Year: 1888

page_text: I, ELIJAH BAILEY BENHAM, mechanical engineer of 44 Broadway Providence, Rhode
Island, United States 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:-
This invention relates to Compound Steam Engines, the object being to provide a
rotary-valve engine of that class, of improved construction, and the invention consist
in the peculiar construction and arrangement of various parts of the machine, all as
hereinafter fully described and pointed out in the claims.
In the drawing forming part of this specification, Figure 1, is an end and Figure 2,
a side elevation, and Figure 3 a longitudinal section of a steam engine constructed
according to my invention. Figure 4, is a longitudinal section of the valve of the
engine, and of an adjusting ring thereon. Figure 5, is a front-end elevation of said
valve. Figure 6, is a rear-side elevation of the central portion of the cylinder-head of
the engine against which the end of the valve shown in Figure, has a bearing, said
Figure 6, showing the open ends of the steam-ports of the cylinders. Figure 7, is a
perspective view illustrating the central portion of the cylinder-head and certain of
the ports therein, and the end of the valve which operates in conjunction therewith,
said Figure having arrows thereon indicating the course of the steam-currents between
said ports and valve.
In the drawing, A, is the base of the machine, and, B, is the cylinder-head thereof,
the latter being bolted to the base, A, as shown in Figures 1 and 2, and having
formed thereon two series of steam cylinders, 17 and 19, of unequal diameters but all
radiating from a common center, the said cylinders and cylinder-head being con-
structed in one piece by casting, in the usual way, and braced and strengthened as
shown in Figures 2 and 3. The said cylinders are properly bored out and their outer
ends are stopped by the heads, 18 and 20, which are screwed into the ends of the
cylinders or are otherwise suitably secured thereto.
The said cylinders are, as above mentioned, of unequal diameters, those indicated
by 17, being the smaller and serving as the high pressure cylinders of the engine, and
the larger cylinders, 19, serving as the low pressure cylinders thereof.
The cylinder-head, B, has a central chamber formed therein, as indicated by J,
Figure 3, which is open at the front side of said head. Said head is provided with a
cylindrical recess at the rear side of the chamber, J, into which is fitted a bushing 21,
of bronze or other suitable metal, to form a proper bearing for the end of the driving-
shaft to which the crank is connected, as below described. As many steam passages, c,
are formed in the cylinder-head, B, as there are cylinders, said passages extending

page_text: '
from the rear side of said cylinders near their outer ends in converging lines towards
the center of the rear side of said head, or to that part thereof which is covered by
the end of the steam-valve, as below set forth. The said passages, c, serve as both
induction and exhaust passages for the cylinders, there being only one of said
passages, c, for each cylinder.
Figure 6, is an enlarged elevation of the rear side of the cylinder-head, and
Figure 7, shows in perspective the central portion of the rear side of said head, there
being shown in both of the last referred to Figures the ports or ends of said steam
passages, c, those for the passages which lead to the high pressure cylinders, 17, being
indicated by, a, and those for the passages which lead to the low pressure cylinders
being indicated by, b. The said ports, a and b, are formed in that portion of the rear
side of the cylinder-head within the projecting ring, y, and said ports are all in the
same plane but located at different distances from the center of said head, that is to
say, the ports, a, are farthest from the center of the cylinder-head and equidistant
from said center, and the ports, b, are nearest said center and also equidistant
therefrom.
One end of the driving-shaft, 2, terminates within the chamber, J, of the cylinder-
head, and has secured thereon the crank, 3, the crank-pin, 4, being secured to or a
part of the latter.
The pistons, 16, are of an ordinary suitable construction and are provided with the
piston-rods, 14, each having a laterally-extending arm, 15, on the end thereof
adjoining the crank-pin. A sleeve, 5, of bronze or other suitable bearing metal
having a flange on one end, as shown, and having its outer end screw-threaded, and
provided with the oil-holes, o, through its sides, is placed on the crank-pin, 4, and the
ends of said piston-rods, 14 are united around said sleeve, 5, and secured in that
position by a metal ring, v, placed over the arms, 15, on the ends of the piston-rods.
The said ring, v, is held in position on said arms, by a metal cap, 6, which is screwe.l
on the end of said sleeve, 5, and said cap, 6, is centrally perforated to receive an
oiling connection, as below described, whereby the crank-pin and its immediately
connected parts are kept automatically lubricated.
The said chamber, J, within the cylinder-head is covered by a cap, 12, which is
bolted to the front side of said head, as shown in Figures 1, 2 and 3, and said cap has
centrally thereon the oil-cup stud, 13, a passage being made through the upper side of
said stud with which a longitudinal passage in the cap communicates, and an oil-
cup, 10), is secured to the upper side of said stud, as shown, and communicates with
said longitudinal passage in the cap or with an oil-conduit placed therein, said conduit
being indicated by, 9, in Figure 3, and consists of a metallic tube having perforations
through its sides near each end, which perforations in one end thereof communicate
with the outlet from said oil-cup, 10. Said oil-conduit, 9, extends more or less into
said chamber, J. A chambered oiling-crank, 7, has a nipple, 8, screwed thereto near
one end which communicates with an oil-passage in said crank, and the said conduit, 9,
enters the latter near its opposite end and the oil-perforations in the sides of said
conduit communicate with the oil-passage or chamber within said crank, 7. One end
of said nipple, 8, enters the perforated end of the above referred to cap, 6, which
screws onto the end of said crank-pin sleeve, 5. The said oiling-crank, 7, has one side
thereof bearing against the inner side of the cap, 12, whereby it is held in proper
position to be rotated by its connection by one end with said cap, 6, and in
consequence of said connection, the nipple-bearing end of said crank, 7, has a rotary
motion coincident with that of the crank-pin, and it swings on the inner end of said
conduit, 9. By reason of the said rotary motion which is given to the said oiling-
crank, 7, oil which runs from the oil-cup, 10, through the conduit, 9, into the interior
of said crank, is discharged through said nipple, 8, into the interior of the cap, 6, and
directly against the end of the crank-pin, 4, and from thence the oil works between
the crank-pin and the sleeve, 5, and emerges from the latter through the oil-holes, o,
and serves to lubricate the outer side of said sleeve so that there shall be no friction
between the latter and the ends of the piston rods nor between said sleeve and the
crank-pin.

page_text: From the above description it is seen that the construction of the cylinder-head, B,
the pistons and their connections with the crank, embracing as it does, the cylinder
and piston parts of a compound engine, is of exceeding simplicity and consequently
comparatively low cost, and embodies great solidity and strength. The said arrangement
of alternately high and low pressure cylinders radiating from a common center is made
practicable by the employment of the below-described peculiarly constructed steam
valve which has a continuous rotary movement in one direction, in engagement with
the side of the cylinder-head in which said ports, a and b, are, its end covering the
latter. Said valve as below described, serves to admit steam under high pressure first
to the high pressure cylinders, 17, in succession, then to receive the exhaust steam
from the latter and transfer it to the low pressure cylinders, 18, and finally to receive
in a passage therein, the exhaust steam from the last named cylinders and conduct it
to an exhaust chamber whence it escapes to the open air.
The valve-case of the engine consists of the cylindrical sections, 22 and 23, the
former being rigidly bolted to the rear side of the cylinder-head, B, and the section, 23,
to the end of said section, 22, as shown in Figures 2 and 3. Said valve-case sections
are constructed internally to adapt them to receive, and to co-operato with the
valve, D, as below described.
The construction of said valve, D, which controls the flow of the steam to and
from the cylinders of the engine as aforesaid, is clearly shown in Figures 4, 5
and 7.
Said valve consists of a cylindrical head having a somewhat reduced diameter a
little back of its larger bearing end, and from said head rearward extends a tubular
portion as shown.
Said valve has a shaft-passage, n, through it from end to end, to receive the driving-
shaft, 2. In Figures 5 and 7 are illustrated the front end of the valve, and when the
latter is placed in the engine in operative relation to the head, B, as shown in
Figure 3, said end of the valve enters within the ring, y, and bears closely against
that portion of the side of the head within said ring in which the ports, a and b, are
formed and covers the latter, and the hub, 30, on the head then enters the recess, m,
in the end of the valve and serves to impart steadiness to its rotary movement by
keeping it always in the same plane as the side of the head against which it bears and
prevents the escape of steam from between those parts. The head of the valve, D,
has the main steam-passage, e, formed therein, extending from about midway between
the ends of said head to the bearing-end thereof, said passage extending circum-
ferentially, nearly half way around the valve-head as shown, said passage communicating
with the ports, a, of the high pressure cylinders, 17.
The said valve has formed therein, the exhaust-steam passage, K, which extends
quite through the head of the valve, and circumferentially nearly half way around the
head, said exhaust-passage communicating with the ports, b, of the low pressure
cylinders, 19.
The head of the valve, D, is also provided with a, so to speak, transverse steam
chamber, h, whose function it is to receive the exhaust steam from said high pressure
cylinders and permit it to flow therethrough into the ports, b, of the low pressure
cylinders, and to that end said chamber is made of the irregular form shown in
Figures 5 and 7.
Looking at Figure 5, the upper portion of said chamber there shown, or that
having the greater radius, communicates with the outer ports, a, and the lower portion
thereof, or that having the lesser radius communicates with the inner ports, b, and
there being free communication all around in said chamber, exhaust steam entering it
from the ports, a, is instantly transferred to the ports, b, and thence into the low
pressure cylinders to act on the pistons thereof. It will be seen that said two portions
of the chamber, h, having the greater and lesser radii, are concentric, respectively,
with the open ends of the steam passage, e, and the exhaust passage, K.
The said valve-case section, 22, has a circular steam chamber, f, therein, with which
the rear end of the steam passage, e, of the valve communicates, whatever may be the
position of the latter, said chamber receiving steam through the inlet pipe, 28.

page_text: An adjusting sleeve, 26, of cylindrical form, is screwed into the said section, 22, and
surrounds the rear portion of the head of the valve (see Figures 3 and 4) and engages
with a shoulder or under-cut annular groove around said head, the object of said
sleeve being, to provide means for holding the front end of the valve-head closely
against the cylinder-head, and to adjust the valve longitudinally to take up for wear,
and avoid unnecessary friction between the valve and head. Said sleeve, 26, has the
end thereof which engages with said under-cut annular groove in the valve-head
sharpened or beveled to fit said groove, and thereby a joint is formed between the
parts which more effectually prevents steam from escaping from the said steam-
chamber, f. The said sleeve, 26, has a flange on its rear end in which are several
perforations, as shown in Figure 4. The border of said flange is located opposite
an opening, D, in the upper side of the valve case section, 23, through which a
pointed tool or bar may be passed to have its end inserted in said perforations
and act as a lever for turning said sleeve to adjust the valve, as aforesaid.
The said exhaust passage, K, in the head of the valve, D, continues substantially in
the form shown in Figure 5, from the end of the valve-head a little more than half
way to the rear end of said head and then has the form of an annular chamber within
said rear end (see Figure 3) which has free communication with the exhaust
chamber, w,
in the rear end of said case-section, 22, from whence the exhaust steam
escapes through the pipe, 29, (see Figure 2). The arrows opposite the steam-inlet
and outlet openings in said section, 22, indicate the direction of the steam currents
therethrough.
A collar, d, surrounds the tubular portion of the valve, D, just forward of the end of
the rear valve-case section 23, and serves to direct the exhaust steam which comes
from the passage, K, in a lateral direction and prevent it from striking directly, the
end of said section, thereby inore or less obviating any tendency to leakage between
said case and valve which may exist. A packing nut, 24, is screwed into the rear end
of the said case-section, 23 and holds suitable packing in an annular groove near the
end of said section whereby leakage is prevented at that point and a second packing
nut, 31, is placed on the shaft, 2, and is screwed into the end of the valve, D, against
suitable packing in the annular groove, g, therein, whereby any leakage of steam
around the shaft is prevented.
A collar, 25, is rigidly fixed on the rear end of the valve, D, in which is a clutch-
pin, 32, having an engagement with a collar, 33, which is secured on the shaft, 2,
whereby the valve, D, is given a constant rotary motion in consonance with said shaft.
The driving pulley, E, is fixed on shaft, 2, near the rear standard, F, as shown in
Figure 3.
In Figure 7, the parts of the cylinder-head, B, and the valve, D, there shown,
together with the arrows between said parts, indicate the movements, successively, of
the live and the exhaust steam between the valve and said head, which is as follows:
The engine being at rest, steam is turned on and first rushes through the passage, e,
on the line of the arrow, a, into the ports, a, covered by the open end of said passage,
and the steam acts on the high pressure cylinders, 17, moving the pistons, inward, and
starting the shaft, 2. At or near the end of said inward movement, the rotary motion
of the valve brings a portion of the transfer-chamber, h, opposite said ports which
received steam, and the exhaust therefrom enters said transfer chamber as indicated by
the arrow, z¹. The said exhaust steam circulates around said transfer chamber and
escapes therefrom into one or more of the ports, b, communicating with the low
pressure cylinders, 19, as indicated by the arrow, a, a, and having acted on the piston
or pistons thereof, it finally escapes through the exhaust passage, K, as indicated
by the arrow, z, and passing through said passage escapes as above described.
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 as my invention is:
1. The cylinder-head, B, having the alternating high and low pressure series of
cylinders, 17 and 19, thereon, said high and low pressure cylinders having

page_text: communication through steam passages in said head with a separate series of
ports, a and b, for each of said series of cylinders, two valve-chamber sections, 22
and 23, secured end to end on one side of said cylinder-head opposite said ports, and
provided with a receiving and an exhaust steam chamber as described, the cylindrically
formed valve, D, capable of a rotary movement in said sections having one end
covering the said ports and having formed therein a steam passage forming a
communication between said receiving chamber and high pressure cylinder ports, an
exhaust passage forming a communication between the ports of said low pressure
cylinders and said exhaust chamber, and a transfer chamber forming communication
between said high and low pressure cylinder ports, combined with a driving shaft, 2,
extending through and connecting with said valve, and suitable pistons, as described,
operating in said cylinders and connected to a crank on said shaft, substantially as set
forth.
2. A compound steam engine consisting of a cylinder-head having two series of
steam cylinders thereon of unequal diameters, side by side and radiating from a
common center, and communicating by a single steam passage for each cylinder
with two series of ports on one side of said head, at different radial distances from the
center, combined with a valve-chamber extending from one side of said cylinder-head,
a crank-shaft, suitable pistons operating in said cylinders and connected with said
shaft, and a valve having one end covering said ports, attached to, and having a
concentric rotary motion in consonance with said shaft, and having direct and exhaust
steam passages, and a transfer steam chamber therein as described, communicating
with both of said series of ports substantially set forth.
3. A compound steam engine cylinder-head having high and low pressure cylinders
radiating from a common center liaving the steam:-ports for said cylinders divided into
two circular groups at different radial distances from the center, combined with a
crank-shaft, pistons connected to said crank, and a valve rotating with said shaft
having one end covering said ports, a passage therein conducting steam through one
series of said ports, to said high pressure cylinders, a chamber in said valve transferring
steam from the high to the low pressure cylinders, and a passage in said valvo
through which steam is exhausted from the latter named cylinders, substantially as set
forth.
4. In combination, the cylinder-head, B, having the ports, b, communicating with
the low pressure cylinders of the engine, the valve-chamber section, 22, and the
valve, D, having therein the exhaust passage, K, having a segmental opening at the
end of the valve communicating with said ports, and terminating rearwardly in an
annular chamber in said valve communicating with the exhaust chamber, w, in said
section, substantially as set forth.
5. In combination, the valve-chamber section, 22, the valve D, having an under-cut
annular groove therein and the adjusting sleeve 26, screwing into said section and
having a beveled end engaging with said groove, substantially as set forth.
6. The crank-pin, 4, the sleeve, 5, having one end screw-threaded, the piston-rods, 14,
engaging with said sleeve and having laterally extending arms, the ring, v, enclosing
said arms, combined with the cap, 6, screwed onto said sleeve and against said ring,
substantially as set forth.
071.
NL
1000