PRESSURE INDICATING APPARATUS FOR HYDRAULIC MINE ROOF SUPPORT RAMS

摘要

1,210,015. Pressure indicators. BERGWERKSVERBAND G.m.b.H. March 26, 1968 [June 1, 1967], No. 14444/68. Heading G1L. In apparatus for providing a pneumatic signal corresponding to the hydraulic pressure of a mine roof support ram the apparatus is connected by sockets 10, 11 to a hydraulic pit prop and, through a hole 8, with the hydraulic system of the pit prop and the arrangement is such that the hydraulic pressure acts on one side of a diaphragm 5 against a supply of compressed air at a constant pressure supplied through an opening 15 to a chamber 12, on the other face of diaphragm 5, and through a gap formed between the end of a tube 20 and out through the bore of the tube 20 and the amount is such that should the pressure on the first face of the diaphragm vary, the gap width will vary, to vary the pressure in chamber 72 which pressure will be shown on indicator 32.