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:
Mar. 12, 1991
Filed:
Nov. 30, 1989
Gert Braun, Essen-Heisington, DE;
Ernst Braun, Essen-Heisington, DE;
Halbach & Braun Industrieanlagen, Wuppertal, DE;
Abstract
A mining tool for the breaking-down of minerals, particularly coal. The mining tool includes a chisel with a chisel shaft with a receiving bore and a chisel holder with an insertion bore. The bores are in alignment when a locking bolt is driven into the bores. The locking bolt is a mandrel screw with a threaded portion which over its length includes a sharp thread and a trapezoidal thread. The circumferential surfaces of the trapezoidal thread form a driving-in cone. The mandrel screw can be easily driven into the receiving bore which includes a chuck. In addition, because of the sharp thread, the mandrel screw can be unscrewed quickly, so that a quick chisel exchange is possible.