IMPROVEMENTS IN THE METHOD OF EFFECTING THE CUT-OFF IN STEAM ENGINES, AND ALSO IN THE REGULATOR FOR CONTROLLING THE SPEED OF STEAM ENGINES
Year: 1866

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the Invention of "IMPROVEMENTS IN
THE METHOD OF EFFECTING THE CUT-OFF IN STEAM ENGINES, AND ALSO IN THE
REGULATOR FOR CONTROLLING THE SPEED OF STEAM ENGINES." -A communi-
cation from abroad by George Herman Babcock and Stephen Wilcox,
junior, residing at the City and County of Providence, in the State of
Rhode Island, United States of America.
COMPLETE SPECIFICATION filed by the said George Tomlinson Bousfield
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 31st December 1866, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN, that I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park,
Brixton, in the County of Surrey, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE METHOD OF EFFECTING THE CUT-OFF IN
STEAM ENGINES, AND ALSO IN THE REGULATOR FOR CONTROLLING THE SPEED OF STEAM
ENGINES," (a communication to me from abroad by George Herman Babcock
and Stephen Wilcox, junior, persons resident at the City and County of

page_text: Providence, in the State of Rhode Island, United States of America,) and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, that is to say :-
Sheet 1, Figure 1 is a side elevation with the bonnets of the steam chest
removed; Figure 2 is a transverse section through the cylinder and steam
chest; Figure 3 shows in detail the connection between the regulator and the
cut-off valve mechanism; Figure 4 is an enlarged view of the valve arrange-
ment of the auxiliary cylinder which works the cut-off; Figure 5 shows an
arrangement for preventing the too rapid admission of steam into the auxiliary
cylinder.
Sheet 2, Figure 6 is a longitudinal and horizontal section through the
cylinder and steam chest; Figure 7 shows in section the arrangement of
steam and exhaust ports; Figure 8 is a view of the under side of the valve
of the auxiliary cylinder, showing the exhaust pockets; Figure 9 shows the
connection of the regulator with its rod.
Sheet 3, Figure 10, is a sectional elevation of a regulator in which the
centre of gravity of the balls is in the same plane for all positions of the
balls; Figures 11 and 13 are details of the same; Figure 12 is a variable
counterbalance applied to the regulator.
The engine herein described does not belong to that class of steam engines
which employ a liberating valve gear, or, in other words, a valve gear, which
to permit a cut-off of the steam to be effected during the stroke of the piston
must be disconnected from the valve in order that the latter may be free to
close in less time than it was opening by an impulse derived from a force
independent of the engine, but it belongs to that class in which the cut-off
valves are operated through an auxiliary steam cylinder and piston by the
steam itself independently of the main valve mechanism.
And the Invention consists in certain devices, combinations, and arrange-
ments by which I make the point of cut-off variable for any desired point in
the stroke of the piston in the main cylinder, and in the combination of the
regulator therewith for determining automatically the point of such cut-off.
In the accompanying Drawings A represents the cylinder of a horizontal
engine, the piston and its connection with the crank shaft being the same as
in ordinary engines of this class, and which being familiar to those acquainted
with the art needs no explanation; B is the main valve, in this instance inde-
pendent of the cut-off valves which are supplemental thereto, and ride upon
its back; the main valve is made with mortices through it near its ends
corresponding with the steam ports in the same manner as the well-known
lap slide valve of this class, and as in this particular instance the steam ports

page_text: are used also as exhaust ports apertures are cut in the under side of the valve
connecting with a hollow space between the two faces of the valve (as shown
in Figure 6), through which the steam is conducted to the main exhaust
pipe C, Figure 2, and the said valve has in consequence sufficient motion given
to it to bring these apertures alternately in connection with the ports in the
cylinder. In other words the valve performs the same functions as the
common D valve, which admits steam through mortises cut in it instead of
at the ends; the main valve B is operated by the properly guided valve rod B',
as shown through the connecting rod B attached to an eccentric on the main
shaft in the usual way; the cut-off valves D, D', have, as here arranged, their
seats upon the back of the main valve, and move simultaneously for the reason
that the rods a, a, connecting them are attached to the piston of a small
auxiliary cylinder b, shown in section in Figures 2 and 6, which is also
mounted upon the back of the main valve B. Steam to operate the piston of
the cylinder and thereby work the cut-off valves is admitted to each side
alternately through steam ports at opposite ends of the cylinder, which are
controlled by the sliding valve E, to which a reciprocating motion is given in
a direction at right angles to the axis of the cylinder by means of the valve
rod d, which passes through a stuffing box in the wall of the steam chest, and
is worked by an eccentric or crank c on the shaft F, with which it is connected
by the link e. Inasmuch as the main valve B has a motion in a line at right
angles with the line of motion of the valve E, and as the latter with the
cylinder to which it belongs rides upon the back of the former it becomes not
only necessary to provide guides f, f, upon the top of the cylinder 6, between
which the valve E can work to control the ports, but also to connect the valve
rod with the valve by means of two check strips g, g, in contact with the valve
at each end, between which the valve is permitted to have its end wise move-
ment due to the movement of the main valve, and by which it can at the same
time be worked in a direction at right angles therewith; the exhaust steam is
worked out from the small cylinder 6 through the ports 9, 9, Figure 7, both
located upon the lower side of the cylinder so as to freely drain the same of
condensed steam, and each port has its appropriate pocket h, h', in the valve E
which connects the port to which it belongs at the proper times with the
exhaust pocket of the main valve, as shown in Figure 2.
For the purpose of
preventing the piston of the auxiliary cylinder from slamming against the
cylinder heads in working the cut-off I cover each port in the valve E with
a plate n, through which is a small orifice o (see Figure 5). Now while the
said valve port is not connected with the cylinder port the steam will bo
working through this orifice, and fill the space occupied by the valve port p,

page_text: acting as a pocket to collect the same, but so soon as the valve port comes
into connection with the cylinder port the steam so pocketed will rush into
the cylinder 6 and start the piston rapidly, but will continue to exert a dimin-
ishing force as it expands in volume until the stroke is completed; the steam
which is being admitted during the stroke through the contracted orifice o not
being sufficiently powerful (from the fact that it is so wiredrawn) to cause the
piston to slam, and the size of this orifice can be adjusted to exactly accomplish
the work required. It is is obvious from the foregoing description that if the
eccentric on the shaft F which works the valve E of the auxiliary cylinder b,
and which revolves coincidently in point of time with the eccentric on the
main shaft which works the main valve, is set relatively to the latter at any
point in advance of it it will cause the valve E to admit steam to the auxiliary
cylinder at à corresponding point in advance of the completion of the stroke
of the main piston, whereupon the cut-off valve which appertains to the part
that is admitting steam to the main cylinder will be instantaneously closed,
and at the same time the cut-off valve at the other end of the cylinder will
uncover the aperture in the main valve to which it belongs preparatory to the
admission of steam through the port at that end for the return stroke so soon
as such port shall be opened by the proper movement of the main valve, and
consequently a cut-off of the steam can be effected at any desired point in the
stroke of the piston by adjusting the position of the eccentric on its shaft F
correspondingly. I determine automatically the point of cut-off according to
the rate of speed of the engine by the following means for combining the
regulator with the cut-off valve mechanism and for controlling the same. The
form of the regulator is shown in Figure 1; in this instance it is of the fly-
ball variety. The rod G (Figures 1 and 3), whose range of upward or down-
ward movement is determined by the plane in which the balls G¹ and G³
revolve, extends through the upright hollow shaft H, which supports the frame
of the regulator, and which is made to revolve upon its axis by means of the
bevel gear keyed to its foot, and driven by the larger bevel gear I
on the shaft I', connected by appropriate gearing with the main shaft; the
rod G terminates with a rack J (Figure 3) of sufficient length to compre-
hend the whole range of motion of the rod G. The shaft I' and the shaft F
before referred to revolve in opposite directions with each other, but in the
same times as the main shaft of the engine, and the connection between the two
is maintained through the bevel driving gear wheel k on the shaft I, the inter-
mediate pinion, and the driven gear wheel on the shaft F. Now, although
these two shafts I¹ and F revolve in the same times, yet a given point upon the
surface of F, which for a given plane of revolution for the balls of the regu-

page_text: lator will coincide at each revolution with a given point upon the surface of I¹,
will not so coincide with such point when the regulator balls revolve in any
other plane, for the reason that the intermediate pinion ¹ turns upon a
vibrating radial axle m (Figure 3), the opposite end of which is flattened, and
has for its pivot the end of the shaft I', and as the end of such axle opposite
to the end on which the pinion is mounted is provided with a segmental gear,
with the teeth of which the teeth of the rack J engage, see (Figure 3), it
follows that for every change in the position of the regulator rod G there will
be a corresponding change in the position of the pinion k', that is to say, it
will be made to take a different position upon the face of the driving gear k,
and will thereby necessarily cause the shaft F, which is the only one of the
two that is free to be shifted in its bearings, to be turned in the one direction
or the other, and thus change the relative relation of the eccentric which
controls the operation of the cut-off valve mechanism to the eccentric which
works the main valve mechanism; the result of which will be that the point of
cut-off will be determined automatically by the speed of the engine. I am
aware that an auxiliary cylinder and piston to work the cut-off valves of a steam
engine has been heretofore used, but its range of operation has been hereto-
fore limited to cutting off the steam at a fixed point within the half stroke with-
out the capacity of being adjusted at will variably with respect to the stroke
of the main piston, while this Invention gives to this variety of cut-off capacity
for cutting off steam at any point in the entire stroke, and adapts the same to
the control of the regulator.
Another division of this Invention relates to the regulator, one modification
of which with details is exhibited on Sheet 3, from Figures 10 to 14 inclusive,
and another modification on Sheet 1, Figure 1, and Sheet 2, Figure 9.
The first modification which I will describe is shown on Sheet 3. The
common fly-ball regulator depends for its action in controlling the engine
upon the fact that its balls will for different speeds of the engine revolve in
planes of different altitudes, and as the consequence of shifting to such
different planes will impart motion through the arms, to which such balls are
attached, to the regulator rod which controls through the valve mechanism or
the throttle valve the quantity of steam to be admitted to the cylinder of the
engine. Now, inasmuch as such balls are suspended by their arms from a
fixed point, it follows that their gravity, or, in other words, the resistance
which opposes any force to make them diverge from each other, varies with
the height of the plane which they occupy, and reaches its maximum when the
arms stand, with reference to the regulator rod, at an angle of 90°. If the
fact were otherwise and the resistance the same for all positions of the balls,

page_text: then for every variation in the speed of the engine there would be an exactly
corresponding change in the plane of revolution of the balls, and this in
turn would be followed by a corresponding change in the size of the aperture
which admits steam to the cylinder. In the practical operation of the engine,
however, whenever the speed of the engine increases by reason of a portion of
the load being thrown off, the first impulse of the regulator is to rise to a
plane which will reduce the steam aperture proportionally to the amount of
load to be carried; owing, however, to the increase in the gravity of the balls
due to such proposed change the centrifugal force for that increased speed is
not sufficient to cause them to rise to the plane which they would occupy if
such element were not involved; the steam aperture is not, therefore, reduced
to the proper dimensions until the engine has so increased its speed that the
augmented centrifugal force given to the balls shall enable them to reach
the proper plane, and thus under such conditions the velocity of the engine
will be subject to greater fluctuations than it would be were it not for the
disturbing element of the variable gravity of the balls for different planes.
It will be seen that by the construction and arrangement exhibited in
Figure 10, Sheet 3, I have reduced the gravity of the balls to a constant
quantity for all positions of which they are capable. H is a hollow shaft
within which is the regulator rod G.; motion around its axis is given to the
hollow shaft by the engine, as shown, and also to the regulator rod G, which
is connected with such shaft by a spline a. The upper end of the hollow
shaft terminates with a fixed head L, which together with the head L' upon
the extremity of the rod G sustains the regulator. The arms M, M, of the
regulator are connected with the head L' by being jointed directly thereto,
and with the head L by means of the links N, N. The length of these
links from joint to joint is equal respectively to the distance from their
joints 6 with the regulator arms to their joint c of suspension at the head L',
and is also just equal to the distance from their joints 6 to the centre of
gravity of the balls, consequently the centre of gravity of the balls will always,
whatever their position, be in the same place; for instead of rising by the
action of centrifugal force to higher planes they will move outward in the
same plane. The regulator rod G is in this instance provided with a toothed
wheel O, which is connected therewith by a feather fitted to a spiral groove d
in the rod, which method of connection will, as the regulator rod rises or falls,
cause the said wheel to be turned either forward or backward, as the case
may be, around such rod, and as such wheel engages with the bevel gear
wheel upon the shaft F which operates the cut-off valve gear, already
explained, it follows that for every change in the speed of the engine there

page_text: will be a corresponding change in the point of cut-off. The effect thus pro-
duced is not different from that already in a former part of this Specification
explained, and which is exbibited in the Drawings, Sheet 1, but the arrange-
ment is more convenient, and perhaps more to be preferred. I also make
use of a controlling vessel P to give greater steadiness to the action of the
regulator; it consists of a close cylindrical vessel bolted to the lower side of
the case which encloses the gearing which drives the regulator, and is to be
filled with oil or other suitable liquid. The regulator rod extends into this
vessel, and is furnished with a piston e which fits the cylinder loosely, or is
provided with apertures for the passage of the oil as the piston is moved up
and down in the cylinder. Owing to the weight of the regulator and its
rod G and the force developed by the centrifugal action, I counterbalance the
same by means of the arrangement shown at Figure 12; it consists of a
lever Q hung upon the fulcrum pin q in the vibrating standard R, and which
standard has a knife-edged foot so that the ends of the lever Q may move
upward and downward in a perpendicular line. The shorter arm of the
lever is forked and embraces and is pivotted to a collar which is loose upon
the regulator rod, the upper face of the collar bearing against a fixed
shoulder or collar upon the rod; the longer arm of the lever is curved near
its end, and from its extremity depends a weight. The effective force of the
levers N, N, multiplied into the centrifugal force which operates the regulator
rod will diminish as the regulator balls diverge, and in nearly the same pro-
portion the resistance which the counterweight makes to the descent of the
rod will be diminished, from the fact that the curved end of the lever Q will
as it rises bring the weight nearer to the fulcrum.
Another arrangement of regulator is shown at Sheet 1, Figure 1, and at
Sheet 2, Figure 9; in this instance the balls occupy different planes for
different speeds of the engine, but their shorter arms have their faces which
act upon the regulator rod made in the form of toes with cam faces, the
peculiar shape of which will maintain nearly the same effective force upon the
regulator rod for all planes which the balls will occupy.
To assist in the construction of both forms of regulator I append appro-
priate formulas. In Figure 14, where the balls have their centres of gravity
for all positions in one and the same plane, let F represent the centrifugal
force; W, the weight necessary to hold the balls in suspension at any position;
d, the distance between the axis of revolution and the point of suspension;
and a and b, the angles which the connecting links N make with the axis of
revolution of the regulator respectively. To find the value of W for any

page_text: other assumed position of the balls in the same plane, which I will call
W, I have WFx cotang a; W₁ = W × cotang b× (sin b+d)
WW cos b
cos a
cotang ax (sin a+d)*
Let do
In Figure 9; let X = distance between the point of suspension and the
tangetial point of the cam toe in a line parallel with the plane of the
horizon; d equal the distance between the point of suspension and the axis of
revolution, and a the angle formed by the axis of the regulator arm with a
line parallel with the axis of revolution passing through the point of sus-
pension. If X be supposed to be equal to m when a equals o, then the
formula will be X =
7
(sina+d) cos a-sin a
What I claim as the Invention, and desire to secure by Letters Patent,
is,-
First, cutting off the steam in its passage into the engine by the use of
an auxiliary piston and cylinder operating the cut-off, to which auxiliary
cylinder the admission of steam can be regulated in point of time to correspond
with any desired point in the stroke of the piston of the main cylinder, in the
manner and on the principle substantially as described.
Second, combining with the main valve or valves an auxiliary piston and
cylinder to operate the cut-off when arranged to travel with the valve, but to
work independently of it, substantially as described.
Third, the intermediate toothed pinion K¹ or its equivalent connecting the
valve gear which controls the cut-off with the moving member of the engine
which actuates such valve gear when the same is arranged to alter the
relation of such valve gear to its moving force without breaking the connection
between the two, substantially as herein described.
Fourth, the combination of the contracted orifice o (Figure 5) with the
pocket p formed by the port of the auxiliary valve E, substantially as described
for the purposes specified.
Fifth, the combination, substantially as described, of a regulator with a
cut-off valve gear of the character and possessing the qualities herein
specified.
Sixth, a regulator constructed in the manner and on the principle sub-
stantially as exhibited Figure 1, Sheet 1, and Figure 9, Sheet 2.
Seventh, a regulator, the centre of gravity of whose balls for all positions
which they can assume is constantly in the same plane, constructed and
operating substantially as shown in Sheet 3, Figure 10.
Eighth, combining a regulator with the cut-off valve gear by means of the

page_text: pinion O, to which an advance or a retrograde movement can be given as tho
regulator rod rises or falls by means of the spiral groove and feather con-
nection d, or the equivalent thereof, whereby the time of the cut-off of the
steam can be varied, substantially as described.
Ninth, the combination of a regulator with a variable counterbalance
(Sheet 3, Figure 12), substantially as described.
Tenth, the combination of a regulator of the character herein described,
with a controlling vessel P, substantially as specified.
In witness. whereof, I, the said George Tomlinson Bousfield, havo
hereunto set my hand aud seal, this Thirty-first day of December, in
the year of our Lord One thousand eight hundred and sixty-six.
GEO. T. BOUSFIELD. (L.s.)