Steam Engines.
Year: 1890

page_text: Date of Application, 19th Aug., 1890-Accepted, 13th Dec., 1890
Steam Engines.
I, JOHN BAIRD, Mechanical Engineer, a citizen of the United States, residing at
No. 324, Lexington Avenue, in the City, County, and State of New York, U.S.A., 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 consists of new and useful arrangements of the principal parts of
steam-engines, especially adapted for marine-engines, but also suitable for stationary
engines.
The essential principle of my invention consists in balancing the weight of the
moving parts of a steam-cylinder by the weight of the corresponding parts of another
steam-cylinder, on the opposite side of the crank-shaft; these moving parts being
connected to each other by suitable bell-crank or elbow levers and links, so that, when
the piston and its attachments of one cylinder are going in one direction, the
piston and its attachments of the other cylinder are going in the opposite direction.
These improvements are especially intended for the improved construction of
compound engines, triple-expansion engines, and quadruple-expansion engines.
Economy in the use of steam, and reduction of the size and weight of the parts of
steam-engines are secured by expanding steam of a high initial pressure to a low
terminal pressure, while doing its work, as well as by a high velocity of piston, and
increased frequency of revolution. To attain these ends, it is of the first importance
that the moving parts should counter-balance each other, and that the weight of
vertically reciprocating parts, such as pistons and their attachments, should be counter-
balanced by the weight of similar parts having the same kind of motion, but in an
opposite direction. Vertically reciprocating pistons and their attachments are
frequently counterbalanced by parts having a revolving motion; this causes side strains
in the shafts, producing a wabbling, unsteady motion, hastening the wear of shaft-
journals, and causing them to get out of line. This is a serious difficulty in the case
of large engines, the moving parts of which are necessarily heavy, and the consequent
strain thereon great.
My improvements effectually eradicate these defects, as, in my plan, the weight of
the large piston and its attachments is counterbalanced by the weight of a smaller
piston and its attachments, plus the weight of the connecting-rod; and by using
proper discretion in the construction and proportions of these moving parts, a close
approximation to perfect counterbalancing can be secured.
My improvements have the great and important advantage of enabling me to place
the cylinders low down on the level of the foundations of the pillow-blocks of the
crank-shaft journals, which is desirable for all marine engines, particularly for those
of naval vessels.
The accompanying drawings show triple expansion engines having a high-pressure
cylinder, an intermediate-pressure cylinder, and two low-pressure cylinders of equal
capacity: the stroke of the crank being greater than that of the piston, which con-
tributes materially to an easy motion in passing dead centres.
That part of the engine at which the steam enters the high-pressure cylinder, I
call the outer or front end; the opposite, the rear end. That portion on the left of a
person standing at the front of the engine, as above defined, and facing it, I call the
left or front side; the opposite, the right or rear side.
Fig. 1 represents a plan or top view of one form of my improved engine, with
he front section thereof partly in horizontal section, on the line 1-1 of Fig. 2;
Fig. 2, a front elevation thereof, with the parts omitted in Fig. 1 in place;
Fig. 3, a vertical, longitudinal section through the front section of the engine, on

page_text: he line 3-3 of Figs. 4 and 5, including the parts shown in Fig 2, and looking
to the right or rear;
Fig. 4, a vertical, transverse section, on the line 4-4 of Figs. 1 and 2 ; and
Fig. 5 a similar section, on the line 5-5 of Figs. 1 and 2, through the front section
of the engine.
The darts in these figures indicate the direction in which the views are shown,
while the arrows indicate the course of the steam.
Fig. 6 represents a partial end view: and
Fig. 7, a side view, partly in vertical, longitudinal section, illustrating a modifi-
cation of the engine in which the elbow-levers, walking-beams, and their connecting-
links extend above the fulcra on which they rock, instead of below it, as in the
organization shown in the preceding figures, 1 to 5, both inclusive.
Fig. 8 represents a diagrammatic plan view, illustrating the adaptation of my
improved engine to the propulsion of two parallel shafts, such as those of twin-screw
propellers; and
Fig. 9, a similar side view of apparatus illustrating the same adaptation..
The various parts are shown as connected with, or mounted in a bed-plate and
frame A. A high-pressure cylinder B, and its valve-chest b, are shown as mounted
on the outer, rear part of the bed-plate; its piston-rod B', is connected by a link B2,
with a pin B³, projecting therefrom at both ends, and passing through the parallel
rocking-arms G, G¹, of an elbow-lever, which rock on a pivot g, on the main frame.
The other ends of these rocking-arms are respectively connected by link-rods H, H²,
with the pendant crank-arms, 2, of a walking-beam consisting of parallel arms I, I¹,
rocking on a fulcrum i, on the main frame.
A pin j, connects the inner or forward end of these walking-beam arms, and a
connecting-rod J, connects this pin with a crank-pin k, on a crank-shaft K, which
may also be the propeller-shaft. The opposite, outer or rear ends of the walking-
beam arms are connected by a pin d³, and link d*, with a piston-rod D³, of a low-
pressure cylinder D, having the usual valve-chests d³, &c.
The intermediate or first low-pressure cylinder C is preferably placed near the
high-pressure cylinder B, and has the usual valve-chest c. A piston-rod C¹, link c²,
and pin c³, connect this cylinder, in a manner similar to that hereinbefore described,
with the rocking-arms G2, G3, of elbow-levers rocking on a pivot g¹, and connected
by link-rods H2, H3, with the pendant crank-arms 3, 4, of the arms 12, 13, of a
walking-beam rocking on a fulcrum is, and connected at their inner or front ends
by a pin , and connecting-rod J¹, with another crank k¹, on the crank-shaft K.
The opposite ends of these walking-beams are connected by a pin d², and link d¹,
with the piston-rod D, of a low-pressure cylinder D¹, having the usual valve-
chests d, &c.
The ends of the bell-crank and walking-beam arms connected with the cylinders
are of equal radius, while the walking-beam arms connected with the cranks are of
slightly greater radius, the result of which is to give the crank a stroke greater than
that of the pistons, and consequent ease of motion in passing the dead centres.
The construction above described secures a very compact organization, as short
walking-beams and elbow-levers can be used, the parts counterbalanced, and all the
working connections are below the fulcra on which they move.
The mechanism above described may be said, in a sense to constitute a double
engine with the two parts side by side, the cylinders of each section being on opposite
sides of the crank-shaft, united by link-rods crossing that shaft, and all co-operating
in actuating it.
on
An air-pump E, is connected by a piston-rod E¹, and link E³, with a crank-arm l
a rock-shaft L, provided with an oppositely projecting arm 1, connected by a
link L', with an arm 12, rocking on the shaft or pivot g', of the elbow-levers G², G³
A condenser F is shown as extending across the frame or bed-plate close to the
cylinders B, C.
Fig. 1 shows my preferred plan of working this engine: Steam from the boilers
passes through a pipe M, and a high-pressure cylinder B; thence through pipes M

page_text: to the intermediate cylinder C; thence through pipes M², to the opposite end of the
engine, where branch-pipes m, m', respectively connect with the valve-chests d, d³,
of the second and third low-pressure cylinders D¹, D*, which are preferably of equal
area, but larger than the intermediate cylinder C. After doing its work in these
cylinders D', D4, the steam is conducted by pipes M, M¹, on opposite sides of the
engine, to the condenser F, which it enters at opposite ends as shown.
The foregoing description applies more particularly to the engine shown in the first
five figures of the drawings.
Figs. 6 and 7 show a modification in which the elbow-levers, walking-beams, and·
their connecting-links are arranged above their fulera, instead of below them, as in
the organization first described.
Like parts being correspondingly lettered in all the figures, their arrangement
will readily be understood.
This last described plan, while not so compact as the other, has the compensating
advantage of simplifying the organization, as it admits of the use of a single elbow-
lever and walking-beam, with forked connecting-rods embracing them, instead of
double arms to straddle the connecting-links, as in the first plan.
Figs. 8 and 9 show an advantageous plan of working two parallel crank-shafts ;
such, for instance, as those of twin-screw propellers. Two triple-expansion engines
are shown as arranged, side by side, in reverse order, the higher pressure cylinders
being on the outer sides, and the larger low-pressure cylinders lying between the
crank-shafts. In this case, duplicate sets of air-pumps and condensers are used, and
at the opposite end of the engines from the plan first described. Each air-pump may
be worked from the walking-beam fulcrum by a long link 12, and bell-crank L²,
instead of from the elbow-levers. 1 thus secure a very compact and convenient
organization, and still keep all the connecting-rod pivots of the walking-beams
directly over the crank-shaft.
Except as hereinbefore stated, the details of construction of the various parts constitute
no part of the subject-matter claimed, and may be greatly varied, within certain limits,
in well-known ways, without departing from the spirit of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is-
1. The combination, substantially as hereinbefore set forth, of a crank-shaft; a
steam-cylinder on each side thereof; two separate bell-cranks or elbow-levers, to
opposite ends of one of which are connected the piston-rod of one of the cylinders
and a connecting-rod directly actuating the crank-shaft, the other of which bell-cranks
is connected with the piston of the other cylinder; and a link directly connecting the
bell-crank and elbow-lever.
2. The combination, substantially as hereinbefore set forth, of a crank-shaft; a
steam-cylinder, and a bell-crank or elbow-lever connected with the moving parts of
the steam-cylinder, on each side of the crank-shaft; a link-connection between the
elbow-levers, crossing the crank-shaft, and a connecting-rod uniting the crank-shaft
with one of the elbow-levers, between their fulcra, the organization being such that
the weight of the moving parts is counterbalanced.
3. The combination, substantially as hereinbefore set forth, of a crank-shaft; a
steam-cylinder on each side thereof; an elbow-lever connected with the moving parts
of one of the cylinders; a bell-crank walking-beam connected with the corre-
sponding parts of the other cylinder, and having arms of unequal length; a
connecting-rod uniting the crank-shaft with the longer arm of the walking-beam,
and a link connecting the elbow-lever and walking-beam; the organization being
such that the moving parts of the steam-cylinders always traverse in opposite
directions, the weight of the moving parts is counterbalanced, and the stroke of
the crank is greater than that of the piston.
4. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; an elbow-lever directly connected with the moving parts thereof; a

page_text: separate walking-beam; a link directly connecting it to the elbow-lever; a low-
pressure cylinder, having its moving parts directly connected with the walking-beam,
on one side of its fulcrum; a crank-shaft; and a connecting-rod uniting the
crank-shaft with the walking-beam on the opposite side of its fulcrum.
5. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; a bifurcated elbow-lever connected with its moving parts; a bifurcated
bell-crank walking-beam; links connecting the bifurcations of the elbow-lever and
walking-beam; a low-pressure cylinder; its moving parts connected with the walking-
beam; a crank-shaft, and a connecting-rod pivoted on the crank at one end, and
between the bifurcations of the walking-beam at the other, and straddled by the
connecting-links below their fulcra.
6. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; an intermediate cylinder into which steam passes direct from the high-
pressure cylinder; elbow-levers connected directly with the moving parts of these
cylinders; a separate bell-crank lever walking-beam; a link-connection between the
elbow-levers and the walking-team; a low-pressure cylinder; the connections between
its moving parts and the walking-beam; a crank-shaft; and a connecting-rol uniting
the crank-shaft and the walking-beam.
7. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; its moving parts; an elbow-lever connected therewith; a walking-beam;
a link-connection between the elbow-lever and walking-beam; a low-pressure cylinder;
its moving parts connected with the walking-beam; a crank-shaft, and a connecting-
rod uniting the walking-beam and crank-shaft, with a duplicate engine having two
cylinders; an elbow-lever; walking-beam; connecting-links, and a connecting-rod
connected with the same crank-shaft as the other engine.
8. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; an intermediate cylinder of larger area, and two low-pressure cylinders of
still larger area, with duplicate, separate elbow-levers, and walking-beams; links
directly connecting the walking-beams and elbow-levers of each set; and connecting-
rods connected with the walking-beams and acting on the cranks of a common crank-
shaft, and constituting a triple-expansion engine.
9. The hereinbefore described triple-expansion engine, consisting of the combination,
substantially as herein before set forth, of a high-pressure cylinder; an intermediate
cylinder of larger area; two still larger low-pressure cylinders of equal area, with
duplicate separate elbow-levers and walking-beams; links directly connecting the
walking-beams and elbow-levers; and connecting-rods connected with the walking-
beams, acting on the cranks of the same crank-shaft; a steam-passage connecting the
high-pressure and intermediate cylinders, and a branch steam-passage therefrom to the
other low-pressure cylinders.
10. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; a larger intermediate cylinder; two larger low-pressure cylinders; separate
elbow-levers and walking-beams; links directly connecting the walking-beams and
elbow-levers; and connecting-rods connected with the walking-beams, and connecting
the moving parts of these cylinders in pairs with a common crank-shaft, a condenser,
and an air-pump.
11. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder an intermediate cylinder of larger area; two other larger low-pressure
cylinders of equal area; separate elbow-levers and walking-beams; links directly
connecting the walking-beams and elbow-levers of each set, and connecting-rods con-
nected with the walking-beams, and uniting the moving parts of these cylinders in
pairs with a common crank-shaft, an air-pump and link-connections for working it
from the fulcrum or shaft of one of the elbow-levers or walking-beams.
12. The combination, substantially as hereinbefore set forth, of a high-pressure
cylinder; a low-pressure or intermediate cylinder of larger area adjacent thereto;
two larger low-pressure cylinders of equal area; interposed separate elbow-levers and
walking-beams; links directly connecting the walking-beams and elbow-levers; and
.connecting-rods connected with the walking-beans, and uniting the moving parts of

page_text: these cylinders in pairs with a common intermediate crank-shaft, a condenser, and
steam-passages entering it at opposite ends from the larger cylinders.
13. The duplex, twin-screw, triple-expansion engine hereinbefore described, con-
sisting of the combination of two duplicate engines; their separate walking-beams
and elbow-levers; links connecting them with their largest low-pressure cylinders
between the crank-shafts; their high-pressure and intermediate cylinders outside the
crank-shaft, and their elbow-levers and walking-beams on opposite sides of their
respective crank-shafts.
14. The combination, substantially as hereinbefore set forth, of two parallel crank-
shafts; a high and an intermediate cylinder outside of the crank-shafts; two low-
pressure cylinders between the shafts; separate elbow-levers and walking-beams;
links connecting them, and connecting-rods uniting the moving parts of these
cylinders with the crank-shaft between them; a generator outside the other crank-
shaft, and steam-passages connecting the cylinders in series with the generator.
Dated this 7th day of July 1890.
JOHN BAIRD.