Improvements in Rotary Engines.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Rotary Engines.
A communication by MONTAGUE JAMES BRETHERTON, of Fort Worth, in the
County of Tarrant and State of Texas, United States of America, Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, and 323 High Holborn in the
County of Middlesex, Civil Engineer, 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 :-
The object of the invention is to provide a reversible rotary steam engine in
which friction shall be reduced to as small an extent as consistent with suitable
packing of the joints, and the pressure on the piston wings be practically balanced,
compensation made for wear and other advantages secured; said invention being
adapted for use in a compound marine engine and it consists in the construction
hereinafter described and particularly pointed out.
In the drawing,
Fig. 1 is a side elevation of two connected cylinders for working steam
expansively;
Fig. 2 is an end elevation partly in section of a cylinder, piston and valve chest,
a cylinder head being removed;
Fig. 3 is a section on line - of Figure 2;
Fig. 4 is a perspective of a piston wing with a part broken out to show joint and
spring;
Fig. 5 is an end elevation of a cylinder and valve chest and
Figs. 6, 7, 8 and 9 are views of ǎetails.
Fig. 10 is a partial section on line y-y of Figure 2.
The numerals 1 and 1' indicate the cylinders. 2 denotes the steam supply pipe.
3 indicates a valve chest, and 2' the outlet for exhaust steam. 4 denotes a valve
rod, 5 an inlet for live steam to cylinder 1, and 6 an outlet for the exhaust. The
valve rod which may be moved in any convenient manner carries the valve 7, 71,
to the opposite sides of the ports 5 and 6, as indicated in dotted lines, when it is
desired to reverse the engine. 8 indicates a conduit for exhaust from cylinder 1 to
cylinder 1 in which it is further expanded, one or more additional cylinders
being employed to fully expand the steam, each cylinder having a rotary piston
wheel and suitable adjuncts.
Within each cylinder, which may be supported in any suitable manner, is a
piston wheel or spider made fast to the axis which is passed through stuffing
boxes 11 in each head. The spider is cast in one piece cored out for the piston
wing recess and other openings, substantially as shown. 16 indicate piston wings
and 15 denote the walls of the piston wing recesses.
17 denote shoes or sections of tire bolted to the sectional rim 14 of the piston
wheel between the piston recesses or pockets, as indicated at 18. 19 are bosses cast
on the rim of the spider and cored out to receive springs 24, which bear upon the
movable packing ring 12.
20 are studs connected to the piston wings and extending through the slots 4' of
the plates 21 at each edge of said wings and into the groove 22 in the inner
surface of each cylinder head. These grooves control mainly the radial movements
of the wings. 23 are springs extending from hub 13' into recesses in the wings to
take up the play of the studs in the grooves and move said wings out to the
periphery of the cylinder when the steam is cut off. 25 are rods screwed into
suitably screw threaded holes in the hub and arranged to guide the springs 23.

page_text: 21 are covering plates secured to the edges of the wing piston recesses of the
piston wheel or spider 15. Two of these are omitted in Figure 2. 27. are
transverse passages in the shoulders or arms 13' of the hub for the passage of steam
to the inner end of the piston wing from the steam space or jacket 28 formed in
the cylinder heads. To form these, the heads are recessed, as shown at 31, and
the recesses are partially covered by the annular plates 29 and packing rings 12,
which latter extend from the plates 29 to the covering plate 21, and are each
located at the side of a rim 14, being pressed outwardly against the inclined face
of the ring or plate 29 by springs 24 in the bosses 19.
26 are thin annular steel plates secured by countersunk screws or otherwise to
the plates 29, their purpose being to exclude steam in the steam jacket from the
joints about the packing ring 12. Annular recesses 30 are formed in the inner
faces of the cylinder heads to furnish spaces for these plates. 31 are check valves
opening from the steam space of the cylinder into the jackets or spaces between
the plates 29 and the recessed cylinder heads.
These recesses extend around the inner surfaces of each head and communicate
freely with the passages 27, whereby live steam is admitted to the bottom of the
piston wings through the openings in the holes that receive springs 23 and rods 25.
By this means steam pressure on the piston wings is balanced until the end of a
wing is fairly seated against the periphery by the action of the groove 22 upon the
studs 20 of the revolving piston wing, whereupon the steam acting through
opening 27 holds the wings against the periphery of the cylinder. The springs in
the wing also act while the steam pressure is balanced to move them outwardly.
During the above described operation steam is excluded from the sides or flat faces
of the wings by the plates 15 and from their edges by the plates 29, packing
rings 12, annular covering plates 26 and plates 21. It may be noted that steam is
excluded from the slots 21 in the plates 21 by the piston wing itself until it has
been moved outwardly a little. It will also be seen that steam circulates freely
about the hub 13.
32 is a cock for drawing off water from the cylinder. 33 are removable plugs
in the cylinder heads placed opposite the groove 22 to permit the removal of the
studs 20, when it is desired to remove the piston wings. The latter can be
withdrawn through openings ordinarily filled by the removable plates 34. The
abutment 35 can be withdrawn through openings closed by plates 36 in the cylinder
head and plate 37 in the annular plate 29. This abutment is made in sections
connected by tongue and groove and provided with packing bars or plates and
springs, the construction being similar to that of the piston wings. 351 indicates
a spring at the top of the abutment adapted to keep it down upon the piston
wheel.
38 are blocks bolted to the cylinder and provided with continuations of the
steam ports of the valve chest. They form a way for the abutment and hold it
vertical against the steam pressure, whereby the pressure on it is partially relieved.
40 are a series of steel springs having their ends resting, preferably, in recesses 41
formed in the cylinder periphery and extending over between the abutment and
the piston to insure the return of the piston wings to their receptacles at the
moment of passing the abutments. They guard against any contact of the wings
and abutment and especially in case the studs of the piston wings break, and they
prevent hammering. The arrangement is such that the wings do not touch the
springs until by the revolution of the piston they are brought near the abutment.
Preferably there are two of these springs fastened to each block 38 near its outer
edge and under the block to just touch the wheel.
The operation of the engine can be readily understood from the foregoing. The
valves being in the situation represented in full lines, steam passes constantly through
port 5 into the space between the cylinder and the piston, a little of it escaping
through check valve 31 to the steam jacket, and operating as above explained.
The steam acting upon the piston and against the abutment which it has passed
revolves the piston and shaft of the engine by its expansive force. The wing next

page_text: passing under the abutment is moved outwardly by the cam groove 22 and the
springs until its edge bears on the cylinder periphery, whereupon it receives the
pressure of the steam until another wing is carried past the abutment and moved
out to the cylinder periphery by the cam and springs.
The partially expanded steam is discharged through port 6 and utilized in another
cylinder or in other cylinders of similar character.
The engine can be reversed by shifting the valves 7, and 7', to the position
indicated in dotted lines, whereupon steam will enter port 6 and escape at 5. The
check valve 31 that is adjacent to the exhaust, in either case, will, of course, be
kept closed by the live steam in the space at its rear.
The piston wings are made in two parts jointed together by a tongueland groove,
but forced outwardly by springs to prevent escape of steam between their edges
and plates 29. 44 are plates placed at the end of the piston wings over the
grooves making a full metal bearing. 45 are steel packing strips inserted in
grooves in the wings, and intended to be pressed outwardly by springs. They have
a tongue and groove connection, but not in the same plane with the groove of the
wing. They prevent steam from passing from the pockets to the exhaust side of
the piston.
The abutment is preferably divided and the parts jointed, substantially, as the
piston wings are. It is also provided with packing strips of similar character.
Springs are admitted in the recess above the abutment to hold it upon the piston
wheel.
Many of the above described details can be varied by mechanical skill without
departure from the invention provided substantially the same principles of operation
and construction are employed.
In Figure 2 is shown mechanism for counteracting the effect of centrifugal force
upon the piston wings, whereby they are otherwise thrown or pressed against the
cylinder periphery with sufficient force to retard the engine. This mechanism
consists of the levers 42 pivoted at 43 in the slots in the walls 15 of the piston
wing pockets. 44 are weights made adjustable on the long arms of the levers,
whereby they can be adjusted for different speeds. 45¹ are set screws and 46 are
regulable stops to limit the throw of the weighted levers. The short arms of each
lever extends into a slot 47 in the face of the piston wing, each slot being sufficiently
long to allow the piston wing to retire within its recess, or on the other hand to be
moved out against the cylinder periphery without obstruction by a lever 42.
When in the latter position the short arm of the levers should bear on the lower
end of the slot, being held in position by springs 48 which are adapted to oppose
extreme movement of the weighted levers in either direction. They prevent
violent concussion or hammering against the wheel and also keep the levers from
flying back too far. It will be understood that when the piston wheel is revolving
and the piston wings thrown outward by centrifugal force, a similar effect is
produced upon the weights, whereby the long arms of the levers are moved
outwardly and the short arms forced against the bottom of the slots in the piston
wings with the effect to counteract outward movement thereof due to centrifugal
action. They are thus kept from producing excessive friction upon the cylinder
periphery.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :—
1. In a rotary engine, the cylinder provided with interiorly grooved head
having removable plugs in the groove and a piston wheel provided with wings
having removable pins, said cylinder having a removable plate in its peripheral
surface, substantially as set forth.
2. In a rotary engine, a steam cylinder having a steam inlet and a recessed head
or steam jacket, a plate covering the recess, a check valve in the plate to admit
steam to said recess or steam jacket, a piston wheel with movable wings and pockets

page_text: or ways for the same having steam inlets near their inner edges, there being free
communication between the recesses or steam jackets in the head and said inlet
in the piston wing pockets, whereby the wings are balanced, substantially as set
forth.
3. In a rotary engine, a steam cylinder having a steam inlet and recessed head
or steam jacket, a plate covering the recess, a check valve in the plate to admit
steam to said recess or steam jacket, a piston wheel with movable wings and pockets
or ways for the same having steam inlets near their inner edges, there being free
communication between the recesses or steam jackets in the head and said inlet in
the piston wing pockets, whereby the wings are balanced, and springs tending to
press the wings outwardly, substantially as set forth.
4. In a rotary engine, a piston wing made in parts connected by tongue and
groove, and provided with a spring in the central groove tending to separate the
parts, and having transverse and jointed packing strips situated in grooves in the
face of the two-part wing and having the joints at one side of the joint between
the parts of the wing to permit the extension of said strips and to prevent steam
from passing between the parts, substantially as set forth.
5. In a rotary engine, an abutment made in parts connected by a tongue and a
groove, and provided with a spring in the central groove, and having transverse
and jointed packing strips situated in grooves in the face of the two-part abutment
and having the joints at one side of the joint between the parts of the abutment
to permit extension of the strips and prevent escape of steam between the parts,
substantially as set forth.
6. In a rotary engine, the combination of the cylinder, abutment and piston with
the steam chest having an inlet and outlet, and having two ports communicating
with the cylinder, and piston valve adapted to admit live steam to the cylinder
through either port and exhaust through the other, and a steam jacket or recess in
each cylinder head provided with a check valve whereby live steam can be admitted
to one recess and behind the piston wings and exhausted from the other recess,
both recesses communicating with the space behind the wings, substantially as set
forth.
7. In a rotary engine, the combination of the steam jackets composed of the
recesses in the cylinder head covered by plates 29, the annular packing located
between the piston wheel rim 14 and the annular plate of the steam jacket and the
flat steel rings 26 attached to said annular plates 29 and extending over upon the
wheel rim, substantially as set forth.
8. In a rotary engine, the combination of the annular packing ring having an
inclined face located between the piston wheel rim and the annular plate of the
steam jacket, also having an inclined face, and the flat steel rings attached to said
annular plates and extending over upon the wheel rim, and a spring to press the
packing against the plate, substantially as set forth.
9. In a rotary engine, the combination of piston wings provided with alots in
their sides, and levers having arms extending through the walls of the piston wing
pockets and normally in contact with the outer end of the slots in the wings when
the latter are in contact with the cylinder, said slots being sufficiently long to
permit the wings to retire without the withdrawal therefrom of the levers and
said levers being adapted under the influence of centrifugal action to oppose the
centrifugal action of the wings and to be thrown out of engagement therewith by
their inward movement, and recalable stops to limit the throw of the levers
substantially as set forth.
11.001
WM. P. THOMPSON & Co.,
Agents for the Applicant.