RECIPROCATING ROTARY ENGINES
Year: 1885

page_text: "
I, LEIGHTON MILLS, of North Shields, in the County of Northumberland,
Engineer, do hereby declare the nature of said invention for IMPROVED
to be as follows:-
RECIPROCATING ROTARY ENGINES
"
My invention relates to an engine operated by steam, water or other fluid
pressure, in such a manner that the reciprocating motion of a piston working in a
cylinder is converted into rotary motion and consists of one or more cylinders
rotating on a common centre. Each cylinder is provided with a piston connected
by means of a rod or its equivalent to a separate crank pin attached to a disc or
discs. The centre, or centres, of such disc, or discs, is, or are, eccentric to the.
common centre on which the cylinders revolve, to an extent which represents half
the stroke of the pistons the reciprocating action of which causes the disc, or discs,
to revolve while the cylinders also revolve round their common centre. When
two discs are fitted one will revolve upon a fixed sheave eccentric to the same
extent as the axis of disc is to the axis round which the cylinders revolve and the
edges of discs may project to meet and form a drum enclosing the cylinders. :
The cylinders may. revolve in trunnion bearings or upon a stationary shaft which
may be called the valve shaft the projecting end of which may be cranked so as to.
work in a bearing on axis of disc. In either case the valve for distributing the
steam is of cylindrical form and may form part of such stationary or valve shaft. :
The cylinders will be preferably single acting but may be double acting and may
or may not revolve in the same plane of rotation. The cylinders may be fitted
so as to revolve round the shaft independently of each other in which arrangement
they form a hinged joiut of the ends of all the cylinders interlocking around the
shaft which represents the hinge bolt. I secure interlocking joints of the binges
on the shaft by a "binding-ring" which allows them independent action.
A modification of the arrangement may be made by placing one or more pairs
of cylinders on each side of the common centre on which they revolve and
connecting the ends of their piston rods in pairs to a crank pin or pins on
the disc or discs as aforesaid. The steam is admitted to and from the cylinders>
by means of passages formed in the aforesaid valve, and through the shaft. or

page_text: trunnions and corresponding passages are cast in or formed in the cylinders to
allow the steam to pass from the valve to the pistons and vice versa. The motion of
the engine is reversed by a movement of the cylindrical valve on its axis changing
the ports but the valve is stationary when engine is running. The power of the
engine will be taken off a shaft concentric with the disc and attached thereto and
may carry a fly wheel if required.
W. LLOYD WISE,
Per F. J. Brougham,
Applicant's Agent.
I, LEIGHTON MILLS of North Shields in the County of Northumberland,'
Engineer, do hereby declare the nature of said invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
My invention relates to an engine actuated by steam water or other fluid
pressure and having reference to my provisional specification of the 19th August
1885, the modification described in the latter part thereof is that which I have
found to work satisfactorily and which prefer to adopt in the practical
application of my invention. And to clearly ascertain how I carry this into
effect, I provide drawings herewith which I explain as follows. Figures 1 and 2
shew a sectional side elevation and a sectional end elevation respectively of an
engine consisting of a disc (1) mounted on bearings (2. 2*) by a hollow shaft
carrying the driving sheave and having a crank pin (3) fixed in its face, to which
is freely attached a crosshead (4) the ends of which receive and hold rigidly the
two piston rods (5. 54) of the pistons (6. 64) working in a pair of double acting,
cylinders (7. 74) which are cast together and have a circular cavity (8) cast in, or
bored through, between them, as nearly as possible at their centre of gravity, with
which the steam passages (9. 9) to and from each end of each cylinder communicate.
The cylinders are supported by, and revolve upon, the cylindrical stationary
valve (10) which is part of my invention-comprising the hollow central shaft (11),
forming the steam passage, the casing (12) and the cranked end (13); and
constitutes the fixed axis carrying the cylinders and upon which they revolve, one
end of the axis being supported in the bracket (14) the other by a pin (15) fixed
in crank (13) and inserted in the hollow shaft of disc (1). The valve casing (12)

page_text: is expansible-so as to adjust its diameter to the wearing of the cavity (8)-and
may in some cases be made of two thicknesses. The cavity in cylinders is made
steam tight at each end by stuffing boxes (150) and packed glands (16), round the
valve casing (12) which at its outer end is closed, and at its inner end is attached
to an internal cone piece (17), kept in position upon the external cone (18)-
forming part of the central shaft (11)-by the packing between the closed end
and a "lantern" (19) and between said "lantern" and the packing rings (20), set
up by the nut (21). The steam enters by the steam pipe (22) to the steam port
in the valve shaft (11) and, by the steam passages (9, 9), to the interiors of the
cylinders (7 7A)-and, as the cylinders revolve, is exhausted at the exhaust port (23)
in the valve and through the annular space around the valve shaft (11) and thence
to the exhaust pipe (24). The valve may be so constructed that the steam may
enter through the annular passage the central passage becoming the exhaust or the
valve may be solid with the steam and exhaust passages formed in it.
For the purpose of lubricating the crank pin (15) of the valve shaft I provide
in the disc an oiling trough (25) into which dips a feather piece (26) attached as
shewn to a lubricating pipe (27). The motion of the engine can be reversed by
rotating the casing (12) and attached cone piece (17) by the handle (28) in the
sector guide (29):
The objects I have in view in this arrangement, as in other modified arrange-
ments of my invention, are: 1st To counteract the wearing tendency between the
surfaces of the valve, and of the cavity revolving thereon, by opposing the pressure
of steam within the valve, acting in one direction, to the pressure of steam within
the cylinder, acting in the opposite direction; the nearer the area of the ports in
valve approximating to that of the pistons, the less being the friction between
the valve and the cavity in cylinders and to further reduce this difference of areas
I may form recesses (not shewn on drawings) in the cylindrical surface of the valve
casing (12) or in the surface of the cavity (8) such recesses having communication
with the initial steam-and being so situated as to keep clear of the steam and
exhaust ports and interposing a film of steam which will have the same effect as
increasing the area of the ports.
2nd To support both ends of the axis which takes the strain in working-
comprising the central hollow shaft (11) the valve casing (12) and the cranked
end (13)-by inserting the crank pin (15) into the hollow centre of the disc (1)
the effect of which is to place the main bearing (2) of the disc in equilibrium, as it
will be seen that the thrust outward of the pistons is neutralised by an equal force
pulling the disc in the opposite direction, through the crank (13) attached to
centre of disc by its pin (15) and vice-versa, the result being that the disc revolves
in its bearings without any strain, except such as from a driving belt when the
power is so taken off.
These objects form special features of my invention and are most important as
securing perfect steadiness at high speeds, strength of the axis, (which is the
fulcrum of the engine), and the minimum wear on the principal working parts.
In lieu of a crank pin and hollow shaft as shewn I may carry a shaft through
the disc and on the projecting end attach the crank, by an adjustable bearing.
When the compound system is desirable I prefer to use four cylinders, all preferably
double acting, arranged one high and one low pressure on each side of the centre
of rotation, which will be as nearly as possible the centre of gravity, all four
cylinders being in the same plane or nearly so and the four piston rods rigidly
attached to one crosshead. The stationary cylindrical valve and the cavity will be
pierced with ports to suit the admission, transfer and release of the steam, the
other details of the engine being the same as already described.
The compound system may also be applied with two cylinders, one high pressure
and one low pressure on each side of centre, being arranged to balance equally.
More than one pair of cylinders may be mounted on the central shaft each pair
revolving in a separate plane and attached by their piston rods and crosshead to
separate crank pins in disc.

page_text: I would have it understood that I do not bind myself to the precise methods
I have described in working out the details as it will be obvious that these may be
varied without departing from the principle of my invention and the special
objects to be attained thereby.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what
I claim is,
:
First. In reciprocating rotary engines the application of two cylinders-preferably
double acting revolving in the same plane on their centre of gravity around a
fixed centre, and having their piston rods connected by a crosshead to one pin in
a revolving crank or disc substantially as described and shewn.
Second. In reciprocating rotary engines, working on the compound principle,
the application of four cylinders-preferably double acting-one high pressure and
one low pressure cylinder on each side of the fixed centre revolving practically in
the same plane and having their piston rods connected by a crosshead to one pin in
a revolving crank or disc substantially as described.
Third. In such or similar rotary engines the application of a cylindrical
stationary valve, either contained within the fixed centre on which the cylinders
revolve, or itself forming that fixed centre, operating in such a way as that the
initial steam pressure counteracts the pull and thrust of the piston upon the pin
in disc, thus relieving the pressure upon the wearing surfaces of the valve:
substantially as described and shewn.
Fourth. In such or similar rotary engines the application of a crank, formed
upon or attached to the outer end of the fixed centre around which the cylinders
revolve with a connection to the centre of the revolving disc; for the double
purpose of opposing, the pull and thrust of the cylinders. upon the fixed centre,
thus placing the disc in equilibrum upon its own centre of rotation by trans->
mitting an opposing force neutralising that exercised by the piston upon the pin
in disc; and of avoiding the injurious strains incidental to overhanging the
working parts with one bearing only substantially as described and shewn.
Fifth. The combination of parts constituting the reciprocating rotary engine com-
prising a crank or equivalent disc, connected by a crank pin and a crosshead to a
pair of cylinders mounted at their centure of gravity upon a fixed centre formning
a cylindrical valve supported at one end in a concentric bearing and at the other
end by means of a crank and pin in another bearing concentric with centre of
disc, means for reversing the motion of engine by altering the position of the
cylindrical valve, and for making and. keeping steam tight the various connections
and working parts of said valve, with the appliance for lubricating the crank pin
upon which the disc shaft revolves the whole constructed and operating substantially.
as described and shewn.
Dated the 7th day of May 1886.
Witness:
T. J. DANSON, F. Inst. P.A.,
Consulting Engineer & Patent Agent,
Newcastle-upon-Tyne.
LEIGHTON MILLS.