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:
Jun. 23, 1978
Hans-Otto Friedrichs, Wuppertal, DE;
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Abstract
A hydraulic, walking, roof-support frame comprising a vertically-movable, pivotable control lever pivotally connected at its lower end portion to a rigid inextensible rocker arm pivotally mounted on a floor runner or skid of the frame and guided at a distance therefrom by a second rocker arm disposed nearer the coal-face end of the frame and pivotally connected to the floor runner and to the control lever, the free or coal-face end of the control lever being pivotally connected to a roof bar or plate pivotably born by hydraulic vertically-adjustable props, in which the said second rocker arm is longitudinally adjustable and is so constructed that it can be held at a predetermined intermediate length between pivots at its ends to enable its length to be changed in either direction as a result of a thrust from the roof.