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. 22, 1979
Filed:
May. 09, 1978
Hans-Otto Friedrichs, Wuppertal, DE;
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Abstract
An hydraulic walking roof-support frame for a coal mine has a roof support assembly comprising a main support and an auxiliary support pivotally connected to the main support for pivoting about a horizontal axis through an angle of 180.degree.. The auxiliary support is caused to pivot by a pair of hydraulically operated extensible and retractable jacks connected between the main support and the auxiliary support, the pivot points where the jacks are connected to the auxiliary support being angularly spaced apart relative to the axis of pivoting of the auxiliary support whereby when (during pivoting of the auxiliary support) one jack is in a 'dead center' position the other jack can still pivot the auxiliary support permitting remote control thereof.