Knox Tractor Unit
In commercial road transportation two great objects to be obtained are low capital investment and low maintenance cost. The Knox Motors Associates have been studying this problem from the road tractor point of view and now announce that in addition to their powerful 8 to 10 ton tractors they are prepared to supply a traction unit which converts a pleasure car into a 3-ton tractor by replacing the rear axle and rear portion of the body of the pleasure car. The company’ xpccts to find a large field for such tractor units in motorizing apparatus in small departments. The 3-ton traction unit is being sold at $550. The unit, together with a used car and fire truck body with rear wheels, make a complete outfit available for departments oi moderate means. The engineers of the Knox Motors Associates have devised a very ingenious method for attaching the traction unit to the pleasure car frame, so that variations in the frame width make no difference in the traction unit. This unit is claimed to be the first device constructed and thoroughly tested out with which a pleasure car chassis can be converted and have a useful load capacity of 6,000 pounds and include the advantages of a road tractor and motor truck. The design embodies the same patented spring suspension as the large Knox tractor, whereby the power plant and the driver are carried on springs suitable to the light load, which also form a substantial cushion, to the driving mechanism against the shocks of starting and stopping. The heavy weight of the useful load is transferred to the traction unit through an entirely separate set of proportionately heavier springs. The necessary gear reduction is accomplished through an internal gear driven rear axle, so that the motor may be run at normal speed and its full power developed under conditions on which its original design was based. This construction gives large capacity with low fuel cost and long tire life, and its maintenance cost is, therefore, exceptionally low. The evolution of this hauling outfit is an exceedingly simple yet interesting change. The old pleasure car is first stripped of its body, from the rear as far forward as the back of the front seat, and the rear axle and’ springs removed. Next the cross channel of the traction unit is slipped over the stripped pleasure car frame, squared up, and after the drilling of four holes in the car frame bolted’ down into place. The propeller shaft is then connected to the internal gear drive axle by means of the special universal joint flange, furnished with each unit, the brake rod hooked up. The tractor is then ready to operate. If a horse-drawn fire truck is to be used as the load carrier, the front axle with its wheels and pole is removed and the special bolster plate furnished with the unit properly fastened in place. The tractor is then backed under the load carrier, which has had its front end jacked up to permit of this operation, the load carrier lowered into place on the tractor turntable and the completed outfit is ready for immediate service.