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:
Oct. 12, 1993
Filed:
Feb. 09, 1993
Lubomir Plevak, Lunen, DE;
Abstract
A mine roof support employs a pair of floor skids carrying hydraulic props on which a roof-engaging structure is mounted. A goaf-shield is pivotably mounted to the roof-engaging structure and is connected with a lever system to the floor skids. A shifting and guide mechanism is disposed between the floor skids and takes the form of an hydraulic ram connected at the rear to a floor rail disposed beneath the ram. The ram is supported at the front end by a bridge member connecting the front ends of the skids together. An hydraulic lifting unit is mounted on the bridge member and when extended the unit bears on the floor rail to partially lift the skids as the shifting ram is operated. The lifting unit can be mounted to the bridge member in one of several alternative height positions. To ensure the lifting unit is always maintained above the lower surface of the bridge member when the lifting unit is retracted a stop piece is mounted beneath the bridge member to effectively provide an extension of the lower surface of the bridge member.