IMPROVEMENTS IN MULTIPLE CYLINDER COMPOUND ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Robert Matthews at the Office
of the Commissioners of Patents on the 7th February 1883.
ROBERT MATTHEWS of Hyde in the County of Chester " IMPROVEMENTS IN
MULTIPLE CYLINDER COMPOUND ENGINES
"
My invention relates to the construction and arrangement of multiple cylinder
engines working as compound engines with steam or other clastic fluid under
pressure.
In order to simplify explanation I will describe a three cylinder engine according
to my invention worked by steam. I arrange the three cylinders with their axes
radiating from the centre of a casing preferably at equal angles with each other.
Each cylinder consists of two parts, its inner part towards the centre is of larger
diameter than its outer part. In the outer smaller part works a plunger which is
a trunk extending outwards from a hollow plunger fitting the inner larger part.
Within the hollow plunger is jointed a connecting rod which links the plunger to
a crank on a central shaft passing through the sides of the casing, all three
plungers being thus connected to one crank. On the central shaft within the casing
is fixed an eccentric which is linked to three sets of slides, one for each cylinder.
These slides govern ports leading to the two parts of each cylinder so that the
high pressure steam is first admitted to act on the plunger in the smaller part of
the cylinder, then it exhausts into a reservoir formed at the side of the cylinder,
from which reservoir it passes into the larger part of the cylinder expanding
therein and acting on the annular area of its plunger, and finally the exhaust passes
into the casing from which it is led away by a pipe to discharge freely or to be
condensed in a condenser. I prefer however, when a condenser is employed; to
lead the exhaust from each cylinder to the condenser without passing it through
the casing.
When it is desired to vary the cut off, this may be effected by fixing on the shaft
a second eccentric working three cut off slides one for each cylinder, and this

page_text: eccentric may be fitted on the shaft with a sleeve provided with a helical feather so
that by sliding this sleeve longitudinally along the shaft either by hand or by the
action of a governor the cut off eccentric can be set more or less forward relatively
to the main eccentric. The main eccentric may itself be on a sleeve provided with
a helical feather so that its set relatively to the crank can be varied either for the
purpose of varying the cut off or for reversing the engine. In this case, the
separate cut off eccentric and the valves worked by it are dispensed with. In cases
where there is no serious objection to long steam passages, the alternation of the
steam for both the high and the low pressure may be effected by a single rotating
slide working on a facing around the centre of the casing, this facing having
ports communicating by passages with the two parts of the three cylinders. When
working fluid at very high pressure is employed, it is of advantage to expand by
more than two stages, and therefore in such a case, I make each cylinder with a
third part smaller than the second part above described, so that there is first
expansion in it, that its exhaust acts in the second larger part, and the exhaust
from this second part acts finally in the largest part of the cylinder, the slides or
valves being arranged suitably to effect this succession. Although I have described
the engine as having three cylinders and being worked by steam it is obvious
that two cylinders might be employed or that four or more cylinders might be
arranged radiating from the centre of the casing and that the engine might be
worked by elastic fluid other than steam, as for example by compressed air.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Matthews in the Great Seal Patent Office on the
6th August 1883.
ROBERT MATTHEWS of Hyde in the County of Chester.
MULTIPLE CYLINDER COMPOUND ENGINES
"
IMPROVEMENTS IN
My invention relates to a construction and arrangement of multiple cylinder
engines in such a manner that they work as compound engines, the working fluid,
which may be steam, compressed air, or other elastic fluid under pressure, being
subjected to double expansion.
The engine may have three or more sets of cylinders, but in order to simplify
explanation I will describe an engine with three sets, referring to the accompanying
drawings.
Fig. 1 is a transverse section, and fig 2 a longitudinal section of one form of
three-cylinder engine, according to my invention.
Each cylinder consists of two parts. The smaller part A' A2 A3 is that in which
the working fluid first acts, and from which, after expansion, it is discharged into
a reservoir C. Although only one reservoir C' is shewn in fig. 2, it is to be
understood that there is such a reservoir for each cylinder. From the reservoir C¹,
the fluid is supplied to the larger part B1 B2 B3 of each cylinder in which it farther
expands, and from which it is discharged into the central cavity D of the engine
casing to pass by the exhaust pipe E either into the atmosphere, or into a
condenser.
The three sets of cylinders are arranged radially at equal angles around the
casing D, cach cylinder having a differential plunger F F F linked by a connecting
rod G G G to a single crank H of a central shaft I which extends through
bearings in the sides of the casings D. On the shaft I is fixed an eccentric J which
is linked by connecting rods such as K' to the three sets of piston slides such as L'
which govern the ports of the respective cylinders. The steam or working fluid
being in each case supplied by a pipe leading to an aperture M' opening into the
slide case, the slide Li, as it makes its instroke, admits fluid at full pressure to the
smaller cylinder A' and also admits fluid at lower pressure from the reservoir C¹ to the
larger cylinder B₁ propelling the plunger F¹. When the slide L' makes its outstroke,
the fluid which had performed work expanding in-A¹ passes into the reservoir C¹,
and the fluid which had performed work expanding in-B' passes into the interior
of the casing D. The same cycle of action takes place with the other
cylinders A B and A³ B³ in succession, each plunger F F2 F3 successively driving
the crank H while it is being propelled, and being successively moved back by the
crank while the fluid that acted on it is being discharged. N is a lubricator for
admitting lubricant to the highest cylinder. The several reservoirs C' may
communicate with one another.
In cases where there is no great objection to long passages for the working fluid,
single rotating slide may be substituted for the three sets of piston slides and the
eccentric and connecting rods for working them. Figs 3 and 4 are longitudinal
ections shewing two forms of such a rotating slide applied to the engine, which,
nother respects, is constructed and arranged as described above. Fig. 5 is a
ection of the rotating slide, shewing the cylinder ports which it governs.
Referring to Figs. 3 and 5, O is an eccentric boss fixed on the shaft I and having
tted on it free to rotate a ring P, outside of which is also fitted free to rotate an
uter ring Q. Both these rings bear against the facing, in which are formed the
orts and passages leading to and from the several cylinders, the passages a¹ a³ a³

page_text: communicating with the smaller cylinders A' A² A³, and the passages 61 62 63
communicating with B1 B2 B3 respectively. The opposite edges of the rings P
and Qare provided with spring packing rings bearing against the cover of the
slide casing.
As the eccentric boss O revolves with the shaft I, the rings P and Q
while free to rotate, have an eccentric movement by which the passages a¹ a² a³ are
successively put in communication with the outer space R that is supplied with
working fluid at full pressure, while the passages 6' 62 63 are also successively put
in communication with the space T between the rings, which space constitutes the
reservoir for the fluid discharged from A1 A2 A3 after performing work therein.
The eccentric movements of the rings P and Q also puts a¹ a³ as successively in
communication with the space T, while the passages 61 62 63 are also successively
put in communication with the central space S and cavity S₁ that receives the
exhaust fluid. The exhaust may be led away otherwise than through the
cavity S¹.
In the arrangement shewn in Fig. 4, the boss O is extended in disc form and the
rings P and Q are fitted with spring packing rings into eccentric recesses hollowed
in the face of the disc O. The steam or working fluid in this case is supplied
from the cavity R¹ to the central space R and the exhaust is taken from the outer
space S, the passage a¹ having its port nearer the centre than the port b'.
A spring V pressing on the back of O keeps the rings P and Q against the port
facing.
I have shewn the eccentric J and the boss O as being fixed on the shaft I. It is
to be understood, however, that when it is desired to have the setting of the
eccentric or rotating slide relatively to the crank capable of alteration for the
purpose of stopping or reversing the engine or of varying the cut off, the boss of
the eccentric or of the rotating slide may be fitted to turn on the shaft and to be
set in any required position on it by means of a sleeve provided with an inclined
or helical key, or by other known means employed in such cases.
Having thus described the nature of my invention and in what manner the
same is to be performed, I would have it understood that I make no general claim
to arranging the cylinders of a multiple cylinder engine radially so that their
pistons act on a single central crank, nor do I claim generally the use of a rotating
slide governing the ports of the cylinders so arranged, but I claim, in respect of
multiple cylinder engines having their cylinders arranged radially around a
central crank :-
First Constructing each cylinder in two parts, an outer smaller part and an
inner larger part fitted with a differential piston or plunger, and provided with
suitable passages and reservoir, so as to work as a compound engine, substantially
as herein described.
Second: In combination with a set of cylinders arranged and operating in the
manner referred to in the preceding claim, a set of double piston slides worked from
a single eccentric on the crank shaft, substantially as described with reference to
figs. 1 and 2.
Third: In combination with a set of cylinders arranged and operating in the
manner referred to in the first claim, an eccentrically rotating double slide,
substantially as described with reference to figs, 3, 4 and 5.
In witness whereof I the said Robert Matthews have hereunto set my hand and
seal this third day of August in the year of our Lord one thousand, eight hundred
and eighty-three