Patent GB-168140-A (GB)
Title: Mechanical stoker for furnaces
IPC: F23K3/04
Filed: 1920-05-21
Abstract: 168,140. Lower, N. M. May 21,1920. Combined fluid-actuated and mechanical gears. -In a mechanical stoker of shovel type, valve mecha.nism is applied to regulate the intensity of the fuel injection, and also to vary the interval between heavy and light fuel injections, so that in consequence more or less fuel may be supplied with either type of injection. The valve mechanism consists essentially of a main valve, Fig. 5, and a mechanically-operated auxiliary valve, Fig. 8, which is adjustable and controls the movement of the main valve. The main valve is mounted on the casing containing the shovel apparatus, and is in connection therewith through the passage 15 and ports 38 and 38<a>, the former port being the smaller. Pressure fluid is admitted through the opening 37 into the casing 32 which contains the double valve having heads 35, connected by a stem 34, each head having leak ports 36 to admit pressure to the spaces between the heads and the end plugs 39, the movement of the valve and consequently the intensity of the fuel injection being controlled by screwed stops 43 provided with graduated heads 44 and pointers 45 which indicate the position of the stops. The said spaces contain valve centring springs 42 and are connected by pipes 41 and 41<a> to the auxiliary valve which consists of a worm 49 and worm wheel 50 rotated by the main engine, the worm wheel being pierced by a passage 53 which in the course of revolution registers alternately with the ports 51<a> and 52<a>. In Fig. 8, the registration of the port 52<a> with the passage 53 exhausts the left-hand space of the main valve through the pipe 41 and opening 47<a> in the casing 47, thus causing the main valve to move to the left and uncover the smaller port 38. The pressure fluid thus admitted to the shovel mechanism produces a light fuel injection. When the port 51 and passage 53 register, the main valve moves to the right and admits a larger quantity of pressure fluid through the port 38<a> to produce a heavy injection. The boss containing the port 52<a>, Fig. 8, is kept in contact with the worm wheel face by a spring 56 and is rotatable about a central axis by means of a lever 57, which rotary adjustment varies the interval between light and heavy fuel injections, and consequently allows more or less time for fuel to descend from the fuel feeding casing 6 and accumulate on the shovel 8<a>, thus varying the quantity of fuel supplied with either type of injection. Fig. 10 shows a modification of auxiliary valve apparatus having pipes 41 and 41a in connection with a cylinder containing a piston 70 which operates the fuel elevating mechanism shown in Fig. 9. The pipes are so situated that when the piston 70 is to the extreme left, both spaces between the valve heads 35 and plugs 39 are exhausted through the port 70<b>, but when the piston moves to the right in consequence of the admission of fluid pressure behind it the pipe 41 is connected with the pressure supply and the main valve moves to the right and admits pressure fluid through the ports 38<a>, the port 38 opening when the piston travels from right to left. The port 54 serves as an exhaust port for the shovel mechanism when the main valve is centred and the shovel plunger is retracted by the spring 16.