CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OP PADDLE WHEELS
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
CARTWRIGHT, of the Dean, near Broseley, in the County of Salop, Farmer,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Eleventh day of January, in the eighth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said Henry
Cartwright, Her especial license, full power, sole privilege and authority, that
I, the said Henry Cartwright, my executors, administrators, and assigns, and
such others as I, the said Henry Cartwright, 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 mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, and in all Her Majesty's Colonics and Plantations
abroad, and in the Islands of Guernsey, Jersey, Alderney, Sark, and Man, my
Invention of CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OP PADDLE WHEELS;"
in which said Letters Patent is contained a proviso obliging me, the said
Henry Cartwright, 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
inrolled in Her Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
lace anyone

page_text: NOW KNOW YE, that, in compliance with the said proviso, I, the said
Henry Cartwright, do hereby declare that the nature of my said Invention,
and the manner in which the same, is to be -performed, is particularly
described and ascertained in and by the following description thereof, refer-
ence being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon, that is to say :-
..
These improvements in the construction of paddle wheels for propelling boats
and other vessels on water are designed to avoid those objections, from loss of
power in the ordinary propelling wheels having fixed radial paddles, which are
found to arise from the resistance of the surface of the water against the broad
face of the paddle on its immersion, which takes place when the paddle is
somewhat horizontal or in a flat position, and the necessary lifting of a volume
of water, from the flat position of the paddle, on its immersion after having
performed the propelling stroke. To correct these evils I so attach to or
mount my paddles in their revolving frame or wheel that each individual
paddle shall be capable of turning upon an axle, in order that it may be made
to enter and leave the water. in nearly perpendicular positions, as will be seen
by the accompanying Drawing.
Fig. 1 represents. a side elevation of my improved paddle wheel; Fig. 2 is
a front view of the same.. A. circular rim a, a, a, having radial arms extending
from the centre like a wheel, carries the paddles b, b, b, eight in number, and
also the machinery by which they are worked. Two of these circular rims or
wheels a are fixed parallel to each other upon the main shaft or axle A, and
which, being braced together. by transverse and diagonal bars, constitute the
rotary frame of the propelling apparatus. The paddles b, b, b, (one of which
is shewn detached, and upon an enlarged scale at Fig. 3, and another slightly
differing in its construction at Fig. 4,) are mounted in the two parallel rims a, a,
upon axles or shafts c, c, which turn in the rims parallel to the main shaft A.
From each of the paddles b, a stem d, coincident with the plane of the paddle,
extends inwards, by means of which stem the position of the paddle turning
upon its axle or pivots c, c, is to be determined. A circle of teeth B, B,
concentric with the axle A, is firmly fixed to the side of the vessel or.. to the
paddle box by lugs or other suitable means; and there are a series of toothed
wheels e, e, e, each having the same number. of teeth as the concentric B taking
into it, the pivots of the axles or shafts of which wheels c, e, e, turn in braces or
stretchers f,f,f, aflixed to the radial arms of the frame wheels. From each of
the shafts or axles of the wheels e, a crank g, g, extends (seen in the detached
Figs. 5), which crank passes through a long slot or opening in the stem d of
the paddle. It will now be perceived that on the paddle frame or carrying

page_text: wheel a, a, a, being made to revolve by the turning of the main shaft A, the
wheels c, e, c, will be carried round with it as planet wheels, by which means
the wheels e, c, e, taking into the stationary rim of teeth B, will all be made to
turn upon their respective axes, and their cranks g, acting in the slots of the
stems d, will, by sliding along the slots of those stems, force all the paddles b, b, b,
as they come round into the several positions shewn at Fig. 1, bringing the
paddle nearly perpendicular which is entering the water, and also that which
is leaving it.
Having now described the construction of my improved paddle wheels, and
the manner in which I cause them to act, for the purpose of avoiding the
objection that ordinary paddle wheels are subject to, I wish it to be under-
stood that I do not intend to confine myself to any particular number of
paddles which may be so mounted in the carrier wheels or circular framing;
but observe that, when more than five paddles are so combined, I do not place
the planet wheels all in the same plane, as they would then interfere with
each other, but I place them at a little distance laterally apart; and in order
that they may all take into the teeth of the stationary rim B, I make that rim
much broader than the wheels, so that its breadth may extend to the situations
of and take in all the wheels e round its periphery. The same parts of the
machinery in the several Figures are all marked with the same letters of
reference; but in Fig. 1 some portions of the crank wheels are omitted that
the concentric wheel may be more plainly seen. The cranks g by this arrange-
ment will, as the carrier wheel revolves, cause the paddles to make independent
revolutions on their own axes, the rotation of the wheels e, c, e, continually
changing the positions of the cranks, which, by passing through the slots in
the stems of the paddles, will cause the paddles to vibrate on their axes,
and to take the most desirable positions for propelling without waste of power.
The crank of each paddle, with its cog wheel, must be so arranged that the
throw of the crank must be at its lowest point of rotation when vertically
coincident with the main shaft; for then, if the paddle wheel be turned round
a distance equal to forty-five degrees of a circle, the lower vertical paddle will
be brought into the position that it would take a little after entering or a
little before leaving the water, as may be seen by the positions of the paddles
in Fig. 1; for it will be perceived that, while the carrier wheel a, a, a, rotates
forty-five degrees, the vertical crank g will have travelled through ninety
degrees, and will then be in the horizontal plane, and by its control over the
stem d the paddle will by that means be brought to a considerable angle
above a radial line drawn from the centre of the wheel. The paddle b, being
in a line with its stem d, will thus, at the time of entering the water, be

page_text: brought into a position as nearly vertical as may be desired, which will
obviate the loss of power occasioned by the pressure of the water attendant
upon the use of radial paddles. The paddles in my improved plan, it will be
seen, are all quite vertical or radial at the point of their greatest immersion,
and will rise from the water in favorable positions for cleaning themselves,
and no one of the paddles will be again in a radial position till it arrives at
the top of the wheel, after which, as it descends, it will gradually turn upon its
axis, and by the time it arrives at the water be in a favorable position for enter-
ing it. The fixed concentric wheel which is marked B, in Figs. 1 and 2, is made
wide on the rim, as seen, to afford room for all the planet or crank wheels e to run
round its periphery; because, when any number of paddles, with their cranks
and wheels, more than five are used, the crank wheels cannot follow cach
other in the same plane or track.. These wheels e may be made very light
and narrow, and may be all cast by the same pattern, with the boss or centre
projecting on one side, but not on the other; and then; if they are put on the
square ends of the cranks with the projecting parts of the bosses or centres
alternately, towards the right and left, as shewn at Fig. 5, the wheels will
work clear of each other, as the crank wheels must be made narrow or thin
for the sake of lightness, they having but little strain to support, and as they
will be required to run in two tracks on the centre wheel, the cogs must
be made of a coarse pitch, in order to obtain strength, and enable them to be
more than usually long to prevent the possibility of their slipping. The con-
centric wheel may have lugs or ears cast upon it, as shewn at Figs. 1 and 2,
to secure it to the side of the vessel or to the framework of the paddle box,
or it may, without having any permanent means of fixing; have a centre with
a cylindrical opening just large enough to allow the main shaft to turn freely
within it, and be supported or carried by the main shaft, and then, by means
of a lever attached to the concentric wheel, as shewn 'at Fig. 8, where B is the
concentric wheel, and C the lever, or by any other well-known means, it may
be turned a little way round in either direction, so as to occasion the paddles
to dip or approach a vertical position more at entering the water than at
leaving it, or more at leaving it than at entering, as shall be found most
desirable for propelling under either usual or varying circumstances, and be
there temporarily fixed. I do not limit myself to any particular material to
make my paddles; but I propose sometimes to make them of plate iron, and
in that case I rivet two pieces of plate iron together lengthwise, with consider-
able breadth of lap; but previous to being rivetted together, a slip or narrow
part, along the middle of that part of each plate which is to form the rivetted
lap, is bent into the form of a chanuel of half circular section, the other part

page_text: of the plate retaining its original plane. The two plates being put together
with the two channels facing each other, and the flat or plano side of one
plate projecting in an opposite direction to that of the other, the rows of
rivets are put in on cach side of the channels. The two channels now form a
pipe, through which a round bar is to be passed, and this bar is to form the axis
whereon the paddle vibrates. A paddle on this method of construction, but not
quite finished, is shewn at Fig. 3 on an enlarged scale, the round bar which
forms the axis passing through it, longitudinally. End views of the plates, before
and after they are put together, are shewn at the left hand of Fig. 3. Or the
paddle may be made of a single plate, in which case I propose to make a
series of short cuts through the plate in a row, the cuts being, in the direction
of the cross section of the plate, but the row in the direction of its length,
and at or near the middle of its breadth. The parts of the plate between the
cuts are bent out alternately on opposite sides, so that a round bar, which is
to form the axis, may be passed up between them. The method of making a
paddle in this manner is shewn at Fig. 4 on an enlarged, scale, with the
spindle passing through it, an end view being shewn at the left hand of
Fig. 4; or the paddle may be made of a single plate, having staples; loops,
or bent iron straps along one side to contain the spindle. Near each end of
the paddle a narrow piece is to be cut out, extending from the inner edge
of the paddle down through the tubular part, which is to contain the.axis, as at
a, a, Figs. 3 and 4. These slits are to allow the rims of the carrying wheel
a, a, to pass through them when attached thereto, there. being holes through
the rims on opposite sides of the wheel properly bushed or defended, in which
the axis of the paddle is to have its bearings; the openings on.the inner edgo
of the paddle, where the slips are taken out, will allow the axle to come
opposite the holes in the rims. The axle is then passed up the pipe or part
which is to contain it, and through the bearings in the rims. The breaches
in the paddles are afterwards closed by having pieces of iron of sufficient size
secured over them with rivets, screws, or short screw pins, as shewn at w in
Figs. 3 and 4. Sometimes I propose to make the paddle of wood, and
strengthen it with iron where it is required; but of whatever material or
materials the paddle is made, I prefer that the axis, spindle, or gudgeons upon
which 'it vibrates should be near the middle of its breadth, in order that the
resistance of the water against the paddle may, be balanced across its axis or
centre of vibration, so as to prevent much leverage or strain from being
thrown on the stem of the paddle or on the crank; but if the points upon
which the paddle vibrates be something nearer the outer than the inner edge
of it, the resistance of the water against it will be balanced with greater nicety,

page_text: because the outer edge will travel through the water something faster than the
inner edge, and the resistance of the water to the outer part of the paddle will
consequently be the greatest for a given area. The parts of the paddles to
which the stems I are attached may be thickened out with pieces of wood
to fill the space between the plate and the ends of the parallel bars of which
the stem is made, and the whole must be secured well together, as shown at
Figs. 3 and 4; but any other material to fill in with besides wood may be
used, or any other suitable method of effectually securing the stems to the
paddle may be adopted. Instead of making the stem of the paddle with a slot
within it, as first described, for the neck of the crank to travel in as it revolves,
I sometimes make the stem of a single solid bar, and in that case there is a
connecting piece which is constructed so as to fit easily on the neck of the
crank, and it contains a short pipe at right angles to the part containing the
neck by which it is passed over the stem of the paddle, and as the crank
revolves, the connecting piece slides freely to and fro upon the stem. The
paddle is thus caused to vibrato by the rotation of the crank in a similar
manner and with the same effect as when the neck of the crank passes through
a slot in the stem.
In Fig. 6 is represented the connecting piece y, part of the stem d, part
of the paddle b, and the crank g. The same letters refer to the same parts at
the profile on the left-hand side of Fig. 6. In the usual construction of the
paadle wheel the throw of the cranks should be a trifle less than the radius of
the pitch circle of the cog wheels; but if it is required to give the paddles a
greater degree of vibratory action, so that they may enter and leave the water
at a greater angle with the horizon, I accomplish it by increasing or lengthen-
ing the throw of the cranks, and lengthening the stems correspondingly; but
if the throw of the cranks is much increased, the necks, or what are usually
called the crank pins, must be shortened to less than half the distance between
the bearings of the crank axles in the opposite sides of the wheel; and then,
if the neck of one crank is put towards the right hand, and the neck of the
next towards the left, as shown at Fig. 7, and so ou alternately, the necks
may pass each other as they revolve without clashing, which the necks of those
cranks that are in the uppermost part of the wheel as it revolves would be
otherwise apt to do, as may be seen by the positions of the cranks in Fig. 1.
The half throw which is given to the crank axles, as seen at Fig. 7, is to allow
head room for the stems belonging to preceding or succeeding cranks. Each
stem d must of course be put towards the same side of the wheel as the neck
or throw of the crank is to which it belongs, and even when the wheel is in
its usual state of construction, the stems immediately succeeding each other

page_text: should not follow in the same but different planes, as seen in Fig. 2. If it is
desid to have the number of the paddles on the wheel much increased, then
I add an ther set of cranks, one set having their cog wheels on the inner side
of the paddle wheel next the vessel's side, as before described, and working
into a concentric wheel fixed to the side of the vessel, the other set having their
cog wheels on the outside of the paddle wheel, and working into a concentric
wheel fixed to the framework of the paddle box; but the cranks would not in
that case reach across the framework of the wheel from side to side, each
crank having a bearing in an intermediate frame fixed on the main shaft in
the midst of the wheel, and this intermediate frame may have another set of
radial arms to carry another rim, when it is required to have three rims in the
breadth of the wheel. The cranks of this paddle wheel will not be of difficult
or expensive construction, as a bar of iron may be easily bent into the required
form. The distance from the bearings of a crank will be so great in com-
parison with the small portion of the neck that will be required to be straight
and parallel with the bearings, that sharp and square angles will not be
required; but the bendings may have compass so as not to break the fibre of
the iron. As the teeth of the concentric wheel B must be of coarse pitch,
and long, to correspond with those of the crank wheels, as well as wide, they
may, for the sake of lightness, be made hollow on their inner sides, as repre-
sented on an enlarged scale at Fig. 9; but for the sake of strength, and to
obtain the means of attaching the wheel to the side of the vessel or to the
framework of the paddle box, an annular plate or shrouding should be cast
on one side of it, and from this annular plate lugs or ears may project, by
which the attachment may be made; and if a small annular plate were cast
on the opposite side of the wheel, it would prevent the crank wheels from
running off. A lantern wheel would, perhaps, for the sake of lightness, be
well adapted for the concentric wheel, consisting of two annular parallel plates,
having rounds instead of teeth passing from one to the other, and it may pro-
bably be cast in one piece,—see Figs. 10, which represent front and edge views
of such a lantern wheel. The cross and diagonal ties, which may be thought
necessary for strengthening this wheel, have not, to prevent confusion, been
represented in the Drawings; but at the points where the ends of the arms
join the rims, cross ties should pass from side to side of the wheel, and these
cross ties, by passing through the ends of the arms as well as through the
rins, may perhaps be found to be a suflicient and suitable means of securing
the rims to the arms. All the parts of this wheel that are subject to friction
and wear are constructed so that duplicates of them may be carried in the
vessel, and any worn or injured parts may be readily removed and fresh parts
substituted.

page_text: Having now described my improvements, I desire it to be understood that I
intend to claim under the above in part recited Letters Patent,
Firstly, actuating the paddles of paddle wheels by means of cranks having
bearings in the framework of the wheel, which cranks in their turns are caused
to rotate by means of cog wheels fixed on their axes, which work into concentric
stationary wheels of the same diameter and number of teeth.
Secondly, passing the rims of the wheel through the paddles, and supporting
the paddles on the rinis by means of axles passing through both in the manner
described.
In witness whereof, I, the said Henry Cartwright, have hereunto set my
hand and seal, this First day of July, in the year of our Lord One
thousand eight hundred and forty-five.