Puleggia della stazione a valle della funivia del Renon

A bullwheel or bull wheel is a large

wheel A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be ...

on which a

rope A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarl ...

turns, such as in a

chairlift An elevated passenger ropeway, or chairlift, is a type of aerial lift, which consists of a continuously circulating steel wire rope loop strung between two end terminals and usually over intermediate towers, carrying a series of chairs. Th ...

or other ropeway. In this application, the bullwheel that is attached to the

prime mover Prime mover may refer to: Philosophy *Unmoved mover, a concept in Aristotle's writings Engineering * Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy ...

is called the drive bullwheel, and the other is the return bullwheel. One of the bullwheels is usually attached to a cable tensioning system, which is usually either hydraulic or fixed counterweights. A double-grooved bullwheel may be used by some ropeways, whereby two cables travelling at the same speed, or the same cable twice, loop around the bullwheel. The bullwheel began use in farm implements with the

reaper A reaper is a farm implement or person that reaps (cuts and often also gathers) crops at harvest when they are ripe. Usually the crop involved is a cereal grass. The first documented reaping machines were Gallic reapers that were used in Roma ...

. The term described the traveling wheel, traction wheel, drive wheel, or harvester wheel. The bullwheel powered all the moving parts of these farm machines including the reciprocating knives, reel, rake, and self binder. The bullwheel's outer surface provided traction against the ground and turned when the draft animals or

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commo ...

pulled the implement forward.

Cyrus McCormick Cyrus Hall McCormick (February 15, 1809 – May 13, 1884) was an American inventor and businessman who founded the McCormick Harvesting Machine Company, which later became part of the International Harvester Company in 1902. Originally from the ...

used the bullwheel to power his 1834 reaper and until the early 1920s when small

internal combustion engine An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal co ...

gasoline engines like the Cushman MotorBreaking the Land: The Transformation of Cotton, Tobacco, and Rice Cultures Since 1880 began to be favored.

References

Mechanical engineering Aerial lifts {{Tech-stub