Driving - Belt

The belt-drive or driving-belt transmits power from one wheel to another, and produces continuous rotary motion. It existed as early as the first century BC in China. It is attested by a passage in Yang Hsiung's book, Dictionary of Local Expressions, of 15 BC. It was developed for use in machines connected with silk manufacture, especially one called a quilling-machine, which wound the long silk fibers on to bobbins for the weavers' shuttles. These machines featured a large wheel and a driving-belt and small pulley. The machines are mentioned again in the book Enlargement of Literary Expositor compiled between 230 and 232 AD.

The Driving-belt was essential for the invention of the spinning-wheel. The belts could run not only round normal wheels with rims, whether grooved or not, but also round rimless wheels. A rimless spinning-wheel may sound a contradiction in terms, and the use of a driving-belt with rimless wheels might at first seem an impossible. But in fact a cat's cradle of fibers strung between wheel spokes which protrude slightly or exist in two sets placed in alternation can create an entirely adequate nexus for a belt.

Needham photographed just such an archaic spinning-wheel in use in Shensi in 1942. It is extraordinary to think that the spinning-wheel of 1270 survives unchanged into the modern era. Yet another DChinese technique of using a driving-belt with a rimless wheel is to mount grooved blocks at the ends of the spokes, and run the belt through the successive grooves.

A refinement of the driving-belt is the chain-drive, invented in China in 976 AD. A chain-drive is essentially a driving-belt which instead of being solid is a chain into the ilnks of which fit sprockets on the wheels around which it is wrapped.

The driving-belt was apparently imported to Europe as part of the technology of quilling-wheels and spinning-wheels introduced into Italy by travelers returning from China. The oldest actual representation of a driving-belt in remained extremely rare in Europe until the eighteenth and nineteenth centuries, indicating that Europeans did not appreciate the potential of this particular element of the Cinese texxtile machines for other purposesto any siginificant degree for mroe than three centuries. Flat belts and wire cables as driving-belts in Europe only began to be used in the nineteenth century.