Page:Popular Science Monthly Volume 92.djvu/288

 A Track-Laying Tractor

Its front wheel lays a track and the whole machine turns in a ten -foot circle

���imi^mn

��Above : Plow- ing a field with the aid of the track- laying tractor

��At right: The tractor can easily make a turn in a ten-foot drde

����Above: The shoes are made of steel stampings. They can be provided with projections for very soft ground

��OUT in California, where the small, farm tractor has been more highly developed than in any other part of the world, an unusual tractor has appeared. It has three wheels like many other tractors. But in this case, to give great pulling power, the front or steering wheel is a track-laying wheel. Still, the unusual characteristic of the tractor is not so much the small track-laying unit used as a front wheel, but the manner in which the frame supporting the unit is employed to carry the small automobile internal-combustion engine and its fuel and water tanks. An inverted, U-shap6d casting, attached to the rear of the frame, permits the whole frame, track-layer and engine, to turn as a unit when the tractor rounds a corner.

The top of the U-shaped casting serves as a turning pivot for a goose-neck frame, to which is attached the two rear steel wheels, and the axle to which the plows or harrows employed are attached.

The tractor is further rharacterized by burning the cheap engine distillate so

��commonly used in California in place of expensive gasoline.

In the accompanying illustrations, it can be clearly seen that the engine is mounted as in any automobile, longi- tudinally of the frame, but that it drives the track-laying wheels by means of a two- part, cone-shaped friction gear mounted on the rear end of the extended engine- shaft. The shoes or face of the endless track, somewhat similar to those used on the famous British "tanks," although much smaller, are made of steel stampings. They can be left flat for running over firm roads or they can be provided with angle-iron grousers or projections to grip very soft ground.

The tractor may be used for any kind of farm cultivation. It has a speed of about two rtiiles an hour when pulling a four gang plow. The machine weighs less than three thousand pounds, has an overall length of one hundred and two inches and can turn completely around in a ten-foot circle. Its small size is one of its grentest assets.

��!272

�� �