IMPROVEMENTS IN ROTARY ENGINES PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER ANALOGOUS PURPOSES
Year: 1885

page_text: We WILLIAM MATHER Engineer, and THOMAS THORP, Works Manager both of
Salford Iron Works, Manchester in the County of Lancaster do hereby declare
the nature of said Invention for "IMPROVEMENTS IN ROTARY ENGINES PART OF
WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER ANALOGOUS PURPOSES "" to be
as follows:-
Our Invention relates to that class of Engines known as Rotary Engines in
which the power is transmitted directly from the piston to the shaft without the
intervention of a Crank or similar device Such Engines have been usually designed
with a view to running at a high speed and have not been suitable for any but
comparatively small powers working with small leverage.
Our Invention however is equally applicable for all purposes and though it is
eminently suitable for running at very high speeds, this is by no means an
essential feature. An Engine according to our Invention has a Cylinder in the
form of an anchor ring or torus i.e. a tube bent into a complete circle the section
in any radial plane being also circular. In this annular tube fits a piston upon
which the steam pressure acts and which is mechanically connected to the shaft of
the Engine. The abutment for the steam pressure consists of a valve which opens
for the piston to pass and then closes immediately to form the abutment for the
steam. We prefer the following construction for our Engine The Anchor ring is
made in halves, the junction being in the plane of the ring. Along the line of
junction on the inner circumference a groove is left which permits the passage of an
arm to which the piston is attached. The arm is carried on a Cylinder or disc
keyed to the shaft and either bearing along its periphery against the inner circum-
ference of the ring or extended into the groove, in either case entirely closing the
aperture, the junction being made steam tight by suitable packing The abutment
consists of a valve worked from the exterior of the ring and may be either a slide
valve, which is withdrawn from the ring when the piston passes or a plug valve
which is rotated through an angle and allows the piston to pass through a suitable
aperture or the valve may be formed of the segment of a Cylinder which is rotated
about its axis so as to be withdrawn from the ring when the piston is passing and
is immediately brought back again so soon as the piston has passed. The steam
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page_text: inlet is placed immediately in front of the abutment and the exhaust immediately
behind it so that the whole length of the ring is available and the steam can be
used expansively to any desired extent. It will be observed that as the exhaust
is opened before the piston reaches the abutment it is unnecessary that the
abutment valve if constructed in the form of a plug valve should be a tight
fit in the ring or that the piston should closely fit the aperture which permits
it to pass.
Though in the foregoing we have described only a single ring with one abutment
it may for some purposes be advantageous to divide the ring by two abutments or
more using a corresponding number of pistons. Again several rings as abovo
described may be placed side by side having their pistons all acting on the same
shaft. In this manner the Engine would be most conveniently compounded or a
Condenser attached-Such an arrangement would also have the further advantage
of eliminating the dead point which occurs in the case of a single ring when the
piston is passing through the abutment valve.
We have described our Invention as being particularly applicable to Steam
Engines The method of construction may however be used for gas Engines, or
for hot air or compressed air Engines or for pumps either for liquids or gases.

page_text: Analogous Purposes.
We WILLIAM MATHER Engineer and THOMAS THORP Works Manager both of
Salford Iron Works Manchester in the County of Lancaster do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
Our Invention relates to that class of Engines known as Rotary Engines in which
the power is transmitted directly from the piston to the shaft without the inter-
vention of a crank or similar device such Engines have been usually designed with
a view to running at a high speed and have not been suitable for any but
comparatively small powers working with small leverages.
We
Our Invention however is equally applicable for all purposes and though it is
eminently suitable for running at very high speeds this is by no means an essential
feature. An Engine constructed according to our Invention has a hollow annulus
ring or circular cylinder which is fixed by being held in a suitable frame or
attached to a bed plate. In this annulus ring or cylinder fits a piston upon which
the steam pressure acts and which is connected or fixed to the shaft of the Engine.
The abutment for the pressure of the motive fluid consists of a valve which opens
for the piston to pass and then closes to form the abutment for the steam.
prefer the following construction for our Engine. The annulus ring or cylinder is
made in halves the junction being in the plane of the ring. Along the line of
junction on the inner circumference a groove is left which permits the passage of
an arın to which the piston is attached. The arm is carried on a cylinder or disc
keyed or otherwise fixed to the shaft and either bearing along its periphery against
the inner circumference of the ring, or extended into the groove, in either case
entirely closing the aperture, the junction being made steam tight by suitable
packing. The abutment consists of a valve worked from the exterior of the ring
either by a suitable arrangement of cams, levers, quadrants, spring and dash pot,
or in some cases by motive fluid such as live steam or steam cushioned up from
the exhaust. The said abutment may take the form of a slide valve which is
withdrawn from the ring when the piston passes or it may be a plug valve which
is rotated through an angle and allows the piston to pass through a suitable
aperture or the said abutment may be formed of a segment of a cylinder which is
rotated about its axis so as to be withdrawn from the ring when the piston is
passing and is immediately brought back again so soon as the piston has passed.
The inlet for the motive fluid is placed immediately in front of the abutment
and the exhaust immediately behind it preferably allowing only sufficient space
for the action of the abutment before the motive fluid is admitted so that as much
as possible of the length of the ring is available and when steam is used it can be
made to work expansively to any desired extent. It will be observed that as the
exhaust is opened before the piston reaches the abutment it is unnecessary that
the abutment valve if constructed in the form of a plug valve should be a tight
.J

page_text: fit in the ring or that the piston should closely fit the aperture which permits it to
pass the abutment.
Though in the foregoing we have described only a single ring with one abut-
ment it may for some purposes be advantageous to divide the ring by two or
more abutments using a corresponding number of pistons and inlets and exhausts
as may be necessary.
Again several rings as above described may be placed side by side having their
pistons all acting on the same shaft. In this manner the engine would be most
conveniently compounded or have a condenser attached. Such an arrangement
would also have the further advantage of eliminating the dead point which occurs
in the case of a single ring when the piston is passing through the abutment valve.
An apparatus constructed according to our Invention may be operated by steam
or other motive fluid but it will be evident that the same principle of construction
may be used for Gas Engines or for Hot Air or Compressed Air Engines or for acting
as pumps either for liquids or gases if motive power be applied to the shaft.
Having explained the nature of our said Invention we will describe the manner
in which the same is to be performed and for that purpose shall refer to the several
figures on the annexed sheet of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 is an end elevation and Figure 2 a side elevation of the Engine
according to our Invention and Figures 3 and 4 are transverse and longitudinal
sections respectively.
In all Figures, a is the hollow annulus ring, or circular cylinder of the engine.
It is carried by a fixed frame work b. The said annulus ring or cylinder a is made
in halves and is truly bored which can be effected by means of a spherical "rest.”
The piston c which works in the ring being turned on its own axis in the same
manner to fit the interior of the said annulus ring or cylinder which I will
hereinafter call the cylinder.
The said piston is carried by a disc d which is securely fastened to the shaft.
The disc may either be as shown in the drawings or may be a thin steel plate
having centre hubs or bosses, and the piston may be either cast or forged solid on
the disc or be fastened on by any suitable means. By having a thin disc the area
exposed to the pressure in the cylinder is reduced and consequently the thrust on
the shaft due to this pressure is diminished.
The piston may be a plain block with a piece cast on for fitting into the disc
and thus forming a sliding or expansion joint to allow for expansion or for the
shaft getting out of centre, as shown in the said piston Figure 7, or it may be made
as shown in Figure 8, in which case the projecting piece may be formed on the
disc (d), and the junk rings turned less than the bore of the cylinder, thus allowing
.the disc to move with the shaft, and the piston packing to the rim in the cylinder,
without giving any extra friction. The packing rings may be made in one or
more pieces (p) and expanded by rings, wedges (w) and springs (8) or by the
pressure of the motive power itself. The joints between the sides of the disc and
the sides of the groove in the cylinder may be kept tight by means of metal rings
faced to the disc, and held up by India-rubber rings and the pressure in the
cylinder as shewn in Figure 4, or by screws as shewn in the enlarged section of
cylinder Figure 9 or by springs or wedges or by any other convenient means.
The valve which forms the abutment for the pressure in the cylinder may be
actuated by Cams, Levers, Quadrants (either teeth or straps), spring and Dash-pot,
or by the pressure of the motive power, or by the exhaust from the cylinder being
cushioned up and then used for this purpose, or by any other equivalent device.
The pressure may be admitted to the cylinder by slide or other valves in the
ordinary way; by a slide-valve worked by an eccentric as shown in Figures 1
and 4. With this arrangement is shown a method of working the abutment by
the pressure in a separate cylinder, but this combination is not essential as the
admission of pressure to the cylinder may be independent of any method of driving
the abutment,

page_text: In Figure 4 the abutment valve e is carried by or secured to a small piston
working in a cylinder g.
The piston rod is extended through the back of the cylinder g, into an air-
cylinder h in which works another piston i; this air-cylinder acting as a dash-pot.
In order to work the abutment, the working fluid, whether steam, gas, or air,
either live or exhaust from the main cylinder, is admitted to the cylinder g by a
slide-valve worked by the wave cam j on the shaft, driving forward the piston f
and with it the abutment. As soon as the abutment covers the bore of the
cylinder and before it gets to the end of its stroke the piston i in the air-cylinder
covers up the hole k, by which air is admitted into and escapes from the cylinder h,
and thus the air remaining in the cylinder is cushioned up and forms a spring
which allows the abutment to close quietly without any knock.
The reverse action takes place by admitting the working fluid to the front end
of the cylinder g, the air being similarly cushioned up in the cylinder h when the
piston i passes the hole k¹.
Figures 5 and 6 show another arrangement of the admission and abutment
valves.
In Figure 5, the admission valve to the cylinder has a circular movement, and
the horizontal spindle of the valve obtains its motion by means of a lever and cam
on the shaft as shown in the drawing.
On the abutment valve spindle is fixed a quadrant m which gears with another
quadrant n carried on a rocking shaft which is actuated by a simple lever and a
cam on the engine shaft as shown.
The abutment is lifted by means of the quadrant & returned quickly to its place
in the cylinder by means of the spring attached to the quadrant at o, quietness in
working being secured by means of a piston at the lower end of the spring working
in the dash-pot as shown.
Another arrangement of abutment valve is shown in Figures 10 and 10ª in which
the abutment e is formed on a ring or disc P fitted to move in a recess or seating L
& held in its place by the valve box cover. The disc P is provided with pins or
projections P engaging in corresponding slots or openings in the disc Q which
carries a piston A, fitted to move in a corresponding groove or cylinder R in the
valve-box cover and worked by the fluid pressure admitted to the opposite ends of
the cylinder R alternately by a slide valve actuated from the engine shaft by a
lever and cam or otherwise so as to cause the piston A and the abutment c to
receive a circular reciprocating or to & fro motion at the required times to permit
of the passage of the piston past the abutment, and then return the said abutment
into position across the cylinder R.
The compression of the exhaust in the cylinder allows the abutment to fit into
its seating without any detrimental knocking.
In place of the abutments as here shown a revolving disc may be used with an
aperture to correspond with the bore of the cylinder and which coincide at the
moment the piston is passing.
The Engine may be governed by any ordinary governor or as shewn in
Figure 11, where the abutment is worked from the cylinder g and piston f. To
drive the abutment from the ring a pressure is admitted by the port B exhausting
at the other end by C and D.
The return of the abutment is effected by opening the port C to the pressure,
and B to the exhaust, and when the piston has passed E. This port opening to
the annular cylinder a just as the abutment covers the bore of it, the feed then
goes on through C and E to the point of cut off when the valve F closes C and the
remainder of the stroke is finished by expansion. The valve F may be worked by
a variable cam connected to a governor of any ordinary type. It is to be under-
stood that although we have in describing the constructions shewn in the drawings,
particularly referred to steam as the motive fluid, yet that machines constructed
according to our Invention may be operated by other motive power and may be
used as pumps as hereinbefore expressed.

page_text: Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is :-
First. The combination of a fixed hollow annulus, ring, or circular cylinder, in
which revolves a piston connected to a shaft; the said annulus, ring, or cylinder
being provided with an abutment for the pressure acting on the piston, which
abutment operates or is operated to allow the piston to pass substantially as
hereinbefore described.
Second. The construction of the piston substantially as and for the purpose
herein before described whether it be cast or forged solid with the disc or its
equivalent or whether it be so constructed and combined with the disc or its
equivalent as to form an expansion joint.
Third. The combination with a hollow annulus, ring, or circular cylinder, and
piston revolving therein of packing rings for the purpose of preventing leakage
across the surfaces, where the disc to which the piston is attached is in contact with
the sides of the said annulus, ring, or cylinder, with wedges, springs, screws or
means admitting the fluid pressure behind the rings, substantially as and for the
purpose hereinbefore described.
Fourth. In apparatus of the kind herein before described and claimed an
abutment valve consisting of a plain slide with rectilinear motion actuated by a
separate piston and cylinder substantially as herein before described.
Fifth. In apparatus of the kind hereinbefore described and claimed the com-
bination with the piston and cylinder actuating the abutment valve of a second
cylinder with a second piston whereby the stroke of the abutment is cushioned,
substantially as and for the purpose berein before described.
Sixth. In apparatus of the kind herein before described and claimed, an abutment
valve with a circular slide formed by the segment of a circle, actuated by quadrants
worked from a cam on the engine shaft in combination with a dash pot and spring
for cushioning the stroke substantially as hereinbefore described.
Seventh. In apparatus of the kind hereinbefore described and claimed the
combination of a circular abutment worked by a cam, with an annular cylinder,
with piston, for the purpose of cushioning the stroke substantially as hereinbefore
described.
Eighth. In apparatus of the kind hereinbefore described and claimed the
combination of a plain slide abutment actuated by a double cylinder as before
described, with an admission valve to the main cylinder of which the piston
working the abutment forms the slide, substantially as and for the purpose
berein before described.
Ninth. In apparatus of the kind hereinbefore described and claimed an admission
valve consisting of a segment of a circle moving about an axis actuated by a lever
and cam, worked from the main shaft of the engine substantially as hereinbefore
described.