Improvements in Rotary Engines.
Year: 1899

page_text: Date of Application, 10th Apr., 1899-Accepted, 20th May, 1899
COMPLETE SPECIFICATION.
Improvements in Rotary Engines.
I, EDWIN HEBER MONTGOMERY, of 538, Marshall Avenue, St. Paul, Ramsey
County, Minnesota, United States of America, 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:-
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This invention relates to improvements in rotary engines and particularly in
the means for controlling the inlet of steam to the piston chamber, and also the
construction of the chamber itself.
In the accompanying drawings forming part of this specification
Fig. 1 is a front elevation of the preferred construction of this engine partly
broken away;
Fig. 2 is a section on line -2 -2 of Fig. 1;
Fig. 3 is a front elevation with the front wall of the piston chamber removed,
and being partly broken away; to show the construction of piston cylinder;
Fig. 4 is a view of the piston chamber removed;
Fig. 5 is a cross section of the piston cylinder;
Fig. 6 shows details of the trunnions;
Fig. 7 is a front elevation partly broken away of a modified construction of this
engine, and
Fig. 8 is a section on line --2 -2 of Fig. 7.
In the preferred construction of this engine shown in Figs. 1 to 6, A represents
the steam chest within which the operating parts of the engine are arranged.
Within the steam chest is arranged a piston chamber 2, carried by a shaft 3,
said shaft having journal supports 4 at the rear of the steam chest, and carrying
a suitable fly wheel 5. Within the piston chamber is a piston carrying cylinder 6,
said cylinder being rotatably mounted upon a fixed shaft 7. Said shaft is pro-
vided with a flange 8 through which pass bolts 9 adjustably securing it to the
front wall 10 of the steam chest. The shaft 7 is arranged somewhat above the
main driving shaft 3, thus holding the piston carrying cylinder in an excentric
position in the piston chamber, said cylinder being in contact with the upper
portion of the chamber. It will thus be seen that both the piston chamber and
the cylinder are rotatably mounted.
Projecting inwardly from the wall of the piston chamber is a fixed wing or
slide 11. Said wing extends between trunnions 12, which turn in recesses 13
in the cylinder. One side of the wing or slide 11 is cut away to form a port 14
which registers with a conduit 15, extending through one of the trunnions. Steam
passes from the steam chest to said conduit through a conduit 16 in the piston
cylinder Said conduit 16 is adapted to be closed by a centrifugal governor 17.
The steam
The steam chest is supplied with steam through the inlet pipe 18.
exhausts from the piston chamber through the exhaust port 19 in the cylinder,
passing through openings 20 in the fixed shaft 7 to the central conduit 21 which
extends through said shaft, as shown in Fig. 2.
The operation of the engine is as follows: Steam entering through the inlet
From the steam chest
pine 18 maintains a constant pressure in the steam chest.

page_text: the steam passes through the port 16 in the cylinder to the port 15 leading through
the trunnion, and issues into the piston chamber from the port 14 in the wing.
In starting, the parts are in the position shown in Fig. 1, so that the steam as it
passes into the piston chamber fills the space between the wing and the point
where the cylinder is in contact with the wall of the piston chamber. The pres-
sure of the steam rotates the piston chamber and the inclosed cylinder. Since
the chamber and cylinder have two different centers it will be evident that as
they revolve the wing will be drawn through the trunnions turning said trun-
nions and gradually cutting off the inlet of steam, said inlet being preferably
cut off from 3/8 to ½ stroke. From that point the expansion of the steam is utilized
until the cylinder has been-turned' sufficiently to bring the exhaust port past the
point where the cylinder is in contact with the chamber to allow the exhausting
of the steam.
In the modified construction shown in Figs. 7 and 8 A represents the steau
chest. Within the steam chest is a fixed cylinder wall 2" forming a piston cham-
ber 3 Within said piston chamber is a piston carrying cylinder 4" said cylinder
being secured upon a rotatable disk 5", which closes one end of the piston chamber.
The piston carrying cylinder is mounted upon a driving shaft 6", which is excen-
trically arranged with reference to the piston chamber.
Working in openings in the sides of the piston cylinder is a pair of slides B₁.
These slides are held in contact with the wall of the chamber to serve as pistons
by means of the pin 7 extending inwardly from the wall 8 of the steam chest
and projecting into an opening y in the inner overlapping ends of the slides,
thus serving as a pivot upon which said slides turn. Suitable packing strips are
arranged in the end of the piston slide. A tight joint is maintained between the
piston slides and cylinder by means of trunnions 11" which are arranged in re-
cesses 12 in the cylinder and between which the piston slides work. It will be
evident that there will be a turning of the piston slides as the cylinder is rotated,
due to the excentric arrangement of the cylinder, and this movement of the slides
is permitted by the trunnions which turn in the recesses 12". The front end of
the piston chamber is closed by the disk 13" secured to the piston-cylinder. Steam
enters the steam chest through an inlet pipe 14ª, passing through an opening 15"
in the rear wall of the piston chamber and a registering opening 16" in the piston
cylinder to a conduit extending through one of the trunnions to a port 18" in the
piston slide. The port 18ª opens upon that side of the slide which is adjacent to
the point where the piston-cylinder is in contact with the wall of the chamber,
thus causing the steam as it issues from the port to exert pressure upon the slide
and rotate the cylinder. The steam is exhausted from the piston chamber through
an exhaust port 19" which is always open. The conduit 15° extends entirely
through the piston cylinder and the walls of the chamber, thus permitting the
steam to pass into the space adjacent the front wall of the piston chamber to exert
pressure upon the packing ring 20 between the front wall and circular side wall
of the chamber. Similar packing rings 21" are arranged between the rear and
side wall. The inlet end of the port 15 is closed by a centrifugal governor 22ª,
normally held away from the conduit by a suitable spring so that the rotation of
the cylinder will throw the governor into closed position.
It will be seen that the trunnions are constructed and work in the same way
in both constructions. They serve as guides for the piston slides as well as inlet
cut-off valves. In the construction shown in Figs. 1 to 6 the piston cylinder and
piston chamber both revolve, whereas in the construction in Figs. 7 and 8 the
piston cylinder revolves within the chamber.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
"
1. In a rotary engine, the combination of a rotary piston chamber, a rotary 5
cylinder excentrically arranged therein, a sliding connection between the wall

page_text: of said chamber and cylinder, and independent axial supports for said chamber
and cylinder.
2. În a rotary engine, the combination of a rotary piston chamber, a supporting
shaft therefor, a cylinder within said chamber, a supporting shaft for said cylin-
der arranged out of alignment and parallel with said chamber shaft, whereby the
cylinder is held in excentric position in said chamber, a piston slide projecting
inwardly from the wall of the chamber, and trunnions arranged in recesses in said
chamber and serving as guides for said slide.
3. In a rotary engine, the combination with a piston chamber, of a piston cylin-
der therein, a piston slidably arranged in the periphery of said cvlinder, a rotary
cut off valve arranged between said piston and cylinder and actuated thereby.
4. In a rotary engine the combination with the steam chest, of an inclosed
piston chamber, a piston cylinder excentrically arranged in said chamber, a piston
slidable in the periphery of said cylinder and normally held in contact with the
walls of the chamber trunnions arranged between the cylinder and piston and
serving as guides for the piston, one of said trunnions being formed with a con-
duit adapted to register with an inlet port and a port leading through the piston,
whereby said trunnions serves as a cut-off valve.
Dated this 10th day of April 1899
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.