Compound Axis in Peritrochio.

Made:
circa 1700-1751 in London
maker:
George Graham
Compound Axis in Peritrochio. Compound Axis in Peritrochio.

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Science Museum Group Collection
© The Board of Trustees of the Science Museum

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Compound axis in peritrochio

The principle of the wheel and axle (the lifting of a large load by a much smaller one) is utilised in the windless and capstan. This object illustrates how, by the addition of a pair of gear wheels, a greatly increased mechanical advantage can be obtained.

A small weight is supported by the string wrapped around the brass pulley, of diameter 2 inches; the steel axle of this wheel also carries small pinion of eight teeth, which engages with a larger brass cog, having forty teeth. This larger cog has a steel axle, of diameter ¼ inch, around which is wound the cord supporting the large weight. The mechanical advantage of the compound system mis 40, whereas without the gearing a value of only 8 would be available.

Details

Category:
King George III
Object Number:
1927-1873
Materials:
brass, steel, mahogany (wood) and cotton (fibre)
Measurements:
overall: 490 mm x 253 mm x 200 mm,
type:
scientific instruments
credit:
King's College, London