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."
Allen and Grater were a draftsman and a foreman, respectively, at the windlass company. Two other models created by the company were donated directly to the Smithsonian in 1883 and 1884.
Frank Allen and Frank A. Grater, Capstan, U.S. patent no. 351,241, Oct. 19, 1886.
Frank Allen and Frank A. Grater, Capstan, U.S. patent no. 231,949, Sept. 7, 1880.
The Providence Directory, 1879