IMPROVEMENTS IN STEAM ENGINES
Year: 1886

page_text: I, GEORGE HENRY CORLISS, of the City and County of Providence in the State
of Rhode Island, one of the United States of America, Engineer, do hereby declare
the nature of my invention for "IMPROVEMENTS IN STEAM ENGINES" to be as
follows:-
I have conceived and reduced to practice improvements relating to the stuffing
boxes, the dash pots, and the governor.
My stuffing box may apply to piston rods as well as to valve-stems. They may
serve with rods or stems which reciprocate or revolve or partially revolve. They
may apply in any situation where there is or can be a yoke exterior to the stuffing
box and through which the rod, shaft or stem works. For each stuffing box
I compress a ring of yielding material which may be of packing or any ordinary
or suitable character and thereby maintain a tight joint around the valve stem,
but I reverse the relations of the parts and hold the packing in a position further
removed from the valve chest than would be otherwise practicable. The packing
is maintained in a cooler condition and when any leakage occurs there is a larger
admixture of water, thereby securing more durability to the packing. In an
arrangement of stuffing box according to this invention a removable casting is
secured to a stationary part of the engine, and provided with a yoke serving as
an outer bearing for a valve stem or other rod. An outwardly extending metallic
sleeve is secured to the casting and adapted to enclose the said stem or rod, and an
adjustable stuffing box proper is adapted at one end to receive the outer end of the
sleeve and leave a cavity between the said end of the sleeve and its other end for
the reception of any ordinary fibrous, metallic or other suitable packing. By
moving the stuffing box proper inward, the packing may be compressed about the
stem or rod to a greater, or less extent. The stuffing box may conveniently be
adjusted by means of nuts working on screw threaded studs which take through
lugs on the stuffing box and are secured to the yoke, lock nuts being employed for
securing the stuffing box in any desired position.
I employ dash-pots having each two pistons one above the other, rigidly con-
nected, with provisions for a vacuum below the lowest and for an excess of pressure
of air ander the highest near the termination of the descending motion.

page_text: I, GEORGE HENRY CORLISS, residing at No 45 Prospect Street in the City and
County of Providence in the State of Rhode Island, one of the United States of
America, Engineer, 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:-
I have conceived and reduced to practice improvements relating to the stuffing-
boxes, the dash pots, and the governor.
In an arrangement of stuffing-box according to this invention a removable
casting is secured to a stationary part of the engine, and provided with a yoke
serving as an outer bearing for a valve stem or other rod. An outwardly extending
metallic sleeve is secured to the casting and adapted to enclose the said stem or
rod, and an adjustable stuffing-box proper is adapted at one end to receive the
outer end of the sleeve and leave a cavity between the said end of the sleeve and
its other end for the reception of any ordinary fibrous, metallic or other suitable
packing. By moving the stuffing-box proper inward, the packing may be com-
pressed about the stem or rod to a greater or less extent. The stuffing box may
conveniently be adjusted by means of nuts working on screw-threaded studs which
take through lugs on the stuffing-box and are secured to the yoke, lock nuts being
employed for securing the stuffing-box in any desired position.
My stuffing-box may apply to piston rods as well as to valve stems. They may
serve with rods or stems which reciprocate or revolve or partially revolve. They
may apply in any situation where there is or can be a yoke exterior to the stuffing-
box and through which the rod, shaft or stem works. For each stuffing-box
I compress a ring of yielding material which may be of packing or any ordinary
or suitable character and thereby maintain a tight joint around the valve stem,
but I reverse the relations of the parts and hold the packing in a position further
removed from the valve chest than would be otherwise practicable. The packing
is maintained in a cooler condition and, when any leakage occurs there is a larger
admixture of water, thereby securing more durability to the packing.
I employ dash-pots having each two pistons one above the other, rigidly con-
nected with provisions for a vacuum below the lowest and for an excess of pressure
of air under the highest near the termination of the descending motion.
The lower piston is valved and at each descent passes any air or other fluid up
through itself into a chamber above it. Between the lower and the upper piston
is a fixed horizontal platform, peculiarly valved to deliver the air upward freely
and let it return downward slowly with means for adjusting the aperture for such
return so as to make the flow of air downward more or less obstructed at will.
The upper piston has no valve. It is intended to move with tolerable tightness
and to keep the same air always imprisoned under it. Little or no sound can
escape.
provide for holding the parts of the compound or double piston together with
great firmness with facility for separation when desired. I prefer to have the
upper and lower portions of equal size.

page_text: I have devised means for raising and holding the fly-ball governor up to any
desired point without friction, so that while the governor may maintain control of
the mechanism for liberating the valve and thus regulating the speed of the engine
perfectly so long as the conditions allow the engine to work expansively with a
certain velocity, yet the moment the speed falls below a given rate the governor
will cease to act, and the action of the valve mechanism will not change farther
but will remain unalterable until the speed again rises.
I can change the point at which this device becomes available and the governor
ceases to act as a governor.
In some cases it may be preferred to set the device so that the governor may
admit steam and maintain the speed of the engine up to about the furthest point
at which. the cut-off mechanism can act reliably. My mechanism for changing
allows such point to be determined with great accuracy, and to be changed from
time to time as may be expedient. In some cases it may be preferred to set the
mechanism so that the governor will be held up to a higher point than this :-in
other words to allow the governor to vary the point of cut off only up to one
quarter or one eighth or some other portion of the stroke which may be preferred
for economy of fuel, or for other cause, and to hold the parts rigidly in that
position refusing to allow the point of cut-off to be longer delayed, notwithstanding
the speed of the engine may be lessened. I operate by simple and durable
mechanism.
may
The invention is applicable to propeller engines, to engines connected with a
water wheel or other auxiliary power, and to steam engines generally. It
serve as a means of slowing the engine or of stopping under any conditions if
desired.
When the engine is run in connection with a water wheel or other auxiliary
power, my invention afford's convenient means for maintaining the governor balls
at the proper elevation to fix the point of cut-off and limit the amount of power
to be developed by the engine, while it, at tlie same time leaves the governor
mechanism untrammeled and free to act as a regulator to shorten the cut-off and
correspondingly diminish the power developed by the engine in case the regular
speed, which may under this condition of running, be controlled by the auxiliary
power should from any cause be exceeded.
It can be operated so as, at will, to suddenly cut off the steam entirely and stop
the engine. When applied to pumping engines my invention fixes the point of
cut-off to regulate the speed and limit the power to be developed so as to run the
engine at any desired rate of delivery.
If the speed should, by reason of any accident to the delivery mains, be increased
the governor is still free to act on the cut-off as centrifugal governors ordinarily
An arrangement of governor according to this invention is as follows:-
act.
A fixed frame-work, provided with hollow arms, carries a horizontal driving
shaft and a driven vertical shaft. The vertical shaft carries by knuckles at the
upper end, arms, carrying fly-balls connected by links to a sleeve which as the
speed of the engine varies rises or falls and changes (by mechanism engaging with
the sleeve) the point of cut-off of the engine.
The above-described mechanism is of ordinary construction: A lever turning on
a fixed center supported by the frame-work, carries an anti-friction wheel arranged
to engage under the lower edge of the sleeve. A dog, connected to the lever and
controlled by a handle and a spring is adapted to engage successively with notches
on the under face of a ratchet-bar, which turns on a fixed pivot. When by
operating the handle the dog is moved downward, the ratchet-bar rests on a
smooth bearing offered by the dog, and the lever may be moved freely in one
direction or the other to raise or lower the wheel. On releasing the handle the
dog engages with the tooth in the ratchet-bar, which is then presented. It holds
the anti-friction wheel at one level or another according as the dog is engaged in
-the different notches. This device is inoperative so long as the action of the
governor holds the sleeve out of contact with the anti-friction wheel.

page_text: a circular sliding valve, generally known as a "Corliss" valve.
Figure
is. a central horizontal section showing the stuffing-box and the
adjacent parts.
Fig. 2 is a corresponding plan view.
Fig. 3 is an end view of one of the parts.
Fig. 4 is an elevation, partly in vertical section.
Fig. 5 is a central vertical section in a plane at right angles to the plane of
section in Fig. 4.
Fig. 6 is an elevation of a portion corresponding to the section in Fig. 5 and.
Fig. 7 is a horizontal section of a portion on the line x, x, in Figs. 4 and 5.
Fig. 8 is an elevation, a portion of the driving-pulley being broken away to
show the parts beyond.
Fig. 9 is an elevation at right angles to that in Fig. 8.
Similar letters of references indicate corresponding parts in all the figures where
they occur.
I will designate by A the principal stationary parts, using additional marks,
as A', A², to indicate particular portions thereof.
Referring to figures 1, 2, and 3, A¹. is a casting, which forms when in position a
portion of the fixed work of the engine.
A is a yoke cast in one with A¹, and serving as an outer bearing for the valve-
stem B. It will be understood that this valve-stem connects at the inner end with
the valve, (not fully represented,) and at its outer end is provided with an arm,
(not shown,) through which it receives from the engine the proper vibratory
motion.
C is a sleeve, of brass or other non-corrosive metal, rigidly set in the casting A¹,
inclosing the valve-stem B, and extending out, as shown.
D is an adjustable stuffing-box, which partially receives the outer end of the
sleeve C. The remaining portion of this cavity is occupied by any ordinary fibrous,
metallic or other suitable packing d, adapted to be confined, when necessary, by
moving the stuffing-box D inward toward the valve to a greater or less extent.
E are studs set in the yoke A2, and extending through lugs D¹ on the stuffing-
box D. For convenience in applying and operating the studs the heads E² are
preferably set fixedly on the studs at a short distance from one end, and the
adjustment is effected by these heads, operated as required in the obvious manner,
and the stuffing-box D is secured at the desired point by the jam-nuts E.
To introduce new packing the stuffing-box D is shifted outward until it strikes
the inner surface of the yoke A². This opens a sufficient space between it and the
sleeve:C to allow packing to be easily introduced. On moving the stuffing-box D
inward and receiving the sleeve C to compress the packing the adjustment by the
heads E allows the packing to be compressed with any required degree of force.
This arrangement, by removing the stuffing-box or gland some distance from the
heat of the steam-chest, thereby affording more surface for the radiation of heat
from and consequent condensation of steam within the sleeve C, maintains the
packing in a cooler and better condition than the ordinary stuffing-box, is easy of
access and adjustment, and insures that when there is a slight leakage around the
stem B the leakage consists of a large admixture of water, and the lubrication is
better with that water than with steam.
Referring to figures 4, 5, 6 and 7 A³ is the lower cylinder of the dash-pot. Its
base is equipped with a stop-cock F, by which it may be instantly relieved from
its vacuum whenever it is desired to remove the piston for any reason.
A is the upper cylinder.
A is the diaphragm, which, for convenience, is made in one with A', and is
provided with a central orifice, a, and air-holes a³, a¹, a². The lower piston, G
and the upper piston G2, work in their respective cylinders with a fit nearly air-
tight, and are connected by the rigid stem G³ which extends through the orifice a
'

page_text: in the diaphram Aº. The stem or connection G¹ is shouldered at g to receive the
sleeve or central boss G³ of the upper piston G². The connection G₁ is screwed
into G and a screw-thread at its upper end secures G2 by a screw-threaded clamp, H,
presenting a ball-bearing, h, and tightly set by transverse clamping screw-bolts H¹.
This method of securing connection between the piston-rod and the ball-bearing is
of importance, because it is desirable that the rod and its two pistons should be
free to rotate in both cylinders, as well as to move longitudinally therein. The
ball-bearing is therefore provided with this screw-threaded clamp, fitted to work
freely while it is being screwed on into its place until it reaches the disk of the
piston. If left in that condition it would work loose. The transverse clamping
screw-bolts H' serve to firmly set the clamp upon the piston-rod, and in practice is
found to prevent the liability of working loose. This form of clamp H, operated
by transverse screw-bolts H, insures at all times a firm connection and true align-
ment of the several parts. The central orifice, a, in the diaphragm A³ is made of
sufficiently larger diameter than the connection G' to allow of the proper passage
of air around the connection G' from one chamber or cylinder to the other. Two
air-holes, a, a, in the diaphragm A³ are covered by a flap-valve I, secured to the
upper face of the diaphragm A' by rivets and opening upward to allow the air
to pass freely from the lower to the upper chamber or cylinder on each upward
movement of the pistons.
An orifice, a, in the diaphragm A³ is for the purpose of graduating the flow of
air from the upper to the lower chamber on the descent of the pistons, more or
less obstructed at will by a screw-plug J, adjusted from the outside and held
firmly by a jam-nut j.
I make the sleeve G³ of the upper piston G² slightly tapering and of larger
diameter than the connection G' in order that as the pistons descend the sleeve G³,
entering the orifice a, will nearly close it and check the flow of air and cushion it
under the upper piston thereby retarding the downward movement of the pistons,
which up to that point has been nearly instantaneous. The air cushioned beneath
the upper piston by the action of G³ is, as regulated by J, discharged through a
into the lower chamber to allow the pistons to settle gently to their seats. The
lower piston G, has air-holes g¹, covered by flap-valves K secured by rivets k.
These valves open upward, when necessary; to allow of the passage of air or other
fluids up through the piston G, to insure an adequate vacuum beneath the piston.
The piston G is also provided with packing to make it air-tight. The ball-
bearing receives a connection, M, (indicated in dotted lines,) which transmits to
the two pistons the motion of the valve-arın, (not shown,) which may be understood
to be one of the rocker-arms of the circular slide-valves known as " Corliss "
valves.
"
Referring to figures 8 and 9 A is a hollow arm supporting the driving-shaft N
which, by means of a belt from the steam-engine running on a pulley N¹, receives
motion. This is transmitted by bevel-gear (not shown) to a vertical shaft O which
is supported in the upright arm A. It carries, by knuckles at its upper end,
arms W, carrying fly-balls W₁, connected by links X¹ to a sleeve X.
As the speed
of the engine varies, the centrifugal force or the gravity of the fly-balls W
alternately master each other, with the result to raise or lower the sleeve X, and
by mechanism (not shown) engaging in a groove, x, change the point of cut-off of
the engine.
So far as yet described, the mechanism is of an ordinary and long-approved
character.
P is a lever turning on a fixed center as supported on a fixed arm A. A center p,
carried on the lever P, or on a short arm therefrom, as shown, supports an anti-
friction wheel, Q, arranged to engage under the lower edge. of the sleeve X.
A dog, R, connected to the lever P at p', and controlled by a handle, R¹, and a
spring, S, is adapted to engage successively with notches on the under face of a
ratchet-bar, T, which turns on a fixed-pivot, a³. When by operating the handle R'
the dog R is moved downward, the ratchet-bar T rests on a smooth bearing offered

page_text: 'by the dog R, and the lever P may be moved freely in one direction or the other
to raise or lower the wheel Q. On releasing the handle R¹ the dog engages with
the tooth in the ratchet-bar, which is then presented.. It holds the wheel Q at one
level or another, according as the dog is engaged in the different notches. This
device is in-operative so long as the action of the governor holds the sleeve X out
of contact with the wheel Q. While the proper speed is thus maintained the
governor regulates with its ordinary efficiency and effect; but when from any cause
the speed is lowered, causing the sleeve X to rest on the wheel Q, the latter then
commences to serve as an anti-friction wheel, turning with the motion received by
friction from the sleeve X, and supporting the latter against any farther sinking,
and consequently maintains the point of cut-off of the engine unchangeably. Thus
conditioned, the governor mechanism is still on duty ready to serve instantly to
prevent any too great increase of speed. A quickening of the engine sends the
balls up with the same freedom and produces the same effect in shortening the
cut-off, as usual; but the balls cannot be lowered and the point of cut-off cannot
be made later in the stroke than that for which my lever P, and its connections
are set. Any reduction of steam-pressure or increase of load will lower the
velocity of the engine below the proper point. The engine will continue to turn
at a reduced rate, working the steam expansively and economically. If the load
is still further increased or the steam-pressure further lowered the engine goes still
slower.
The slowing of the engine and the stopping may be induced under ordinary
conditions at any time by pulling the lever P sufficiently upward.
The lever P and its connections may, whenever desired; be rendered entirely
inoperative by moving it downward as far as it will go. This lowers the wheel Q
out of contact with the sleeve X, even in the lowest position of the latter.
Modifications may be made in the forms and proportions without departing from
the principle or sacrificing the advantages of the invention.
The sleeve C may be held to the part A¹ by other means than the collar and
riveting shown. It may be made in one with the casting A¹.
Other means than the studs E, check-nuts E¹ and heads E' may be employed to
move the stuffing-box D.
One aperture with a suitable valve may serve, instead of two, to pass the air up
through piston C and up through the diaphragm A³.
I can dispense with the spring S and lever R¹, and employ other means of
operating the dog R..
I can dispense with the dog R and confine the lever P by friction applied
laterally, or by any other convenient means.
Parts of the invention may be used without the whole.
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. The combination, with the rod or stem B, of the fixed head A, the long
sleeve C, fixed rigidly therein, and adjustable stuffing-box D and inclosed packing d,
all arranged for joint operation as herein specified.
2. The fixed portion A¹, with its yoke A², studs E check-nuts E' and heads E²
in combination with each other and with the stem B, stuffing-box D and sleeve C,
adapted for joint operation as herein specified.
3. A dash-pot for steam-engine valve-gear, consisting of two cylinders A³ A*, of
equal or nearly equal diameter, having a common axis, with a diaphragm A³,
situated between them, and provided with means for allowing the air to flow
freely through it on each upward movement of the pistons, and with means for
restricting the return-flow at will, in combination with each other and with the
pistons G G2 working air tight, or nearly so, in the cylinders, a rigid connection G³
_ and a suitable connection to the valve mechanism.

page_text: 4. The cylinders A³ A*, and diaphragm A³ with its orifice a, and valve or valves I,
in combination with the double piston G, G², sleeve G³ connection G₁ and with
means, as J for adjusting the area for allowing the air to escape from the cylinder A*
into the cylinder A³, and a suitable connection.to. the valve mechanism, as herein
specified.
5. The screw-threaded clamp H and its operating means H' in combination with
the stem G', and two pistons G, G, and with the enclosing-cylinders A³ A and a
suitable connection, as M, to the valve-operating mechanism, the clamp H being
arranged as shown, so as to serve the double functions of confining the piston G²
to the stem, and forming a bearing for the connection M as herein specified.
6. A screw-threaded clamp, H and transverse clamping screw-bolts H', in
combination with each other and with a screw-threaded connection G¹, said
clamp H being adapted to work freely while it is being screwed onto the
connection G until it reaches its, seat, and then to be firmly set upon the
connection G¹ by the transverse screw-bolts H to insure at all times a firm
connection and true alignment of the parts, as shown and described.
7. In a dash-pot for steam engine valve-gear, the piston G² provided with a
sleeve G³ combined with a connection G', diaphragm A5, provided with a central
orifice a, piston G¹ and cylinders A³ A, said sleeve G³ being of slightly larger
diameter than the connection G¹ and adapted to more completely fill the orifice a,
thereby checking the flow of air from A* into A³ and retarding the descent of the
pistons, as herein specified.
8. The combination, with a speed-governor for steam-engines of an anti-friction
wheel, Q, arranged, as shown, relatively to the sleeve X and adapted to afford a
frictionless bearing for said sleeve and hold the governor out of action when the
speed is below a certain rate without imposing any appreciable friction, substan-
tially as herein specified.
9. The combination, with a speed-governor for steam-engines of the anti-friction
wheel Q, lever P, spring-dog R, and ratchet-bar T, arranged to serve as herein
specified.