Patent Page

Fairbanks Fuel Injection

| October 2005

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.