IMPROVEMENTS IN STEAM ENGINES
Year: 1877

page_text: LETTERS PATENT to Henry Simon, of No. 7, Saint Peter's Square, Manchester,
in the County of Lancaster, for the Invention of "IMPROVEMENTS IN STEAM
ENGINES." A communication from abroad by Max Westphal, of Berlin, in the
German Empire.
Sealed the 5th April 1878, and dated the 24th October 1877.
PROVISIONAL SPECIFICATION left by the said Henry Simon at the Office
of the Commissioners of Patents on the 24th October 1877.
HENRY SIMON, of No. 7, Saint Peter's Square, Manchester, in the County of
Lancaster. "IMPROVEMENTS IN STEAM ENGINES." [A communication from abroad
by Max Westphal, of Berlin, in the German Empire.]
According to the present Invention the cylinder of a steam engine is provided
with three pistons, so arranged and operated by two sets of valves that high-pressure
steam is admitted between the ends of the cylinder and the two outer pistons, causing
these to perform their in-strokes consecutively, after which the steam passes from the
ends of the cylinder between the outer pistons and the middle piston, which has
either a longer stroke or larger area than the outer pistons, or both combined, so that
the steam entering expands in causing the pistons to perform their respective strokes
away from each other.
According to the arrangement employed, by preference, for carrying out the said
Invention, the middle piston connected by a piston rod and connecting rod to the
middle crank of a crank shaft; the rod of the hindmost outer piston passes through
the back end of the cylinder, and is connected by a cross head and side rods to a
second cross head in front of the cylinder, to which is also connected a tubular rod
from the front outer piston, the rod of the middle piston being made to pass steam-
tight through each tubular rod. The said second cross head is connected by two

page_text: connecting rods to two cranks, one on each side of the central crank of the crank
shaft, to which they are diametrically opposite. Thus, the one outer piston performs
its in stroke at the same time that the other performs its out stroke, while the
middle piston completes its strokes at the same time that each outer piston com-
pletes its in stroke, thus bringing at that time the one outer piston and the middle
piston close together.
From the above arrangement it will be seen that at the same time that the high-
pressure steam is passing in behind the one outer piston, causing it to perform its in
stroke, the steam is passing from behind the other outer piston between it and the
middle piston, and in expanding causes the latter to approach the first-named outer
piston, the steam which has already done duty between these two being at the same
time allowed to escape to the condenser.
Two sets of slides or other valves of known construction are provided for regulating
the admission and cut-off of the steam to the two ends of the cylinder and its
passage to between the two outer pistons and middle piston, and thence to the
exhaust.
The cranks to the outer pistons might be on a separate shaft from that of the
middle piston, the two being geared together.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Simon in the Great Seal Patent Office on the 17th April
1878.
HENRY SIMON, of No. 7, Saint Peter's Square, Manchester, in the County of
Lancaster. “IMPROVEMENTS IN STEAM ENGINES." A communication from abroad
by Max Westphal, of Berlin, in the German Empire.
According to the present Invention the cylinder of a steam engine is provided
with three pistons, so arranged and operated by two sets of valves that high-pressure
steam is admitted between the ends of the cylinder and the two outer pistons,
causing these to perform their in strokes consecutively, after which the steam passes
from the ends of the cylinder between the outer pistons and the middle piston,
which has either a longer stroke or a larger area than the outer pistons, or both
combined, so that the steam entering expands in causing the pistons to perform their
respective strokes away from each other.
According to the arrangement employed, by preference, for carrying out the said
Invention, the middle piston is connected by a piston rod and connecting rod to the
middle crank of a crank shaft; the rod of the hindmost outer piston passes through
the back end of the cylinder, and is connected by a cross head and side rods to a
second cross head in front of the cylinder, to which is also connected a tubular rod
from the front outer piston, the rod of the middle piston being made to pass steam-

page_text: tight through such tubular rod. The said second cross head is connected by two
connecting rods to two cranks, one on each side of the central crank of the crank
shaft, to which they are diametrically opposite. Thus, the one outer piston performs
its in stroke at the same time that the other performs its out stroke, while the
middle piston completes its strokes at the same time that each outer piston completes
its in stroke, thus bringing at that time the one outer piston and the middle piston
close together.
From the above arrangement it will be seen that at the same time that the high-
pressure steam is passing in behind the one outer piston, causing it to perform its in
stroke, the steam is passing from behind the other outer piston between it and the
middle piston, and in expanding causes the latter to approach the first-named outer
piston, the steam which has already done duty between these two being at the same
time allowed to escape to the condenser.
Two sets of slides or other valves of known construction are provided for regulating
the admission and cut-off of the steam to the two ends of the cylinder and its
passage to between the two outer pistons and middle piston, and thence to the
exhaust.
The cranks to the outer pistons might be on a separate shaft from that of the
middle piston, the two being geared together.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shews a side elevation, and Fig. 2 a plan, partly in section, of a steam
engine constructed according to the above-described Invention.
The cylinder A contains the three pistons B, C, and D, of which B is connected
directly by a connecting rod to the middle crank E' of the engine shaft E, while C
is connected by a tubular piston rod C₁ (through which the rod of B passes steam-
tight) to the cross head F, which is connected by connecting rods to the two side
cranks E2, E2, of E, these being diametrically opposite to the middle crank. The
rod D of the piston D passes through the back end of the cylinder, where it has a
cross head G, connected by side rods H, H', to the cross head F. Thus, C and D
perform their strokes simultaneously, while B performs its strokes in such manner
that it moves towards each of the other pistons as these perform their in strokes,
the length of its stroke being considerably greater than that of C and D. The steam
enters the slide casing I through the inlet K, and passes thence through the slides
L, M, and ports behind the piston D, causing this to perform its in stroke, while at
the same time C is caused to perform its out stroke. The pistons D and C having
completed their strokes (this being the position shewn at Fig. 2), the steam behind
D is caused by the slide L to pass between the pistons D and B, causing B to
perform its stroke toward C, while this is at the same time making its in stroke
owing to steam being admitted behind it by the second set of slides in the slide
casing I, the ports and passages of which are omitted at Fig. 2.
On the completion of the stroke of B, when it will have approached C as closely
as shewn in relation to D at Fig. 2, the expanded steam is led by the exhaust passage
N into the condenser O, which is exhausted by the air pump P. This pump may be
conveniently worked by connecting its piston to one of the before-mentioned rods
H' connecting the two cross heads, as shewn. The other rod H is in like manner
utilized for working the feed pump Q.
It will be evident that the above-described Invention may be carried out in
variously modified ways, both as regards the proportion of strokes and relative
diameters of the pistons, their connection to the crank shaft and the positions of
the cranks relative to each other, and I do not therefore limit myself to the arrange-
ment shewn on the Drawing.
Having thus described 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
claim the construction of compound steam engine with three pistons in line with

page_text: each other in one and the same cylinder, thus forming four chambers, two for the
high-pressure steam, and two supplied therefrom with the expanded or low-pressure
steam, substantially as herein described.
In witness whereof, I, the said Henry Simon, have hereunto set my hand and
seal; this Second day of March, in the year of our Lord One thousand
eight hundred and seventy-eight.