Improvements in Rotary Engines.
Year: 1892

page_text: Date of Application, 9th Mar., 1892-Accepted, 30th Apr., 1892
Improvements in Rotary Engines.
A communication from GUSTAV JENTSCH, of Scifhennersdorf, Saxony, in the
German Empire, Manufacturer.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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 rotary engine operates by means of a piston in the shape of a blade adapted
to revolve within a cylindrical casing and secured to a shaft located in the centre
of the casing. The impulse of the motive power agent is regulated by a sliding
diaphragin, tightly fitting the walls of the casing or cylinder and adapted to fit
against the nave or boss of the piston-blade. To enable this blade to pass when
required, the said sliding diaphragm is adapted to be removed from the cylinder
by means of suitable gearing, either in a radial or an axial direction, as soon as
the piston has passed, it is by the same means caused to move in the reverse
direction and re-enter the cylinder. While this sliding diaphragm is thus moving
into or out of the cylinder, the supply of driving fluid is cut off. The piston or
blade is then moved beyond the sliding diaphragm by the momentum of the fly
wheel, whereupon the driving fluid or motive power agent is again admitted to
impart positive motion to the blade.
One forin of engine constructed in accordance with this invention is shown in the
accompanying drawings, the driving medium to be employed for its operation being
assumed to be steam.
In these drawings
Figs. 1 and 2 are, respectively, a cross section and a longitudinal section, both
vertical and at right angles to each other.
A is the cylindrical casing, through the centre of which passes a shaft a supported
in stuffing-boxes, properly fitted on each side. Upon this shaft a is rigidly keyed
or otherwise secured a blade arranged to act as a piston. This blade is a flat
piece extending as far as the wall of the cylinder A. c is the steam inlet, d the
outlet. Between the two there is arranged a sliding diaphragm e extending radially
in relation to the cylindrical case and fitting steam-tight against both the wall and
the nave of the piston blade b, while a stuffing-box or suitable packing completes a
tight joint between it and the casing outwardly.
Supposing now the sliding diaphragm e at the outset occupies the position shown
in Fig. 1, ie. its lowermost position, and that the blade or piston 6 turning in the
direction of the arrow, is at the distance shown from the steam-inlet c, towards
which it is moving. The inlet being open, steam is admitted behind the piston or
blade, and being repelled by the diaphragm e against which as it rushes in, it
impinges, it is thereby caused to act upon the piston b and drive it forward. In
the meantime the steam that had served in the preceding revolution of the piston,
escapes through the outlet d which is constantly open. So long as the steam-inlet
is open, the steam exercises its pressure to its full extent, while, when the inlet is
closed, expansion takes place. This enables the degree of expansion of the steam
within the cylinder to be controlled in the same way as is done by ordinary valve-
gearing in cylinders fitted with a reciprocating piston. When therefore the piston
is brought up close to the diaphragin e, as indicated in Fig. 1, the inlet c is first
closed by means of the valve-gearing, and then the diaphragm e is withdrawn from
As the blade
the casing so as to enable the blade b to pass freely underneath it.
does so, however, it receives no positive impulse, but moves on owing to the
momentum stored up by the fly-wheel. Or a preferable arrangement would be to

page_text: .
arrange two casings or cylinders upon the same axis in such a position that their
respective piston-blades are at 180° to each other. This double acting or twin
engine will then operate similarly to the well-known compound engines, the steam
discharged from one cylinder, after operating its piston, being utilized for the
operation of the other, larger piston.
The operation of the gear whereby the diaphragm e is controlled is as follows,-
By means of bevel-wheels motion is conveyed from the main shaft a, through an
intermediate shaft, to the shaft f. Upon this shaft is mounted a tappet g adapted
at proper intervals to act upon a bell-crank lever / connected with the diaphragm e
to raise it to allow the blade or piston to freely pass it. The slide then descends
by its own weight or by means of a spring or the like.
The steam-inlet valve c by means of a spring i exerting its influence on the
valve-rod k is kept closed until the cam or tappet upon the shaft depresses the
valve-rod k when the valve is opened and by which cam the valve is kept open as
long as necessary.
By providing separate gearing to control the inlet and outlet respectively one
mechanism being always at rest while the other is in operation, the engine is made
capable of being driven either backwards or forwards, as required, and in this
condition it will be found suitable as a locomotive or marine engine or the like.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is,-
1. A rotary engine comprising a piston such as in the shape of a flat piece or
blade adapted to revolve about the central axis of a cylindrical casing A and a
sliding diaphragm such as e serving as a rebounding surface for the motive power
agent tightly packed and fitting and adapted to bear against the nave of the piston
which diaphragm e when the steam-inlet c is closed is withdrawn from the cylinder
in an axial or radial direction under the action of suitable gearing such as f g h
in order to enable the piston blade to pass it un-impeded and then return to its
normal position substantially as described and illustrated in the accompanying
drawings.
2. The combination and arrangement of parts constituting the complete rotary
engine substantially as described and illustrated in the accompanying drawings.
Dated this 9th day of March 1892.
ALFRED J. BOULT,
Chartered Patent Agent.