Improvements in and relating to Pressure-regulating Apparatus, Chiefly Designed for Use in Connection with Steam-boilers.
Year: 1888

page_text: Improvements in and relating to Pressure-regulating Apparatus,
Chiefly Designed for Use in Connection with Steam-boilers.
I, HENRY HARRIS LAKE, of the firm of Haseltino, Lake & Co. Patent Agents,
Southampton Buildings, in the County of Middlesex 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 :-
This invention relates to that class of pressure regulating apparatus which is
composed of a pressure motor and an auxiliary motor, the former operated by
variations in the pressure to be regulated, and the latter operating to prevent such
variations.
Apparatus of this class has long been known, but the results heretofore obtained
have been far inferior to those which are now practically obtained in the improved
apparatus.
In the accompanying drawings.
Figure 1 shows that form of apparatus intended for use where the pressure to be
regulated is high; for example, where the boiler pressure is to be regulated by
controlling the damper of the furnace.
Figure 2 shows that form of my apparatus adapted for use where a low pressure is
to be regulated.
Figures 3, 4 and 5 show details of construction which are hereinafter explained.
The main feature of the invention relates to the construction and operation of the
valve which controls the auxiliary motor, but before explaining further it is necessary
to make it clear that the inlet and outlet ports of this valve are opened or closed by
variations in the pressure which operate the pressure motor, and therefore if slight
variations of pressure are to be utilized for this purpose, the valve must be delicately
balanced and as frictionless as possible.

page_text: In the drawings B represents the valve casing or shell. This shell is bored to
receive a series of rings, and these rings are a driving fit within the bore.
After the rings are driven into place they are reamed to receive the spindle g. The
smaller cylinder, forming part of the valve spindle g, is cut away on two sides near
its junction with the larger cylinder, and also cut away on two sides some distance
below;
the first pair of cuts being preferably at right angles to the second, as shown
in Figure 3. The cylinder thus left between the two cut away parts is longer than
the distance between the rings ff, but is filed off to form V-shaped projections y y'
as shown in Figures 3 and 4. The purpose of this is, that the cylindrical portion
between the two cut away places never wholly leaves the rings ff' thus always keeping
the axis of the valve spindle g coincident with the axis of the rings f and yet
allowing sufficient flow of water from pipe G through the exhaust, which is the central
hole through ring f, when the valve is in the position shown in figure 3; or a
flow from through the inlet port, which is the contral hole through ring, when
the valve spindle g is in the position opposite to that shown in figure 3; for as will be
clear without detailed description, the valve spindle in one position connects G with
the exhaust I and in the other position allows the water to flow from the pressure
pipe into the pipe G which connects with the motor M. The valve which I havo
thus described and which is hereinafter referred to in my third claim is for use only
with apparatus substantially as described. The valve spindle is connected with
lever L, in figure 1, by a yoke v¹ the hole through which, is slightly larger than that
part of the valve spindle g which lies in it so as to allow a slight motion of the yoke
on the ball or knob which forms the outer end of the valve spindle g. A plug is
secured in yoke v and through this plug the screw 2 passes and is adjusted so that it
The upper
is very nearly in contact with the ball on the end of the valve spindle g.
part of the screw 2 passes through the cross piece of the yoke. A check nut binds
together the yoke v plug e and cross piece, whereby valve spindle g is held to the
yoke but not so rigidly as to tend to make the valve spindle g cramp in its caso B.
The lower cross-piece of the yoke is connected in the usual manner by the forked
These details of
stem to lover L in figure 1 and a cross-bar L in figure 2.
construction as to valve Bg, while seemingly of trifling importance are yet very
material so far as concerns the accurate operation of the steam weighing apparatus,
for it is essential that the work done by that apparatus, should be reduced to the
minimum if the pressure weighing device of which lever L is the scale beam is to do
its work with any thing like accuracy. In Figure 1, lever L is shown as a scale
beam, but in Figure 2 the counterbalancing weights are hung directly to the
cross-bar L and the reason for this is, that Figure 2 shows an apparatus designed for
regulating low pressures, while the apparatus shown in figure 1 is for regulating high
pressures, thus making it practical to apply the counterbalancing weight directly in
figure 2 which would not be practical in Figure 1. Morcover a variation of two per cent.
would be a variation of 2 lbs to the square inch in figure 1, if the steam weighing
apparatus were connected to, a boiler in which the desired pressure was 100 lbs. to the
square inch, while in Figure 2, in which the steam pressure device is connected to a
low pressure chamber if the desired pressure in that chamber was 10 lbs. to the square
inch a variation of two per cent. would be only th of a pound and consequently if
both apparatus be required to regulate the pressure to the same degree, not relatively
but absolutely, the apparatus in figure 1 must work far more accurately than that
shown in Figure 2.
It is for this reason that sundry features of the invention are shown in Figure 1
which are not shown in Figure 2, for where extreme closeness of operation is required
it is desirable to modify the action of valve-spindle g by giving it a motion with relation
to its casing B opposite to the motion given it by the pressure motor, and this is more
especially true in the apparatus used as a damper regulator to regulate pressure of
steam in the boiler by controlling the damper of the furnace. This part of my inven-
tion will be clear from the following example. Suppose the valve to have a lap of
32nd of an inch so that the motion of the valve spindle g must be say, 32nd to clear
the lap and th additional to afford a passage through which water can flow into
61

page_text: the cylinder of the motor M fast enough to give a slow motion to the piston rod m.
Such a motion of the valve would move the piston about an inch in from five to ten
seconds and the piston might move at that rate for about three inches and if there
were no change in boiler pressure a piston would keep on moving at that rate to the
end of its stroke, but on many boilers it is desirable to prevent this full stroke of
the piston unless there be so great a rise in boiler pressure as to require it, and for that
reason, Figure 1 shows the piston rod m of the damper motor M connected to lever s¹
which is fast to cam s which cam is under pipe G to which the valve casing B is
fast, and the cams is so shaped that as the piston rod m is moved by the water entering
the cylinder M after valve spindle g has been moved as above supposed by lover L, the
motion of piston m springs pipe G and the valve casing B upwards, and thereby closes
the inlet port and shuts off the further supply of water, this taking place when the
piston rod m has moved say one-half its stroke. If then the pressure in the boiler
continues to rise, the valve-spindle g will be opened still further by lever L and more
water admitted to cylinder M until the piston rod m inakes its full stroke and closes
the damper. If on the other hand the steam pressure in the boiler should not rise
more than enough to move the valve spindle say ths of an inch, then the piston
rod m would stop rising as soon as the lever s' has caused cam s to spring pipe G far
enough to close the inlet port of the valve by the motion of the casing B over the valve
spindle and the damper will be held only partially closed, and the boiler pressure
then decreasing slightly the valve spindle will be moved in the opposite direction
by lever L thus allowing the water to flow back through the pipe G out through
exhaust I which permits piston rod m to descend slowly under the influence of weight s³
thereby opening the damper.
It will be obvious that the piston rod m may be connected by a variety of devices
to the valve casing B, and also in lieu of connecting the said piston rod with the
valve casing B, it may be connected with the valve spindle in which case the
pressure motor will move the valve spindle g as before, but the auxiliary motor M will
inove the valve spindle 7 in the opposite direction, and it will be clear that the slight
motion of the said valve spindle g in a direction opposite to the direction in which
it is moved by the pressure motor will bo precisely the same thing so far as concerns
the ports of the valve as the slight motion of the valve casing B in the same direction
as that in which valve spindle is moved by the pressure motor. Figure 6 shows one
form of apparatus in which the casing B is stationary and the valve spindle y is first
moved in one direction by the pressure motor and afterwards in the opposite direction
by the auxiliary motor. In that figure the yoke connects the lever L with the valve
spindle y through the lever s, and after the valve spindle has been raised to open
the inlet port and close the outlet port by the lever L it is moved in the opposite
direction by the motion of piston rod m imparted to the lever s¹, and the valve spindle
is thereby moved backwards in its casing B sufficiently to cut off the inflow of water
into the cylinder of motor M.
This feature of the invention, viz., connecting the valve spindle g with the pressure
motor and its casing B with the piston rod m of the auxiliary motor substantially as
shown; or what is in substance the same thing, connecting the pressure motor with
the spindle to give it the proper motion in one direction, and the auxiliary motor
with that spindle to give it the proper motion in the other direction, is of very great
importance where the variations of boiler pressure are to be kept at the minimum,
for the reason that if the boiler pressure should in any case tend to rise rapidly and
open the inlet very wide, then the valve closing motion due to the operation of the
auxiliary motor M is not sufficient to completely close the inlet port, for any rapid
increase of pressure will move the lever L far enough to keep the inlet open and
so, mutatis mutandis, of any rapid decrease of pressure. But where the increase or
decrease is not rapid the valve spindle g will first move slightly with relation to its
casing B to open the inlet port and close the outlet port, and the motion of piston
rod m caused by opening the inlet port will result in closing the inlet (either by
moving the casing B the same direction that valve spindle y was moved by the
pressure-motor as in Figures 1 and 5, or by moving valve spindle g in the direction

page_text: opposite to that in which it was moved by the pressure motor as in Figure 6).
After the motion of piston rod m has thus closed the inlet, the valve spindle g and
casing B will be so nicely adjusted that a slight decrease of pressure will open the
outlet or a further slight increase will open the inlet a second time.
In practice it frequently happens that the piston rod m will move slightly up then
slightly down, then slightly up again and so on, feeling as it were for that position of
the damper which would best regulate the boiler pressure.
;
In a pressure motor adapted for high pressure it has heretofore been found
practically impossible to so adjust the strut d and the piston D, as to make the
apparatus uniformly sensitive to variations of pressure under the diaphragm a, and 1
have discovered that this is because the strut à should not always be exactly concentric
with the piston D as was formerly thought to be necessary. The theory according to
the present invention is that the diaphragm a cannot be made exactly uniform in
thickness and strength, and that the pressure under it therefore tends to slightly cant
the piston D and the strut d, and that the lower end of the strut should be nicely
adjusted not with the view of making it exactly concentric with the piston D, but of
making it stand in such relation with the piston D as to remedy slight defects in the
diaphragm and this feature of my invention consists in combining the strut d with
the piston by means of the step d' which is adjustable with relation to piston I) so
that the pressure of this strut d will not tend to cant the piston D. The most
convenient way of mounting the step d is that shown in Figures 1 and 7, where a
box is found upon the piston D, which box receives within it the step d', tho step
being adjusted by means of set screws as clearly shown in Figures 1 and 7,
Figure 7 being a cross-section of box showing the set screws d³ and the step d',
the step d is conveniently held in place before it is finally adjusted by the stem d* of
piston D, as shown in Figure 1. After the pressure weighing apparatus is set up
and the pipe K is connected to the boiler or other source of pressure, the stem d* will
cant when the pressure under diaphragin a is counterbalanced, and the set screws d
are then adjusted until the stem ceases to cant when it will be found that the
pressure weighing apparatus is exceedingly sensitive to minute variations of pressure
under the diaphragm a; but what is still more important, is that the difficulty heroto-
fore experienced in making such pressure weighing apparatuses uniform in sensitive-
ness, no longer exists.
Another feature of the invention is the apparatus shown in Figure 2, in which a
high pressure chamber (commonly the boiler of a steam-engine) is connected through
conduit N with a low pressure chamber which is supplied through conduit P by means
of a valve Q which valve is controlled by motor M that motor being controlled by
valve Bg, and that valve being controlled by the pressure motor whose diaphragm a
is under pressure from the low pressure chamber fed by conduit P. Neither the high
pressure chamber nor the low pressure chamber, are shown in the drawings, for the
reason that they will be understood without description by all skilled in the art.
Moreover, it has been common heretofore to control a valve, in all substantial respects
the equivalent of valve Q, directly by a steam pressure motor whose diaphragm was
under pressure from the low pressure chamber.
While it will be seen that there is some analogy between the reducing valve and
the damper and also some analogy between the low pressure chamber connected with
the pipe P and the boiler when the steam pressure motor, the valve Bg and the
auxiliary motor M are used to control the damper by variations of pressure in the
boiler, yet it will also be clear that regulating the supply of steam from the high
pressure chamber through the pipe N to the low pressure chamber through pipo P by
means of the regulating valve Q, is wholly unanalogous to regulating the pressure in
the boiler by controlling the damper; and this part of the invention is the
combination of the reducing valve Qwith the pressure motor by means of the
valve Bg and the auxiliary water motor M, when the pressure motor is connected
with the low pressure side of the reducing valve Q. The reducing valve Q is a double
poppet valve and stands open when the parts are in the position shown in Figure 2;
but when steam from the boiler is admitted through pipe N it flows freely past the
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page_text: reducing valve Q and through pipe P into the low pressure chamber until the
pressure in that chamber reaches the desired point, but as pipe K connects the low
pressure chamber with the chamber of the diaphragm a, the pressure under
diaphragm a is always the same as that in the low pressure chamber, and when the
pressure in the low pressure chamber has risen to the desired point, the cross bar L'
of the pressure motor is lifted against its counter-weight and the valve spindle g
moved thereby to open the inlet port which allows water under pressure to flow past
the valve spindle a into cylinder of motor M thereby raising the piston rod m and
closing valve Q. As steam is drawn from the low pressure chamber, the pressure
falls, and as the pressure falls the counter-weight depresses the cross-bar L' and with
it the valve spindle g opening the outlet port of valve Bg, and the piston rod m is
moved downward by the counter-weight near its upper end, and valve Q is opened
sufficiently to allow more steam to pass and preserve the desired pressure in the low
pressure chamber. It will be clear that the other features of the invention may be
used with the apparatus shown in Figure 2, but as that apparatus is rarely used with
a pressure of over 10 or 15 pounds, those features are not essential nor even
desirable, but where the pressure in the low pressure chamber is over 25 pounds they
will be found desirable and the greater the pressure in the low pressure chamber the
greater will be the need of those features of my invention in the apparatus shown in
Figure 2.
It will be seen that the counter weight in Figure 1 acts upon the piston of the
diaphragm through lever L while in Figure 2 the counterweight is hung to a cross-
rod 1 and that cross-rod is hung to cross-rod L. I have discovered that it is
practically impossible to make a diaphragm pressure motor so sensitive as to be
operated by slight variations of low pressure when a counter-weight and lever aro
used; and one feature of my invention is based upon this discovery and consists
in a pressure motor whose counterweight is hung below the diaphragm chamber by
means of a frame which is balanced upon the piston of the diaphragm. This gives
a freedom of motion and consequent sensitiveness under low pressures which I have
been unable to obtain in any other way, and is a matter of very great value and
importance in all pressure motors designed for low pressures.
The water which actuates the motor M escapes through pipe R into chamber formed
above the diaphragm to receive it and runs to waste through pipe R' from that
chamber. In practice the diaphragm chamber below diaphragm a is filled with water
and thereby the heat of the steam is prevented from hardening the diaphragm. In
Figure 1 the arms 1, 2 are fast to the shaft of the damper and that damper controls
the flue of the boiler furnace. In Figure 8 the chainber 3 is connected by a
suitable bore 4 in the walls of the casing B with the exhaust passage I, for the
water under pressure from inlet H will leak slowly between spindle and ring f
into chamber 3 and should be provided with a free exit through outlet I as otherwise
it would greatly impair the operation of the valve spindle g.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to mo
by my foreign correspondent I declaro that what I claim is :-
First A pressure regulating device consisting of a pressure-motor, a valve and
an auxiliary motor the valve being combined with both motors, substantially as
described so that after the port is opened to operate the auxiliary motor, the piston
rod of that motor operates to close the port either by moving the valve casing in the
same direction that the pressure motor moved the valve spindle, or by moving the
valve spindle in a direction opposite to that in which it was moved by the pressure
motor, all substantially as shown.
Second In combination with valve spindle g and its casing B, the rings ƒ, ƒ³, ƒ³,
and substantially as described.
Third In a valve, for apparatus substantially as described, the V-shaped pro-
jections y, y', substantially as, and for the purpose, specified.

page_text: Fourth In a pressure-motor the strut d combined with a piston D by means of
the adjustable top d', substantially as described.
Fifth The pressure reducing apparatus, consisting of a steam pressure motor, an
auxiliary water motor, a valve between the two, the conduit N for the high pressure
steam and conduit P for the low-pressure steam and the reducing valve Q between
them, the pressure motor being connected with and operated by varying pressures of
the low pressure steam the reducing valve Q being connected with and operated by
the auxiliary motor M, and a valve of motor M being operated by the pressure motor
and controlling the inflow and outflow of water into and out of the cylinder of
the auxiliary motor, all the parts being arranged and operating substantially as
described.
Sixth The combination of the diaphragm its chamber and piston with a frame
and counterweight, the frame balanced on the piston and carrying the counter-weight
below the chamber of the diaphragm, all substantially as described.
2000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.