IMPROVEMENTS IN AND RELATING TO SAILS FOR SHIPS AND OTHER VESSELS, APPLICABLE IN PART TO OTHER PURPOSES WHERE SHEETS OF CANVAS OR OTHER TEXTILE MATERIAL ARE USED
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by James Capper at the Office of the
Commissioners of Patents on the 4th June 1883.
JAMES CAPPER of Liverpool in the County of Lancaster
'IMPROVEMENTS IN
AND RELATING TO SAILS FOR SHIPS AND OTHER VESSELS, APPLICABLE IN PART
TO OTHER PURPOSES WHERE SHEETS OF CANVAS OR OTHER TEXTILE MATERIAL
ARE USED
"
The canvas or other cloth of which the sails for vessels are made, continually
stretches as the sails are used, and tightened in position, and often when old the
sails extend greatly beyond their original limit, and although many means have
been tried, I do not know of any way in which this stretching has been successfully
prevented or compensated for. The great objection to mariners of this stretching
of the sail, is, that it is very difficult to get the sail spread flat to the wind,
without having a
bag" in it.
"
My invention is designed with the object of furnishing a sail of any ordinary
shape, which will at all times be more easily spread flat, and consists in introducing
into the sail near its foot, a rope so placed that it will approximately form the arc
of a circle. Along the "tack" of the sail I place a band in a position similar to
that of the rope in the foot of the sail, which prevents the stretching of the sail in
that direction; a similar band may also be placed along either side or edge of the
Sail. Where the strain is great, a rope may be used instead of the band.
25
"
"
In carrying out the invention, I make the sail leaving it hollowed out between
the "tack" and the clew ог "sheet", the bottom of this part of the sail
forming the path which I intend the rope to take. I then sew together the parts
which it is intended shall form the foot of the sail, the top part of this corresponding
in contour with the bottom part of the sail already cut.
Between these two parts
and to each of them I sew the rope, its one end being made fast to the "tack
and its other to the "clew of the sail. The position of this rope will be such
clew,"
that it would form with a straight line drawn from the "tack" to the
the segment of a circle. The other sides or edges of the sail may be cut straight
or curved outwards, that part which comes in contact with the masts and yards
being preferably straight, and the free edges being made curved outwards to gain
greater area of canvas.
"

page_text: I do not confine myself to one rope only, as a second or third may be introduced
into the sail if desired or found necessary.
For reefing the sails, I can by this invention do away with the necessity of
having double reef points, and at the same time provide a simpler and quicker
method of reefing. In a sail where two or more of the before described curved or
circular ropes are placed along the foot, I attach one end of each "reef point" (rope
used for tying up the sail) to the curved rope, and pass it up at the back of the
sail over the next curved rope above and through a hole or eye in the sail. By
pulling or tightening the several reef points along the length of the sail, the lower
rope is raised up to the one next above it, or to the one over which the reef points
pass. These are then made fast by a "half-hitch" and the sail reduced to the
size required. This method of reefing or shortening sail will be found very
convenient during rough and stormy weather, as the operation may be performed
much more quickly than by the present method.
The circular or curved ropes which I have described as attached to sails, I find
are also applicable to other purposes where sheets of canvas or other textile
material are used, and where it is an advantage to prevent stretching in any
particular direction, such for instance as tents, rick-covers, window blinds,
et cetera.