IMPROVEMENTS IN REGULATING MOTIVE POWER ENGINES
Year: 1853

page_text: LETTERS PATENT to John Wright Child, of Halifax, in the County of York,
and Robert Wilson, of Low Moor Iron Works, in the same County, Engineers,
for the Invention of "IMPROVEMENTS IN REGULATING MOTIVE POWER
ENGINES."
Sealed the 29th March 1854, and dated the 19th October 1853.
PROVISIONAL SPECIFICATION left by the said John Wright Child and
Robert Wilson at the Office of the Commissioners of Patents, with their
Petition, on the 19th October 1853.
We, JOHN WRIGHT CHILD, of Halifax, in the County of York, and ROBERT WILSON,
of Low Moor Iron Works, in the same County, Engineers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN REGULATING MOTIVE POWER
ENGINES," to be as follows:-
This Invention relates to the so constructing and arranging the parts of steam
engines and other prime movers or motive power apparatus that greater uniformity
of rate in such motive power apparatus may be secured than has been hitherto
accomplished. This system of regulation is capable of being carried out in practice
under various modifications of mechanism, but it is conveniently applicable for
working in conjunction with the ordinary pendulum governor. When so used,
instead of connecting the governor directly to the throttle, or regulating or
expansion valve of the engine, the sliding ring or other adjusting detail of the
governor is connected in the first place to a an intermediate link passing to the
valve of a small detached cylinder. Such cylinder is made and fitted with a
piston, just like a miniature steam engine, and the valve so connected with the
governor is made to communicate with both ends of the cylinder by upper and
ower ports in the usual manner. In this way the valve chest of the cylinder is
made to communicate with the top or bottom of the cylinder, and consequently
with one or other side of the piston, just as the necessary shift occurs from the
variation in the engine's rate, forcing the slide of the governor up or down. The
valve chest of this small cylinder communicates by an inlet pipe with the water in

page_text: the condensing cistern of the engine, or with any other covenient reservoir, whilst
the opposite exhaust pipe of the valve chest passes into the condenser itself. This
furnishes a means of obtaining a suitable working pressure on either side of the
piston, at pleasure. The piston of the small cylinder has a rod working out
through the usual end stuffing box, and it is this rod which forms the means of
communication with the large engine valve through which the engine's rate is to
be immediately controlled. The result of this combination of parts is, that just as
the engine's rate varies so will the valve chest of the small cylinder be put into
communication with one or other end of the cylinder, and hence a motive pressure
will be brought to bear upon one or other surface of the piston, so as to cause its
rod to operate suddenly and effectively upon the large controlling valve; and just
as the governor's rate of change may be quicker or slower, so will the piston action
on the large controlling valve be also quicker or slower. Hence the disturbed rate
of the engine will be at once toned or reduced down to its standard speed,
whatever may be the circumstances under which the initial derangement took
place. The actuating pressure for the small cylinder may be obtained from various
sources.

page_text: by the said John Wright Child and Robert Wilson in the Great Seal Patent
Office on the 19th April 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOIN WRIGHT
CHILD, of Halifax, in the County of York, and ROBERT WILSON, of Low Moor
Iron Works, in the same County, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters Patent,
bearing date the Ninteenth day of October, in the year of our Lord One thousand
eight hundred and fifty-three, in the seventeenth year of Her reign, did, for Herself,
Her heirs and successors, give and grant unto us, the said John Wright Child and
Robert Wilson, Her special license that we, the said John Wright Child and Robert
Wilson, our executors, administrators, and assigns, or such others as we, the said
John Wright Child and Robert Wilson, our executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and at 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 "IMPROVEMENTS IN
REGULATING MOTIVE POWER ENGINES," upon the condition (amongst others) that
we, the said John Wright Child and Robert Wilson, by an instrument in writing
under our hands and seals, or under the hand and seal of one of us, 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.
NOW KNOW YE, that we, the said John Wright Child and Robert Wilson, do
hereby declare the nature of our said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the letters
and figures marked thereon, that is to say :-
Our said Invention relates to the so arranging and constructing the parts of
steam engines and other prime movers or motive power apparatus that greater
uniformity of rate in such motive power apparatus may be secured than has been
hitherto accomplished. This system of regulation is capable of being carried out in
practice under various modifications of mechanism, but it is conveniently applicable
for working in conjunction with the ordinary pendulum governor. When so used,
instead of connecting the governor directly to the throttle or regulating or
expansion valve of the engine, the sliding ring or other adjusting detail of the
governor is connected, in the first place, to an intermediate link passing to the
valve of a small detached cylinder; such cylinder is made and fitted with a piston.
just like a miniature steam engine, and the valve so connected with the governor
is made to communicate with both ends of the cylinder by upper and lower ports
in the usual manner. In this way the valve chest of the cylinder is made to
communicate with the top or bottom of the cylinder, and consequently with one or
other side of the piston, just as the necessary shift occurs from the variation in the
engine's rate, forcing the slide of the governor up or down. The valve chest of this
small cylinder communicates by an inlet pipe with the water in the condensing
cistern of the engine, or with any other convenient resorvoir, whilst the opposite
exhaust pipe of the valve chest passes into the condenser itself. This furnishes a
means of obtaining a suitable working pressure on either side of the piston, at
pleasure. The piston of the smaller cylinder has a rod working out through the
usual end stuffing box, and it is this rod which forms the means of communication
with the large engine valve through which the engine's rate is to be immediately

page_text: controlled. The result of this combination of parts is, that just as the engine's rate
varies so will the valve chest of the small cylinder be put into communication with
one or other end of the small supplementary pressure cylinder, and hence a motive
pressure will be brought to bear upon one or other surface of the piston so as to
cause its rod to operate suddenly and effectively upon the large controlling valve;
and just as the governor's rate of change may be quicker or slower so will the piston
action on the large controlling valve be also quicker or slower, hence the disturbed
rate of the engine will be at once toned down or reduced to its standard speed,
whatever may be the circumstances under which the initial derangement took
place. The actuating pressure from the small cylinder may be obtained from
various sources. And in order that our said Invention may be properly understood,
we shall now proceed to describe the Figure on the Drawing hereunto attached.
This Figure is a longitudinal elevation of one form, under which the regulating
arrangement may be conveniently carried into effect in conjunction with the
ordinary rotating pendulum governors. The governor A, which answers as the
original source of the regulating power, may be constructed after any of the usual
forms. In the model here selected the upper portion of the main vertical spindle B,
is bored longitudinally for the reception of the traversing link C, passed down
through the top of the spindle and connected through a lateral slot with the sliding
ring D, operated upon by the pendulum links. A short link E, at the top of the
link C, serves to convey the traverse movement of the ring D, to one extremity of
a long horizontal lever, free to oscillate on the fixed stud centre F. The other
extremity of this lever is jointed at G, to a pendant rod H, descending to the steam
throttle valve I, and in communication also with the small pressure cylinder J.
The throttle valve I, placed in the line of steam pipe K, is a plain oscillating disc,
and the projecting end of the valve spindle has upon it a lever handle L, of the
usual kind. The connection between the link H, and this throttle valve lever is
of a differential nature, being effected by a double rack and pinion movement.
The link H, terminates at its lower extremity in a toothed rack M, in gear with a
small spur pinion N, which pinion again gears with a second and corresponding
but reversed tooth rack O. This latter rack O, is fast on the upper end of the
vertical piston rod P, of the pressure cylinder J. These two toothed racks M, O,
and the pinion N, are passed through or contained in a flat narrow box piece Q,
entered upon the lateral stud pin of the valve lever L, this stud pin forming the
centre of motion of the pinion N. The box Q, merely serves to hold the toothed
gear details together, the lever stud being fast in the lever at one end, whilst it
projects sufficiently to enable it to pass transversely through the box Q, to which
it is held by an external washer, the pinion N, running quite loose upon the stud.
The small brass cylinder J, secured to the base R beneath, is accurately bored to
receive a solid piston fast to the lower end of the rod P, passed through a stuffing
box at the top of the cylinder, which is also fitted with a valve S, and upper and
lower ports respectively communicating with each end of the cylinder. This valve,
as here represented, is constructed on the oscillating, cylindrical, or conical system,
for which we have already obtained a grant of Letters Patent, bearing date the
Twelfth day of September, One thousand eight hundred and fifty-three. Its chest
communicates by the inlet pipe T, with the water of the condensing cistern of the
engine, or with any other conveniently available fluid source. Similarly the outlet
pipe U opens direct into the engine condenser, so that in the average of condensing
engines a power of about twelve pounds per square inch is directly available for
causing the traverse of the piston in the cylinder J, in either direction, just as the
inlet is directed to the top or under side of the piston. The valve S is worked by
a projecting spindle, carrying the slotted lever arm V, to which the lower end of
the pendant rod W is connected, the connecting stud being adjustable in the
longitudinal slot of the lever, so as to produce a long or short throw, as may be
desired. The rod W is formed with an eye at its upper end for connection with
the link H above, so that as the governor balls expand or collapse, the traverse
of the sliding ring D nets correspondingly upon the lever V, to open or close

page_text: the valve in either direction. Hence, with this arrangement, as the lever L
is moved up or down so will be the motion of the piston contained in the
cylinder J. But unlike the action of the governor under ordinary circumstances
of arrangement, the governor requiring the engine to run at an increased
speed to cause its sliding ring to continue to move in the same direction;
in this case the pressure piston in the cylinder J will continue to move
in the same direction so long as the lever V is in the least degree out
of the horizontal line. In this way, instead of the action upon the piston
being confined to a certain proportion due to the positive variation in the
engine's rate of working, the slighest deranging influence will cause the
piston to traverse throughout its entire stroke, should this alight derangement
in rate continue sufficiently long; and the absolute motion of the piston invariably
bears a determined proportion to the actual deviation in the rate above or below
the standard rate of the engine, as pre-determined. Hence neither the load upon
the engine, nor the pressure of the actuating steam, can have any relation to the
speed of working; therefore the engine will run at its proper speed irrespective of
any deranging influences of this nature. So much is this the case that in ordinary
cases, where the engine is not subject to excessive or sudden variations in the load
or pressure, the pendulum governor may be connectly directly to the lever V of the
small pressure cylinder valve, whilst the piston rod P is directly connected to the
throttle valve lever without the use of the differential gearing M, N, O, the action
of which special movement we have not yet described. But it is by the adoption of
this differential movement that exact regularity of working may be secured even
in engines which are peculiarly subject to derangement of rate under the ordinary
arrangements. With this addition between the governor and the regulator the
primary impulse of the governor slide may be made to bear upon the regulator or
throttle valve at the same time that the governor acts upon the valve of the
pressure cylinder; and in this way the regulating valve is opened or shut more
rapidly for the earlier checking of undue variations in rate, whilst the motion of
the regulator continuing in the same direction brings the governor back to its
standard position as the engine is brought back to its standard rate. This must be
obvious to the practical engineer from the arrangement shewn in our Drawing.
As the toothed rack M, is shifted either up or down by the governor, the impulse
of the governor is conveyed, not only directly to the lever V of the pressure cylinder,
but also through the pinion N to the reversed rack O, as the piníon rolls down or
up this rack, and to the stud pin of the lever L. Thus the piston of the pressure
cylinder follows in the same direction, and by still further acting upon the valve I,
the engine at once returns to its standard rate, and the governor to its standard
position, ready to not in either direction on the occurrence of any further change.
This compound movement greatly improves the quick action for the restoration of
the balance of motion, as the governor and pressure cylinder may either act
together, separately, or in reverse directions; for the pinion may be acted upon
either by the governor or the pressure cylinder, as the pinion will roll upon either
rack just as it is operated upon by the reverse rack; and when the governor is
returning to its standard position, whilst the lever V is yet out of the horizontal
line, the rack of the pressure cylinder will be moving in one direction, whilst that
of the governor is moving in the other direction, so that the pinion may, in fact,
revolve upon its centre whilst the lever L is at rest. This is the case when the
opposite actions are equal, and they generally are so in practice. When the pressure
cylinder arrangement is in connection with an expansion valve, the rack and
pinion movement is not required, for the same action will be attained by the
governor having a slight command over the engine through the throttle valve, with,
at the same time, a complete command over the lever of the pressure cylinder.
The necessary power for the pressure cylinder is obtainable from many sources;
for example, it may be taken from the feed water pipes of the boiler. In high
pressure engines it is convenient to lead a pipe from the feed pipes, putting
a small air vessel on the pipe, with a valve, so as to secure a continuous pressure

page_text: whether the pump is in action or not; or a pipe communication may be formed
with the water in the boiler, so that a pressure equal to the pressure of the steam
is available for the small cylinder.
Having now described and particularly ascertained the nature of our snid
Invention, and the manner in which the same is or may be used or carried
into effect, we may observe, in conclusion, that we do not confine or restrict
ourselves to the precise details or arrangements which we have had occasion to
describe or refer to, as many variations may be made therefrom without deviating
from the principles or main features of our Invention; but what we consider to be
novel and original, and therefore claim as the Invention secured to us by the
herein-before in part recited Letters Patent is,-
First, the general arrangement and construction of mechanism, apparatus, or
means for the regulation of motive power engines, as herein-before described.
Second, the system or mode of regulating motive power engines by the use of a
secondary pressure action or movement in conjunction with the ordinary or other
governor.
Third, the system or mode of regulating motive power engines by the aid of a
secondary movement continuing in force after the governor or primary regulator
has returned to, or nearly to, its standard position.
Fourth, the application and use of a differential or reverse action between the
primary governor and the secondary motion, for the purposes herein-before
described.
In witness whereof, we, the said John Wright Child and Robert Wilson, have
hereunto set our hands and seals, the Fifteenth day of April, One thousand
eight hundred and fifty-four
J. W. CHILD. (L.S.)
R. WILSON.
(L.S.)