AN IMPROVEMENT IN STEAM AND GOVERNORS." OTHER ENGINE
Year: 1872

page_text: LETTERS PATENT to Obadiah Marland, of Boston, in the County of
Suffolk, and State of Massachusetts, United States of America, for
the Invention of "AN IMPROVEMENT IN STEAM AND
GOVERNORS."
OTHER ENGINE
Sealed the 6th June 1873, and dated the 17th December 1872.
PROVISIONAL SPECIFICATION left by the said Obadiah Marland at the
Office of the Commissioners of Patents, with his Petition, on the
17th December 1872.
I, OBADIAH MARLAND, of Boston, in the County of Suffolk, and State
of Massachusetts, United States of America, do hereby declare the
nature of the said Invention for "AN IMPROVEMENT IN STEAM AND OTHER
ENGINE GOVERNORS," to be as follows:-
The primary object of this Invention is prevention of injury of pro-
pelling machinery of vessels when by reason of pitching or rolling
propellers are for short times less immersed than when such vessels are
on an even keel, such lessened immersion causing the racing of the.
propelling engine.

page_text: The first part of this Invention consists in a peculiar device for
operating a valve to control the amount of steam admitted in accordance
with the amount of load or resistance, and this may be used to advantage
upon stationary as well as upon marine engines.
The second part of this Invention consists in the introduction into an
engine of a valvular arrangement by which when and as steam is shut
off communication from the cylinder with the condenser is closed and a
communication is established between both ends of the cylinder, the
arrangement being such also that when and as the steam is again let on
the communication between the cylinder and the condenser is restored,
and that between both ends of the cylinder is closed, the object of this
part of the Invention being to prevent application to the piston of the
expansive force of the steam enclosed between the throttle and the
piston and the action of the vacuum which such steam would form.
The third part of this Invention consists in the combination with the
main engine provided with the valvular arrangement mentioned in
the second part of this Invention and with its regulator of an auxiliary
or donkey engine, so arranged as that when the regulator causes the
throttle valve to close it shall also cause the donkey engine to make one
stroke, by which communication between the cylinder and the condenser
is closed and communication between both ends of the cylinder is
opened, and also so that when the regulator causes the throttle to open
it shall also cause the donkey engine piston to make a reverse stroke, by
which the said communications are reversed.
The device referred to, forming the first part of this Invention, may be
briefly termed a governor. It is made preferably as a cylinder, with
two parallel grooves extending around it connected by an inclined
groove, and at the junction of each parallel with the inclined groove
switches are placed, which are kept in a normally closed position by the
action of springs. This cylinder is made to rotate by any suitable time-
keeping motor, usually a small engine. The engine to be governed
causes by suitable gearing or other connections a roll or pin which
extends into said grooves to rotate about the axis of the grooved cylinder,
while at the same time said pin or roll has capacity for motion in the
direction of the axis of said cylinder. When the grooved cylinder
and said roll or pin rotate synchronously in the same direction then no
motion in the direction of the axis of the grooved cylinder will be given
to the roll or pin; but if the roll or pin moves faster or slower than the

page_text: grooved cylinder it will by the action of the inclined groove be made to
traverse in the direction of the axis of the grooved cylinder until it
becomes located in one of the parallel grooves, and by suitable con-
nections the longitudinal motion thus and as obtained will control a
valve or a system of valves in shutting off or letting on steam to the
piston of the engine to be governed. When the pin or roll is in one of
the parallel grooves steam is wholly shut off, and when in the other it is
fully let on, and while in either of said grooves the pivoted spring
yielding switches allow passage of the pin without strain or breakage of
the parts, whether the pin or the cylinder rotates the fastest, or whether
one part rotates and the other does not.
No effort has hitherto been made to prevent after wholly shutting off
steam from an engine the effective expansive action on the piston thereof
of the steam on the engine side of the throttle or shut-off valve, or to
prevent the formation of a vacuum by the aid of such steam, such
vacuum being in its action very efficient in keeping up the motion of
the piston of the engine which is to be stopped.
The second part of this Invention comprises the introduction and use
of any arrangement of valves by which the effective action of the steam
or of the vacuum is prevented, or lessened, or neutralized when and as
the communication between the engine and boiler is closed, and by
which also the normal valvular condition of the engine is restored when
and as communication is again opened between the engine and the
boiler. Under this part of the Invention a valve is introduced between
the engine cylinder and the condenser, and is so connected with the
mechanism which shuts off steam from the cylinder that said valve is
closed as and when steam is shut off from, and is opened as and when
steam is let on to the cylinder.
Under the same part of this Invention another valve is introduced,
which as and when communication with the boiler is closed is opened by
suitable mechanism to let the imprisoned steam act by its expansive
force equally on both sides of the engine piston, thereby placing it in a
balanced condition, the arrangement of mechanism being such as will
close said valve as and when communication between the engine and
boiler is again opened.
Preferably the valve controlling communication with the cylinder and

page_text: same time are connected, and as one opens the other closes, and vice
versa.
Instead of opening communication between both ends of the cylinder
at the same time the mechanism may be adapted where a link and a
▷ slide valve are used to throw the link to its central position when both
steam ports will be covered by the lands of the valve.
The generalization of the third part of this Invention has already been
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Obadiah Marland in the Great Seal Patent Office on
the 6th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, OBADIAH
MARLAND, of Boston, in the County of Suffolk, and State of Massa-
chusetts, United States of America, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of December, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Obadiah Marland, Her special licence
that I, the said Obadiah Marland, my executors, administrators, and
assigns, or such others as I, the said Obadiah Marland, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVEMENT IN STEAM
AND OTHER ENGINE GOVERNORS," upon the condition (amongst others) that
I, the said Obadiah Marland, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Obadiah Marland, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement :-
The primary object of this Invention is the prevention of injury or
breakage of the propelling machinery of vessels, when by reason of
pitching or rolling paddle wheels or screw propellers are for short times
thrown out of the water, or are less immersed than when such vessels
are on an even keel, such lessened immersion causing the racing of the
propelling engine. Breakage may occur during such increase of speed,
but it is more likely to happen and does happen by sudden blows and
torsion, when under increased speed the wheels or propellers strike the
water or are suddenly immersed at or below their normal position,
consequent upon the pitching or rolling of the ships.
The description of this Invention will be made as applied to the
engine of a screw-propelled sea-going steamer, and as it is addressed to
competent marine engineers, description of details of construction with
which the profession are familiar will be omitted, leaving them to
exercise their professional skill and judgment in connecting the Inven-
tion to engines already in existence, or in incorporating it into such new
engines as they are called upon to produce.
The first part of this Invention relates to a peculiar device for
operating a valve to control the amount of steam admitted in accordance
with the amount of load or resistance, and this may be used to advantage
upon stationary as well as upon marine engines.
The second part of this Invention relates to the introduction into an
engine of a valvular arrangement by which when and as steam is shut
off communication from the cylinder with the condenser is closed, and
a communication is established between both ends of the cylinder, the
arrangement being such also that when and as the steam is again let
on the communication between the cylinder and the condenser is
restored and that between both ends of the cylinder is closed, the
object of this part of the Invention being to prevent application to the
piston of the expansive force of the steam enclosed between the throttle
and the piston, and the action of the vacuum which such steam would
form.

page_text: The third part of this Invention relates to the combination with the
main engine, provided with the valvular arrangement mentioned in the
second part of this Invention, and with its regulator of an auxiliary or
donkey engine, so arranged as that when the regulator causes the
throttle valve to close, it shall also cause the donkey engine to make one
stroke, by which communication between the cylinder and the condenser
is closed, and communication between both ends of the cylinder is
opened, and also so that when the regulator causes the throttle to open,
it shall also cause the donkey engine piston to make a reverse stroke, by
which the said communications are reversed.
Description of the governor as arranged in the example herein shown
for illustration of the Invention, it being understood that the governor
is not limited in its application to steam, air, gas, and other engines, but
may be applied to control or regulate the speed of water and wind wheels
and other motors.
The governor is shown in plan in Figure 1, in longitudinal section in
Figure 2, and in longitudinal elevation in Figure 3.
a is a suitably mounted shaft which is made to rotate by connection
with the small time-keeping engine f¹, shown, or by any other time-
keeping source of power; this shaft has fixed thereupon the cam b, in'
the cylindrical face of which are formed two parallel grooves n, m, which
are connected by an inclined groove o, formed in part in the material
between the parallel grooves, and in part by two switches f and g, each
of said switches being capable of opening only in one direction. On
shaft a the disc c is made to revolve, being fixed on the sleeve & which
bears a pulley or a gear k which is driven from the main motor, the
speed of which it is designed to regulate, or said disc and pulley or gear
may be fixed on a shaft separate from a, but in the same axial line.
On such sleeve or shaft is a sliding sleeve e so arranged that it must
rotate with d, though free to slide thereon in the direction of its axis.
The sleeve e is made with a projection i, in the end of which is a pin or
roll which enters the grooved cam 6. Projection i has guide pieces j,j,
and friction rollers h¹, h¹, on either side of it. Suppose now that said
pin or roll h is located in the inclined groove in cam b, midway between
the parallel grooves, then it will be obvious if shaft a is rotated
isochronously and in the same direction with sliding sleeve e which
is driven by the main engine that no endwise motion of said sliding

page_text: sleeve will take place.
But if the speed of said sliding sleeve varies
from the speed of shaft a then there will be a relative rotation between
cam 6 and the pin or roll h, resulting in causing longitudinal motion of
sliding sleeve e, which by connections such as are sketched in Figure 3,
or by other suitable devices, may be made to control the throttle or
the variable cut-off of an engine, or the valve of a valve moving donkey
engine, or the gate of a water wheel.
Suppose cam 6 to be rotated in the direction of the arrow seen in
Figure 3, and the lever / connecting sleeve e with the connections of
the throttle valve of the main engine so arranged that if the pin or
roll h is in groove n the throttle will be wide open; then if said pin or
roll is in groove m the throttle will be fully closed. By use of the
hinged switches ƒ and g it will be seen that complete relative rotations
between cam 6 and pin or roll / can take place while the throttle is
held wide open or fully closed, the switches yielding to allow passage of
the pin or roll h. Whenever with a fully open throttle the speed of the
engine increases, so that the pin or roll h is driven faster than the cam 6,
then the pin or roll & strikes the unyielding side of switch g, and enters
the inclined groove of cam b, moving therein from groove n to groove m
until the throttle is closed, unless before that time the rotations of cam 6
and the pin or roll / shall be synchronous, and in that case the pin or
roll h will remain at rest relatively to the inclined groove of the cam.
If now the speed of h should slacken relatively to the speed of the
regularly moved cam, consequent upon the slowing of the main engine,
then the pin or roll / would move in the inclined groove toward
groove n, which would result in opening the throttle. If at any time,
or from any cause, either the engine to be governed or the time-keeping
engine should cease to actuate that part of the governor allotted to it,
the other engine could continue its motions independently, and for an
indefinite time, without accident or injury to any part of the governing
mechanism, the switches yielding as they pass the pin or roll, or as the
pin or roll passes them.
In practice it will be desirable, for a purpose to be described beyond,
to so arrange the throttle valve connections that the valve shall be fully
closed before the pin or roll enters the groove m; and to admit of
movement of the throttle valve after it has shut off steam a throttle of
construction adapted to that end must be used. One or more of such
throttle constructions will be described hereafter.

page_text: More than one pair of switches might be used, or the same result
accomplished by the use of more switches, would be reached with less
expense by increasing the speed of the driver of the pin or roll h, the
speed of the time-keeping engine being also increased correspondingly.
"
The detail of the mechanical construction and arrangement of the
switches may be varied by the constructing engineer. Devices well
adapted for the purpose are shown in Figure 4, which is an end elevation
of the cam b, and parts therewith connected; Figure 5 shows one of the
switches in side elevation, and removed from the cam b. This Figure
exhibits the pivot or shaft on which the switch turns, as made solid with
the switch, and with upper and lower bearings; Figure 6 shows the
switch in plan, with the arm to which one end of the switch closing
spring is attached.
Figures 7 and 8 are respectively a plan and side elevation of the
bearing for the upper pivot of the switch; Figure 9 is a perspective view
(on a larger scale) of a fragment broken from one of the parallel grooves.
and showing one of the recesses to be occupied by a portion of the free
end of one of the switches.
The arrangement of the switch closing springs is best seen in Figures 2
and 4.
Description of Matter coming under the Second Head of this In-
vention.―Figure 10 is a cross sectional view of so much of an ordinary
slide valve engine as is needed to show the connection therewith of the
valvular arrangement, by which application of motive force to the piston
is prevented after steam is shut off. p represents the steam chest ;
q, the steam cylinder; and the exhaust steam space, which in con-
densing engines is connected to the condenser, and in non-condensing
engines with the atmosphere. With the steam chest p is connected an
auxiliary chest in which the valves works, and with the exhaust space r
is connected an auxiliary chest in which the valve t works.
Between the steam chest p and the chest for valve s is a valve u
designed to be kept closed, except at such times as when the propelling
wheel or screw is liable to be thrown more or less out of its normal
position with respect to the water.
8
The valves s and t, as shown, are of the kind known to engineers as
the "Corliss" valve, which under reversed pressure start off from their

page_text: seats, to which they again return on removal of such pressure. These
valves & and t are shown in the position which they maintain when not
in operation, and when located and arranged as shown may be most
conveniently worked together by segment gears on the valve stems,
which segments mesh together. Valve t is shown as leaving the port v
open, so that the exhaust steam can pass directly through w to the
condenser. The ports s², v, and u³, have each an area equal to the ports
with which they connect in the cylinder. Now suppose that at the
moment steam is shut off between the boiler and the engine the valve s
is opened and the valve t is closed, then it is obvious that no steam can
flow to the condenser to form a vacuum, thereby its condensation and
also that part of the steam which was contained in the pipe passages
and steam cylinder, between the shut off valve and valves will pass
through port s¹, and will cause an equal pressure of steam on both sides
of the main piston; therefore all that is left to move the engine after
the steam is shut off is the momentum of the parts, which prior to this
Invention has been supplemented by the expansive force of the steam,
and by the force resulting from the creation of a vacuum.
It will now
be seen that in a steamer, or elsewhere, an engine provided with this
part of this Invention can by its aid be brought to a state of rest more
quickly than the same engine without such an adjunct.
While the valvular arrangement involved in the second part of this
Invention might be worked by hand by the engineers on duty it will be
obvious that it would be best to have said arrangement made to work
automatically and by power at the instant steam is shut off from the
engine, as is done by the third part of this Invention, which will now be
described.
Figure 11 shows in longitudinal section an engine designed to open
valves and shut valve t by one stroke, and to shut valve s and open
valve t by one reverse or return stroke, the valvular arrangement of said
engine being so connected with the governor as to be operated thereby
when and only when the steam is shut off from the main engine, and
when after being shut off it is again let on. This engine being non-
rotative, and making its strokes at irregular intervals, which may be
infrequent, no reliance can be placed on compressing or cushioning its
exhaust steam to check or bring up the piston at the end of each stroke.
Inspection of Figure 11 will show that the cylinder of this donkey
engine is made unusually long to receive inside of the fixed heads

page_text: movable pistons x, x, of greater area than the head of the working
piston y. These piston heads x, x, are kept pressed against shoulders in
the cylinder by steam which is admitted into spaces left between the
fixed heads of the cylinder and the piston heads x, x, the front one of
which is provided with a stuffing box for the working piston, which also
passes through a stuffing box in the fixed front head of the cylinder.
The inlet ports z, z, for passage of steam to work the piston y being in
part formed in the piston heads x, x, guide pins a¹, a¹, are used to keep
said heads x, x, from turning with relation to said ports. The steam
valve for shifting the steam passage is marked b¹, and is shown as of the
ordinary D variety, operated by the valve rod c³.
The cam described may instead of working the valve rod of the
donkey engine be made to work the valves s, t, in which case the
strength of the connections must be made sufficient and the power of
the time-keeper increased.
The valve worked by the governor to throttle and to shut off steam
from the main engine must (when the governor also works the valve of
the donkey engine for the purpose described) have capacity for motion
after the steam is shut off by the throttle, in order that a further move-
ment of the governor can take place by which the valve of the donkey
engine is worked.
There are many forms of valves which have capacity for motion while
remaining closed. One of simple form is shown in Figure 12, which is
represented as just closed, while it has capacity for moving several
degrees without opening. A valve which has no capacity for motion
after closing might be substituted for a throttle if a yielding or spring
connection should be interposed between the valve lever and the slide of
the governor.
To make the connection of the valve rod c¹ with the
governor rod d, whatever the location and arrangement of the parts, so
that just after the steam is shut off from and just before it is let on to
the main engine by the throttle, it shall also be let on to donkey engine
piston y, and to connect said piston to the valves & and t so as to cause
them to move, as and for the purpose before described, will require no
Invention, but only the exercise of ordinary professional engineering skill
and care; and as, in practical application of this Invention, the location
and arrangement of the combined parts, viz., the governor, the throttlo
valve, the adjunctive valvular system, and the donkey engine will vary

page_text: in almost every instance no special example of such connection is
shown in the Drawings.
As to the second part of this Invention some modifications may be
made, some of which are and others are not improvements therein, and
which, as they are included within its scope, are mentioned here. For
example, the valve t may alone be used, in which case if the steam valve
of the main engine is so constructed that it will lift from its seat without
damage, the steam will pass to and press equally (when valve t is closed)
upon both sides of the piston, or if the main shifting valve of the engine
will not leave its seat then an auxiliary valve in the nature of a spring
safety valve may be employed, which will let the steam escape as it is
compressed from one to the other side of the main engine piston.
according to its location.
After steam is shut off from the engine the steam confined exerts
more active force by reason of its capacity for the formation of a vacuum
than it does by its expansive force, hence no skilled engineer would
dispense with the use of the valve which closes communication with the
condenser; still, if this should be done, and a valve opened allowing the
confined steam to pass to both sides of the main engine piston, no effect
would be produced thereon by expansion of the steam. If no condenser
passage controlling valve t should be used, and if valve s or any other
should be used opening communication with both sides of the piston at
the moment of closing the throttle valve, then all the steam on the
engine side of the throttle would at once rush into the condenser and be
condensed, and a vacuum would be established throughout the engine to
the throttle, and the piston would receive no accretions of force. This
however would be wasteful of steam.
Where the main engine valve is a D slide worked by a link motion, if
the link is so connected with the donkey engine (the valve of which is
worked by the governor) that one stroke thereof brings the main engine
valve so that its lands cover each steam port then no steam can enter
the main cylinder from its steam chest, or can escape from the cylinder
to the condenser, and in such case all adjunctive valves corresponding in
function to s and t are dispensed with; but in such a D slide so used
there must be located two spring safety valves where they will be over
the steam ports when the valve is at rest, where the centre of the link
leaves it, in order that the steam contained in the cylinder on either side
of the piston may find vent under the pumping movement of the piston,

page_text: which movement will result from momentum alone. These vent valves
may be elsewhere located so as to vent the cylinder, and allow the steam
to pass out of the cylinder as the piston moves therein. In this case it
would be well to convey the steam so vented by suitable pipes into the
main steam pipe on the boiler side of the throttle, and even when the
vent valves are located in the D slide it may in some cases be necessary
or advisable to carry a vent pipe around the throttle, placing a suitable
check valve therein opening toward the boiler.
If the throttle valve is constructed with relieving valves opening
toward the boiler, as shown in Figure 12, then special conduits to the
boiler side of the throttle may be dispensed with, for if the reciprocations
of the main engine piston, caused by the momentum of the parts,
compresses the steam into the steam pipe on the engine side of the
throttle to a higher pressure than exists on the other side, the relief
valve will open and will close by gravity if properly arranged, or the
closing may be in whole or in part effected by use of springs. Some steam
will remain at about boiler pressure between the slide valve and the
cylinder and piston heads, but not enough to prevent formation of a
partial vacuum in the space traversed by the piston, which according to
the degree of the vacuum will act as a drag or break upon the momentum
of the parts. The connection between the link and the donkey engine
may be detachable, so as not to interfere with moving the link to reverse
the engine.
In heavy seas, when it is desirable to keep the vessel's head to the
wind, it often requires full engine power, in which case the throttle may
be disconnected from the governor and set open, and the link left so
that under the action of the governor the donkey engine will throw the
link to the centre as often as the propeller lifts, and will return the link
to its normal position as often as the propeller is submerged.
Engines are almost never reversed in a sea way where the governing
apparatus described is called into action. When in rivers, harbors, or
in working into docks where the water is not rough the governor is
disconnected from the throttle, because, if it remained connected its
action upon reversal of the engine would be to open the throttle, unless
the timekeeper should be at the same time reversed in the direction of
its motion.
In the use of the first part of this Invention there is a matter of
great convenience and importance, viz., the capacity for changing the

page_text: rate of speed at which it may at any moment be desirable to move the
main engine. This is accomplished by changing the speed of the time
keeper which if it is (as it will generally be) a small engine, is changed
by letting more or less steam into the time keeping engine. If the speed
of this is increased it will result in opening the throttle valve of the
main engine causing increase of speed in that, and vice versa. In such
case the engineer answers the signal to slow or to run at full speed by
simply manipulating the steam gate g¹ of the time keeping engine.
Similar letters refer to the same
parts in all the Drawings.
OBADIAH MARLAND. (L.S.)