Patent GB-538882-A (GB)
Title: Improvements in or relating to liquid pressure remote control systems, more particularly for operating soot blowers of boilers and the like
IPC: F28G15/00
Filed: 1940-02-16
Abstract: 538,882. Fluid-pressure soot-blowers &c. AUTOMOTIVE PRODUCTS CO., Ltd., and JELFS, R. E. Feb. 16,1940, No. 2940. [Class 99 (ii)] [Also in Group XXIX] In liquid pressure remote control systems particularly for soot-blowers, double-acting motor cylinder units of the kind described in Specification 538,880 execute a pre-determined number of reciprocations and then automatically cease working, the supply of pressure liquid being transferred to another unit. From a reservoir 11 and pump 10, Fig. 1, liquid passes to one of a series of change-over units 13a, thence either to successive units 13b, 13c in the series, or to a reversing valve and auxiliary motor 18a distantly controlling the reciprocating unit 20 and blower shaft 32 through piping 24a, 25a, 28a as described in Specification 538,880. Figs. 2 and 3 show the change-over devices 13b, 13c.Liquid from the pipe 12b enters the changeover unit 13b by the inlet 12d (Fig. 2), passing left or right through the valves 44, 45 dependent on the rocker-members 60, 61. Between the valves 45, 46 is a port 17d leading to the pipe 17b and the reversing valve system 18b for the unit 20, while aport 48 between the valves 43, 44 leads by way of the pipe 12c to the succeeding change-over member 13c. The rounded lower ends 62, 63 of the valve tilting levers 60, 61 are engaged in recesses in a reciprocating carriage 64 suspended by links 66, 67 from the body of the change-over member, and intermittent movement is imparted to this carriage by a ratchet and pawl connection 29 with the stem 21 of the reversing valve 18a. A bush 82 slidable within the carriage 64 is formed on its underside with ratchet-teeth 30 engaged by the pawl 29 and with positioning recesses 83 engaged by spring- pressed balls 84. A control-rod 86 slides within the bush 82 and on being pushed in to set the mechanism to make the required number of reciprocations, frees the ratchet teeth by depressing a masking plate 92, having oblique slots engaged by transverse pins secured in the rod. The number of reciprocations to be made is determined by rotating a drum 106 having surface slots 119 of different lengths, any one of which may be aligned with a projection 101 on the bush 82. Each forward reciprocation of the valve stem 21 advances the ratchet and the bush 82 by one tooth; the penultimate stroke brings the stud 101 against the end 120 of the slot with which it is aligned; the last stroke moves the drum and the carriage 64 to the right, and throws over the valve levers 60, 61. The valve 45 closes and pressure is cut off from the port 17d which by the opened valve 46 and pipes 50, 51 is vented to the reservoir return pipe. Simultaneously the valve 44 is opened, and by the port 48 pressure liquid is supplied to the succeeding change-over unit in the series. To enable the blower 19b to commence operation before the blower 19a ceases, a valve 14, preventing access to the return pipe 27 is closed by the last movement of the drum 106 of the unit 13a; the resulting pressure opens valve 43 to port 48, pipe 12b and unit 13b. An interlocking device preventing series operation, if any unit is not appropriately set, is also provided. Specification 538,879 also is referred to.