AN IMPROVEMENT IN THE CON- STRUCTION OF WINDLASSES
Year: 1857

page_text: LETTERS PATENT to Albert Demerit Bishop, of Woolwich, in the County
of Kent, Engineer, for the Invention of "AN IMPROVEMENT IN THE CON-
STRUCTION OF WINDLASSES."
Sealed the 20th October 1857, and dated the 23rd April 1857.
PROVISIONAL SPECIFICATION left by the said Albert Demerit Bishop at
the Office of the Commissioners of Patents, with his Petition, on the
23rd April 1857.
'I, ALBERT DEMERIT BISHOP, of Woolwich, in the County of Kent, Engineer,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT
IN THE CONSTRUCTION OF WINDLASSES," to be as follows:-
The object of this Invention is to reduce the friction of the journals of wind-
lass barrels upon their bearings, and thereby to render of avail in the winding up
or letting out of heavy chains or ropes pairs of windlass barrels, over or around
which the chain or rope is to be laid, the chain passing from one barrel to the
other as it is wound up. This system of winding up chain cables has been
proposed in place of the ordinary capstan, as it ensures the steady winding up
of the cable, and prevents any sudden strain, whether lateral or longitudinal,
being put upon it, which strain is due to the slipping of the cable from the
larger to the smaller_diameter of the capstan barrel; the excessive amount

page_text: of friction, however, put on the bearings of the windlass has hitherto rendered
this construction of windlass practically useless. In order to reduce this
friction, I form on the ends or other suitable parts of the periphery of the
two barrels which are intended to receive the chain or rope, a plain cylindrical
surface, and between the barrels (in the same frame) I mount one or more
antifriction rollers, which will bear against the cylindrical surfaces on the
barrels, and rotate with the barrels. The strain, therefore, put on the barrels
by the chain coiled around them at tension, (which strain has a tendency to
draw the barrels together,) will be neutralized by the antifriction rollers, and
thus neither the bearings nor the journals of the barrels will be required to
resist the multiplied strain of the coiled chain or rope.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Albert Demerit Bishop in the Great Seal Patent Office on
the 23rd October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALBERT
DEMERIT BISHOP, of Woolwich, in the County of Kent, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of April, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Albert Demerit Bishop, Her special license that I, the said Albert
Demerit Bishop, my executors, administrators, and assigns, or such others as
the said Albert Demerit Bishop, my execntors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "AN IMPROVEMENT IN THE CONSTRUCTION OF WINDLASSES," upon the con-
dition (amongst others) that I, the said Albert Demerit Bishop, by an instru-
ment in writing under under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be perform, and cause the same to be filed in the Great
'Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Albert Demerit Bishop, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
The object of this Invention is to reduce the friction of the journals of
windlass barrels upon their bearings, and thereby to render of avail for the
drawing in or letting out of heavy chains or ropes of pairs of windlass barrels,
mounted in one and the same frame, and over or around which the chain or
rope is lapped, the chain passing from one barrel to the other, in the act of
drawing in or slackening off. The adoption of this system of winding up
chain cables has already been proposed in place of the ordinary capstan, as it
possesses the advantage of ensuring the steady winding up of the cable, and
prevents any sudden strain, whether lateral or longitudinal, being put upon it,
which strain is due to the slipping of the cable from the larger to the smaller
diameter of the capstan barrel; the excessive amount of friction, however,
put on the bearings of the windlass by the grip of the coiled rope or chain
on the barrels has hitherto rendered this construction of windlass practically
useless.
In order to reduce this friction I adopt the arrangement shewn in the
accompanying Drawing, which shews my improved windlass in front elevation
at Fig. 1, and in cross section at Fig. 2. a, a, are grooved barrels, mounted
in suitable bearings in the standards b, b. On the periphery of the two barrels
a, a, which are intended to receive the chain or rope, I form plain cylindrical
surfaces a, a. These plain surfaces are intended to press against antifriction
wheels or rollers c, c, which are mounted on a shaft d that turns freely in self-
adjusting bearings carried by the standards b, b. The strain, therefore, put on the
barrels by the chain coiled around them at tension (which strain has a tendency
to draw the barrels together) will be neutralized by the antifriction wheels,
and thus neither the bearings nor the journals of the barrels will be required
to resist the multiplied strain of the coiled chain or rope. The windlass must
of course be provided with the usual appliances for giving the barrels rotary
motion, and also for preventing the back draft of the chain so long as it is
required to be kept taut.
Having now set forth the nature of my Invention of an improvement in
the construction of windlasses, and explained the manner of carrying the same
into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim relieving the journals and bearings of capstan barrels.

page_text: of undue strain by the interposition of antifriction wheels or rollers, as above
described.
In witness whereof, I, the said Albert Demerit Bishop, have hereunto set
my hand and seal, the Twenty-third day of October, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. D. BISHOP. (L.S.)