Patent Page

By Staff
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Lloyd Yost and Charles Jahnke, assignors to Fairbanks-Morse, were awarded patent no. 1,096,585 on May 12, 1914. Their invention is a fuel injection system for oil engines, said to maintain a constant combustion chamber temperature, thus providing consiste
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Governing parts exposed on a Model EK engine.
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A simple fuel pump consisting of a body, plunger, two check balls and a return spring
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A Hercules engine with different operating parts, but with the same governor bracket, weights, spindle and shaft as the hit-and-miss.
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An illustration showing how fuel is inducted.

Gas Engine Patents of Note

While most of the general public believes fuel injection is a relatively new concept, gas engine enthusiasts know that fuel injection has been around since as early as the 1880s.

This particular invention, a “Divided-Spray Injection-Engine,” was patented by Lloyd Yost and Charles Jahnke, assignors to Fairbanks, Morse & Co., on May 12, 1914. The patent (no. 1,096,585) sought to “provide a device in which the temperature of the igniter portion of the combustion space is maintained substantially constant regardless of varying loads upon the engine, thereby insuring uniform satisfactory operation of the engine.”

How it Works

As shown in Figure 1, a fuel injector (24) is threaded into the side of the cylinder on a horizontal oil engine. The cylinder consists of an outer wall (10), an inner wall (6) and a water jacket (12) between the two walls.

Figure 2 shows a cutaway of the injector. Oil fuel is introduced through the main oil line (28), passes through a central passageway (30), swirls around several smaller passageways (56) cut into a valve (36), and exits through the tip (34). The injector is spring-loaded (40) and rests on a seat (38) contained within the cap end of the nozzle (32).

To run the engine, the ignition chamber (18) must first be preheated with a torch. Note the ignition chamber is not water-jacketed in order to keep as much heat as possible contained within. Oil fuel is then shot through the injector, exiting at two separate sets of discharge ports (46, 48 – Figure 3). Oil exiting through the upper ports (48) shoots directly into the combustion chamber (8). Oil exiting through the lower ports (46) shoots downward into the ignition chamber, where it is then ignited with the aid of the heat previously applied. The combustion in the cylinder will reheat the ignition chamber as well as the inner cylinder wall so they will remain hot enough to ignite on the next stroke.

Additional Information

The size and number of ports in the tip depended on engine size, loads required, compression ratio, etc. This configuration could be used on either a horizontal or vertical engine; however, the inventor(s) said, “When the device is applied to a vertical engine the igniter chamber is located at the top of the cylinder so it will not become filled with residuals draining into it.” Another advantage to this configuration was that the use of dirt-accumulating splash plates could be discontinued, as the spray from the lower discharge ports was positively injected into the ignition chamber.

Although archaic by today’s standards, you can bet this was very hi-tech in 1914 and helped pave the road for modern fuel injection – something to think about the next time you’re driving your electronically fuel-injected vehicle.

Know of an interesting patent? Contact Gas Engine Magazine at:?1503 S.W. 42nd St., Topeka, KS 66609-1265;

Hercules Engine News

Throttle-Governed Engines

By Glenn Karch

The Hercules throttle-governed models EK through SK engines are certainly not as common as the hit-and-miss models. But, I would not consider them rare. However, there is a certain mystic about them. Illustrated at right (Photo 1) is the typical Model EK engine with the flywheel removed for a better view of the various parts.

To better understand how it all works, several cutaways help us see just what it takes to make it all work.

The illustration in Photo 2 (opposite page) shows all the essential parts. The throttle-governed engine has the same governor bracket, weights, spindle and shaft as the hit-and-miss engines, but the operating parts differ. The governor (7) causes the arm (8) to make the throttle rod (9) pivot, engaging an adjustable link (17) that moves the throttle shaft and butterfly (10). The throttle is in a separate body and each engine size requires a different one. The fuel bowl cutaway shows the internal parts. It shows the fuel pump (11), the fuel pump lever (14), the fuel bowl drain (13) and the attaching fuel lines. With the drain valve shut, it becomes an overflow-type fuel system with the surplus fuel returning to the tank once the fuel is up to the proper level.

The fuel pump shown in Photo 3 is simple – it consists of the body (5), plunger (7), two check balls (2 and 3) and a return spring (not numbered). The pump screws in through the bottom of the fuel bowl. The little circle above the top check ball (3) is a small pin through the plunger to keep the check ball from floating up too high. If the fuel pump becomes badly worn, a small leather washer snugly fit between the plunger and spring will aid the pumping action.

Photo 4 shows the fuel intake part of the system. The fuel adjustment valve (5) fits into the fuel opening (6) and regulates the amount of fuel going through the fuel tube (7). The airflow inlet (1) size varies, depending on engine size.

To start the kerosene engine, all kerosene must be drained back into the main fuel tank and the drain valve must be closed. Through the top opening in the fuel bowl, gasoline for starting must be poured in until the fuel runs into the overflow. With the fuel valve turned on, the engine is started on gasoline. Once started and running steadily, the fuel pump will begin to pump kerosene into the fuel bowl, and eventually, the engine will be running on straight kerosene. Near the top of the cylinder head is a fitting and a line to the throttle body. This is to supply a small amount of water to the fuel mixture when the engine is running on kerosene under heavy load and starts to pound.

Glenn Karch is a noted authority on Hercules engines. Contact him at: 20601 Old State Road, Haubstadt, IN 47639;

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