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. 30, 1996
Filed:
Jun. 07, 1994
Frank Calandra, Jr, Pittsburgh, PA (US);
John C Stankus, Canonsburg, PA (US);
John G Oldsen, Butler, PA (US);
Jennmar Corporation, Pittsburgh, PA (US);
Abstract
A flexible multi-strand steel cable of a preselected length is inserted in a bore hole drilled in a rock formation above an underground excavation. The cable includes an anchor end portion positioned in the bore hole for frictionally engaging the cable to the wall of the bore hole. The anchor end portion may also be chemically bonded to the surrounding rock formation. The cable extends out of the bore hole and includes a drive end portion that retains a bearing plate opposite the opening into the bore hole. The drive end portion includes a pair of diametrically positioned jaw members on the cable. The jaw members form a frustoconical outer surface positioned within a tapered bore of a collar. The collar advances on the jaw members to compress them into nonrotational gripping engagement with the steel cable. End portions of the jaw members extend out of the collar on the cable. A torque transmitting device engages the ends of the jaw members removed from contact with the collar to transmit upward thrust and rotation through the jaw members to the cable and place the anchored cable in tension to reinforce the overlying strata of the rock formation.