Lincoln Motor Car Works

Lincoln Motor Car Works was an automobile company in Chicago, Illinois. It produced cars for Sears Roebuck from 1908 until 1912. Nine models were offered, priced between US$325 and $475, with the Model L advertised at $495 complete. They were sold by mail, out of the Sears catalog. Sears had a very lenient return policy: cars were sold on a ten-day trial basis.

The cars had an air-cooled, two-cylinder, horizontally opposed engine, similar to that later used on BMW motorcycles. The engine was located under the floorboards, beneath the driver’s feet, and started from a hand crank in the front. Early cars were rated at 10 hp, and later models developed 14 hp. At least one of the engines used was a Reeves Model P.

In the interest of simplicity, all models used a friction-drive transmission. A roller (a metal wheel with a rubber surface vulcanized to increase its grip) on the front sprocket shaft was pressed against the machined rear surface of the engine flywheel, thus driving the sprocket shaft, the drive chains and the rear wheels. Moving the shift lever set the drive roller to various positions on the flywheel, either nearer the center or nearer the edge, effectively changing the "gear ratio" for climbing hills or driving on level roads. Moving the roller past the center point spun it backwards to give reverse gear. The front sprocket drive shaft was free to slide forward and backwards slightly, just enough to allow the roller to move away from the flywheel. The "clutch pedal" worked differently from most other cars, in that the operator had to hold their foot on the pedal to keep the roller pressed against the flywheel (the catalog claimed that the weight of the operator’s foot was sufficient to provide forward motion). Removing the foot from the pedal allowed the roller to spring back from the flywheel, effectively providing "neutral" so the car could be cranked without moving forwards.

The engine was lubricated by an "oiler", essentially a tank mounted under the seat which had several adjustable drip feeds with separate lines to the engine bearings and other areas. All components of the transmission were exposed, so several bearings and pivots had to be oiled or greased manually from time to time.

A form of differential action was obtained by building each front drive sprocket with a two-way clutch. These clutches engaged when the shaft upon which they were mounted turned in either direction, but disengaged when the wheel turned them faster than the shaft. When driven in a straight line, both clutches would engage, and provide power to both rear wheels. When the car went around a corner, the outside wheel turned slightly faster than the inside wheel, disengaging the sprocket for the outside wheel, and propelling the car with the inside wheel only. On slippery roads, such as in deep mud, snow, or sand, if one wheel lost traction the other wheel would continue to pull, allowing the car the continue moving until either both wheels found traction once more, or both wheels lost traction completely. Because the cars were very light weight, they were capable of being driven through mud or snow which would immobilize heavier cars with conventional differentials.

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