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:
Jun. 13, 1978
Filed:
Dec. 09, 1976
Abstract
In a longwall mining operation the roof of the breast extending laterally from a heading or gangway is supported by at least two pairs of pit props. Each pair is substantially identical, having an elongated upper part and an elongated lower part displaceable away from each other by hydraulic rams. In addition a shield is provided extending vertically between the upper and lower parts of each prop at the upstream end of the prop turned toward the stowage area. In addition the props furthest from the mine are substantially longer than the props closest to the mine and are provided at their ends turned toward the stowage area with side shields forming a closed chamber so as carefully to segregate the gob from the breast. The upper parts of the props are formed of several articulated sections so as to allow these upper parts to conform to the shape of the roof. In addition that prop closest to the mine is provided with laterally extending upwardly pivotal flaps usable to support the roof at the opening between the breast and the mine.