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:
Apr. 01, 1980
Filed:
Mar. 27, 1978
Roger I Swanson, Butler, PA (US);
Other;
Abstract
An improved device for anchoring mine roofs utilizing bolts prestressed to place them under high tension loading is disclosed. The bolt is secured by an anchor consisting of an expandable shell and an expander nut with the nut being movable lengthwise of the hole by turning the bolt. The surfaces of the anchor which engage the surfaces of the hole in which it is installed are coated with sand bonded thereto by a thin coat of a suitable adhesive. By the use of a polywax material to lubricate the threading of the bolt and the camming surfaces of the expander nut, very high lateral expansion forces are generated to press the sand coated surfaces of the anchor against the rock walls creating a high tension load supporting engagement between the anchor and the rock matrix.