GB1104428A - Travelling hydraulic support frames for mine roofs - Google Patents

Abstract

1,104,428. Mine-roof supports. GEWERKSCHAFT. EISENHUTTE WESTFALIA. 18, March, 1965 [19, March, 1964; 13, June, 1964], No. 11519/65. Heading EIE. In a travelling hydraulic support frame for mine roofs, an extendible hydraulic prop 2, 3 (Fig. 1) is operably associated with a support member 9 engaging the roof and a spring element 6 is between the prop 2, 3 and the member 9, so that when the prop 2, 3 is retracted, the member 9 is kept in resilient roof contact by the spring 6 and when extended, the spring 6 is compressed, the prop 2, 3 urging the member 9 against the roof. There is a ball-and-socket joint 5, 6 at the top of the prop 2, 3 and the spring 6 may be secured to the socket 5 or it may rest against it, the socket 5 being constrained against moving horizontally relative to the member 9 by the latter's channel walls. The ends of the spring 6 are bent over and engage withdrawable bolts 8 on prop retraction. In a modification the spring 6 is secured directly to the prop, the ball part 4 being retained in the part 5 in the prop by a retaining ring, and has a portion slidable axially of the prop. The spring 6 is divided by the prop into two portions, pivotally attached thereto, and may have extensions converging towards the prop, to maintain the member perpendicular thereto, or separate further springs to do so.