IMPROVEMENTS 1 ROTARY ENGINES"
Year: 1881

page_text: LETTERS PATENT to James Swalwell, of Acre Street Battersea, in the
County of Surrey, for an Invention of "IMPROVEMENTS 1 ROTARY
ENGINES"
PROVISIONAL SPECIFICATION left by the said James Swalwell at the Office
of the Commissioners of Patents on the 28th April 1881.
JAMES SWALWELL, of Acre Street, Battersea, in the County--of Surrey,
IMPROVEMENTS IN ROTARY ENGINES."
This Invention has for its object improvements in rotary engines.
My rotary engines are of the type in which a rotating axis passing concentrically.
through a cylindrical casing. carries a radial piston, and in which there is an
abutment, serving, together with the piston, and during the greater part of the
revolution, to separate off the one from the other two chambers within the casing.
One of these chambers receives the steam or fluid from the source of supply, and as
the piston is driven round increases in capacity, a corresponding decrease of
dimensions simultaneously taking place in the other chamber which is in
communication with the outlet.
The abutment in my engine consists of a cylindrical block or roller contained
within the casing in a side cavity provided for it; it revolves in contact with the
axis carrying the radial piston, or rather with a jacket by which this axis is
surrounded. The roller abutment has a recess in it to receive the piston as it
comes round. The piston axis and the roller abutment are geared together outside
the casing, so that they revolve at the same rate.
The steam inlet and the outlet passage are on opposite sides of the abutment,
and the former is furnished with a cylindrical valve, to which a rocking motion is
imparted. The port in the valve consists of a longitudinal slit from which the
steam issues into the engine when the slit corresponds with the corresponding
opening or port in the casing.
The cylindrical valve is rotated by an axis having an arm upon it which is
connected by a link with a lever. The lever at its other end has its fulcrum upon
the base of the engine, and intermediate to these there is a bowl upon the lever
which by a spring is pressed into contact with a cam upon the axis carrying the
niston

page_text: In order to ensure steam tight contacts the jacket surrounding the axis of the
piston is loose upon it, and is supported by springs which press it towards the
roller abutment. The jacket at its ends is in contact with spring rings lodged in
annular cavities in the casing. Three rings are provided at each joint, an inner
broad ring and two rings surrounding it, each of half the width, and breaking joint.
Coiled springs press this system of rings up to the end of the jacket. The joint
against the end of the roller abutment is also made by means of packing rings. I
provide also two longitudinal packing strips resting in steam tight contact
upon the top of the roller abutment, and I equalize the pressure upon the
abutment by admitting steam upon it in the space between these packing strips.
In some cases for engines of large size I substitute a wheel for the axis carrying
the piston, and this wheel is not entirely enclosed by the casing, but steam tight
joints are made around the rim of the wheel by packing rings. The abutment
roller 1 can drive by eccentric gearing, so that its movement is rapid at the time
of the passage of the piston, and slower during the remainder of the revolution.
I sometimes construct double engines where the roller abutment is common to
two revolving pistons, and is situate between the cases in which they work. I use
rocking valves, but of a different construction from those previously described.
The valve is of a U section, and, rocks within a cylindrical chamber. The steam is
supplied to the chamber exterior to the valve, and when by the rocking of the
valve a port in the side of the chamber is uncovered the steam passes by this port
into one of the casings of the engine and propels the piston contained therein.
The exhaust from the other casing of the double engine is through the interior
of the valve of the first, and the outlet is from the end of the valve.
The valve motion is similar to that previously described, but double, the cam
operating two levers, one on either side of it. The links connecting the levers
with the arms on the axes of the valves can be varied in length, and a change
from one cam to another, together with an alteration in the length of the links,
effects the reversal of the engines. The links are made with notches engaging
with pins on the lever ends. The two links are connected, and the upper one is
formed with a handle, so that both links together can be disengaged from the
levers. Then by another reversing lever the valves are moved partly round and
the links are caused to reengage.
The valves can be actuated by eccentrics in place of cams, and the abutment
roller in some cases may be fitted with the spring packing to form the steam tight
contact with the piston axis.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Swalwell in the Great Seal Patent Office on the 28th October
1881.
JAMES SWALWELL, of Acre Street, Battersea, in the County of Surrey.
"IMPROVEMENTS IN ROTARY ENGINES."
This Invention has for its object improvements in rotary engines.
My rotary engines are of the type in which a rotating axis passing concentrically
through a cylindrical casing carries a radial piston, and in which there is an
abutment serving, together with the piston, and during the greater part of the
revolution, to separate off the one from the other two chambers within the casing.
One of these chambers receives the steam or fluid from the source of supply, and
as the piston is driven round increases in capacity, a corresponding decrease of
dimensions simultaneously taking place in the other chamber which is in
communication with the outlet.
The abutment in my engine consists of a cylindrical block or roller contained
within the casing in a side cavity provided for it; it revolves in contact with the
axis carrying the radial piston, or rather with a jacket by which this axis is
surrounded. The roller abutment has a recess in it to receive the piston as it comes
round. The piston axis and the roller abutment are geared together outside the
casing, so that they revolve at the same rate.
The steam inlet and the outlet passage are on opposite sides of the abutment, and
the former is furnished with a cylindrical valve, to which a rocking motion is
imparted. The port in the valve consists of a longitudinal slit, from which the
steam issues into the engine when the slit corresponds with the corresponding
opening or port in the casing.
The cylindrical valve is rotated by an axis having an arm upon it, which is
connected by a link with a lever. The lever at its other end has its fulcrum upon
the base of the engine, and intermediate to these there is a bowl upon the lever
which by a spring is pressed into contact with a cam upon the axis carrying the
piston.
.
In order to ensure steam tight contacts, the jacket surrounding the axis of the
piston is loose upon it, and is supported by springs which press it towards the
roller abutment. The jacket at its ends is in contact with spring rings lodged in
annular cavities in the casing. Three rings are provided at each joint, an inner
broad ring and two rings surrounding it, each of half the width, and breaking joint.
Coiled springs press this system of rings up to the end of the jacket. The joint
against the end of the roller abutment is also made by means of packing rings.
I provide also two longitudinal packing strips resting in steam tight contact upon
the top of the roller abutment, and I equalize the pressure upon the abutment by
admitting steam upop it in the space between these packing strips.
Figure 1 on the Drawings annexed represents an end elevation partly in section
of an engine of this construction.
Figure 2 is a transverse vertical section, and Figure 3 is a longitudinal, and
vertical section of the same.
A is the main axis of the engine, and B is its radial piston; C is the casing
enclosing this piston and the abutment block or roller D which is contained in a
ide compartment of the case. The main axis A and also the axis D¹ of the
butment block D pass out through bearings in the end cover of the casing, and
on the outside they are geared together by the spur wheels E, E, so that they
evolve at equal speeds in opposite directions. D is the recess in the abutment
lock to receive the piston as it passes round; F is the inlet for the steam or other

page_text: fluid, by the pressure of which the engine is rendered active; G is the outlet by
which the steam or fluid passes away when it has done its work in the engine;
I is the cylindrical valve; the steam or fluid enters it at the end and passes into
the engine by a slit in the side of the cylinder when this slit corresponds with the
inlet port F. The valve H is held to its face by springs H, HI, and a film of steam
surrounds it.
The valve receives a rocking motion by means of the arm H2, which is keyed
upon the spindle or axis of the valve, and is connected by the link I with the
lever this lever has its Eulerum at J', and a spring Kacting against the lever
forces the bowl which the lever carries into contact with the cam L upon the
main shaft A. By means of the lever M the cam 1 can be slidden along the shaft
to vary the cut off, the cam being suitably formed in different parts in give the
desired range of variation. The arrangements for maintaining the joints of the
engine fluid tight are as follows:-There is a jacket N which surrounds the main
shaft, and the cylindrical part of the piston and the springs N₁, N', acting against
strips N, N, keep this jacket up to the abutment block D. At its ends the
jacket N abuts upon the packing rings 0, 0, which are kept up to it by the
springs 0, as shown. Steam tight joints are made against the ends of the roller
abutment by other packing rings and springs Pand " the means for packing the
radial piston are clearly shown in Figures 2 and 4, the latter being a section fakeu
through the radial piston from end to end. 13* is a cap on the end of the piston
which is pressed outwards by coiled springs which appear in the Drawing; the
said spring act beneath a strip which is immediately under the cap. B**, **, are
packing strips at the ends of the piston, they also are pressed outwards by springs
to form a steam tight joint against the end covers of the casing. Q, Q. are packings
which bear against the upper surface of the roller abutment; the steam is admitted
between them by the passage R, so as to equalize the pressure above and below
the axis.
I will now proceed to describe another form in which I arrange my engine.
In some cases for engines of large size I substitute a wheel for the axis carrying
the piston, and this wheel is not entirely enclosed by the casing, but steam tight
joints are made around the rim of the wheel by packing rings. The abutmeni
roller I can drive by eccentric gearing, so that its movement is rapid at the time of
the passage of the piston, and 'slower during the remainder of the revolution.
I sometimes construct double engines where the roller abutment is common to
two revolving pistons, and is situate between the cases in which they work. I use
rocking valves, but of a different construction from those previously described.
The valve is of a U section, and rocks within a cylindrical chamber. The steam
is supplied to the chamber exterior to the valve, and when by the rocking
of the valve a port in the side of the chamber is uncovered, the steam passes
by this port into one of the casings of the engine and propels the piston
contained therein. The exhaust from the other casing of the double engine is
through the interior of the valve of the first, and the outlet is from the end of the
valve.
The valve motion is similar to that previously described, but double, the cam
operating two levers, one on either side of it. The links connecting the levers with
the arms on the axes of the valves can be varied in length, and a change from one
cam to another, together with an alteration in the length of the links, effects the
reversal of the engines. The links are made with notches engaging with pins on
the lever ends. The iwo links are connected so that both links together can be
disengaged from the levers. Then by another reversing lever the valves are moved
partly round and the links are caused to reengage.
The valves can be actuated by eccentrics in place of cams, and the abutment
roller in some cases may be fitted with the spring packing to form the steam tight
contact with the piston axis.
Figure 5 is an end elevation, and Figure 6 is a vertical and transverse section
of an engine in which the roller abutment is common to two revolving pistons.

page_text: A, A, are the axes, and B, B, are the radial pistons; C, C. are the casings; D is
the abutment block between the two, it carries the packing pieces. The axes A, A,
and the axes of the abutment block are geared together by means of three equal
spur wheels F, F; and G, G, are the inlet and outlet passages, the former being
the inlets and the latter the outlets when the engine is running forward, but
otherwise when the engine is reversed; the cylindrical valve chambers in this case
contain valves of a U section, and by a rocking motion imparted to them the
valves uncover at the proper times the inlet ports, so that the steam may pass into
the engine. The outlet port is in each case always open into the cavity of the
valve, and there is an outlet for the exhaust steam at the end of the valve, as is
clearly seen in Figure 7, which is a longitudinal section of one of these U valves.
In the same Figure the arrangement of the packing is also shown. The cut off
may if desired be controlled by the governor, as the Drawing indicates (see
Figure 6), by giving motion to a cylindrical valve like those in Figure 2, and
which is here employed as a throttle. The reversing gear of this engine is clearly
represented in Figure 5. The cam on one of the axes A operates two levers J, one
for each valve and connected with it by a link I, a notch in the link engaging with
a pin upon the end of the lever; S is the reversing lever, it has its fulcrum at $! and
it can slide vertically upon the fulcrum. The lever S carries a lifting cam S2 by
which it can be raised so as to disengage the links I from the ends of the levers 1.
and this having been done the links and the valves can be moved independently of
the levers to reverse the engine, and they can when in the new position be again
made to engage with the levers J but by the of her notches, and simultaneously the
operation of the cam can be altered by sliding along the shaft. A connection with
the reversing lever will effect this object.
The abutment block D it will be seen is formed with longitudinal projections
and recesses, and the projections receive caps which are free to a certain extent to
be pressed outwards by coiled springs beneath them, and they are thus each, as it
comes round, held in steam tight contact with the boss of the axis A carrying the
radial piston.
Figure 8 is a transverse section showing a modified form of the double rotary
engine. Here the abutment is provided with two hollows to receive the pistons,
and by altering the sizes of the gear wheels it is driven at half the speed of the
axes which carry the radial pistons. There are steam passages through the
abutment block connecting its two cavities, and consequently one steam admission
at F serves to convey it to the two radial pistons.
Figures 9, 10, 11, represent a compound engine, high and low pressure, con-
structed according to my Invention. In this engine the main shaft carries two
radial pistons for each engine, and each engine has two corresponding abutment
blocks.
Figure 9 is a transverse section of the smaller engine in which the high pressure
steam works before it passes to the larger engine; Figure 10 is an end elevation of
the same; many of the parts being similar to those in the engines previously
described, it will be unnecessary to describe them in detail. The main shaft
revolves at half the speed of the abutment blocks; H, H, are the steam valves by
which the steam is admitted and cut off at the proper times; T, T, T, T, are four
reversing valves, which being turned reverse the engine. The low pressure engine
has similar reversing valves, and the reversing gear moves all these valves
simultaneously; U, U, are trunks which lead away the steam which has done its
work in the high pressure engine direct to the valves of the larger or low pressure
engine. This engine is similar in all its main features to the smaller engine, and
the two engines have their pistons at right angles.
The exhaust steam from the low pressure engine passes into a condenser in the
base or bed of the engine.
The arrangement of valve gear in the high pressure engine is as follows:-The
two cylindrical admission valves are linked together, as shown, so that they move
simultaneously, and they are both controlled by the slotted lever a; the slot receives

page_text: a pin at the end of a lever b which has its fulcrum at ', and the lever can slide
along a motion block surrounding the fulcrum pin.
The position of the pin on the lever 6 in the slot of the lever is controlled by
the governor through the rode from which the lever is suspended at the point b*,
and by which the lever is lifted and lowered to accomplish the desired automatic
variation in the cut off. The outer extremity of the fever b carries a pin which
engages with a slot in the lever d. At the upper end of this lever a catch is
formed, and a bolt e engages with it. The slide f receives a constant to and fro
movement from an eccentric,as the Drawing indicates, and the bolt e passes through
it. The bolt being suspended at e¹ thus receives a pendulous movement, it engages
with the catch, draws back the lever opening the valves, then at a certain point
the catch slips off the end of the bolt, and the valves are instantly closed. The
closing is effected by the lever d, to the axis of which there is attached by an arm
and link, the float g, which whilst the valves are opening is sunk down into a
vessel containing water, but which immediately the lever is released rises and
effects the sudden closing of the valves. The engine may also be worked without
this contrivance by connecting the lever d directly with the slide f. for which
provision is made in the Drawing. The position of the pivots of the bolt e can be
varied by means of a hand wheel and screw, to render the cut off earlier or later in
the stroke.
The larger or low pressure engine is similar in construction to the smaller
engine, except that no provision is made for varying the expansion, this being
unnecessary.
A film of steam is allowed to pass behind the abutment blocks to equalize the
pressure. A single packing strip at the back of each block may be provided to
prevent the steam blowing through.
Figure 12 is a transverse vertical section, and Figure 13 is an end elevation
partly in section of my engine arranged as a rotary gas engine. The main shaft
carries two radial pistons, and the two abutment blocks revolve at twice the speed
of the main shaft. The impulse by the gas explosion is not however given more
frequently than once in each revolution, and the action upon the two radial pistons
is simultaneous. V, V, are a pair of pumps for drawing and compressing the
charges of gas and air, and W, W, and X, X, are respectively the air and the gas
inlet valves. They are operated by slides moved by eccentrics upon the main axis
and by springs, but the governor also controls the gas valves and prevents them
opening when the speed of the engine tends to become excessive. Y, Y, are valves,
which open during the inward stroke of the pistons of the compressing pumps and
admit the charge of admixed gas and air into the body of the engine; these valves
represented in the Drawing are open. The ignition is effected through a vent at Z,
by which, as soon as the valves at Y are opened, a portion of the charge enters a
small pipe leading to the valve A, A, which being opened at the right moment by
a cam allows a portion of the explosive mixture to pass into the chamber B, B.
The bottom of the chamber B, B, is of thin metal, and is kept always at a
sufficiently high temperature to fire the mixture by a gas flame burning beneath
it. Consequently, as soon as the valve A, A, opens, the explosion to propel the
engine ensues.
At C, C, and C, C. valves are fitted, which lift to admit air at each alternate
passage of the piston past the abutment block, that is to say, when the charge of
gas and air is not supplied. This admission of air serves both to prevent back
pressure and to sweep the products of combustion out of the engine. The valves
C, C, close when the pressure within exceeds atmospheric pressure.
A single gas engine may be similarly arranged.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim,-
First. My improved rotary engine, substantially as described in respect to
Figures 1. 2. 3. and 4.

page_text: Second. In a rotary engine the cylindrical valve, substantially as described in.
respect to Figures 1 and 2.
Third. In a rotary engine the arrangement of packing to ensure fluid tight
contacts, substantially as described in respect to Figures 2, 3, and 4.
Fourth. My improved double rotary engine, substantially as described in respect
to Figures 5, 6, and 7.
Fifth. In a rotary engine the U forin valve, substantially as described in respect
to Figures 6 and 7.
Sixth. In a double rotary engine my improved reversing gear, substantially as
described in respect to Figures 5, 6, and 7.
Seventh. In a rotary engine the arrangement of packing to ensure fluid tight
contacts, substantially as described in respect to Figure 6.
Eighth. The modified form of my double rotary engine, substantially as described
in respect to Figure 8.
Niuth. My improved engine as a compound high and low pressure rotary engine,
substantially as described in respect to Figures 9, 10, and 11.
Tenth. My improved engine as a rotary gas explosion engine, substantially as
described in respect to Figures 12 and 13.
In witness whereof, 1, the said James Swalwell, have hereunto set my hand
and seal, this Twenty-second day of October, in the year of our Lord One
thousand eight hundred and eighty one
JAMES SWALWELL.
(L.S.)