IMPROVEMENTS IN GOVERNORS FOR MOTIVE POWER ENGINES
Year: 1881

page_text: LETTERS PATENT to John Bourne, of Richmond Road, Bayswater, in the
County of Middlesex, Civil Engineer, for an Invention of "IMPROVEMENTS
IN GOVERNORS FOR MOTIVE POWER ENGINES."
PROVISIONAL SPECIFICATION left by the said John Bourne at the Office
of the Commissioners of Patents on the 17th June 1881.
JOHN BOURNE, of Richmond Road, Bayswater, in the County of Middlesex,
Civil Engineer.
"IMPROVEMENTS IN GOVERNORS FOR MOTIVE POWER ENGINES."
My Invention consists of a new kind of centrifugal spring governor intended to
produce a more rapid controlling action than such governors have hitherto been
able to reach. The arrangement is an improvement upon my original spring
governor patented on October 8th, 1838, and also upon the modifications of this
governor patented by me on the 30th June 1870, No. 1859. In centrifugal
governors of every kind, the weights which by their centrifugal action when put
into rotation move the throttle valve and control the supply of steam, generally
begin their range of motion when the engine begins to move, and in spring
governors the springs are almost or altogether discharged from tension when the
engine is at rest. The range of the springs moreover is not great, and this rango
if divided by the number of strokes per minute gives so small an amount of travel
to the throttle valve from the difference in centrifugal force due to the acceleration
or retardation of a stroke in the minute that its effect is inappreciable, and the
governor is consequently deficient in sensibility.
In my new governor the springs are placed under strong compression or tension
before they are introduced into the governor. Their range is very large if left free
to expand, so that a considerable amount of travel is produced by the application
of a moderate force. The compression or tension applied to the springs as a
permanent pressure or load is such as just to balance the centrifugal force of the
balls at the intended velocity of the engine, and a stop is applied at some convenient
point in the combination to prevent the springs from expanding or travelling
beyond this point. The result of this arrangement is that the throttle valve is
1.1

page_text: kept full open until the engine reaches the intended velocity of rotation. But if
that be in the least exceeded, the centrifugal force being more than sufficient to
balance the tension or compression of the springs will begin to close the throttle
valve, and by employing a suitable form of valve and a sufficient length of spring
the change in the centrifugal force due to the acceleration of one stroke per minute
will carry the throttle valve from full open to full shut. In other words, it will be
quito impossible for an engine fitted with one of the improved governors to be
accelerated one stroke per minute, and in point of fact the amount of acceleration
possible may be reduced to any small fractional portion of a stroke per minute
that may be desired. An engine possessing sufficient power for the work it has to
do will, if fitted with such a governor, never fall below the desired speed if kept
supplied with steam; neither will it be able to exceed the prescribed speed even if
the load is suddenly taken off.
It will be obvious from the foregoing description that it is immaterial to the
proper action of this governor whether the springs which resist the centrifugal
force are placed in tension or in compression. Neither is it material whether the
springs are flat, spiral, volute, or of any other kind. The only material conditions
are that the range of motion of the point communicating with the throttle valve shall
be great either from the structure of the springs themselves or from the intervention
of levers or other expedients for multiplying motion, and that of this large range
that part alone shall be used in moving the valve which represents a compression
or pressure sufficient to overcome the centrifugal force of the balls or weights at
the prescribed speed of the engine. A weight may be used to compress the spring
or springs when that arrangement is preferred.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Bourne in the Great Seal Patent Office on the 17th December
1881.
JOHN BOURNE, of Richmond Road, Bayswater, in the County of Middlesex,
Civil Engineer.
"IMPROVEMENTS IN GOVERNORS FOR MOTIVE POWER ENGINES."
My Invention consists of a new kind of centrifugal spring governor intended to
produce a more rapid controlling action than such governors have hitherto been
able to reach. The arrangement is an improvement upon my original spring
governor patented on October eighth, one thousand eight hundred and thirty
eight, and also upon the modifications of this governor patented by me on the
thirtieth June, one thousand eight hundred and seventy, No. 1859.
In centrifugal governors of every kind, the weights which by their centrifugal
action when put into rotation move the throttle valvo and control the supply of
steam, generally begin their range of motion when the engine begins to move, and
in spring governors the springs are almost wholly or altogether discharged from
tension when the engine is at rest.
The range of the springs moreover is not great, and this range, if divided by the
number of strokes per minute, gives so small an amount of travel to the throttle
valve from the difference in centrifugal force due to the acceleration or retardation
of a stroke in the minute that its effect is inappreciable, and the governor is
consequently deficient in sensibility. In my new governor the springs are placed
under strong compression or tension on their introduction into the governor.
Their range is very large if left free to expand, so that a considerable amount of
travel is produced by the application of a moderate force. The compression or
tension applied to the springs as a permanent pressure or load is such as just to
balance the centrifugal force of the balls at the intended velocity of the engine,
and a stop is applied at some convenient point in the combination to prevent the
springs from expanding or travelling beyond this point. The result of this
arrangement is that the throttle valve is kept full open until the engine reaches
the intended velocity of rotation. But if that be in the least oxceeded the centri-
fugal force, on increasing beyond what is required to balance the tension or
compression of the springs, as the case may be, will begin to close the throttle valve,
and by employing a suitable form of valve and a sufficient length of spring, the
change in the centrifugal force due to the acceleration of one stroke per minute
will carry the throttle valve from full open to full shut. In other words, it will be
impossible for an engine fitted with one of the improved governors to be accelerated
one stroke per minute.
In the accompanying Drawing Fig. 1 is a front elevation of a governor embodying
my Invention; Fig. 2 is a side view of the governor; and Fig. 3 is a vertical
central section of the same with the throttle valve attached; Fig. 4 is a sectional
plan view of the throttle valve; Fig. 5 shews in plan view the pulley through
which rotary motion is imparted to the governor; and Fig. 6 is a plan of the cross
head.
A is the cover of the box or pipe which contains the throttle valve, and screwed
into the centre of this cover is a sleeve A¹, which forms a vertical support for the
governor. Passing up this sleeve is the valve rod B, which carries at its lower
end the valve B'; C is the pulley by which the governor is rotated and which I
prefer to make of wood encased in brass to avoid the transmission of heat to the
driving cord.
Fitted to the centre of this pulley C is a tube C' which runs loosely on the
sleeve A'. This tube C' is threaded on its upper end to receive the cover D' of a

page_text: spring box D.
Contained in this box D are coiled springs D2 which have a
tendency to face the box D from its overlapping cover D', but permit of the box
sliding telescopically within its cover when a counteracting pressure is applied
thereto.
c, c, are lugs carried by the pulley C, and fitted with steel seatings to receive
knife edges carried by the governor ball arms E.
These arms, instead of being pendent as usual, rest upon the seatings of the
lugs c, and are held in position by arms E' pendent from the cross head F.
This cross head is carried by the valve rod B, it being loose thereon, but retained
between collars affixed to the rod in order to allow of the rotation of the cross
head and the parts in connection therewith without an axial motion being
imparted to the valve rod. The throttle valve B' at the lower end of the rod B
is shewn as consisting of a short cylinder connected by arms with a central boss.
The periphery of the cylindrical valve is pierced with a ring of holes, and
corresponding holes are made in the tubular steam passago A³ in which it works
and which is contained in the valve box.
The throttle valve B¹ is prevented from rotating with the governor by a pin b,
which projects downwards from the cover A. and engages one of the arms of the
valve.
The governor ball arms E are formed at their lower ends with short cranks
which when the arms are at rest or in their normal position, as shown in Fig. 1,
bear upon the upper side of the pulley C.
These cranks are notched on their upper edges to form seatings for double knife
edges e, which are interposed between the cranks and the bottom of the spring box
D and form rests for that box against the downward pressure of the springs D³
When therefore on the rotation of the pulley C the governor balls are caused by
centrifugal action to move outwards the arms E will be rocked and the cross head
F will be raised, thereby causing the valve rod B to lift its valve and throttle and
cut off the supply of steam to the engine.
So. soon however as the speed of the engine begins to slacken the springs D
will, through the box D, put pressure upon the crank ends of the arms E and tend
to return them to their normal position.
In order however that the supply of steam to the engine may not be reduced
until the engine begins to exceed its intended normal speed, it is necessary that
the springs should exert sufficient power to retain the governor ball arms in their
normal position until this result is attained. It is for this purpose that the cover
of the spring box is made adjustable; thus by screwing down the cover D' on the
Ecrewed tube C' any desired amount of compression may be put upon the springs
to counteract the tendency of the governor balls to leave their normal position.
From the foregoing it will bo understood that the amount of acceleration of
speed possible to the controlled engine may be reduced to any small fractional
portion of a stroke per minute that may bo desired. An engine possessing
sufficient power for the work it has to do will, if fitted with such a governor, never
fall below the desired speed if kept supplied with steam, neither will it be able to
exceed the prescribed speed even if the load is suddenly taken off.
It will also be obvious that it is immaterial to the proper action of the governor
whether the springs which resist the centrifugal force are placed in compression,
as shewn in the Drawing, or in tension. Neither is it material whether the springs
are flat, spiral, volute, or of any other kind, or whether the weights or levers of
the governor which generate the centrifugal force are pendant or otherwise, or
whether the structure of the throttle valve is of the forin represented or of any other
form. The only material conditions aro that the range of motion of the cross head
attached to the throttle valve spindle shall be large, either from the structure of
the springs themselves or from the intervention of levers or equivalent expedients
for multiplying motion, that of this large range that part alone shall be used in
moving the valve which represents a compression or pressure sufficient to overcome
the centifrrgal force of the balls or weights at the prescribed speed of the engine,

page_text: and that the levers or their equivalent by which the centrifugal force of the balls
is transmitted to the springs shall operate on the principle exemplified in the
Drawing, which is the same as that embodied in the well known levers of a
Stanhope printing press, and of which the effect is to place a greater tension on
the springs as the balls move outwards, whereby their power to overcome the
tension if made greater in nearly the same proportion as the tension itself
increases. A weight may be used to compress the spring or springs when that
arrangement is preferred.
Having now set forth the nature of my Invention of " Improvements in
Governors for Motive Power Engines," and explained the manner of carrying the
same into effect, I wish it to be understood that under the above in part recited
Letters Patent, I claim,-
First. Neutralizing by means of adjustable springs (either in compression or
tension) the centrifugal force generated in centrifugal spring governors until the
intended normal speed of the engine has been reached, and thus preventing-the
action of the throttle valvo until that speed is exceeded, as above explained.
Secondly. The arrangement above described whereby the levers which constituto
the arms of the governor act with increasing force to overcome the compression
of the springs in nearly the same proportion in which in the action of the
instrument the compression itself is increased.
In witness whereof, I, the said John Bourne, have hereunto set my hand and
scal, the Seventeenth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
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