IMPROVEMENTS IN STEAM ENGINES
Year: 1886

page_text: I, GEORGE WASHINGTON PRICE, Machinist, of the City of Baltimore, in the
State of Maryland, one of the United States of America, do hereby declare the
nature of my invention for "IMPROVEMENTS IN STEAM ENGINES," and in what
manner the same is to be performed, to, be particularly described, and ascertained
in and by the following statement:-
Referring to the accompanying drawings in which-
Fig. 1 is a plan of an engine constructed according to my improvement in its
preferable form.
Fig. 2 is an upright sectional view of the same, the cylinders on the steam side
being shown partly in full, and partly broken away. It also shows the two cranks
on that side of the figure, one up and the other down, and on the right they stand,
horizontally, on opposite sides of the shaft; this figure also shows the pistons to
correspond with the cranks.
Figure 3 shows an end view of the same, partly in section, and showing the
four cranks with their connecting rods in dotted lines.
Fig. 4 is an upright sectional view of a modification of my engine in which
is shown, hollow or recessed pistons; illustrating a method by which the steam
may be introduced from the side, instead of at the tops of the cylinders, and having
the same arrangement of steam and exhaust passages.
Fig. 5 is a sectional end view of one of the cylinders as shown in Fig. 4.
Fig. 6 is an upright sectional view of that form of my engine shown in Figs. 1,
2 and 3 showing the same position of pistons and cranks as in Fig. 2 and the
ports in the cylinders and steam passages.
Figs. 7, 8, and 9 are views of the same showing different positions of the piston
and the steam exhaust passages,
My invention relates to that class of steam engines in which the piston is used
as a valve, to open and close the steam ports, and consists in a novel arrangement
of ports and passages, whereby I am enabled to use an ordinary plain piston, and
provide but two ports in each cylinder to be opened and closed by the piston in
passing.
Let A B C and D represent the cylinders and abc and d their respective pistons.
In the cylinders A and B, I provide the ports a¹ and b¹ located about midway of

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the stroke of the respective pistons and construct them about equal in length to the
thickness of their respective pistons. From the port a¹ in cylinder A, I construct
a passage way which I have marked a c, which leads to a port marked which
opens in the bottom of cylinder C, and from the port b¹ in cylinder B, I construct
a similar passage way, marked b d, leading from said port to the port marked d³
which opens in the bottom of cylinder D.
In cylinders C and D, I have provided a similar arrangement; the ports c¹ and
being for convenience located on the opposite side of said cylinders, though this is
not necessary, as they would work just as well on the same side as the ports of
cylinders A and B. These ports c¹ and dare shown in dotted lines in Figures 6
and 8 and partly plain and partly dotted lines in Figures 7 and 9, according to
whether they are exposed or covered by the position of the piston; from the port c¹
in cylinder C, I construct the passage way marked ca which leads to the port a²,
opening in the bottom of cylinder A, and from the port d¹ in cylinder D, the
passage way db, to the port 62, opening in the bottom of cylinder B.
The cranks pertaining to each cylinder and piston I have marked respectively
a, b, c, d, and the connecting rods a, b, c, d, which are pivoted to the piston,
and connected directly with the cranks.
Thus it will be seen that each cylinder has but two ports or openings, one
located about midway of the stroke of its piston and the other at the bottom; it
will also be seen that each of the ports located about midway communicates with
the cylinder next but one from it, and at the bottom, that is to say, cylinder A, is
connected from at or near the middle to the bottom of cylinder C. Cylinder B is
connected in the same way with cylinder D, cylinder C is connected in the saine
way with cylinder A, and cylinder D, with cylinder B. The purposes and uses of
making these connections in this way will be explained more fully hereafter, in
describing the mode of operation of the machine..
Upon the tops of these cylinders I have cast or otherwise secured the steam
tight box or chest E, which runs from the cylinders up to the shaft F, and furnishes
the means for supporting said shaft; this steam chest is divided by the steam tight
partition wall G, which separates the chest into two compartments, thus. leaving
two cylinders located on each side of the partition wall G.. A cover H, is then
secured to the steam chest, of such shape and form as to continue the compartments
thus formed, and, the stuffing boxes e and journal bearings f are thus forined in
two halves, one half upon the walls of the steam chest and the other upon the
corresponding walls of the cover as shown in Fig. 2. The cover is provided with
the openings I and I', one of which may be used as an inlet and the other for the
exhaust of the steam. Either may be used as matter of choice, but in order to
explain, I have chosen the opening I as the steam inlet and I¹ as the exhaust. Let
us first.take. the Figure 2, with the position of the pistons as shown in that figure
and allow the steam to enter the opening. I in the cover, the pressure of steam
would be primarily upon the tops of the two pistons a and b, but as piston bis
below the top of port 61 the steam passes out of said port through the passages b d
and has entered cylinder D, below the piston &; piston b being at the bottom of
its stroke and just ready to move upwardly, it would encounter the full pressure of
steam against it were it not for the fact that piston d is also running upwardly and
just at this point is beginning to uncover the port d, allowing the steam to pass
out through the passage way db into the bottom of cylinder B, and below piston b,
thus counterbalancing the pressure of steam on the other side of that piston.
Now the condition of the pistons as to pressure would be as follows: piston a,
which is just ready to begin its downward movement, will have a full head of
steam upon it direct; piston d, which is moving upwardly, will have a full pressure
of steam upon it below, and piston 6 will be counterbalanced by a pressure of steam
on both sides.
Before leaving Fig. 2 it would be well to explain the exhaust as it occurs in that
position of the pistons. Two of the four cylinders are exhausting; cylinders A
and C. Piston a is just beginning to move downwardly, and its cylinder is just

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case, the steam which has forced piston a to the top of its stroke
now begins to exhaust through the port a³ and passage way ca, out through
port cl, which is just being uncovered by the downward movement of piston c, and
up through the opening I; and cylinder C, (whose steam has followed the piston a
since the descent of its piston began) now exhausts through its lower port.c³,
passage way a c, into cylinder A, and out through port a' and passage way o a,
above piston c, through the exhaust opening I¹.
In Figure 8, the positions of the pistons are exactly reversed, piston à is just
beginning its upward movement, piston 6 just beginning to come down, pistón cat
about half stroke, moving upwardly, and piston d in about the same position,
moving downwardly.
The pressure of steam here, as always, is upon the tops of the two pistons a
and b, but it has passed out of cylinder A, through the port a¹ and entered below
piston c through the port c³; it is now beginning to pass out of the port c¹ into
the port a² and is counterbalancing the piston a; the cylinders B and D are
exhausting; the piston b is forcing the steam through the exhaust and d¹ out
through the exhaust opening I, and the piston d, is forcing the steam below it,
through the ports d² and b¹ into cylinder B, and out through 6 and d¹ to the
exhaust opening 1; the position of the pistons as to pressure is as follows: piston a
is counterbalanced, piston b has full pressure of steam on top to force it down, and
piston d, has full pressure of the steam below to force it up."
It will now only be necessary to notice figures 7 and 9, showing pistons a and b
at half stroke, and pistons c and d at full stroke; these two figures have the
positions of their cranks reversed; inure 7, the crank of piston d is up and
that of piston c down; in figure 9, the crank of piston c is up and that of a down;
now if we follow the course of the steam and exhaust whilst the pistons are in
these positions it will be seen, that the steam as usual is at full pressure on the
tops of pistons a aud b; that it is just beginning to pass out of cylinder A, and
enter below piston c which is about commencing its upward movement, that the
port 6' is just closed off, which has let the steam into cylinder D, to force piston d¹
to the top of its stroke and back again to counterbalance piston b; it will also be
seen that piston d is just beginning to descend and force the steam below it, under
piston ; and that piston b is just beginning to open port 6' below, and allow the
exhaust steam from cylinder D to enter, following piston b up as it ascends
until piston & goes down far enough to open port d' at the top, and allow both B
and D to exhaust. To describe Figure 9 it will only be necessary to reverse the
description just given.
It will thus be seen that the engine constructed as shown in Figures 1, 2, 3, 6,
7, 8, and 9 operates the pistons a and b from the top, and c and d from the bottom;
that cylinders A and B exhaust direct through C and D; and C and D exhaust
through A and B, and back again, each over its own respective piston.
In the modification shown in Figs. 4 and 5, the ports and passage ways are
arranged and operate in the same way, the pistons in each of these cylinders have
hollow spaces or recesses between their heads which spaces act as steam chests;
instead of having the pressure of steam upon the top of the two pistons a and b,
the engine is arranged without the steam chest and cover above, leaving the shaft
and cranks exposed.
The steam in the cylinders Fig. 4 enters by the port at the side; as the engine
stands in the figure, piston a is at the top of its stroke and the steam occupies the
space in the recess between its heads, piston b has passed down below. the port bl
and the steam has passed out of that and is operating piston d from below, which
is on its upward movement, and is just beginning to open the port d and allow
the steam to enter below piston b, which is just beginning its upward movement;
cylinders A and C are exhausting-A through the passage ca into the recess of
piston c, and out through the exhaust, and cylinder C through the port c³, into
cylinder A, below piston a, out through a², passage way ca, into the recess of
piston c, and the exhaust pipe.

page_text: The passages for the steam and exhaust are just the same and operate in the
same way as those heretofore described, but all of the pistons are operated by
pressure of steam upon the bottoms of the pistons.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In a steam engine two companion cylinders as A, and C, each having two
ports as a and a² c¹ and c³ and one piston arranged combined and operating with
the ports and each other, so that a portion of the steam operating on top of the
piston in cylinder A may pass out the port al when piston a has descended to open
said port and into its companion cylinder C and below the piston c to force said
piston upwardly and pass out of the port cl when the piston c has uncovered the
lower end of said port, back into cylinder A at the bottom and under piston, a to
counterbalance the steam on the opposite side of said piston during its upward
stroke.
2. In a steam engine, two companion cylinders as A and C each having two
ports as a¹ and a³ c¹ and c³ and one piston, arranged, combined and operating with
the ports and each other, so that the steam first enters cylinder A, and passes
thence to cylinder C and under piston c, to propel said piston, and out of cylinder C
back again to cylinder A and under piston a to propel it, substantially as shown
and described.
3. In a steam engine two companion cylinders as A and C, each having two
ports as a¹ and a² c¹ and c², and one piston, arranged, combined and operating with
the ports, and with each other, so that the steam from cylinder A will exhaust
through cylinder O direct, and the steam from cylinder C will exhaust through
cylinder A, and then back through cylinder C on the opposite side of its piston.
4. A steam engine having two or more pairs of cylinders, one half of which
have their pistons exposed to direct pressure of the steam on top and the other
half arranged to receive the pressure of steam on the bottom, substantially as
described.
',
Dated this 5th day of February 1886.