IMPROVEMENTS IN THE CHAIN WHEELS USED ON CAPSTANS WINDLASSES, AND OTHER AXES
Year: 1855

page_text: LETTERS PATENT to James Clark, of 25, Billiter Street, in the City of
London, for the Invention of "IMPROVEMENTS IN THE CHAIN WHEELS
USED ON CAPSTANS WINDLASSES, AND OTHER AXES."
Sealed the 12th February 1856, and dated the 26th November 1855.
PROVISIONAL SPECIFICATION left by the said James Clark at the Office
of the Commissioners of Patents, with his Petition, on the 26th November
1855.
I, JAMES CLARK, of 25, Billiter Street, in the City of London, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN THE CHAIN WHEELS
USED ON CAPSTANS, WINDLASSES, AND OTHER AXES," to be as follows:-
This Invention has for its object improvements in the chain wheels used on
capstans, windlasses, and other barrels, in order that chains and chain cables
of several sizes may be worked thereby more effectively than by the chain
wheels heretofore employed. For this purpose, each wheel consists of two
flanches or plates, between which towards the axis of motion is a groove
suitable for receiving the largest thickness of metal of which a chain (to be
worked by the wheel) is composed. Beyond the outer circumference of this
groove there are radial projections, and it is the manner in which these radial
projections are connected together that constitutes the peculiarity of this
Invention. The outer ends of the radial projections on each plate or flauch

page_text: curve,
are at such a distance apart as to receive between them the longest link, and
each two neighboring radial projections on each of the plates or flanches are
connected together by a bearing surface, which is composed of a compound
that is, concave on a radius from the centre of the wheel to the periphery,
and concave between the two neighboring projections. By this arrangement
the groove or hollow around the wheel will be divided into several divisions or
compartments, each suitable for receiving a link of the largest and smallest
sizes intended to be worked by the wheel, as well also as the intermediate sizes
of links; and the links in each case will have a much more extensive contact
and support than heretofore, by reason of the bearing surface, which connects
or is intermediate of each two neighboring radial projections, being of a
compound curve, as above mentioned.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Clark in the Great Seal Patent Office on the 26th
May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CLARK, of 25, Billiter Street, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of November, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Clark, Her special licence that I, the said James Clark,
my executors, administrators, and assigns, or such others as I, the said James
Clark, my executors, 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 "IMPROVEMENTS IN THE
'CHAIN WHEELS USED ON CAPSTANS, WINDLASSES, AND OTHER AXES," upon the
"condition (amongst others) that I, the said James Clark, my executors.or
'administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,
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 James Clark, do hereby declare. the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
This Invention has for. its object improvements in the chain wheels used on
capstans, windlasses, and other barrels, in order that chains and chain cables
of several sizes may be worked thereby more effectively than 'by the chain
wheels heretofore employed. For this purpose, each wheel consists of two
flanches or plates, between which towards the axis. of motion is a groove
suitable for receiving the largest thickness of metal of which a chain (to be
worked by the wheel) is composed. Beyond the outer circumference of this
groove there are radial projections, and it is the manner in which these radial
projections are connected together that constitutes the peculiarity of this
Invention. The outer ends of the radial projections on each plate or flanch
are at such a distance apart as to receive between them the longest link, and
each two neighbouring radial projections on each of the plates or flanches are
connected together by a bearing surface, which is composed of a compound
curve, that is, concave on a radius from the centre of the wheel to the periphery,
and concave between the two neighboring projections. By this arrangement
the groove or hollow around the wheel will be divided into several divisions or
compartments, each suitable for receiving a link of the largest and smallest
sizes intended to be worked by the wheel, as well also as the intermediate sizes
of links; and the links in each case will have a much more extensive contact
and support than heretofore, by reason of the bearing surface, which connects
or is intermediate of each two neighboring radial projections, being of a
compound curve, as above mentioned.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 is a side view of a capstan ring constructed according to my
Invention; Figure 2 is a plan, in section, of the same; Figure 3, a vertical
section, taken at the line 1, 2, of Figure 2; and Figure 4, a vertical section,
taken at the line 3, 4, of Figure 2. a, a, are two flanches or plates of metal,
between which is a groove b, suitable for receiving the metal of which the
largest chain to be worked by the ring is composed; c, c, c, c, are radial pro-
jections, the outer ends of which are at such a distance apart as to receive
the link of the largest chain between them. The radial projections c. c. are

page_text: connected together by bearing surfaces d, d, which are composed of compound
curves, that is to say, they are concave on every radius or line drawn from the
centre of the wheel to the circumference, and are also concave on the circum-
ference of any circle struck from the centre of the wheel.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the exact details described; but what I claim is, the compound curvilinear
form of the bearing surfaces d, d, by which the radial projections c, c, aro
connected, as described.
In witness whereof, I, the said James Clark, have hereunto set my hand
and seal, this Twenty-fourth day of May, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
R. T. SMITH.
JAMES CLARK. (L.S.)