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:
May. 12, 1981
Filed:
Jul. 02, 1979
Alfred Maykemper, Wuppertal, DE;
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Abstract
The roof-engaging assembly of a support frame for a mine roof comprises a main beam having a cantilever extension pivoted to the main beam by pins. In order to pivot the cantilever extension through an angle of about 180.degree.-200.degree. between a stowed position and an operative position, a link is pivoted at one point to the main beam and is pivoted at another point to one end of a double acting jack. The other end of the jack is pivoted to the main beam so that, by extending or retracting the jack, the link member pivots one way or the other. The cantilever extension has a pin which runs in a slot in the link member, the arrangement being such that pivoting of the link member by the jack produces pivoting of the cantilever extension through a much larger angle, e.g., double the angle.