IMPROVEMENTS IN ROTARY ENGINES APPLICABLE TO BE WORKED BY WATER, STEAM, OR OTHER FLUIDS, ALSO TO BE USED AS A MEANS OF RAISING AND FORCING FLUIDS
Year: 1861

page_text: LETTERS PATENT to Charles Sorby Dawson, of Thames Ditton, in the
County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN
ROTARY ENGINES APPLICABLE TO BE WORKED BY WATER, STEAM, OR OTHER
FLUIDS, ALSO TO BE USED AS A MEANS OF RAISING AND FORCING FLUIDS."-
A communication from abroad by William Kennish, resident at the City of
New York, in the State of New York, in the United States of America.
PROVISIONAL SPECIFICATION left by the said Charles Sorby Dawson
at the Office of the Commissioners of Patents, with his Petition, on the
9th January 1861.
I, CHARLES SORBY DAWSON, of Thames Ditton, in the County of Surrey,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN ROTARY ENGINES APPLICABLE TO BE WORKED BY WATER, STEAM, OR
OTHER FLUIDS, ALSO TO BE USED AS A MEANS OF RAISING AND FORCING FLUIDS,"
communicated to me from abroad by William Kennish, resident at the City
of New York, in the State of New York, in the United States of America,
to be as follows:-
Within a cylindrical case I apply a snail or other suitable shape piston
affixed to or forming part of a hollow axis, such piston having an opening or
openings on its face communicating with the hollow axis, and another or others
on its back, which openings are separated from each other to their connections

page_text: with the hollow shaft by diaphragms. There is also an internal hollow shaft
divided with a diaphragm, so that one part may serve for induction and the
other for eduction, so that whilst (in the case of the apparatus being used as a
motive power engine) the power employed enters by one part of this internal
shaft, thence by passages therefrom to act between the piston and a moveable
abutment, and it then passes away by another part of the internal shaft.
In some cases the internal hollow shaft is not used, and then a diaphragm
is applied to the hollow axis to which the piston is affixed, and corresponding
with that in the piston. The abutments are obtained by hinged pieces which
open against the central hollow axis, and then fold back into recesses for then
in the case, and they are worked for this purpose by the engine.
Patent, bearing date the Ninth day of January, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Charles Sorby Dawson, Her special licence that I, the said Charles
Sorby Dawson, my executors, administrators, and assigns, or such others as
I, the said Charles Sorby Dawson, 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 ROTARY ENGINES APPLICABLE TO BE WORKED BY WATER,
STEAM, OR OTHER FLUIDS, ALSO TO BE USED AS A MEANS OF RAISING AND FORCING
FLUIDS," communicated to me from abroad by William Kennish, resident at
the City of New York, in the State of New York, in the United States of
America, upon the condition (amongst others) that I, the said Charles Sorby
Dawson, 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

page_text: 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.
NOW KNOW YE, that I, the said Charles Sorby Dawson, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement :-
Fig. 1 is a central vertical section of the machine when used with a
stationary central tube or hollow shaft; Fig. 2 is a horizontal cross section of
the same; Fig. 3 is a plan of cam plate; and Fig. 4, a central vertical section
of the machine when used without a stationary central tube or hollow shaft.
Similar letters of reference in each of the Figures 1, 2, 3, and 4 indicate cor-
responding parts.
The nature of my Invention consists in a diaphragmed snail or other
suitably shaped piston, which has an opening in its face and another one in
its back in combination with a diaphragmed bollow shaft, which has cor-
responding openings with those of the piston, so that a continuous supply and
exhaust of the water may be effected, and thus the full effective force or
pressure of the water secured.
My Invention enables me to construct a bighly efficient and compact rotary
hydraulic moter, which can easily be transported from one place to another.
To enable others skilled in the art to make and use my Invention I will
proceed to describe its construction and operation.
A is a stationary circular box, which may be provided with suitable flanges
to fasten it in any desired place by means of screw bolts. A tube I fits in a
hole in the centre of the top of the box A, while the lower end of the tube
has its bearings in the bottom of the box, as seen in Fig. 1. The tube thus
held in a vertical position is free to revolve in its bearings in the top and
bottom of box A. A snail-shaped piston C is fastened to the tube I, the distance
of the most, eccentric point Fig. 2 of the snail from the centre of the box A
being equal to the radius of the latter. The snail is divided in two parts by a
horizontal partition X. The upper part contains an opening a, b, e, d, Fig. 2,
in the front of the piston corresponding to the outer shape of the snail, while
the lower one has a flaring opening l, m, o, n, in the back of the snail part of
the piston.. The upper opening (which is also marked with the letter E) cor-
responds with an opening F in the tube I and the lower opening (marked E'
in Fig. 1) corresponds with an opening F in tube I. A hollow central shaft
D O passes through the tube I, so that the latter, and the piston C with it, can
turn about the shaft D while it remains stationary, or shaft D and tube I may

page_text: be keyed together so as to turn together. This hollow shaft contains a hori-
zontal diaphragm H, dividing the hollow space in its centre into two parts, the
upper one communicating with the opening E of the snail by means of hole G.
The inside of the box A is furnished with two recesses diametrically opposed
to each other, into which gates B, B', fit. These gates are pivoted at one
end, and (by mechanism hereafter to be described) they are swung on their
pivots so as to alternately close and open the space between the inside circum-
ference of the box A and the piston C.
This mechanism consists of a crank J attached to each of the pivots of the
gates, the crank pins falling into a cam groove in the under surface of a disc L
keyed to tube I. As the disc L revolves together with the tube I, the
cam groove operates the cranks J in such a manner as to keep one gate open
while the other one is shut, as seen in Fig. 2. The water which is intended
to drive the machine enters through the upper part of the hollow central
shaft D, and passes through the opening G, F, into the snail-shaped aperture
in the piston, and thus imparts to the piston a rotary motion in the direction
of arrow 4, Fig. 2. As the gate B in front of the piston is shut (as seen in
Fig. 2) the water can nowhere escape in front of the piston, and therefore its
whole force is spent in moving round the piston. By the time the end c of
the snail has passed the gate B', the latter (gate B¹) is shut, and the gate B
is gradually being opened by the action of the came groove above described,
and the water which has acted upon the piston during the passage from B to
B' is now free to flow off through opening E' in the back of the snail, and
through apertures F2 and G¹, and the hollow space in the centre of the shaft D
below the diaphragm H, as indicated by arrows 8, in Fig. 1 and 2.
Thus it will be seen the whole force of the water is made useful towards
impelling the piston while the water which has spent its force is free to flow off
without impeding the motion of the piston in any way. The whole device is
so simple in its construction, that it can easily be transported from one place to
another, and applied to any of the water pipes. usual in our cities, or to any
other water power.
Fig. 4 shows a modification of the device; the central hollow shaft D is
here dispensed with, and the tube I is provided with a diaphragm H¹ in the
place of the one H, as shown in Fig. 1. The operation of this device is the
same as the other. The upper surface of disc L may be provided with cogs
for the purpose of driving machinery to be connected with it by means of
proper gearing.
Figs. 5, 6, and 7 show a device by which the gates or abutments B, B', may
be made to slide in and out of their recesses instead of turning on pivots;

page_text: the box A is provided with recesses diametrically opposite to each other, as
before, but elongated, to receive the gates or abutments crossways, as in Fig. 5.
The gates or abutments are slided in the recesses P, P¹, alternately on to the
concentric part of the snail C by means of springs s, s, s, s, or any other
suitable mechanical arrangement attached, as seen in Figs. 5 and 7, to rods
Q, Q', which rods pass through stuffing boxes d', d, and are attached to
slides B', B, which slides are alternately forced from that position by means of
cam D, E, N, on disc or cam wheel A, B, Figs. 6 and 7, which disc passes
through opening F, and is keyed to shaft I, Fig. 6, pushing against revolving
pins X, X. These pins are attached to the rods which work the rods Q, Q,
as seen in Fig. 7, so that one slide is open whilst the other is shut.
This machine may be used for raising and forcing fluids by attaching a
suction pipe to the top of the hollow axis or shaft (which is also the supply
when used as a motive power) and by mechanical means the snail is caused
to revolve, thereby creating a vacuum between the abutment B and the face
of the snail C, and the water rushes in through the suction pipe to fill it.
Having performed half a revolution, the abutment B' is thrown to the con-
centric part of the snail C, which continuing to recede, forms another vacuum,
and so on.
As long as the machine is kept in motion the fluid is forced out
through the opening in the back of the snail and out through the bottom part
of the shaft.
This machine can also be made to measure and correctly index the quantity
of water it makes use of by attaching a suitable indicator to the axis or
revolving shaft.
What I claim as my Invention, and desire to secure by Letters Patent, is a
diaphragmed snail or other suitably-shaped piston C, which has an opening
in its face and another in its back in combination with a diaphragmed hollow
shaft D, which has corresponding openings with those of the piston and the
folding or sliding abutments, substantially as and for the purposes set forth.
In witness whereof, I, the said Charles Sorby Dawson, have hereunto
set my hand and seal, this Eighth day of July, in the year of our
Lord One thousand eight hundred and sixty-one.
CHARLES SORBY DAWSON. (L.S.)