AN IMPROVEMENT IN THE CONSTRUCTION OP PADDLE WHEELS FOR PROPELLING SHIPS, BOATS, AND OTHER VESSELS
Year: 1829

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, the
Honorable WILLIAM ERSKINE COCHRANE, of Regent's Street, in the County
of Middlesex, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourteenth day of January, in the ninth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the
said William Erskine Cochrane, His special licence, that I, the said William
Erskine Cochrane, my executors, administrators, and assigns, or such others
as I, the said William Erskine Cochrane, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time and
at all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, and also in all His said Majesty's Colonies and
Plantations abroad, my Invention of "AN IMPROVEMENT IN THE CONSTRUCTION
OP PADDLE WHEELS FOR PROPELLING SHIPS, BOATS, AND OTHER VESSELS;" in which
said Letters Patent is contained a proviso obliging me, the said William
Erskine Cochrane, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be enrolled
in His said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said recited Letters Patent, as in

page_text: and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Erskine Cochrane, do hereby declare that my said Invention is
described and ascertained in manner following (that is to say):
:-
The Drawing Sheet I. hereunto annexed, is a representation of a paddle
wheel for propelling ships, boats, and other wheels, which paddle wheel
is constructed according to my improvement. Figure 1, Sheet I., is a lateral
elevation thereof, and Figure 2 is a section of the same paddle wheel through
the axis thereof. The paddle wheel is composed of two circular rims or
wheels, which are mounted and fixed on the same axis with a set of paddles
disposed around their circumferences, so as to occupy the space between the
two wheels. A, A, is the horizontal axis or shaft on which the whole paddle
wheel is mounted; C, C, are two centre pieces firmly fastened on the axis
A; and D are the arms of the wheel radiating from the centre pieces C, being
fixed into suitable sockets formed in those centre pieces; E, E, are the
circular rims or circumferences of the wheels; they are fastened to the
outer extremities of all the arms D, D, in order to unite them together,
and form a complete wheel; B, B, are two smaller circular rings fastened
to each set of the arms D, to unite the same more firmly to each other,
and thus strengthen each of the wheels. F, F, F, F, Figure 2, are
diagonal braces, each one being fastened at one end to the centre piece
C of one wheel, and at the other end to one of the arms D of the other
wheel, whereby the braces cross each other diagonally, and give so much
lateral strength to both the wheels as will render the compound paddle
wheel firm enough upon its axis to afford a steady support to the paddles
which are disposed around its circumference in the space between the two
rims E, E. Note, the two wheels C, D, E, B, of which the paddle wheel
is composed, may be made with sufficient strength in their arms D, D, and
their rims E, E, to enable each one to stand firm enough upon the axis to
preserve its own place lateraly, without support or assistance from the central
part C of the other wheel, and in that case the diagonal braces F, F, Sheet 1,
may be omitted, as is represented in Sheet 2. Thus far the paddle wheel is
constructed very nearly in the same manner as the paddle wheels commonly
used in steam vessels for propelling the same; and the paddle wheel repre-
sented in the Drawing may be put in motion and turned round with con-
tinuous circular motion by the force or power of a steam engine or of steam
engines, or of men or of animals, applied by the intervention of suitable
machinery to turn the axis A, A, of the paddle wheel continually round in the

page_text: same manner as the paddle wheels commonly or heretofore used are turned
round. It is not necessary to enter more fully into the explanation of the afore-
said parts of the paddle wheel represented in the Drawing, nor of the manner
of applying steam power, or the strength of men or of animals, to turn the same
round, nor of the manner of disposing and applying such paddle wheel on
board ships, boats, cr other vessels, in order to propel the same, whether
within the vessel in a suitable space in the centre thereof, or whether applied
at the outsides of the vessel, or whether applied in the space or interval
between two vessels suitably combined and united together for that purpose,
because those circumstances form no part of my Invention, and they all admit
of many variations & modifications which are well known to persons con-
versant with the construction of steam boats or vessels, being either in
common uso therein, or else being well known as having been heretofore
tried or practised; and where a common paddle wheel is or may be applied,
there a paddle wheel constructed according to my improvement may be
applied with greater advantage. G, G, are the paddles disposed in the space
between the two circular rims E of the wheels. Each paddle G is mounted
upon two pivots a, a, one pivot being fixed fast to each end of the paddle, and,
the two pivots being in a line one with the other, that line passes along the
middle of the breadth of the paddle G. The two pivots a, a, for each of the
paddles, are fitted into suitable sockets, formed either at the extremities of
the arms D, D, of the wheel, as is represented in the Drawing, or else they are
fitted into sockets affixed to the exterior rims E, E, whereby each paddle is
attached to its proper place at the circumference of the wheel, and is poised
upon a horizontal axis around which it can be turned about. On the extreme
end of one or both of the pivots a, a, of each paddle G, a crank or handle H is
firmly fixed, for the purpose of guiding or governing the position of that paddle,
and the pin b at the extremity of each of the cranks II is inserted through
a hole in a circular connecting ring K, which ring connects the pins 6 of all
the cranks H together, and is itself suspended upon those pins so as to have
no other support; its weight therefore causes all the cranks H to hang
perpendicularly downwards at all times, or in a vertical position; and the
several cranks H are so fixed on the ends of the pivots a, a, of the paddles,
in respect to the planes of those paddles, that the planes of all the paddles will
stand in a vertical position or edgeways upwards whilst they are passing
through every part of the circle that they describe during their rotation with
the paddle wheel; for when the paddle wheel turns round, the weight of the
connecting ring K, which ring also turns round together with the rest of the
paddle wheel, causes all the cranks H to hang downwards, so as to retain all the

page_text: paddles in a vertical position. The paddles being thus kept in a vertical position,
their lower edges descend into the water in the most favorable position for enter-
ing the same, that is, edgeways downwards; and when they are down in the
water they act flatways against the water in the most favorable position to compel
the ship, boat, or vessel forwards; likewise in rising out of the water they ascend
edgeways upwards, which is the most favorable position to leave the water. Sheet
2 of the Drawing is also a representation of a paddle wheel constructed according
to my improvement, which paddle wheel is the same in effect and in operation
as the former one; and the same letters denote the same parts; but instead
of the heavy connecting ring K being applied at the outside of the wheel
to the pins of the cranks H, which are fixed on tho ends of the pivots a of
the paddles, either at one or both ends thereof, as before described, the said
heavy ring K is applied to the pins m of cranks R, which are formed at or
near to the middle of the length of the paddles. For this purpose each of the
paddles G, Figure 4, is cut away in the middle part so as to reduce its
breadth merely to a pin m, which pin being firmly fastened by means of
its cranked arms to the two parts of the paddle at each side of the opening
which is cut out, those parts are united together by that pin m, which
nearly corresponds with the lower edge of the paddle. Upon the pin m the
heavy connecting ring K is suspended, having sockets formed all round
withinside of it, as is shewn in Figure 3, to receive the several crank pins m
of all the paddles with which the wheel is provided, thereby uniting them
all together, and by its weight, which is intirely suspended upon the said crank
pins, keeping all the paddles vertical in all cases when the paddle wheel
is revolving. In either case, Sheet 1 or Sheet 2, the connecting ring K is
merely suspended upon the pins b, b, or m, m, of the several cranks H or R,
without any confinement or other attachment, in order that it may by its weight
cause all the paddles to assume the vertical position, as before stated; and the
paddle wheel with my improvement is thereby well adapted for a vessel which
is intended to use sails occasionally, without aid from her steam or other power
and paddles, for whenever the engine or machinery is stopped the connecting
ring K can be very easily raised or hoisted up, by applying any suitablo
purchase tackle, such as is commonly used on board ship, to the upper parts of
the ring at, and thereby the weight of the ring may be taken off from all tho
cranks, whereby, instead of hanging down, they may be brought to a hori-
zontal position; and the ring K being then secured in that position by making
the tackle fast, all the paddles will then stand horizontally instead of vertically,
so as to oppose only their then edges to the water, in which situation they
will not materially impede or retard. the advancement of the vessel through

page_text: the water by means of her sails, although the machinery is not working, nor
the paddle wheels turning round. This is an advantage by my improvement
which could not be obtained if the connecting ring K were confined or
retained, as has been heretofore attempted to be done, by or between rollers,
or by revolving about a fixed excentric circle, so as to allow it to revolve,
but is to keep it in such a position as would cause all the paddles to preserve
a vertical posture. My improvement is to leave the ring freely at liberty to
obey its own gravity when the wheel is turning round, and in so doing the
ring keeps all the paddles properly in their vertical positions. And as to
the dimensions and strengths of the parts of paddle wheels to be constructed
with my improvement, and also the materials of which they are to be
made, no rule can be laid down, because they will vary so much, according
to the magnitude of the ship, boat, or other vessel which is to be propelled,
and thereby and according to the manner in which the paddle wheel or paddle
wheels are to be applied for that purpose, and also according to the power
of the engine or machinery by which the paddle wheel is to be turned round.
All that can be directed is, that the several parts of the paddle wheel must
be made strong enough to endure the strain occasioned by the impelling
power, and by the resistance the paddles have to encounter from the water.
The weight of the heavy connecting ring K must be such as will cause
all the paddles to hang so steadily downwards in the vertical position that
they will not be materially diverted therefrom by the first action of the water
against the lower edge of each paddle when they are descending or entering
into the water in succession one after another; for it is only at that part of
their course that the water will make any considerable effort to disturb the
vertical position of the paddles. When they have descended so as to be
completely down in the water, the resistance thereof acting above the centre
of the paddles as well as below, the same is nearly balanced. What weight
in the heavy connecting ring will produce that steadiness of vertical position
in the paddles will depend entirely upon the resistance, and that will vary so
much with circumstances, as aforesaid, that no rule can be given; but a
competent engineer, taking all the circumstances of any particular case into
consideration, will have no difficulty in determining the proper weight for
the ring. It should be observed that whatever weight that ring may require
to have, it will act by its energy of motion by way of fly-wheel to the
machinery, for its centrifugal force is counteracted by its own form, and cannot
give the paddles any tendency to fly out from the centre, as was the case
when it has been heretofore attempted to load each paddle with a distinct
and separate weight, in order to make it hang down vertically.

page_text: Having now described the complete paddle wheel constructed according to
my improvement, I do hereby declare that my Invention consists in the mode
herein-before described of applying the gravity or weight of a heavy con-
necting ring to cause all the several paddles which are disposed around the
circumference of the paddle wheel to preserve a vertical position during
the rotation of the wheel, in order that they may act more advantageously
in the water to propel the ship, boat, or other vessel, and particularly that they
may enter into and draw out of the water perpendicularly. Tho paddles
being, according to my improvement, kept vertical by means of the weight
of the heavy ring which connects together the pins of all the cranks that
are applied to the several paddles, the application of the weight of that
heavy connecting ring to effect the purpose of keeping all the paddles vertical
without any confinement of that ring constitutes my Invention. And I wish
to be understood that I do not claim the mounting of the paddles upon
centres or axis at the circumference of the paddle wheel, nor the application
of distinct or separate weights to the lower edge of each paddle in order
to keep the same vertical, for that has been tried by me and by others before
the date of my Patent, but without success, because it requires so heavy a
weight to be applied to each paddle to cause it to hang down steadily enough
in the vertical position to enable the paddles to act against the water at
entering the same; but, according to my improvement, the weight of the heavy
connecting ring is suspended by the crank pins of all the paddles so as to
govern them all, and yet it will nevertheless oppose its whole weight to resist
the effect of any effort that may be exerted upon any one of the paddles to
force it from the proper vertical position. Nor do I claim the mounting
of the paddles on centres or axes at the circumference of the paddle wheel
with cranks fixed to each paddle, in order to govern their positions, by uniting
together the pins of all those cranks by one connecting ring, in order to keep
all the paddles in a vertical position, in any case where such connecting ring
when revolving with the paddle wheel is guided or retained in the position
which will so keep the paddles vertical by any means except that of its own
weight or gravity; which application of the weight of the ring without any
confinement of the ring is, as before stated, the sum total of my Invention.
In witness whereof, I, the said William Erskine Cochrane, have here-
unto set my hand and seal, this Fourteenth day of July, in the year
of our Lord One thousand eight hundred and twenty-nine.
W. E. (L.s.) COCHRANE.

page_text: AND BE IT REMEMBERED, that on the Fourteenth day of July, in
the year of our Lord 1829, the aforesaid William Erskine Cochrane came
before our said Lord the King in His Chancery, and acknowledged the
Specification aforesaid, 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 Fourteenth day of July, in the year of our Lord One
thousand eight hundred and twenty-nine.