GB1049471A - Advancing hydraulic mine roof support frame assembly - Google Patents

Abstract

1,049,471. Hydraulic jacks. GEWERKSCHAFT EISENHUTTE WESTFALIA. Feb. 14, 1964 [Feb. 16, 1963; April 27, 1963], No. 6317/64. Heading B8J. [Also in Division E1] In an advancing mine roof support three hydraulic props 10, 11, 12 are released from the roof one at a time and are individually advanced parallel to a shifting cylinder 43 by actuation of a four-way valve 52 connected to supply and return fluid lines 28, 35. The cylinder 43 shown comprises a first hollow piston 44 acting as a cylinder for a second piston 45, the floor cups of the props 10, 11, 12 being rigidly connected respectively to the piston 45, the piston 44 and the cylinder 43. A guide bar 48 on the cylinder 43 is slidably engaged by a bar 47 on the floor cup of prop 11. The upper ends of the props may be guided for parallel movement by telescopic links; alternatively the upper end of prop 10 may carry a guide bar parallel to the cylinder 43 and slidably engaged by sleeves attached to the upper ends of the props 11, 12. In a modification the cylinder 43 is replaced by a shifting cylinder connected to one prop and incorporating two opposed pistons connected to the other two props, the fluid supply being controlled by two four-way valves and a non- return valve. In this construction the floor cup of prop 12 and its attachment bars may be swung about the cylinder axis, after removal of the props, to facilitate transport.