Patent GB-189820558-A (GB)
Title: New or Improved Construction of Mechanical Stoker, and Means for Controlling same, and Certain Air Supplying Apparatus Used therewith.
Inventor: STONES WILLIAM GRIMSHAW
Filed: 1898-09-29
Granted: 1899-09-02
Abstract: 20,558. Stones, W. G. Sept. 29. Mechanical stoking; air supply &c., regulating.-Relates to the construction of a mechanical stoker, and to means for automatically controlling its action in accordance with the pressure of steam in a boiler to which it is fitted, the automatic regulating-apparatus being applicable also for controlling the supply of air or gases to the furnace in connection with apparatus described in Specification No. 9375, A.D. 1898. Fuel is fed from the hopper 15 to one or more reciprocating boxes 13 which deliver it into one or more fan chambers 7, whence it is ejected by revolving fans as shown. The issuing stream of fuel may be guided by adjustable plates 6 arranged and operated as described in Specification No. 26,983, A.D. 1897. The whole of the mechanism is driven from the fan shaft 9, which is rotated by a pulley with a clutch which can be readily thrown in or out of gear by hand or automatically by the apparatus described below The feedboxes 13 are operated by adjustable mechanism (only partly shown in Fig. 2) as follows:-The shaft 9, by worm gearing, drives a crank or eccentric operating a vertical slotted lever, the throw of which can be adjusted by shifting its fulcrum. This lever operates a transverse bar, which, by a special arrangement of bell-crank levers in the back end of the casing, operates the feed-boxes 13. The point of action of each bell-crank lever on the corresponding feed-box is adjustable, so that the stroke of each box may be independently varied. The fulcrum of the vertical lever may be shifted by a band-screw, or automatically by means of a weighted piston exposed to the varying pressure of steam in the boiler, or by any equivalent apparatus to which it is connected by means of a chain with a spring insertion. After this apparatus has acted to reduce the supply of fuel to the minimum, further movement of the chain (the spring insertion yielding) acts to throw the clutch abovementioned out of gear and stop the stoker altogether. The chain may also operate the cock by which steam is supplied to the air-supplying apparatus. An agitator 17 in each fuel hopper is operated by ratchet mechanism, the ratchet-wheel having teeth on both faces acted on by two pawls on the transverse reciprocating bar which operates the feed-boxes 13, and which moves in a line parallel to the axis of the ratchet-wheel. The fan casing has a hinged door 74 held in position by a spring 75, and a lid 78 is fitted to the top of the feed-box casing. The fire-doors have inspection openings. For lubricating purposes, the feed-boxes each carry a strip of felt adapted to absorb oil or grease, and the recessed floor of the back part of the casing forms an oil well serving also to lubricate the operating-mechanism. The hand-wheels of the various adjusting-screws are furnished with indicating-scales and pointers, and with spring detents engaging notches in the wheels to hold them in position.