AN IMPROVEMENT IN STEAM ENGINES
Year: 1868

page_text: LETTERS PATENT to James Wing Chamberlain, of the State of
Massachusetts, of the United States of America, for the Invention
of "AN IMPROVEMENT IN STEAM ENGINES.-A communication by
William Tyler Chamberlain, residing at Norwich, in the State of
Connecticut.
COMPLETE SPECIFICATION filed by the said James Wing Chamberlain
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 13th May 1868, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL PERSONS TO WHOM THESE PRESENTS MAY COME,
BE IT KNOWN that I, JAMES WING CHAMBERLAIN, of the State of
Massachusetts, of the United States of America, am in possession of
"AN IMPROVEMENT IN STEAM ENGINES," the same being communicated
to me by one William Tyler Chamberlain, a resident of Norwich, in
the State of Connecticut, and I do hereby declare the nature of the said
Invention, and the manner in which it is to be performed, to be fully
described in the following Specification, and represented in the accom-

page_text: panying Drawings, of which Figure 1 denotes a vertical and longitudinal
section, and Figure 2 a transverse section of an engine constructed with
my improvements.
The nature of the said Invention consists in an improved engine,
consisting not only of a cylinder open at both ends, and having a
partition across its middle, but of two pistons applied to a single rod,
the pistons being on opposite sides of the partition, and the said cylinder
having not only a valve and steam chest but two induction ports leading
'laterally into the cylinder.
The nature of the Invention further consists in the combination of
a movable partition and a packing and clamp screw with the cylinder
(open at its ends), and the two pistons and their rods, the cylinder being
provided with a valve and steam chest, and induction and eduction
ports.
b
The nature of the Invention further consists in the combination of
a condenser with the improved engine made substantially as described.
The said engine has one long straight cylinder A open at each end,
and provided at its middle with a movable circular partition, whose
circumference is grooved to contain packing a, a. It also has a groove
extending in and around such circumference, such groove being to
receive the pointed ends of two or more clamp screws c, c, screwed into
the cylinder, and against the circumference of the movable partition B,
the same being as shown in Figure 2. These screws serve with the
groove 6 to hold the partition in place within the cylinder. By having
a movable partition made and applied to the cylinder in manner as set
forth a single cylinder may be used, it being easier to bore a single
cylinder to one uniform diameter and with a straight axis than to bore
two separate cylinders to one diameter of bore. Furthermore, the
single cylinder having no joint at its middle like a compound cylinder
composed of two cylinders united at their ends by flanges and screws is
not liable like the compound cylinder to leak steam at its middle. A
piston rod C extending through the partition B, and working in
stuffings or stuffing rings d, d, properly applied thereto, carries two
heads or pistons D, E, one of which is arranged on one side and the
other on the other side of the partition B.
Induction passages or
ports e, f, lead from a steam chest F into the interior or bore of the
cylinder or other parts of it which are on opposite sides of the
partition B, a valve G being employed to alternately open and close

page_text: such ports. Furthermore, eduction passages or ports g, h, lead out of
the lower part of the cylinder. Each of these eduction ports should be
so arranged that when its piston is at its terminus of outward motion
the port will be closed to and uncovered by the piston, which during its
outward movement passes across and beyond the port, the same being
in order to permit steam employed in propelling the piston to escape
through the port.
•
The operation of the engine so constructed will be as follows:- If we
suppose the parts to be in position shown in Figure 1, steam will be
flowing through the induction port f, and by its action against the
piston E it will propel such piston along in the cylinder or away from
the partition B, and the piston D will be driven toward the said
partition. As soon as the piston E may have passed beyond the eduction
port steam employed in propelling the piston will escape through
the said port; at this moment the valve G should close the port f and
open the port c. Steam will then enter the cylinder through such
port, and act against the piston D and propel it away from the
partition B until it may pass by the eduction port g, this port then
being open; and between the piston D and the partition B steam used
.in so propelling the piston D will rush from the cylinder and escape
through such port. Next the steam should be made to propel the
piston E as before; thus a reciprocating rectilinear motion will be
imparted to the piston rod. During each retreat or return movement
of cach piston, provided a vacuum or partial vacuum between it and the
partition B may have been produced in those parts of the cylinder by
the escape of steam therefrom, the pressure of the atmosphere on the
piston will operate to aid the steam in propelling the other piston,
such aid depending on the excess of atmospheric pressure over the
pressure of the steam which may remain between the retreating piston
and the partition.
In order to attain the advantages of an atmospheric engine combined
with those of a high-pressure steam engine there may be combined with
the improved engine exhibited in Figure 1 and above described a
condenser or condensing apparatus, and a pump for extracting the
condensed steam from such apparatus.
In Figure 3 I have shown such a combination. In such Figure i
and k are ports leading out of the cylinder A in opposite sides of the
partition B and by pipes l, m, to a cock o connecting with a condenser H

page_text: arranged in a tank K containing water, there being a pump I applied
to such condenser for extracting from it the water or condensed steam
contained therein. The cock e is to alternately put the ports i, k, in
communication with the condenser, one of them being out of com-
munication while the other is in communication therewith. By such
means it is believed a vacuum may be produced in the cylinder, so as
to cause the pressure of the atmosphere on the retreating piston to aid
in accelerating or effecting the advance of the other piston.
Instead of one partition B in the cylinder there may be two of such
placed near together or with a small or narrow space between the two,
such space to be filled with packing to encompass the piston rod.
Having thus described my engine, what I claim as my Invention is
as follows:-
I claim the improved engine as described, viz., as made with the
cylinder A, the partition B, the two pistons D, E, the rod C, the induction
ports e, f, and eduction ports g, h, arranged in manner substantially
as specified.
I also claim the combination of the movable partition B, its packing
and clamp screws, or the equivalents of the latter, with the cylinder A,
provided with induction and eduction ports, and two pistons D, E,
arranged to operate as described.
I also claim the combination of the condenser with the improved
engine made substantially as described and shown in Figure 3, that is,
the cylinder A, the partition B, the two pistons D, E, the rod C, and
the induction and eduction ports e, f, i, h, g, k, arranged as set forth,
the condenser being connected with the cylinder by means substantially
as specified, or the equivalents thereof.
In witness whereof, I, the said James Wing Chamberlain, have
hereunto set my hand and seal, this 6th day of March
1948
JAMES WING CHAMBERLAIN. (L.S.)