CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF SHIPS' WINDLASSES
Year: 1827

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SOWERBY, of Change Alley, Cornhill, in the City of London, Merchant, do send
greeting.
WHEREAS His most Excellent Majesty King George the Fourth, by
His Letters Patent under the Great Seal of Great Britain, bearing date the
Fourth day of July, in the eight year of His reign, did give and grant unto
me, the said Thomas Sowerby, my exors, adññiors, and assigns, His special
licence, full power, sole privilege and authority, that I, the said Thomas
Sowerby, my exors, adñiors, and assigns, during the term of years therein
expressed, should and lawfully might make, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVEMENTS IN THE CONSTRUCTION OF SHIPS' WINDLASSES;" in which said Letters
Patent there is contained a proviso, obliging me, the said Thomas Sowerby,
by an instrument in writing under my hand and seal, to cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, to be inrolled in His Majesty's High Court of Chancery
within two calendar months next and immediately after the date of the said
recited Letters Patent, as in and by the same (relation being thereunto
had) may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Sowerby, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly

page_text: described and ascertained in and by the annexed Sheet of Drawings, and
in the following description thereof, that is to say :-
The first of my improvements in the construction of ships' windlasses
consists in the application of a pall of a peculiar form, to prevent, in a more secure
and effectual manner than has hitherto been done, the return or backwards
motion of the windlass while at work, or to retain it from moving round in the
direction of the weight or strain which it bears; and the second of my improve-
ments in the construction of ships' windlasses consists in a mode of giving addi-
tional security to the windlass, and holding it quite firm and fast when the vessel
is riding at anchor, as will be herein-after described.
Figures 1, 2, 3, and 4 on the Sheet of Drawings exhibit both my improvements,
Figure 1 being a section through the middle of the windlass; Figure 2, another
section through the windlass; Figure 3, a side view of part thereof; and Figure
4, a front view of the whole machine. D, Figures 1, 2, and 3, is my improved
pall, which I call a wedge-pall; it is made in a segment of a circle of about
one quarter of the circumference, and it has teeth somewhat like the teeth of a
ratchet-wheel formed on its concave surface, adapted to correspond with and fit
into the teeth on the rim or ratchet B of the windlass barrel A, as shewn in the
Drawing; the wedge-pall D is at liberty to slide up and down with its back
surface bearing against the pall plate a, a, which is bolted or otherwise
securely fixed against the upright or pall bit C, C; and the pall D is guided
and kept perpendicular in such sliding motion by a pin s, fixed into the pall,
and sliding in grooves formed in the flanges e, e, of the pall plate a, a, see
Figure 3, 1, I, I, in the line of the deck to which the pall bit and other
stationary framing of the windlass are firmly fixed in the usual manner; and L, L,
is a timber fixed firmly to the deck on which the plate b, b, is supported, see the
Figures. When the barrel A of the windlass is at work for heaving the anchor
or otherwise, and is turned round forcibly in the direction of the arrow Figure 1,
the teeth on the rim or ratchet B can slide under the teeth on the wedge pall
D, and the said pall alternately rises and falls perpendicularly or parrallel to the
pall plate a, a, as the rim or ratchet B advances a tooth in its revolution, each
tooth in the wedge pal! D being raised up at the same time by the teeth on
the ratchet B immediately behind it, until the said tooth on the wedge pall
is raised up over the extremity of the corresponding tooth on the rim or ratchet,
and then the tooth on the wedge pall will by reason of the weight of the pall drop
into the next cavity between the teeth of the rim B, advancing to meet it, and
so on for each successive tooth of the rim B, and the barrel A will therefore be
at liberty to move round in the direction of the arrows, Figure I. But when

page_text: the strain is reversed by the windlass bearing the weight of the anchor or other
heavy resistance which tends to impel the windlass barrel in the direction of
the arrows, Figure 2, then by the action of the teeth on the rim B against the
teeth on the wedge pall D, the said rim tends to force the pall D round in the
direction of the arrows, and as the wedge-like shape of the pall prevents its so
moving without forcing the pall bit C away from the barrel, the barrel A will
be held fast and prevented from moving round in the direction of the arrows,
Figure 2. When the windlass is exposed to the strain in the direction of the
arrows, Figure 2, as above described, my improved wedge pall offers a more solid
resistance, and is much more secure than the series of palls commonly used in the
construction of ships' windlasses, as in the latter case each pall only bears upon
one tooth of the rim, whereas my improved wedge pall is in contact with and
offers resistance to every tooth on nearly a quarter of the circumference of tho
rim, and as the strain increases it becomes more firmly fixed, provided the pall
bit remains good, neither is the wedge pall liable to be upset by any reaction
of the barrel, as is the case with the palls commonly in use. I have shewn
my improved wedge pall in the Drawing, a segment of about one quarter of
the circumference of a circle, which is the proportion I consider most advan-
tageous; but it may, nevertheless, be slightly varied as occasion may require,
observing that it should not exceed one quarter of the circumference.
My second improvement in the construction of ships' windlasses intended to
give additional security to the windlass when the vessel is riding at anchor, is
also exhibited in Figures 1, 2, 3, and 4. E, in the said Figures, a toothed
segment adapted to take into the teeth on the rim B in a manner similar to that
already described for the wedge pall, and which toothed segment E I call the
riding chock. Its back surface bears against the pall bit C, as seen in the
Figures, and it is adapted to slide up and down parallel to the pall bit, so as by
such sliding motion to bring the teeth on the riding chock E into or out of
contact with the teeth on the under side of the rim or ratchet B; this is done
by means of a wedge G, which is driven under the riding chock E when it is
desired to bring it into gear with the rim B, as seen in Figure 2, or instead of
the wedge G any other suitable means may be used for raising the riding chock
into gear with the rim or ratchet. The riding chock E in its up and down,
motion slides against a plate b, b, which I call the riding chock shoe; this
plate is bent at a right angle, one side thereof being fixed to the pall
bit C, C, and the other to the deck, see Figure 1; and it has flanges
c, c, projecting from it to retain the riding chock E, and also the wedge G
sideways. Now, when the said riding chock E is wedged firmly into contact

page_text: or gear with the rim B, see Figure 2, during such time as the ship is riding
at anchor the barrel A cannot move in the direction of the arrows, Figure .2,
without forcing the riding chock against the wedge G, nor in the direc-
tion of the arrows, Figure 1, without forcing the said riding chock, against, the
pall bit, (see Figure 2,) and the barrel will, therefore, by such. double
operation or resistance of the riding chock E, be bound fast, and become a
complete fixture with the deck, so long as the fixed supports of the windlass
remain firm. The riding chock E is guided in its up-and-down motion and
kept at all times parallel to the pall bit by a bolt o fixed into it, and sliding in
grooves formed in the flanges c, c, of the riding chock shoe, see Figure 3. The
above-described riding chock is only to be brought into action when the, ship
is riding at anchor, or when some permanent strain is laid on the windlass; but
when the windlass is being turned round to heave the anchor or other weight,
the wedge G is withdrawn, and the riding chock suffered to fall into the
position shewn in Figure 1. The riding chock may be a quarter of a circum-
ference, or nearly a half circumference, or any other suitable proportion, pro-
vided it be such as will allow it to be thrown properly in and out of gear with
the teeth on the rim. Figure 5 is a detached view of my improved wede
pall. When such pall is of very large dimensions I sometimes make it with
open work, as shewn in the Figure 5, in order to diminish its weight.
Figure 6 is a detached view of the riding chock E, also made with open work;
and Figure 7, a front view of the riding chock shoe b, b; c, c, Figure 8, is a
detached view of the rim or ratchet B. It is fitted on the barrel in the usual
manner by wedges driven in around the said barrel between it and the inside
of the rim or ratchet. The teeth on the rim or ratchet B, on the wedge pall
D, and on the riding chock E, may be formed, as in the Drawing, like
ratchet teeth, but rounded at their extremities and at their roots, or they may
be quite round, or of any other suitable shape. The rim, wedge pall, and
riding chock, as also the pall plate and riding chock shoe, may be made of cast
iron, and the wedge G of wood or iron. The side framing or bits and bearings
for the necks of the windlass barrel are constructed in the usual manner.
Note. The windlass shewn in the annexed Drawing is of such proportions
as are suitable for a ship of two hundred and fifty tons burthen, and the
dimensions may be found by measuring them according to the scales on the
Drawing.
I have now described my Invention of certain improvements in the con-
struction of ships' windlasses in such manner as to enable persons conversant
with works of a similar nature to put the same in practice; but the form and

page_text: proportions of the various parts thereof, as well as the materials of which the
same are to be made, may be modified or varied according to the circum-
stances of the case and the discretion of the workman employed to construct
the same, without departing from the essential points of my Invention, as
herein-before set forth and described.
In witness whereof, I, the said Thomas Sowerby, have hereunto set
my hand and seal, the Third day of September, in the year of our
Lord One thousand eight hundred and twenty-seven.
AND BE IT REMEMBERED, that on the Third day of September, in the
year of our Lord 1827, the aforesaid Thomas Sowerby came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Third day of September, in the year of our Lord One