Improvements in Rotary Engines, applicable for use as Motors, Pumps, Blowers, or the like.
Year: 1896

page_text: Date of Application, 24th Dec., 1896
Complete Specification Left, 23rd Sept., 1897-Accepted, 20th Nov., 1897
Improvements in Rotary Engines, applicable for use as Motors,
Pumps, Blowers, or the like.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the City
of London, Civil Engineer and Chartered Patent Agent, 'do hereby declare the
nature of this invention (a communication to me from Henry Low Webster, of
Klerksdorp, in the South African Republic, Engineer,) to be as follows:-
.This invention relates to rotary engines of a type in which two discs or drums
are mounted on parallel shafts and caused to revolve at a uniform speed but in
opposite directions; the one disc carrying upon its periphery a radially projecting
piston of circular or other suitable form which at each revolution enters a suitably
formed cavity in the other disc or drum.
In constructing an engine according to this invention, the piston is mounted
upon the periphery of a disc keyed on a shaft passing through stuffing boxes or
glands in a casing which encloses the piston and disc; the piston fitting accurately
an annular channel in the said casing, in which channel the piston makes its
orbital path or revolution. In alignment with the disc which carries the piston,
and keyed on a shaft arranged parallel with the before mentioned shaft, is another
disc having secured to its periphery a stopper or head which may be in the form
of a hollow annular cylindrical body fitting accurately and revolving in a second
annular channel in the casing. In one side of the casing is the inlet for the
pressure fluid and in the other side are the admission port to the piston-channel
and the exhaust port therefrom. The shaft in this case also passes through
stuffing boxes or glands. The annular channels are preferably disposed so that the
path of the one intersects the path of the other; a space or an opening being left
in the periphery of the stopper to allow of the passage of the piston during a
portion of its revolution, the sides of the opening being closed to prevent the
escape of pressure fluid and for maintaining the balance of the stopper during its
revolution Communication between the steam inlet and the port to the piston-
channel is established by means of, a circular port and a quadrantal countersunk
passage formed in the disc which carries the stopper. Undue pressure and friction
on the face of the admission port to the piston-channel may be obviated by allow-
ing access for the fluid on either side of the stopper-disc, provision for economising
wear on the latter being made by constructing it of hardened steel: Springs and
packing rings may be employed where found necessary for maintaining the parts
in working contact and in steam tight condition. If desired an expansion valve
in the form of an annular ring having suitably arranged ports-controlled by a
governor may be employed: The discs are geared together by means of spur
wheels keyed on their shafts the piston and stopper thereby revolving simul-
taneously. The shafts are supported in bearings carried on a bed-plate which
latter as also the casing is preferably divided in two longitudinally and fastened.
together by bolts. The piston-shaft may be furnished with a fly-wheel or pulley.
For controlling the speed, the admission pipe may be furnished with a suitable
governor combined with a throttle valve. In order to start the engine at any
point of its revolution, an auxiliary starting valve, such as a small pipe and stop-

page_text: cock, may be provided for establishing communication between the interior of the
casing and the steam inlet.
According to a modified construction, the stopper may revolve at right angles to
the plane of rotation of the piston. In this arrangement, a disc, cuts through the
piston orbit; the peripheries of both the piston-disc and the stopper-disc touching.
The stopper has an opening in the outer portion of its web through which the
piston passes on the simultaneous revolution of the discs; the solid part of the
web of the stopper closing the orbit and making fluid-tight joint immediately on
the passage of the piston. The balance of the web is effected by connecting the
piston passage, in front of the stopper, with two small spaces situate on either side
of the orbit at the back of the stopper, the areas of which being equal to the piston
leave the web of the stopper free to revolve without friction on the faces of the
aperture.
According to a further modification, the stopper may consist of a reciprocating
plate fitting accurately a slit or opening which cuts the piston orbit radially at
right angles to. the plane of revolution of the piston; the said plate sliding out-
wards freely in the slit, and being connected at its upper edgo with a piston which.
works in a small auxiliary cylinder fixed radially on the casing of the engine.
The stroke of the auxiliary piston and of the reciprocating plate may be rather
more than the length of the diameter of the piston. The up and down or recipro-
cating movement is effected by ports connecting the admission and exhaust of
the auxiliary cylinder by two quadrantal slots or passages in the disc which carrios
the piston (which in the reciprocating and dise stopper type take steam or pressure
fluid from the centre of the piston casing) as the latter revolves over the apertures.
These ports are so situated that the upper and lower ports of the auxiliary cylinder
are opened simultaneously to the exhaust and steam admission alternately and
cause the auxiliary piston to reciprocate rapidly; the movements thereof being
proportioned to the distance apart of the ports and the diameter of the piston of
the engine. The balance of the plate in order to avoid friction at the commence-
ment of the up-stroke is effected by means of a C-shaped or other suitable port
disposed in the engine casing and having two openings into the piston channel,
one opening being on each side of the exhaust port, or behind the stopper plate.
The C-shaped port admits steam from the back to the front of the piston as the
latter passes over the exhaust port, thereby balancing the plate and rendering it
free to rise by the up'stroke of the auxiliary piston:
In this arrangementi a parabolic toe in front of the piston ensures the lifting
of the stopper plate by the piston in case of accident to the auxiliary piston or rod;
whereby the stoppage of the engine in the event of the stopper plate failing to rise
at the proper time is obviated.
The action of the 'engine is as follows:-
On pressure fluid entering the casing of the revolving stopper, the whole pressure
acts upon the surface of the piston until it arrives at the point of cut-off, which
may be arranged to take place at about one-third of the revolution of the stopper,
the latter being caused to revolve in a contrary direction to that of the piston by
means of the spur wheels. The quadrantal passage having passed the admission
port, the space or opening in the periphery of the stopper forms a fluid-tight
chamber wherein the fluid expands, thereby forcing the piston to travel in its
annular passage or orbit until it reaches the exhaust port; the momentum of the
engine enabling it to complete the remainder of its revolution, which may vary
from one-eighth to one-tenth, according to the substance or thickness of the piston
and the relative diameters of the piston and stopper, or according to whether the
latter revolves in the same or in a different plane, such as at a right angle, to that
of the piston:
..
The piston-disc and stopper-disc revolve in spaces in the casing; the piston
being connected with the disc through an annular opening between the inner sides
of the annular channel by being bolted to a plate having a shank let into the peri-
phery of the dise and cottered through the web.
anti

page_text: The compounding of engines constructed as herein described may be readily
effected without multiplying the parts other than the pistons. By the improved
method of working, the pressure of the fluid is applied at the most advantageous
position, viz.,, at a point tangential to the radius of the path of the piston; the brake
power developed will more nearly correspond with the actual expenditure of fluid
and nominal horse-power, and, no shock is apparent between the revolutions owing
to the arrest of flow or cut-off.
The engine may be employed inversely as a pump or it may be utilized, as, an
engine and pump combined:
The positions of the admission and exhaust ports may be varied, and suitable
reversing gear and expansion valves may be employed, in the working of the
engine.
Dated this 94th day of Decembe
1322
COMPLETE SPECIFICATION...
Improvements in Rotary Engines applicable for use as Motors,
"
Pumps, Blowers or the like!
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in,the City
of London, Civil Engineer and Chartered Patent Agent, do hereby declare the
nature of this invention (a communication to me from Henry Low Webster, of
Klerksdorp, in the South African Republic, Engineer,) and in what manner the
same is to be performed. to be particularly described and ascertained in and by
the following statement:--
This invention relates to rotary engines of a type in which a radially projecting
piston carried on the periphory of a disc or drum, mounted on a shaft, is caused to
revolve in an annular channel or orbit; the engine being capable of employment
with any fluid under pressure, and, in a modified form, as a gas or internal combus-
tion engine; the term steam and its derivatives are therefore used in this
specification to indicate the motive fluid.
The invention has for its objects to provide a simple and economical motor of
the rotary type having a small number of parts, and being simple in construction,
same being operated at a high rate of speed, and in which the steam may be used
expansively; to provide a revolving, or reciprocating stupper or head which, on
being introduced into the piston, orbit at each revolution, serves as an abutment
for the steam pressure and means for balancing and actuating the said stopper;
and further to provide suitable admission-ports and a novel expansion valve and
operating mechanism.
Another feature, of the invention is the construction of a compound engine in
which several pistons are mounted on one drum but each revolving in its own orbit
and having its own stopper; to provide a novel and simple arrangement of the
ports whereby the steam is led from the first or high pressure orbit to the succeed-
ing ones by the shortest possible passages, namely, through-the walls of the piston
carrier, or drum as hereinafter described. The invention alsa comprises an
improved method of attaching the pistons to the carrier.
In the accompanying drawings; Fig. 1 is a part side elevation and transverse
section of a rotary engine of the revolving stopper type having one piston and one
stopper; Figs. 2 and 3 being respectively a corresponding plan in section and an
end, view, of the same. Fig. 4, is a part vertical section and end elevation of an
engine having a reciprocating stopper; the reciprocating, mechanish and stopper-
plate being arranged radially. Fig. 5 is a corresponding plan one half being

page_text: shown in section. Fig. 6 is a side elevation of the same, part of the casing being
removed to show the method of attaching the piston to the carrier on disc, the
ports for admitting steam to the piston-orbit and auxiliary cylinder and the
quadrantal countersunk passages which control the admission-ports. Figs. 7, 8
and 9 are respectively a part side elevation and transverse section, a plan, partly in
section, and a front view of a multiple compound engine of the revolving stopper
type, having six rectangular pistons mounted on one drum and shaft, with six
corresponding stoppers mounted on a parallel shaft; the disposition of the
admission-ports, expansion valve and governing mechanism the sectional structure
of the stoppers and method of connecting them together and actuating them in
unison with their respective pistons; the relative positions of the pistons and
stoppers, the admission-ports and the steam passages between the piston-orbits in
the cylindrical wall of the piston-carrier or drum being clearly shown.
A. is a radially projecting piston mounted on the periphery of a disc B which is
heyed an a shaft C the latter passing through stuffing-boxes cc in the casing D
which encloses the piston A and disc B. The piston fits accurately an annular
channel D in the casing D in which channel the piston makes its orbital path or
revolution. In alignment with the disc B and keyed on the shaft E arranged
parallel with the shaft C is another disc F having secured to its periphery a
stopper or head G-which may be in the form of a hollow annular cylindrical body
fitting accurately and revolving in a second annular channel Dº in the casing D.
In one side of the casing D is the inlet d for the steam and in the other are the
admission-port id and the exhaust-port d³. The shaft E also passes through
stuffing-boxes or glands ee. The annular channels D and Do are disposed so that
the path of the one intersects the path of tho other, the periphery of the disc B
rolling on the periphery of the stopper G as shown in Fig. 1. A space or open-
ing G is left in the periphery of the stopper G to allow of the passage of the piston
during a portion of its revolution. Communication between the steam-inlet d
and the port d to the piston-channel D is established by means of a circular
port. and the quadrantal counter-sunk passage f' (shown in dotted lines in Fig. 1
and 2) formed in the disc F. Undue pressure and friction on the face of the
port d may be obviated by allowing access for. the steam on either side of the
stopper disc. The admission-port may be provided with a ring d of hardened
steel for the purpose of economising wear. A spring and packing ring ds may
be employed for maintaining the parts in working contact and in steam-tight con-
dition. For controlling the speed an expansion valve in the form of
I in Fig. 2, having
an annular ring as indicated in dotted lines at
suitably arranged ports controlled by governor, may be employed;
the inlet pipe may be furnished with a governor such
ог
av
as indicated
at K combined with a throttle valve. The discs B and F and consequently the
piston and stopper G are caused to revolve simultaneously by means of spur-
wheels B and F of equal pitch and diameter keyed on their respective shafts C
and E. The shafts C and E are respectively supported in adjustable bearings c c
and e¹ el secured to a bed-plate H; the latter as also the casing D being preferably
divided in two longitudinally and fustened together by bolts. The piston-shaft C
may be furnished with a fly wheel or pulley I. The piston- and stopper-discs B
and F respectively revolve in the spaces D and D; the piston A being connected
with the disc B through an annular opening between the inner sides of the orbit D'
by being bolted to a plate having a shank let into the periphery of the disc and
cottered through the web. l'acking rings b and 6 are inserted in the openings in
the casing through which the discs B and F work to effect steam-tight junction a
those parts.
According to a modified construction (not illustrated) the stopper may revolve
at right-angles to the plane of rotation of the piston. In this arrangement the
stopper consists of a disc which cuts through the piston-orbit; the peripheries o
both the piston-disc and stopper-disc touching. The stopper has an opening in
the outer portion of the web through which the piston passes on the simultaneou

page_text: The
revolution of the discs; the solid part of the web of the stopper closing the orbit
and making steam-tight joint immediately on the passage of the piston.
balance of the disc is effected by connecting the piston-orbit, in front of the
stopper, with spaces situated at either side of the piston-orbit at the back of the
stopper, the combined areas of which being equal to that of the piston, the pressure
on both sides of the disc is equal at every point in the revolution of the piston and
it is consequently free to revolve without friction on the faces of the aperture. The
stopper-disc is suitably enclosed in a casing bolted to, or forming part of, the
piston casing and is actuated in unison with the piston by a suitable combination
of bevel- and worm-gearing.
In l'ig. 4 the stopper consists of a reciprocating plate O designed in this case to
work radially, but it may also be designed to work parallel with the main shaft
if desired. The plate O fits accurately a slit or opening which cuts the piston-
The plate slides
orbit at right-angles to the plane of revolution of the piston,
freely in the slit and is connected by a rod N with the piston M, the latter working
The stroke of the
in a small auxiliary cylinder L carried by the casing I).
auxiliary piston M and of the plate O must be more than the diameter of the
Suitable packing strips and
pistou A in order to overlap the piston area D.
springs are let into the lower edge of the plate and the sides of the slit in order
to make steam-tight joints as shown at r, Fig. 6. The reciprocating movement of
the piston M and consequently of the stopper-plate 0 is effected by means of the
quadrantal countersunk passages and in the disc B, (Fig. 6) which bring the
auxiliary cylinder ports and Fig. 4, respectively into alternate communication
with the steam ports s and s and the exhaust ports e and e³ through the ports
and passages and c. The positions of the ports s and s which communicate
with the annular spaces d, and of the ports e2 and e, e and c and the lengths of
the quadrantal passages, are such, that the upper and lower ports of the auxiliary
cylinder are opened simultaneously to the exhaust and steam admission alternately
and cause the auxiliary piston to reciprocate rapidly; the movement thereof being
determined by the distance apart of the ports and the. diameter of the piston A.
The balance of the stopper-plate O in order to avoid friction at the commencement
of the upstroke, is effected by the C-shaped by-pass b b (Fig. 6) in the casing
which opens into the piston-orbit on (each side of the exhaust port d², the object
of the said by-pass, being to admit steam from the back to the front of the piston A
as the latter passes over the exhaust port d and thereby balance the plate 0 and
at the same time render it free to rise by the upstroke of the auxiliary piston. A
parabolic toe T (Fig. 6) which forms a part of the plate a by which the piston. A
is secured to the disc B, is placed in front of the piston; the purpose of which toe
is to ensure the lifting of the plate O by the piston A in case of accident to the
auxiliary piston or rod. In this design steam is admitted to the annular spaces de
in the piston casing, communication with the piston-orbit D being established
by means of the nort f aud countersunk, passage f in the disc B, which pass over
the admission-port d admitting steam during one third of the piston revolution
through the passage f. The admission-port d is provided with a hardened steel
5 ring as in the former case. The governor gear and expansion valve mechanism
may be similar to that indicated in Fig. 2. and will be referred to later on when
describing the compound engine. As shown in Fig. 6 the piston A has nearly
completed its revolution. The exhaust port being closed and the by-pass b
allowing steam to pass from the hack to the front of the piston, the pressure on
50 both sides of the stopper-plate is equal. The parabolic toe T in front of the piston
will lift the stopper-plate as the piston advances in the absence of other provision
for doing so. The quadrantal passages 3 and 4 (Figs. 4 and 6) place the auxiliary
cylinder ports and into communication with the steam and exhaust ports s
and e respectively, so that the auxiliary cylinder is taking steam at the lower cnd
55 and exhausting from the top, causing the piston M and the plate 0 to lift rapidly.
As the piston A advances to the position immediately in advance of the stopper-
plate O, the passages 3 and shaving passed over the ports 's and e³ and placed the

page_text: ports and in communication with the ports, e and s, the auxiliary cylinder
takes steam at the top and exhausts from the lower end; this condition is main-
tained until the piston A has completed its revolution when the. operation is
repeated. Provision is made for cushioning the auxiliary piston stroke by steam
spaces in the cylinder ends. Packing rings as at b, Figs. 4 and 5, and in other
parts of the piston casing adjacent to the, steam spaces are inserted where necessary
to reduce friction and make steam-tight joints.
The compounding of engines constructed as herein described may be readily
effected without multiplying the number of parts other than the pistons aud
stoppers. In double reversing and compound engines two or more pistons are
fixed around one main shaft cach revolving in its own orbit; stoppers of corres-
ponding areas being fixed on another shaft parallel with the main shaft. The
dead centre between the intersection of the piston- and stopper-orbits may be
obviated by setting the pistons at different points on the circumference of the
piston-carrier or drum.
P!
A multiple compound engine is shown in Fig. 8, in which six graduated
pistons A to A are fixed on the periphery of a piston-carrier or drum B mounted
on a shaft C. The piston-carrier is constructed hollow to ensure lightness and for
convenience of fixing the pistons thereto, these latter are provided with strong
shauks which pass through the cylindrical wall of the piston-carrier and are
secured on the inside with cotters or mits as shown in Fig. 7. In order to main-
tain the rigidity of the pistons notches are formen in the outer surface of the
carrier into which the pistons fit accurately and tightly making steam-tight joints.
D to D show the disposition of the piston-channels or orbits and the partitions
between them in the casing 1). Mounted on the shaft E are six stoppers G, G, G,
G, G, G. which by means of the gear wheels B F revolve in unison with the
pistons A to A6 Apertures G to Go in the stoppers allow the pistons to pass. in
the portions of their orbits which are intersected by the stopper-orbits. In order
to secure lightness in the larger sizes the stoppers are constructed as shown in
Fig. 8. They are hollow annular rings with the distance rings 9.9, 9, equal to the
thickness of the partitions between the piston-orbits inserted between them. In
addition to a feather key on the shaft E the bolts h h having countersunk heads
and nuts securely fasten them together. The ports and passages P, P, etc., in
the end and cylindrical walls of the piston-carrier B admit steam to the several
piston-orbits by the shortest possible course, without external radiation.
Fig: 7, is the admission-port to the first orbit D; P being the exhaust, the
latter communicating by way of the passage in the thickened part of the cylin-
drical wall B* with the inlet P3 of the second orbit 1. P P are the second
exhaust and third inlet ports respectively. It will be seen that the piston A¹
has completed its revolution under pressure, the port P is opening and admitting
steam to the second piston-orbit through the passage P3 and so on through the
series until it arrives at the exhaust d Fig. 8,, where it may be taken into a con-
denser if required. In the end cover of the casing adjacent to the inlet-pipe d,
are the annular space and the annular expansion discs do and (Fig. 8).
The disc do is loose on the shaft C and has a circular port and countersunk quad- 4
rantal passage corresponding with f f Fig. 6, which gives a fixed cut-off at, sny
one third of a revolution, a small feather or stud in its outer edge preventing its
rotation with the shaft C but permitting of a slight lateral movement in order to.
make a steam-tight contact joint with the end and port P of the piston-carrier B*
as the latter revolves. The annular disc d is also fopse on the shaft C and forms 5
a variable expansion valve, it has a quadrantai opening do corresponding with the
port in do. On its outer edge spur teeth are formed which mesh with the
pinion d, this latter, by means of a small shaft to which it is keyed and the lever k
attached to the governor lever k, causing the disc d to partially rotate forwards.
or backwards, and, by means of the quadrantal passage, entirely cutting off the 5
steam supply. or lengthening the period of admission as the speed and position of
the governor may determine.

page_text: Packing rings are placed in the piston-carrier ends, as at d (Fig. 8), in the
partitions between the piston-orbits adjacent to the piston-carrier. Rectangular
packing pieces are placed in the stopper-orbits inside the points of intersection
with the piston-orbits adjacent to the spaces G and G. Fig. 7. Tho. piston pack-
ings are also rectangular pieces; provision being made in them for a slight
expansion when under steam pressure by tapering them to'a thin edge, towards the
back of the piston. They are also secured in the piston by naving lugs on the side.
pieces which enter recesses in the piston blocks thus preventing them from flying
out.
The structure of the bed-plate H is entirely dependent on the arrangement of
the different parts of the engine and need not be further described. It will be
eadily understood that a great many modifications may be made in the minor
structural details of the engine and the arrangement of the various' parts, without
sacrificing any, of the principles or advantages of the invention, according to the
purpose for which it is designed and whether it be intended to act as a motor, or
pump, and blower, or air-compresser. Its application also as a gas or internal
combustion engine, on the compound principle will be evident, and its operation
and advantages will be sufficiently clear to those skilled in the art, from the forc
going description and the accompanying drawings
Having now, particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I claim :-
1. The improved rotary engine, constructed substantially as herein described
and comprising a disc carrying on its periphery a radially projecting piston, a
stopper or head arranged on a disc which serves as the valve for the pressure fluid;
the piston and stopper revolving simultaneously in intersecting channels or chases
in the casing, whereby the piston enters the path of the stopper, the latter being
formed with a cavity to perinit the piston to pass.
2. In a rotary engine of the character herein referred to, the employment of a
disc such as B having a radially projecting piston, such as A of circular or other
suitable form secured to its periphery; the disc revolving in a cavity in the casing
and, working in steam-tight contact with the casing at or near its rim, substantially
as described.
3. In a rotary engine of the character herein referred to, the employment of a
stopper, such as G, having an opening G in its periphery and mounted on a disc,
such as F, the latter revolving freely within the casing (D) and being provided
with means for admitting and cutting off the flow of fluid pressure, substantially
as and for the purposes specified
4. In a rotary engine of the character herein referred to, the combination with
the casing D. having an inlet-port d and an admission-port d', of a rotating disc F
having a port f and a quadrantal countersunk passage f substantially, as described
and for the purpose specified.
5. In a rotary engine of the character herein specified, the improved mode of
mounting the piston consisting in bolting the same to a plate having a shank let
into the periphery of the disc and cottered through the web, substantially as
5 described.
6. In a rotary engine in which the stopper-disc ievolves in a different plane to
that of the pistom, the mode of balancing the pressure on the back and front of
the stopper-disc, same consisting in connecting the piston-orbit in front of the
stopper and providing spaces at either side of the piston-orbit, whereby the pressure
Dat every point of the piston revolution is equal on both sides of the stopper-diso
and the latter is consequently free to revolve without, friction on the faces of the
aperture, substantially as described.
7. In a rotary engine in which a reciprocating stopper-plate is used instead of
a revolving stopper-disc, the improved method of reciprocating the stopper-plate
5 by means of a small auxiliary cylinder in which a piston connected' to the stopper-
plate by a rod is actuated positively by the steam as the piston-disc revolves,

page_text: whereby the ports of the auxiliary oylinder are brought into communication with
the steam and exhaust ports alternately by means of the quadrantal countersunk
passages in the disc, substantially as described and for the purpose specified.
8. In a rotary engine in which a reciprocating stopper-plate is used instead of a
revolving stopper-disc, the method of balancing the stopper-plate at the commence-
ment of the upstroke by the C-shaped by-pass disposed in the casing and having
an opening into the piston-orbit on each side of the exhaust port, whereby steam
passes from the back to the front of the piston and equalizes the pressure on both
sides of the stopper-plate, substantially as and for the purposes specified.
'
In a rotary engine wherein a reciprocating stopper-plate is used as an abut-
ment or head for the steam, the herein described method of admitting steam to
the piston casing in the annular channels on each side of the piston-disc in order
to balance the latter, and of establishing communication between the piston-orbit
and the steam-inlet by means of the port and quadrantal countersunk passages in
the piston-disc as the latter revolves, substantially as specified.
10. In a rotary engine in which a reciprocating stopper-plate is used instead of
a revolving stopper-disc, a parabolic toe or lifter, fixed in front of the piston,
whereby the lifting of the stopper-plate by the piston is ensured in case of accident
to the auxiliary piston or rod, substantially as described:
11. In a compound rotary engine of the character herein described, the improved
method of mounting the pistons on a hollow cylindrical piston-carrier by letting
the same into notches in the outer surface of the piston-carrier and having strong
shanks secured with cotters or nuts on the inner side of the cylindrical wall of the
piston-carrier, thickened at these points, each piston revolving in an annular
channel or orbit in the outer casing and working in unison with a corresponding
stopper having an aperture in its periphery for the passage of the piston mounted
on a shaft parallel to the piston-shaft, both shafts being furnished with spur
wheels of equal pitch and diameter meshing with each other, substantially as
described.
12. In a compound rotary engine of the character herein described wherein a
number of graduated pistons are fixed on the periphery of a revolving piston-
carrier mounted on a shaft and working in unison with a corresponding number
of stoppers mounted on a parallel shaft, forming the steam passages and ports con-
necting the piston-orbits in the cylindrical wall of the piston-carrier or drum,
whereby the steam is conducted between the orbits by the shortest possible way
and external radiation entirely prevented, substantially as herein described.
13. In a rotary engine of the character herein referred to having a rotary dise
or drum carrying a radially projecting piston which revolves in an annular channel
or orbit and a revolving or reciprocating stopper or head to form an abutment
for the steam, the annular expansion discs in the side of the casing in conjunction
with the annular steam space in the same, the inner disc moving in a lateral direc-
tion and having a port and quadrantal passage forming a fixed cut-off, the outer
disc being capable of partial rotation by means of the spur teeth on its edge mesh-
ing with a spur pinion on the shaft connected to the governor lever; and the
quadrantal passage in the disc being concentric with the passage in the inner dise
and the annular steam space in the casing, its rotation in a forward or backward
direction shortening or lengthening the period of steam admission according to
the speed and position of the governor and its lever substantially as described
and for the purpose specified.