US 357548 A
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W.- L. BRADFORD. 1
ITRESTLE TREE. v w No. 357,548. Patented Feb. 8, 1887 I hue n+0)":
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inclosed by and adjacent to the trestle-tree is:
UN TED STATES PAT NT OFFICE.
\VILLIAM L. BRADFORD,
OF PORTLAND, MAINE.
SPECIFICATION forming part of Letters Patent No. 357,548, dated February 8, 1887.
Application filed September 9, 1886. ScrialNo. 2l3,053. (No model.)
To all whom it incty concern.-
Be it known that I, WILLIAM L. BRADFORD, a citizen of the United 'States, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Trestle-Trees; and 'I do hereby declare thefollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.
My invention relates to trestle-trees such as are used on masts; and it consists in the application to the sides of the mast, or to the interior surfaces of the trestle-tree, where the same come in contact with the mast, of strips of metal or other suitable material, by which an air-space is formed between the mast and the trestle-tree, and by which the water is quickly drained off and a circulation of air assured.
As ordinarily made, trestle-trees are of oak, while the masts to which they are applied are usually of pine. The upper portion of the mast is squared, and the trestle-tree is fitted somewhat loosely around it, its object being to support the cross-trees and the lower end'of the topmast. The mast usually has a taper toward the top, and the trestle tree being square there is formed an open space between the upper side of the trestle-tree and the mast, into which the water runs. This water has no means of discharging itself, owing to the fact that the lower edge of the trestle-tree and the sides of the mast come into close contact. The result is, that that portion of the mast which is the first to decay, necessitating expensive repairs. This portion of the mast has been known to decayim two years time, so that anew top had to be spliced on, the balance of the mast being in perfect condition. The contact of pine and oak when dampness is present is particularly favorable to decay, the oak giving out an acid which acts rapidly on the pine. This decaying of the mast-head is a matter which has caused much trouble to vessel-owners, and to remedy the difficulty it has been quite a common practice to bore a vertical hole down through the center of the mast from the top, extending down to the trestletree, and filling the same with salt-Water or other liquids which impregnate the wood and tend to preserve it. This remedy is quite effcctive when the hole is kept full and is properly attended to; but when neglected the hole is liable to get full of rain-water, thus hastening the decay of the mast.
My invention is illustrated in the accompanying drawings, in which Figure 1 is aperspective View of mast-head, showing trestletree with my improvement. Fig. 2 is a view of trestle-tree disconnected from the mast.
Fig. 3 is atransverse section, one half immediately above the trestle-tree and one half immediately below. Fig. at is a perspective View of portion of mast, .showing venting grooves cut in the shoulders.
A is the trestle-tree, a abeing the sides, and a a the forward and after nuts, as they are called.
B B are strips of metal or other suitable material secured to the four inner faces of the trestle-tree, a sufficient number being used to furnish a good bearing. The lower ends of strips B B do not extend quite to the bottom of the trestle-tree, so that when the latter is put in place on the mast, its lower edge resting on the shoulder 0, there will be a clear space around the mast immediately above the shoulder. As the water runs down between the strips B B it quickly finds its way to the corners of the mast, where it is discharged.
Grooves may be cut in the shoulders c, to vent the spaces formed by the strips B to run off the water and allow the entrance of air. This construction is shown in Fig. 4.
As thus constructed, my trestle-tree allows the water which works in around the mast to pass away quickly, allows the air to circulate within this inclosed space, and it prevents the oak and pine usually employed from coming in direct contact, to the detriment of both woods. I he same result as here indicated can be less perfectly attained by forming corrugations or grooves in the mast itself, or in the inner faces of the trestle-tree, thus forming a space for discharging water and admitting air.
The material which I prefer to use for the strips B is brass or composition, although galvanized iron will do very well.
In place of the strips B running vertically they may run diagonally; or the same result may be attained by the use of small disks, which may be used in sufficient numbers to provide a good bearing and form an efficient air and water space. These strips or pieces B maybe secured to the mast with the same effect as if secured to the trestle-tree.
The grooves cc, formed in the shoulders of the mast-head, may be out at right angles to the grooves, as shown in Fig. 4, or along the lower edge of the plain side. These grooves should be made to connect with the spaces be tween the trestle-tree and the mast-head. The trestle-tree may set on low blocks, and so dispense with the necessity of the grooves c c.
I claim- 1. A trestle-tree having secured to its inner face vertical strips of metal or other suitable material, and thereby forming grooves or spaces between said trestle-tree and the mast head, and a set of grooves or spaces formed between the shoulder of the mast and the un- VILLIAM L. BRADFORD.
S. \V. Barns, WILBUR F. LUNT.