Improvements in Multiple-cylinder Engines.
Year: 1895

page_text: Date of Application, 10th Sept., 1895-Accepted, 15th Feb., 1896
Improvements in Multiple-cylinder Engines.
Communicated by HAMILTON JAY COMBES, of 126 Liberty Street, in the City,
County, and State of New York, United States of America, Merchant.
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, 118 New Street, Birmingham in
the County of Warwick and 31 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 :-
This invention relates to multiple-cylinder engines having cylinders radially
arranged, in pairs, around a common shaft, with the arms of the pistons of each pair
of cylinders engaging the crank, and with their opposed ends loosely connected
together thereat, and having a disk-valve mounted on and rotating with the shaft,
to govern the cylinder-ports in the inlet, cut-off and exhaust of steam; and this
invention comprises the combination with the foregoing parts, of means for
adjusting the valve to its seat, for preventing collisions between the pistons and
cylinder-heads, and for reversing the engine.
Figure 1 is a side elevation of an engine containing the invention;
Figure 2 is an enlarged lateral section on the line, ac, Figure 1;
Figure 3 is a similar section;
Figure 4 is an enlarged elevation of the valve ;
Figure 5 is a view in detail of the shaft-bearing for the valve; and
Figure 6 is a longitudinal central section of the engine.
A, A1, A2, A3, are the cylinders which are radially arranged, in pairs, around a
shaft, B, common to them all, and with the cylinders of each pair on opposite sides
of the shaft. The respective pistons are at a, a, a², a³, and each piston has an
arm, a, preferably rigid on the piston, and reaching to and engaging the shaft-
crank, . The opposed ends of each pair of piston-arms are loosely connected
together at their bearing on the crank, which may be accomplished by yoke-
plates, a, carried one by each arin, with bolts, a³, passing through laterally
extended ends of said yokes, and springs, a', placed between the bolt-heads and the
yoke-plates. The pistons are thus held yieldingly to a bearing on the shaft-crank,
through their arms, a', and are maintained at all times in proper position relatively
to their mates and the crank; and this is accomplished with a minimum of friction
at the bearing of the piston-arms on the crank, which is conducive to high speed
with little wear of the parts.
C is the disk-valve mounted on and rotating with the shaft, B, and having the
steam-inlet port, c, and exhaust-port, c', governing the cylinder-ports, a, and
steam-ports, a, leading from the steam-chest, a¹0. Steam enters the chest at all,
and exhausts from the cylinders, the pistons of which are single-acting, through
apertures, a, in the valve, and, a¹³, in the engine-frame, into the central
chamber, a, of the engine, and escapes therefrom at a¹³. The valve has the
balancing-ports, c³, and it works to a seat, a¹, on the engine-frame, within a chest
constituted by the recessed head, B'; and it rotates between said seat and an
annular plate, C¹, carried on a face, d², of a frame, D, having a shank, d, which is
preferably of considerable size and fits closely in a socket, 61, in the head, B', with

page_text: a set-screw, D', working through the end of said socket and impinging upon the
head of said shank. The plate, C¹, is preferably separate from and loosely
mounted on the frame, D, by pins, d', set in the face, d, and entering slotted
recesses, ², in the plate. The face, d, on the frame, D, and the opposite faces of
the valve, C, and those of the plate, C', should be parallel planes; and the
shank, d, should preferably project centrally from the frame, D, and should have
its longitudinal axis, together with that of its socket, b', at right angles to said
parallel plane faces. When the shank, d, is cylindrical, lugs, 62, on the interior of
the head, B¹, adapted to engage corresponding lugs, d³, on the frame, D, may be
provided to prevent rotation of said frame and its plate, C, with the valve. The
set-screw, D, is preferably provided with an operating hand-wheel, d, and a lock-
nut, d; and the frame, D, is laterally apertured at d, to permit the passage of
exhaust steam. These described devices furnish means for adjusting the valve on
its seat and for maintaining the faces of the valve parallel to its seat-faces.
The peripheral web of the valve, C, between the inlet-end, c', of its steam-port, c,
and its exhaust-port, c', is made of such length, or duration, that, as the valve
rotates, the said web, C, will interrupt the exhaust from the cylinders, successively,
at a point desirably near the end of the return, or outward, stroke of the respective
pistons. In Figure 2 the direction of rotation of the crank is indicated by an arrow,
the cylinder, A2, having full inlet of steam on its piston, a², at half working-stroke,
cylinder, A3, exhausting with its piston, a³, at half return-stroke, while steam is
about to be cut off to cylinder, A', with its piston, a', approaching the end of a
working-stroke, and cylinder, A, having its exhaust interrupted by said web, C2,
of valve, C, with its piston, a, approaching the end of a return-stroke. The steam
thus confined in cylinder, A, between its piston and head will be compressed and
form a cushion between said head and piston having a resistance greater than the
boiler steam-pressure, and will act to prevent collision between the piston and
cylinder-head; and when the valve establishes steam-connection between the
steam-chest and said cylinder, A, the said cushion-pressure created between the
piston and cylinder-head will equalize with the live steam-pressure. This operation
of the valve provided with the said web, C, will be successive, during its rotation,
upon the several cylinders. The web, C, has the balancing-port, c.
In the bearing-face of the axial aperture, E, of the valve, C, is formed a
channel, e, that is circumferentially coincident in length therein with the steam-
port, c, in the valve, and a slot, el, is provided in the valve-disk, leading into said
channel. Upon the shaft, B, at its bearing for the valve, is fixed a feather, b³,
adapted to pass said slot, e', and enter and seat loosely in said channel, e, when the
valve is mounted on the shaft. The rotation of the shaft in the direction indicated
in Figure 2 will, by the engagement of said feather, 63, with one end of the
channel, e, rotate the valve, C, in the same direction; and when said feather
engages the opposite end of said channel, the rotation of the shaft in that direction
will reversely rotate the valve; the shaft beiug capable of rotation in either
direction through the distance of the length of said channel without thereby causing
the rotation of the valve.
When the engine is working in the direction indicated in Figure 2, it may be
reversed by first stopping it, with the pistons and valve in, say, the positions shown
in said figure; piston, a, about to begin a working-stroke, piston, a', about to begin
a return-stroke, and pistons, a², a³, at half-stroke, with cylinder, A2, taking steam,
and cylinder, A³, exhausting; and then, by means of a hand-wheel, B, on shaft, B,
turning the shaft backward through the distance of the length of the channel, e.
This will bring the crank and pistons into the positions relatively to each other and
the valve-ports, shown in Figure 3, the valve not moving; namely, piston, a, about
to begin a return-stroke, and its cylinder, A, to exhaust, piston, a', about to begin
a working-stroke and its cylinder, A', to take steam, and pistons, a³, a³, at half-
stroke, with the cylinder, A2, in communication with the steam-chest, and
cylinder, A³, in communication with the exhaust. Steam being now turned on, the
movement of piston, a², will act to throw the crank, b, in the direction of the arrow

page_text: in Figure 3, and the successive working-strokes of all the pistons will continue such
throw of the crank, thus giving the reverse motion to the engine.
Having now particularly described and ascertained the nature of the said
invention, 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 multiple-cylinder engine, the combination with the cylinders, their pistons
and piston-arms, a crank shaft common to all the cylinders and pistons, and around
which said cylinders and pistons are radially arranged, in pairs, with the opposed
ends of each pair of piston-arms engaging the crank of said shaft and loosely
connected together, and a disk-valve mounted on and rotating with said crank-shaft,
of an annular plate, between which and its seat on the engine-frame said valve
works, a frame carrying said plate, a shauk on said frame, a socket on the valve-
chest head for said shank, and a set-screw working in the end of said socket and
bearing upon the head of said shank, substantially as specified.
2. In a multiple-cylinder engine, the combination with the rotary disk-valve
which governs the ports for the inlet, cut-off and exhaust of steam, of an annular
plate, between which and its seat on the engine-frame said valve works, a frame
having a face fitting to a face of said plate, and provided with pins adapted to enter
slotted recesses in said face of said plate, a shank on said frame, a socket on the
valve-chest head for said shank, and a set-screw working in the end of said socket
and bearing upon the end of said shank, substantially as specified.
3. In a multiple cylinder engine, the rotary disk-valve which governs the ports
for the inlet, cut-off and exhaust of stearn, provided with a balanced web between
the steam-inlet end of its steam-port and its exhaust-port, of a length, or duration,
adapted to successively interrupt the exhaust from said cylinders during a
portion of the return-stroke of the respective pistons thereof, substantially as
specified.
4. In a multiple-cylinder engine, the combination with the rotary disk-valve
which governs the ports for the inlet, cut-off and exhaust of steam, provided with
a channel in the bearing-face of its axial-aperture, circumferentially coincident in
length therein with the steam-port of the valve, and a slot leading into said
channel, of a crauk-shaft common to all the cylinders and provided at its bearing
for said valve with a feather adapted to pass said slot and to enter and play in said
channel, substantially as specified.
Dated this 9th day of September A.D. 1895.
WM. P. THOMPSON & Co.,
Agents.