Improvements in sails.
Year: 1895

page_text: Date of Application, 23rd Apr., 1895-Acc pted, 1st June, 1895
Improvements in sails.
I, NATHANIEL GREENE HERRESHOFF, residing at Walley Street, in the Town
of Bristol, in the County of Bristol, and State of Rhode Island, United States of
America, Engineer and Naval Architect, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The invention applies to all approximately triangular sails, as jibs, foresails and
staysails.
Sails are exposed to tensile strains in all directions, but the forces in different
directions widely vary. The greatest strain in a sail of this form practically
coincides with the directions in which it is most important to attain permanence of
dimensions. The parallel cloths in the upper and lower parts of my sail receive
the greatest strains in directions substantially transverse to their lengths, and the
arrangement also attains permanence of dimensions in the same directions. In
the central area the tapering cloths each extend smoothly and continuously across
the sail, and the upper and lower parts are properly joined by continuous seams
which extend quite across, and all oblique junctions, with the weakness, elastic
yielding and liability to shrinkage incident thereto, are avoided.
It is common to manufacture sails from comparatively narrow strips of canvas,
technically cloths, strongly and smoothly sewed together, and much attention has
been given to the arrangement thereof. As sail canvas is usually manufactured it is
stronger and firmer and less subject to stretching and shrinking transversely than
longitudinally of the cloth, and it is desirable to so arrange the strips in sails that
the cloths shall be presented transversely to receive the heaviest strains and to
maintain the most permanent dimensions. Arrangements have been proposed and
tried with more or less success to attain this end, but as heretofore carried out,
such arrangements. have, in triangular sails, been believed to require a diagonal
seam across the sail and oblique junctions of the ordinary seams therewith. There
are objections to such, for the reason, among others, that there is an unavoidable
want of uniformity in the elastic yielding, stretching and shrinking between such
bias junctions and the other portions of the sail. I have discovered that it is
practicable to avoid such angular junctions and attain the desired presentation of
the cloths over a large portion of the sail area, and to present the cloths all in
continuous lengths each extending quite across the sail.
In my improvement, instead of employing the usual diagonal or mitered seam
running across the sail from the clew to the luff, and joining the upper and lower
parts which have the cloths extending in different directions, I make the sail so
that the upper and lower parts are composed of ordinary parallel cloths, joining
them by means of cloths cut tapering, the seams of which radiate from a point or
from several points on or outside the luff of the sail and opposite the clew. From
the edges of these tapering cloths, parallel breadths are joined by sewing or in any
other manner, until the whole sail is completed. These parallel cloths may be
perpendicular to the leech in the upper part and perpendicular to the foot in the
lower part. I prefer arranging them perpendicularly to imaginary lines running
to the head and tack from a point in the sail a little distance inside of the clew.
The invention keeps the weft of the fabric in the general.direction of the greatest

page_text: Fig. 7 is a yacht's stay foresail.
All show the joints plainly marked by single lines. It will be understood that
the joints may be made with double seams, and with all the ordinary or suitable
provisions for strength and smoothness.
Similar letters of reference indicate corresponding parts in all the figures where
they appear.
Referring to Figure 1, I will describe the entire sail area as divided into three
parts, A. indicating the upper portion, and B the lower portion. An imaginary
center line c, a, extends from the head a to a point c near buc considerably within
the clew d. The cloths in the portion A are of full breadth and arranged at right
angles to this line. The cloths in the portion B are similarly of full breadth and
arranged parallel to each other and at right angles to an imaginary line c, b, which
extends from the same point c to the tack.
D is the area of the sail hetween the parts A and B. For this the cloths are
cut tapering and are inserted fan-wise, with their broader ends presented to the
leech and foot respectively, and the narrower ends to the forward edge, the luff, of
the sail.
Modifications may be made without departing from the principle or sacrificing
the advantages of the invention.
In Figure 1 I have shown the taper as converging to a single point considerably
forward of the luff. I prefer such in order to give an attractive appearance, but
this may be varied. Thus the uppermost of the several cloths in the part D may
taper at such rate that if continued the boundaries would come to a point at a
certain distance beyond the luff, and the adjacent tapering cloth may converge at
a different rate so as to come together at a more distant point. Figure 2' shows
such an arrangement.
In Figure 3 the tapering cloths all converge to a single point, as in Fig. 1, bat
the proportions of the sail are different.
In Figure 4, a jib-headed topsail, the area D bears a larger proportion to the
areas A and B, but the arrangement of the gores is the same..
Figure 5 shows the application of my invention to a sail in which the form
departs slightly from the triangular or jib form. In this the area of the part D is
less than in the last.
In Figure 6 the seams in the part D range towards a point which is only a little
outside of the luff rope.
Economy may be attained with my tapering forms of the cloths in the mid
portion by reversing the arrangements of the cloths, cutting sufficient lengths of
ordinary fabric obliquely longitudinally, retaining one selvedge on each portion,
and utilizing both the tapering pieces thus produced by turning one relatively to
the other. This presents the yarns but slightly oblique and may serve for ordinary
use, but in preparing the sails for the best class of yachts, such economy may be
overruled, and the required taper be given by cutting equally from each side of
each of the tapering cloths. For small sails with sufficiently wide material it is
possible to make the part D of a single cloth properly tapered."

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In the manufacture of jibs or other approximately triangular sails, the
combination of a middle portion having tapering cloths arranged fan-wise and
extending each continuously across the sail, with two other portions, one above, in
which the seams are parallel and run across the sail from the leech to the luff, and
the other below in which the seams are parallel and run across the sail from the
foot to the luff, as herein specified.
2. In a triangülar sail manufactured with the seams in the upper portion
extending perpendicularly to a line near the leech and in the lower portion
perpendicularly to a line near the foot, connecting the two portions with a
portion in which one or more tapering cloths are used, arranged radially so as
to fill up the space between the upper and lower portions substantially as herein
specified.
3. A sail in three portions with the cloths extending in different directions, all
constructed, combined and arranged to serve substantially as herein specified.
Dated this 23rd day of April 1895.
ALLISON BROS.,
Agents for the Applicant.