GB538880A - Improvements in or relating to liquid pressure remote control systems, more particularly for operating soot blowers of boilers and the like - Google Patents

Abstract

538,880. Fluid-pressure soot-blowers &c. AUTOMOTIVE PRODUCTS CO., Ltd., and EVES. F. S. Feb. 16, 1940,No. 2938. [Class 99 (ii)] [Also in Group XXIX] A liquid-pressure remote control system, particularly for soot-blowers, comprises a double-acting fluid-motor unit 19 connected with a reversing-valve 13 by a pair of interchangeable supply and return pipe-lines 15, 16, the reversing valve being actuated by pressure-liquid fed thereto through a shunt pipe-line 38 under the control of the unit 19. Valve-reversal is effected when the shunt-conveyed fluid acts through passages in the valve on the piston 42 of a double-acting auxiliary motor. A quickthrow of the valve is obtained by the snap-over action of the linkage shown to the left of Fig. 1. The valve-stem 70 is hollow and formed with radial and peripheral channels controlling not only the action of the shunt 38 and motor 42, but the supply and circulation of pressureliquid from the pump 10 and reservoir 11 to the flow and return pipes 15, 16. Pressure is set up in the shunt 38 when the double-acting piston 24, 25 engages one of the pins 32, 33 and opens the corresponding ball valve 30, 31, further ball-valves 34, 35 also being fitted to prevent neutralizing action through the pipe 32. In a modification intended for soot-blowers of the non-retractable type, the drive is through ratchet-gearing which occurs during the movement to the right of the pistons 24, 25. Each piston is moreover provided with a resilient face for engaging the pins 32, 33, producing a quicker opening of the associated ball-valves. In a soot-blower of the retractable type, Figs. 3 and 4, the nozzle-shaft 140 is actuated through a screw-and-nut gearing from a gear wheel 155. A double-acting unit 166 of the general type described above oscillates a pinion 169, axially and obliquely bored to receive rods 76, 179, the latter of which penetrates into a recess on the hub of the wheel 155. Dowels 186, designed to shear under excessive torque, such as that occasioned by jamming of the blower nozzle, are also lodged in the adjacent end faces of the wheel 155 and shaft 168. Such shearing dislodges the rod 179 and moves the rod 177 axially to push aside the support for the roller 201. The valve 194 in the pressure feed-line 18S, 188a is then closed by the spring 196 and the unit 166 is brought to a standstill. Reciprocation of the double-acting piston is in this construction effected by mechanism comprising a gear 218 integral with a drum 221 the surface of which is grooved as a cam to be engaged by a spring-pressed finger 223. Tilting of the finger about its pivot 224 moves the roller 233 and opens one or other of the valves 29, 30, bringing into use the shunt 38. The cam groove provides for both long and short nozzle strokes, and is stepped at the junctions to ensure unidirectional travel of the pin 222. Specifications 538,881 and 538,882 are referred to.