducing material is positioned between a nut threaded on the roof bolt and the underside of the expansion shell ring portion.