Capstan, Patent Model

Description
The Smithsonian collected this capstan model from the Patent Office in 1926 without documentation of its maker or patent date. Of the 85 capstan patents granted in the U.S. between 1790 and 1895, it matches the drawings and specifications of an 1886 design by Frank Allen and Frank A. Grater, and is presumed therefore to be the model they submitted with their 1879 application.
The U.S. Patent Office stopped requiring models as part of patent applications in 1880. Many applications were still in the system when the requirement changed, and many post-1880 patent grants had corresponding models as a result. Frank Allen and Frank A. Grater developed two similar capstan designs for the American Ship Windlass Company of Providence, Rhode Island, in 1879. They submitted patent applications for both at the end of that year. The first design, for a capstan operated by hand cranks, was granted in September 1880, but the second was delayed until 1886, probably because of its similarity to the first design. Both designs were manufactured for many years and fitted aboard vessels throughout the United States.
Allen and Grater's capstans contain an internal arrangement of pawls, ratchets, and compound gears that allows for two-speed operation. When the capstan's head is turned in one direction, the warping drum below it turns in the same direction, but when the head is turned in the opposite direction, "the capstan-barrel will continue in the first direction with less speed, but with greater power." The inventors describe this operation at length. "When the capstan bars are manned and it is found that the power exerted when moving the barrel directly is inadequate, by simply changing the direction in which the men move, the power exerted is increased threefold...." As with many marine patents, improved safety was a key selling point: "The facility of instantly increasing the power without the loss of an instant of time is of great importance on board a ship, the safety of which frequently depends on the instant exertion of power in the capstan greater than the normal power."
Location
Currently not on view
Date made
1886
Associated Place
United States: Rhode Island, Providence
Physical Description
brass (overall material)
Measurements
overall: 10 in x 7 1/2 in; 25.4 cm x 19.05 cm
ID Number
TR.308539
catalog number
308539
accession number
89797
subject
Patent Models
See more items in
Work and Industry: Maritime
America on the Move
Transportation
Data Source
National Museum of American History, Kenneth E. Behring Center

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