THE CHARTER GAS ENGINE
Fig. 1 The Charter Gas and Gasoline Engine.
Reprinted from The Engineer magazine, April 1, 1905 issue, submitted by Richard Mock, 159 Dirkson Ave., West Seneca, New York 14224.
The Charter engine is of the four-cycle type and is built for electric lighting, factory, hoisting and portable service, specially arranged units being provided for pumping, one for deep well and the other for tank duty. The general appearance of the horizontal stationary engine is shown in Fig. 1. Various arrangements of engine, fuel tank, etc., may be adopted to meet the requirements in individual cases. One of the more convenient plants is shown in Fig. 2, in which the tank is buried, with pipes extending to the surface of the ground for filling, drawing out and the return of the overflow from the engine. The gasoline is drawn from the tank by a pump geared to the main shaft and is forced into the standpipe from which it is admitted into the air pipe, N, through the nozzle, H. The flow is regulated by the throttle valve, A, the over-flow returning to the supply tank through the vertical pipe running parallel to the standpipe. Gasoline can reach the cylinder of the engine only when the plunger, G, is opened, which occurs only during the suction stroke of the engine, when the spray will be drawn up to the valve, B, and carried into the cylinder with the air supply. When the engine is above speed so that no gasoline is desired, the governor prevents the plunger, G, from opening, thus isolating the gasoline from the air except at the time when it is carried to the cylinder. This reduces the chance for an explosion to practically nothing.
Valve B is of the poppet type and works by suction to admit the charge of air and gas or gasoline. When hot-tube ignition is used, the fuel for this is supplied from a separate tank, I, from which it flows by gravity. This tank may be in any convenient position, but should be placed at least four feet above the burner. The air pipe, N, is turned at right angles and carried inside the base of the engine to prevent picking up dirt and dust from the air of the room.
Electric igniters are furnished with each engine, and also battery, spark coil and switch, or, if desired, the battery may be replaced by a small dynamo at a slight additional cost. The dynamo, which is shown in Fig. 3, is arranged so that when the flywheels are turned by hand the speed of the dynamo will be sufficient to make a good spark. This obviates the necessity of using a primary battery in order to start the engine. When the engine is running at its regular speed the dynamo pulley is brought in contact with the rim of one of the flywheels just enough to maintain the speed of the dynamo for which the governor is set. With this arrangement the possibility of damage due to excessive speed is eliminated.
The exhaust from the cylinder is controlled by the valve, D, Fig. 2, which is operated by a cam from the geared shaft. The arrangement of the exhaust, and also the circulating pump mechanism, is indicated in Fig. 4.
Fig. 5 shows the arrangement of the plant when viewed from the head end of the cylinder, the cooling water for the cylinder being supplied from a water tank. A small pump shown in Fig. 4, is driven by an eccentric attached to a side shaft on the engine frame opposite the valve gear, which shaft is driven by a sprocket chain from the main shaft of the engine, and takes water from the bottom of the tank and forces it into the lower part of the cylinder jacket. The water rises through the jacket and returns to the tank through the upper pipe. The sprocket chain is made the breaking piece in this arrangement, so that in case of stoppage of the pump the chain will be the part to give way.
A drain valve should always be provided below the level of the pump, so that when the engine is not is use, the jacket and pump maybe entirely drained. Then if the suction pipe is slightly inclined toward the water tank, an air cock in the suction pipe will allow all the water to flow back into the tank when emptying the latter. The governor, which is seen in Fig. 1, is of the centrifugal type and operates the rod of the pump, G, Fig. 2. The plunger, G, is driven by a vertical lever seen in Fig. 2, which is moved by a cam on the geared shaft. This vertical lever strikes a projection on the horizontal rod connected to the bell crank, which operates the plunger, G, and the governor swings this side rod out, so that the vertical lever does not come in contact with its striking piece when the engine does not need to take a charge.
The arrangement for starting consists of the match striker and air pump shown in Fig. 6. This is used on engines of 20 horsepower and over and on portable engines of like sizes. The pump, which is worked by hand, compresses air and gasoline in the combustion chamber of the cylinder and this mixture at the proper time is ignited by a match which is placed in the match striker. For the smaller sizes this device is not found necessary.
The cylinder and base of the engine are cast separately, so that in case of accident to any part of the frame or cylinder, only the broken part need be replaced. The exhaust is carried into a muffler to deaden the noise and to keep down the back pressure.
Both ends of the connecting rod are adjustable for taking up wear. The wearing surfaces are large and carefully scraped to a good bearing, thus reducing wear to the minimum. In the vertical engines a single flywheel is used, as this allows of putting more weight in the rim, which is the effective part of the wheel. For the horizontal engine two wheels are used. The principal difficulty when starting a combustion engine is often with the compression before a stroke can be obtained. To over-come this difficulty, a relief valve is placed on top of the cylinder, as indicated in Fig. 2.
The smaller sizes are of the vertical type, as this is somewhat more economical of space and affords a more convenient arrangement. For the horizontal type, engines are made from 4 to 40 brake horsepower. All engines have the same construction as to valve and pump mechanism, but different arrangements of frame are adopted for engines to be used for pumping and for portable work; the principle, however, is the same.
The Charter Gas Engine Co., Sterling, Illinois is the builder.