Date of Application, 26th Sept., 1890
Complete Specifications Left, 26th June, 1891 -- Accepted, 1st Aug., 1891.
I, John Charles Barron Jarvis of Albert Villa Albert Street, Tayport, Fife, Scotland, Shipmaster do hereby declare the nature of this invention to be as follows:-
This invention relates to certain improved means for bracing the yards in square rigged ships and consists in a combination of two or more sets of drums, of conical form, as will hereinafter appear according to the number of yards which it is desired to bring under control.
As at present practised each yard is braced by itself to the port and starboard sides of the ship. When the ship is sailing and is required to go on a new tack the one side has to be eased off and the other side hauled in by members of the crew.
In this the braces are carried from the yard-arms of the foremast to the mainmast and thence through blocks to the set of drums or winches upon which the hauling will be effected. The number of drums will be according to the number of yards. As example suppose there be six yards on the foremast, viz. lower yard, upper and lower top sail yards, upper and lower top gallant yards and the royal yard. The braces of the first third and fifth yards are carried to the corresponding drums, that is the port brace to the port drum and the starboard brace to the starboard drum. The second fourth and sixth yards are worked by ordinary rope braces as at present, but the yards being all connected together by the sails the pulling round of the lower yards will bring the other yards round also.
The said drums are made conical for the purpose that when the yards are square, that is at right angles to the line of the keel each drum will be half filled by the wire rope brace wound upon it the fixed ends being in each case next the centre. As the yards is slewed the "sum" of the length of the two braces becomes shorter than their "sum" was when the yard was square, consequently the conical drum becomes necessary in order to take up more of the brace hauled in and to give off less of the brace paid out. The drums are held in position by friction pulleys and by pawls so they can be worked together or independently or be adjusted to the required lengths.
The pinion for driving may be toothed as 1 to 5 of the purchase wheel; the cogs connecting the drums are all of the same size and number of teeth so that the drums all make the same number of revolutions.
The coning of the drums must be proportional to the differences in the length of the braces when squared and when slewed. The sizes of each drum or pair of drums must be proportional to the actual lengths of braces governed by distance apart of masts and lengths of yards.
The difference between lower yard drums and third and fifth yard drums must be proportional to the difference in lengths of the respective yards and these gradations can be most easily settled in each case by making cast iron frames preferable with six, twelve or twenty four faces and piecing up with hard wood blocks which can be turned and bevilled [sic] to the required dimensions.
Dated this 26th day of September 1890.
HUGHES, ELI & HUGHES,
76, Chancery Lane, London, W.C., Agents for the Applicant.