Control system
AssigneeFletcher Sutcliffe Wild Limited
InventorsLewis R. B. Bower, Philip W. Dudley, John C. Smith
Life of this patent
Estimating the term…
Abstract
A control system for a hydraulically powered self advancing mine roof support, which system ensures that a hydraulically extensible chock leg of the support is set to a predetermined pressure, irrespective of the length of time that a main inlet valve is held open comprises an auxiliary valve interposed between a main valve and a chock leg(s) in a fluid supply line extending from a high pressure line to the support, a bypass line connected to the high pressure line in advance of the main valve and extending to the auxiliary valve, the auxiliary valve being so constructed as to open upon sensing a predetermined pressure and to close upon sensing a higher predetermined pressure.
Claims5
A mine roof support control system comprising at least one hydraulically powered, self-advancing mine roof support, at least one hydraulically extensible chock leg forming part of said mine roof support, a high pressure fluid line, a fluid supply line extending from said high pressure line to said support, a main valve, an auxiliary valve interposed between said main valve and said chock leg(s), a bypass line connected to said high pressure line in advance of said main valve and extending to said auxiliary valve, said auxiliary valve being so constructed as to open upon sensing a predetermined pressure and to close upon sensing a higher predetermined pressure.
Dependencies are inferred from the claim text.