With many of Detroit's newer model offerings being equipped with a continuously variable transmission (CVT), there seems to be an equally increasing amount of information that refers to this as a "new" technology. While it is relatively new to the mass production offerings from Chryselr, Ford and General Motors, the technology itself is not new at all. In fact, CVT technology has been around since the early 20th Century and the actual concept is widely credited to Leonardo da Vinci around 1490. With regard to use in automobiles, many sources credit Dutch car maker DAF with the first use of a CVT with the introduction of their Variomatic transmission in the 1958 DAF 600. Use of a manual forerunner of the CVT, however, can be traced back to the early 1900s.
Patented by John William Lambert in 1904, the gearless friction disk drive transmission first saw production use in 1902 on the Union automobile and in 1905 on both the Lambert automobile as well as the Cartercar. The friction drive transmission is similar to the modern CVT in that both transmissions allow for an infinite number of engine speeds and both mechanically allow all drive speeds, from the lowest to the highest, in both forward and reverse.
The friction drive transmission was based on a large-diameter aluminum disk which was faced with a replaceable aluminum disk of equal diameter. This "drive" disk was attached to the crankshaft, thus rotated at engine RPM. A second, transverse mounted disk which was slightly smaller in diameter and faced with either paper (Cartercar exclusive) or strawboard fibrous rings was used to transfer the engine's power from the drive disk to the rear wheels. The traverse disk was engaged to the drive disk through a foot operated pedal which would set the vehicle in motion. Vehicle speed was then controlled through a combination of engine speed and a hand operated bell crank which controlled the placement of the traverse disk in relation to the drive disk.
Often advertised as the "Car of a Thousand Speeds," the Cartercar required replacement of the paper fibrous rings on the transverse mounted disk approximately every 4,000 miles. At a cost of $5 for this maintenance, the gearless transmission offered a savings of nearly 50% versus the cost for grease packing in a geared transmission, which needed to be performed at a similar interval.
Including the Union and Lambert, as well as those vehicles which later employed the use of a friction-drive transmission such as the Metz and Petrel, none enjoyed the durability or fame of the Cartercar.
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