Improvements in Compound Steam Engines.
Year: 1889

page_text: Date of Application, 8th July, 1889
Complete Specification Left, 8th Apr., 1890-Accepted, 10th May, 1890
PROVISIONAL SPECIFICATION.
Improvements in Compound Steam Engines.
1, ROBERT EDWARDS, of 19, Avenue Road, Grantham, in the county of Lincoln,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to a simple form of triple or quadruple compound expansion
engine; and has for its object to construct an engine having three or four cylinders
of unequal diameters and so that, though each cylinder has its own piston rod or
rods, only two connecting rods are required to connect the piston rods to two
cranks (or to one crank in a diagonal engine) used on the crank-shaft.
In the three cylinder engines, in order to effect this, two of the three cylinders
are placed side by side relatively to the centre line of the crank-shaft, their piston
rods being connected to one cross-head, so that one connecting rod then serves to
connect the same to one of the cranks of the crank-shaft. In order to avoid
injurious side strain on the piston rods, the motion blocks are rigidly attached to
the cross-head and are generally made longer than is usual. One slide valve may
be employed for the two cylinders, or two, one to each cylinder, and in the latter
case the valves may be worked singly, but, by preference, their rods are attached
to one guided cross-head which is connected to the eccentric-rod or link or other
reversing or expansion motion. Supplementary cut off valves also can be used.
The third cylinder is placed on one side of the other two cylinders, its piston rod
being connected by a connecting rod to the other crank. The smallest of the three
cylinders exhausts into the steam chest of the next larger and this cylinder into the
steam chest of the largest.
In a four cylinder engine two of the cylinders are arranged in a similar manner to
the two combined ones in the three cylinder engine hereinbefore described and the
other two also in a similar manner but taking the place of the third cylinder in the
three cylinder type. The smallest cylinder exhaust into the steam-chest of the next
largest and so on to the largest.
A diagonal engine can also be arranged in a similar manner with three or four
cylinders two connecting rods being used, connected however to only one crank.
These engines can be used in any position with all the cylinders close together or
the cylinder or cylinders of each crank more or less apart; they can also be arranged
for locomotive, traction, portable, seni portable or fixed engines with a boiler attached
either above or below or at the side of the engine as required. Condensers may also
be arranged in conjunction with the cylinders, and worked according to any of the
usual methods.
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COMPLETE SPECIFICATION.
Improvements in Compound Steam Engines.
0.1, ROBERT EDWARDS, of 19, Avenue Road, Grantham, in the county of Lincoln,
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 :-.
My invention relates to improvements in the construction of triple and quadruple
5 compound' horizontal expansion engines, and has for its object to construct an engine
having three or four cylinders of unequal diameters and so that, though each cylinder

page_text: has its own piston rod or rods, only two connecting rods are required to connect the
piston rods to two cranks on the crank-shaft.
In the three cylinder engines, in order to effect this, two of the three cylinders are
placed, one above the other, their piston rods being connected to one cross-head, so
that one connecting rod then serves to connect the same to one of the cranks of the
crank-shaft. In order to avoid injurious side strain on the piston rods, the motion
blocks are rigidly attached to the cross-head and are made longer than is usual. One
slide valve may be employed for the two cylinders, or one for each cylinder, and in
the latter case the valves may be worked singly, but, by preference, their rods are
attached to one guided cross-head which is connected to the eccentric-rod or link
or other reversing or expansion motion. Supplementary cut off valves also can be
used.
The third cylinder is placed on one side of the other two cylinders, its piston rod..
being connected by a connecting rod to the other crank. The smallest of the three
cylinders exhausts into the steam chest of the next larger and this cylinder into the
steam chest of the largest.
In a four cylinder engine two of the cylinders are arranged in a similar manner to
the two combined ones in the three cylinder engine hereinbefore described and the
other two also in a similar manner but taking the place of the third cylinder in the
three cylinder type. The smallest cylinder exhausts into the steam-chest of the next
largest and so on to the largest.
These engines can be used in any position with all the cylinders close together or
the cylinder or cylinders of each crank more or less apart; they can also be arranged
for locomotive, traction, portable, semi-portable or fixed engines with a boiler attached
either above or below or at the side of the engine as required. Condensers may also
be arranged in conjunction with the cylinders, and worked according to any of the
usual methods.
In order to enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawings:
Figures and 2 represent a plan and side elevation respectively of a three cylinder
engine constructed according to my invention.
Figure 3 is a cross section on an enlarged scale on line a b of figure 2.
In this arrangement the smallest cylinder A is placed over the larger cylinder B,
the exhaust port C of the cylinder A opening to the stean chest D of the larger
cylinder B, and the piston rods E and F of the two cylinders are connected to one
cross-head H having long motion blocks I attached rigidly thereto, a connecting rod
(not shown in the drawings) being attached to the cross-head H and to one of the
cranks L. The steam chests M and D of the cylinders A and B respectively are
arranged at the outside one above the other. The third or largest cylinder O is placed
at the opposite side to the steam chest side of the other cylinders and the exhaust is
taken from the larger cylinder B to the steam chest N of the largest cylinder O, this
steam chest N being placed at the side of the cylinder O furthest from the cylinders A
and B. A connecting rod (not shewn in the drawings) connects the cross-head R of
the cylinder O to the second crank S.
In a four cylinder engine another cylinder still larger than the largest cylinder O
in figure 3 is placed above or below the latter cylinder, and the rods of the two are
connected to one cross-head with long rigid motion blocks and to the crank S by a
connecting rod as in the case of the two smallest cylinders.
Figure 4 is a side elevation of a three cylinder engine arranged to work with a
locomotive type of boiler; and
Figure 6 is a cross section (on a larger scale) on line c d of figure 4, the chimney
not being shewn.
T is the boiler arranged over the engine, the smoke-box end V being placed over
the cylinders, and the fire-box end W at the crank shaft end.
Figure 5 is a similar view to figure 4 but shewing the cylinders of the engine
placed under the barrel X of the boiler and the crank shaft at the front of the
smoke-box V.

page_text: I sometimes arrange my engine (without a boiler) with the two smaller cylinders
and the larger cylinder or cylinders placed some distance apart and in that case the
steam chests can be placed at the inner side instead of at the outer side of the
cylinders as herein before described and shewn.
The advantage of making three or four cylinder engines according to my invention
are that only a small number of parts is employed and that the cylinders are arranged
so that the steam from the boiler is taken in at the steam chest of the smallest
cylinder which is placed horizontally at the top over the next larger cylinder, the
exhaust steam from the smaller cylinder being led to the next larger which is placed
underneath and from thence underneath to the steam chest of the largest or third
cylinder which is placed on one side, the piston rods of the two smallest cylinders
engaging one cross-head with rigid long motion blocks which is connected to one
crank by a connecting rod, the piston rod of the other cylinder in its turn being
connected to another crank.
In four cylinder engines the fourth cylinder is placed above or below the third
cylinder and has its own piston rod and that of the cylinder connected to one
cross-head having long rigid motion blocks and connected to one crank by a connecting
rod.
In the drawings I have shewn the cylinders placed vertically one over the other but
it will be obvious that they may be placed diagonally. I have also shewn and described
the boilers as placed above the engines. I wish it to be understood, however, that the
engines may be placed above the boilers.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In horizontal engines having three or four cylinders of different diameters, the
arrangement and combination of parts, substantially as described and illustrated in
the accompanying drawings.
2. The combination of a locomotive type of boiler and an engine with three or four
cylinders of different diameters, arranged as herein before described and illustrated in
figures 4, 5 and 6 of the accompanying drawings.
3. In horizontal engines having three (or four) cylinders of different diameters,
placing the two smallest cylinders with the smallest at the top and connecting both
pistons to one cross-head with long rigid motion blocks and at the same time placing
a third, (or a third and fourth) larger cylinder (or cylinders) at the side, substantially
as described and illustrated in the accompanying drawings.
Dated the 8th day of April 1890.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.