CERTAIN IMPROVEMENTS IN PRO- PELLING VESSELS
Year: 1824

page_text: PERKINS'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JACOB
PERKINS, of Fleet Street, in the City of London, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth, by His
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Ninth day of August, in the fifth year of His reign, did,
for Himself, His heirs and successors, give and grant unto me, the said
Jacob Perkins, His especial licence, that I, the said Jacob Perkins, my exors,
adiiors, or assigns, or such others as I, the said Jacob Perkins, my exors,
adñiors, 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 "CERTAIN IMPROVEMENTS IN PRO-
PELLING VESSELS;" in which said Letters Patent there is contained a proviso
obliging me, the said Jacob Perkins, 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 His Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said recited Letters
Patent, as in 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
Jacob Perkins, do hereby declare the nature of my said Invention to consist in

page_text: a double paddle or set of paddles, each paddle or set of paddles revolving on a
separate axis from and in a contrary direction to the other, and each arm of
the said paddle or paddles standing at an angle with the shaft on which it
revolves, placed in and acting against the water in such manner as to propel
the ship or vessel to which the same are attached; and in further compliance
with the said proviso, I, the said Jacob Perkins, do hereby describe the manner
in which I perform my said Invention by the following description thereof,
reference being had to the Drawing annexed, and the Figures marked
thereon (that is to say):-
DESCRIPTION OF THE DRAWING.
Fig. 1 is a plan of the principal parts of my said Invention, showing such
parts as will tend most clearly to explain the same. A, A, is the outline of the
after part of a vessel, from which I project the framework R, R, R, R, turning
on the axes S, S. One end of the shafts of the paddles rest on and move with
this framework, as will be hereafter explained. C, C, are the two arms of the
outer paddles, which arms I call propellers, and B, B, are the two arms or
propellers of the second or inner paddle. These propellers are here drawn as
they would appear if looking down upon them when brought to an exactly
horizontal position; and from the Drawing the proper angle will be seen at
which they should be placed, but which angle, it should be observed, may be
varied in proportion to the velocity required. The angle here represented is
intended to be 22 degrees at a, a, a, a, and 45 degrees at 6, b, b, b, from the
line of the shaft on which they are placed. The propellers are fixed to their
respective shafts by being rivetted to the bosses marked e, e, and g, g, which
bosses are fixtures on and turn with their respective shafts. It will be seen
that there are two shafts, and two propellers on each shaft. The shaft of the
propellers B, B, is hollow, and the shaft of the propellers C, C, passes through
it, and revolves within it. By this arrangement each shaft may revolve entirely
independently of the other, and thus a contrary direction may be given to the
two shafts, which is a particular object of my said Invention, since by so doing I
keep the vessel steady, and give an equable motion to her; and in order to
produce a propelling action in the same direction from both paddles, though
the motion of each is directly contrary to the other, the propellers are placed
on their respective shafts in contrary directions, as shown in the Drawing. In
order to procure this contrary motion of the two shafts I attach to them the
following apparatus (that is to say):-D, E, F, G, are four mitre wheels; D is
fixed to the end of the hollow shaft, and E to the end of the solid shaft; I and
H are spur wheels connected with the driving shaft, and uniting by means of

page_text: fast and loose catches with the mitre wheels F and G. By means of a parallel
movement, herein-after explained, the driving gear is either brought into con-
nection with G, which then turns D and E, while F continues to revolve,
but without effect, or else into connection with F, which then becomes the
acting medium for communicating motion to D and E, while G continues to
revolve, but without effect; and by this apparatus it is that I vary the motion
of the paddles, thus giving either a forward or backward motion to the vessel.
On an inspection of the paddle shaft it will be seen that the shaft T is a hollow
cylinder, supported entirely on the shaft J, which passes through one end of it.
This shaft J is supported in a bearing Z, attached to the back part of the frame
R, R, R, R, while the other end is supported by the bearing brass M, through
which it passes. This brass M turns on axes, as will be more particularly
shown when I describe Fig. 2, and the object of its so doing is as follows;
(that is to say,) when the vessel is heavily laden, and I wish to raise the paddles
further out of the water, which otherwise would be too deeply immersed in it,
I press downward upon the ends W, W, of the framework marked R, which
turns, as before described, on the pivots S, S, and thus the back part of the
framework is raised, and with it the bearing Z and outer end of the shaft J.
Now it is quite evident that if the bearing M at the other end of the shaft J
did not turn on axes, and if those axes were not exactly on a line with the
pivots on which the frame marked R. turns, the mitre wheels would be thrown
out of gear, which by the arrangement of this bearing M, here described, is
avoided, and the paddle shafts may be raised and depressed as cccasion requires,
without throwing any of the apparatus connected with them out of gear.
Fig. 2 is a representation of the driving gear generally, shewing the bearing
brass M, and the parallel movement by which the spur wheels H and J are
thrown alternately into and out of gear. It will be seen by this Figure that the
axis O of the wheels G and I bears and turns in one end of the bearing brass M,
while the axis N of the wheels F and H bears and turns in the other end of
the bearing brass M. The aperture ✗ in the centre of the bearing brass M is
that through which the shaft J passes; and by this arrangement it is evident
the shaft J may be raised or depressed at its outer end without altering the
relative position of any of the gear connected with its inner end. The manner
of supporting the bearing brass M is shown in the next Figure, it being left out
in the Figure now under description from a fear of confusing the Drawing.
But now of the parallel movement for causing the paddle shafts to be turned
either by the mitre wheel G or the mitre wheel F at pleasure, one being used
to propel the vessel forward, and the other to drive her backwards. K, K, K, K,
is a framework clasping a groove cut in the axes of the spur wheels H and I

page_text: at r, T.
This framework is acted upon by the screw and winch handle L, L,
which draws the framework to one side or the other, according as the handle
is turned one way or the other; and the bosses on which the grooves r, r, are cut
being fixed to or a part of their respectivo spur wheels H and I, it will be
seen that these spur wheels must be acted upon also by the screw having
precisely the same motion as the framework. Now on the spur wheels H and I
are what are termed fast and loose catches, which take into the wheels F and G
respectively next to them; and by this arrangement it will be seen that when
by means of the screw and winch L, L, the spur wheel H is drawn away from
the wheel F, the spur wheel I is by the same movement drawn into connection
with the wheel G, and thus G becomes the wheel communicating motion to
the two paddle shafts, and F continues to revolve, but without effect; but when
by the same means the spur wheel H is brought into connection with the
wheel F, the same movement forces the spur wheel I away from the wheel G,
and then the wheel F becomes the wheel communicating motion to the paddle
shafts, while the wheel G continues to revolve, but without effect. It should
here be observed that the spur wheels H and I are supposed to be immediately
in connection with the motion shaft of the steam engine or other power used
to give the first motion to the machinery, and which power it has not been
thought necessary to describe, as it forms no part of my said Invention, and
may be derived from any suitable source.
Fig. 8 is a section of part of Fig. 2, showing the manner of supporting the
bearing brass M, and which is here represented as done from the deck. Tand
J are portions of the paddle shafts, and D and E are sections of the mitre
wheels attached to them. P is the support for the bearing brass M to rest
upon, and is the plate which confines it down upon the bearing, having four
screws pass through it into P. This plate is omitted in Fig. 1 and 2, in order
more clearly to shew the bearing brass M.
Fig. 4 and 5 are representations of the bosses to which the propellers are
rivetted, showing the angles at which they stand with reference to their
respective shafts. It may be proper here to add, that the bosses here shewn
aro made on short cylinders, which slip over the ends of their respective shafts
where they are fixed, so as to turn with the shafts.
Fig. 6 is a side elevation of Fig. 1, showing the upper part of the framework
or casing within which the paddles work. The same letters of reference aro
used for all similar parts throughout all the Figures.
Now such an apparatus as is described on the Drawing annexed, and which
constitutes my said improvements, being to the best of my knowledge and
belief entirely new, and never before used in that part of His said Majesty's

page_text: United Kingdom of Great Britain and Ireland called England, His Dominion
of Wales, and Town of Berwick-upon-Tweed, nor in any of His said Majesty's
Colonies or Plantations abroad, I do hereby declare this to be my Specification
of the same, and that I do verily believe this my said Specification doth
comply in all respects, fully and without reserve or disguise, with the proviso
in the said herein-before in part recited Letters Patent contained, wherefore I
do hereby claim to maintain exclusive right and privilege to my said Invention.
In witness whereof, I, the said Jacob Perkins, have hereunto set my
hand and seal, this Ninth day of February, in the year of our Lord
One thousand eight hundred and twenty-five.