Improvements in Rotary Engines.
Year: 1893

page_text: Date of Application, 14th June, 1893-Accepted, 22nd July, 1893
Improvements in Rotary Engines.
I, GEORGE HARLEY GRAHAM, of Oak Park, in the County of Cook, and
State of Illinois, United States of America, Clerk, 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:-
This invention relates to rotary engines; and has for its object to provide a
compound or double expansion rotary engine, which will be simple in construction,
efficient, and utilize the double expansive force of the steam to the best possible
advantage.
A further purpose of the invention is the provision of instrumentalities for con-
veniently altering the force of resistance of the governor to change the speed of
the engine, said instrumentalities being located within the piston and operated
through an opening in the head of the casing which opening is closed by a screw
plug or other convenient means of closure.
A still further purpose and the primary object of the invention is the improve-
ment of the general construction of this class of engines, whereby their usefulness
and efficiency are increased to an eminent degree.
The improvement consists of the novel features and the peculiar construction
and combination of the parts which will be hereinafter more fully described and
claimed and which are shown in the annexed drawings in which:
Figure 1 is a side elevation of an engine embodying my invention, parts being
broken away to show the roller valve and its casing.
Fig. 2 is a section about on the line X-X of Fig. 1 looking to the right, showing
the steam inlet and exhaust ports in the piston in full.
Fig. 3 is a front view of a valve casing and the mechanism for controlling the
valve, showing the relation of the same to the cylinder of the engine.
Fig. 4 is a side elevation of the piston, the cap plate being removed, showing the
governor.
Fig. 5 is a detail view of the primary head of the piston on a larger scale.
Fig. 6 is a detail view of the governor setting mechanism.
Fig. 7 is a detail view of the roller valve and its casing.
Figs. 8, 9, and 10 are diagrammatical views, showing the relation of the valves
and the piston heads.
The cylinder 6 mounted on the bed or base 7 is closed at its ends by the heads 8
and 9 which are centrally apertured to receive the shaft 5 to which the piston 10
is secured and to which the balance wheels 11 are fastened. The bearings K for
the shaft 5 are bolted to the cylinder heads and may be of any desired form. The
packing L confined between the bearings and the said heads, prevents leakage of
steam. The steam inlet passage H is formed in the head 9 and communicates with
an annular chamber on the inner side of the head and surrounding the shaft 5.
The steam exhaust passage J provided in the head 8 communicates with the annular
chamber formed in the inner side of the said head and surrounding the shaft 5.
The steam inlet passage A in the piston communicates with the annular chamber h
and extends through the primary head a of the piston. The exhaust passage C
leading into the annular chamber j extends through the peripheral surface of the
piston just in the rear of the primary piston head. The secondary piston head b
located diametrically opposite the primary piston head a is constructed to present
considerable more surface for the action of the steam than the primary head, being
deeper. A passage B formed tangentially through the piston extends through the
head band through the periphery of the piston just in the rear of the said head,

page_text: The steam after its primary expansion, escapes through the said passage B to be
expanded a second time.
The cylinder is provided with four radially disposed valves which are disposed
at an equal distance apart around the said cylinder, and which are adapted to slide
within casings 12 bolted to or otherwise provided on the said cylinder. The valve
heads 13 are recessed on their inner faces to receive rollers 16 which are designed
to travel on the piston and relieve friction, and with a slot in one side in which is
fitted a packing strip 15, the same preserving a close joint between the valve and
piston. The outer face of the head 13 is depressed to receive a plate 14 which
overlaps the outer portion of the packing strip 15 and which is held down at one
edge by a scarf joint and bolted to the head at the other edge. The valve stem 17
passes through the plate and screws into the valve head, having a shoulder just
above the plate 14 to rest thercon and assist in securing the said plate. The valve
head fits snugly within the casing 12 and to equalize the outward pressure on the
inner face thereof, passages V are provided in one side of the casing for the escape
of steam to the outer side of the said valve head. This construction admits of
the valve head being essentially a balanced valve. A lever A¹ is pivotally con-
nected between its ends to the head B₁ of the valve stem 17, and its ends have a
spring connection with the cylinder heads. The heads have lugs C¹ near their
periphery, through which rods D are inserted and secured at their inner ends by
being screwed into the hub portions of the said heads. Heads E are mounted to
slide on these rods and are connected with the ends of the lever A¹ by rods F F
which pass through suitable openings in the lugs C. The springs d mounted on
the rods and confined between the lugs C¹ and the heads E press the said heads E
toward the centre of the cylinder and through the rods F F draw the levers A¹ in
and press the valves close against the piston. A packing strip T is inserted in a
channel just in the rear of a piston head and is held therein by binding screw W.
The front edge of this strip projects sufficiently far in front of the piston head to
preserve a steam tight joint between the piston and the cylinder. A packing or
cushion S is provided in the depressed portion of the piston front of the piston
heads to receive the blow of the valve and prevent noise and unnecessary wear.
The valve the instant it leaves the head, strikes the piston in front of the said head
a smart blow. The cushion is provided to relieve the force of the blow. The
packing may be of any suitable material and may be laminated or in one piece and
is secured to the piston in any convenient manner, preferably by being sprung into
a recess formed therein and having under cut edges. The piston is hollow being
open on one side which side is closed by a removable cap 19 which is bolted thereto,
and receives the governor and the mechanism for setting the governor to control
the speed of the engine.
The gate K' for controlling the inlet port A is connected with a bell crank
lever J, which is connected with the long arm of the equalizing lever H by
connecting rod I which is adjustable to change the relation of the gate or cut-off K¹
to the port A. The weighted levers F and F approximately parallel with each
other and with the equalizing lever H', are pivoted at diametrically opposite points
and extend in opposite directions on each side of the shaft 5 and are connected
with the equalizing lever by the links L¹ and G, respectively. The spring M for
controlling the action of the governor, is connected at one end for the sake of
convenience to the weighted lever F2 and at its other end to a head N which is
adapted to slide between parallel ribs X. A threaded rod Q is connected with the
head N and passes through two lugs r r between which is confined a nut P threaded
to correspond with the thread of the said rod Q on which it is mounted, and having
a worm gear to mesh with the worm shaft-O which is parallel with the shaft 5.
The outer end of the worm shaft O is countersunk in the cap plate 19 so as to
come flush therewith and is constructed to be engaged by a suitable instrument
to be rotated thereby to turn the nut P and move the rod in its bearings so as to
increase or diminish the tension of the spring M. The head 9 is provided with an
opening opposite the worm shaft O which is closed by a screw plug 20 to admit of

page_text: access to the said shaft for changing the force of resistance of the governor. After
the governor has been properly regulated the engine will run at a uniform speed.
As the free or weighted ends of the levers F and F fly out the cut-off will be
projected across the steam port A and shut off the steam and as they move toward
the centre the cut-off will be withdrawn so as to open the port A wider and admit
more steam to the engine. The live steam enters passage H, annular chamber h
and passes through the passage A into the cylinder. Suppose the valves 1, 2, 3,
and 4 and the piston to be in the position shown in Fig. 8, the steam entering
through port A exerts its expansive force against valve 2 and the primary piston
head a.
As the piston revolves, see Fig. 9 which shows the valve 1 and 3 partly
closed for the sake of better illustrating the application of the invention, the high
pressure is partly against valve 2 and the said valve 3, while the steam is expanding
a second time between the secondary piston head band the valves 4 and 1.
the piston reaches the position shown in Fig. 10 valves 1 and 3 are entirely closed,
and the primary expansion is against 3 and secondary valve 1, while between
valves 2 and 3 is inclosed steam once expanded and between valves 1 and + steam
twice expanded. On a farther rotation of the piston, the primary expansion is
still against valve 3, while the once expauded steam from between valves 2 and 3
escapes through passage B and acts against valve 1 and the secondary piston head,
while the twice expanded steam inclosed between valves 1 and 4 escapes through
the exhaust port C.
When
I desire to state that solid valves provided with packing on their edges which
bear upon the piston may be substituted for the roller valves, and that receding
ribs on the piston may be employed to let the valves down from the piston heads
gradually; or eccentric cams, properly shaped on the inner sides of the fly wheels
may engage with lugs on the spring carriages and accomplish the same result.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a rotary engine, the combination with the casing, a hollow piston located
within said casing, and having one side arranged to work steam tight against a head
of the said casing, and a governor located within the said piston, of a governor
controlling mechanism located within the said piston and adapted to be reached
through coincident openings in the said steam tight fitting side of the piston and
the head of the casing, and a plug for closing the opening in the head of the
casing, substantially as described.
2. In a rotary engine, the combination with the casing having a lateral opening
in one of its heads, a hollow piston having one side open, and having the open side
closed by a cap plate, said piston fitting steam tight between the heads of the
casing and having an opening in said cap plate to register with a corresponding
opening in a head of the casing, of a governor and a governor controlling mechanism
located within said piston and the governor controlling mechanism adapted to be
actuated through the said coincident openings and a plug for closing the opening
in the casing head, substantially as described.
3. In a rotary engine, the combination with a casing, a hollow piston arranged to
work in the said casing, and a governor placed within said hollow piston, of a
spring connected at one end with the governor, a head connected with the other
end of the spring and working in guides, and a mechanism for moving said head
in the guides to vary the tension on the said spring adapted to be actuated through
coincident openings in a side of the piston and a head of the casing, substantially
as set forth.
4. In a rotary engine, the combination with a hollow piston, and a governor
located within the said piston, of a spring connected with the governor, a threaded
rod attached to the said spring, a nut mounted on the said threaded rod and having
a worm gear, and a worm threaded shaft to rotate the said out to vary the tension
of the said spring, substantially as and for the purpose described.

page_text: 5. In a rotary engine, the combination with a piston having a steam inlet port A
formed therein, and a cut-off to control the said port, of weighted levers, one on each
side of the axis of the piston, an equalizing lever connected with the said weighted
levers, and connections between the said cut off and the said equalizing lever,
substantially as described.
6. In a rotary engine, the combination with a piston having a steam inlet
port A formed therein, and a cut-off to control the said port, of weighted levers,
one on each side of the axis of the piston, an equalizing lever, the three levers
being approximately parallel and links connecting the weighted levers with the
equalizing lever, a bell crank lever connected with the cut-off and an adjustable
connecting rod between the said bell crank lever and the equalizing lever,
substantially as described.
7. In a rotary engine, the combination with a piston having a.steam inlet port A
formed therein, and a cut-off to control the said port, of weighted levers, one on
each side of the axis of the piston, an equalizing lever, the three levers being
approximately parallel and links connecting the weighted levers with the
equalizing lever, a bell crank lever connected with the cut-off, an adjustable
connecting rod between the said bell crank lever and the equalizing lever, a spring
connected at one end with one of the weighted levers, and a tension controlling
mechanism connected with the other end of said spring, substantially as
described.
8. In a rotary engine, the combination with a cylinder, and four valves equally
disposed around the same, of a piston having a primary and a secondary head to
use the expansive force of the steam twice, the secondary piston head being of
larger area than the primary piston head to admit of the once used steam exerting
a force on the said secondary piston head about equal to that exerted in the first
instance on the primary piston head.
9. In a rotary engine, the combination with a piston having a primary and a
secondary piston head, a steam passage being formed through the said secondary
piston head, of a cylinder, and four valves equally disposed around the said
cylinder, substantially as described.
10. In a rotary engine, the combination with a piston having a primary and a
secondary piston head, a steam passage being formed through the said secondary
piston head, the steam inlet port extending through the primary piston head, and
having the exhaust port leading through the piston just in the rear of the said
primary piston head, of a cylinder and four valves equally disposed around the
said cylinder, substantially as described.
11. In a rotary engine, the combination with the cylinder having a casing, of a
valve head 13 having a slot in one side and provided with a roller on its inner face,
and having a depression in its outer face, a packing strip 15 inserted in the said slot,
and a plate 14 fitted in the said depression and bearing down on the upper edge of
the said strip 15, substantially as and for the purpose specified.
12. In a rotary engine, the combination with the cylinder having a valve casing,
a radially working valve located in and having its stem working through the valve
casing, and radial guide 1ods D exterior to and supported by the cylinder heads, of
a lever A¹ pivoted midway of its ends to the said valve stem, rods F connected at
their outer ends with the ends of the pivoted lever A¹ and guided in their
movements by lugs on the sides of the cylinder heads, cross heads E mounted to slide
on the rods Ď and connected with the inner ends of the rods F, and springs d
mounted on the rods D and held between the said cross heads and the lugs,
substantially as set forth.
13. The improvements in rotary engines, substantially as and for the purposes
herein before described, set forth, and illustrated in the drawings annexed.
Dnd his 14th day of Tunn 1002
F. W. BARKER,
Applicant's Agent.