Year: 1885

page_text: I THOMAS CRAWTE HOPPER of West Walnut Lane Germantown in the City
of Philadelphia State of Pennsylvania United States of America Manufacturer
of Gas Meters 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 :-
The object of my invention is to regulate the pressure of gas in mains or other
conduits without the use of the variable or shifting weights now employed for the
purpose and this object I attain in the manner which I will now proceed to
describe reference being had to the accompanying drawing in which Figures 1
and 2 are sectional views of apparatus embodying my invention.
Figures 3, 4, 5 and 6 are views illustrating modifications of part of the apparatus
and
Figures 7 to 11 are views illustrating one of the features of the invention.
In Figure 1, A represents part of a pipe communicating with the gas holder or
other reservoir of gas under pressure, and A¹ part of a distributing pipe or main,
both of these pipes communicating with the valve box B in which is a valve
casting D, the valve box being divided by a partition a into two chambers b d the
chamber b surrounding the lower portion of the valve casing and communicating
with the inlet pipe A, and the chamber d surrounding the upper portion of said
casing and communicating with the the distributing pipe A¹.
Fitting snugly in the casing D is a cylindrical valve F to a transverse bridge f
in which is connected the valve rod g-secured at the upper end to a bell float G,
the lower edge of which is submerged in the water or other liquid in a tank H, and
with the interior of this bell, above the level of the water in the tank, communicates
a pipe h, which is in communication with the distributing pipe A¹ preferably at
some distance from the valve box.
In the lower portion of the valve casing D are formed openings m, through
which the gas has free access to the interior of said casing, and to the interior of
the hollow valve F, and in the upper portion of the valve casing above the
partition a are formed a series of ports n, which are closed by the valve, when the
latter is elevated to its full extent, but are opened as the valve descends, so that a
passage of gradually increasing area is afforded through which the gas may pass
from the inlet to the distributing pipe.
This is a common form of pressure regulating apparatus, the pressure of gas in
the distributing main or pipe serving to maintain the bell G at such a height, that

page_text: the valve will be held so far open, as to permit a flow of gas necessary to maintain
the requisite pressure in said distributing pipe,,the lowering of the pressure therein
permitting the bell to fall and open the valve to such an extent that a freer flow
of gas into the distributing pipe is permitted, and the normal pressure therein
restored, excess of pressure in the pipe lifting the bell and partially closing the
valve so as to restrict the flow through the valve box..
In adapting this governing device to a distributing main, it is necessary to
provide for the maintenance of different pressure therein, a light pressure being
carried during the day, and a heavier pressure at night, hence, it has been usual to
provide means for imparting additional weight to the bell at such times as it
is necessary to increase the pressure of gas in the main, the extra weight being
removed when a lowering of the pressure becomes necessary.
I dispense with the necessity of variably weighting the bell by so constructing
the same that it will present a variable area for the pressure of gas, thus as shown
in Figure 1, the upper portion of the bell is considerably less in diameter than
the lower portion y, there being an intervening flaring section w.
The operation of this device is as follows:-
During the day the bell occupies the position shown in Figure 1, and is exposed
to the pressure of gas over the full area of the enlarged lower portion y, the
weight of the bell being thus distributed over this large area, and imparting a
light pressure only per square inch to the gas in the distributing pipe, the valve F
occupying such a position as to restrict the flow of gas through the valve box and
thus maintain this light pressure.
In the evening, however, when the increased demand upon the distributing pipe
begins, there is a consequent reduction of pressure therein, and the bell falls, so as
to open the valve and permit a freer flow of gas into the said pipe, but as a
smaller area of the bell is now exposed to the pressure of gas than before it will
not be raised by the increased pressure, hence the increase gained is held, and
becomes the normal pressure, until, upon further demand, there is a reduction
below this new normal pressure, whereupon there will be a further drop of the
bell, a further opening of the valve and a further increase in the pressure in
the distributing pipe. When the bell reaches the position shown in Figure 2,
the maximum pressure will have been reached, the weight of the bell, less that
of the water displaced thereby being now exerted upon an area only about one
fourth as large as that exposed when the bell was in the position shewn in
Figure 1 and the pressure maintained in the pipe A¹ being increased accordingly.
As the demand upon the distributing pipe slackens the free flow into the same
causes an excess of pressure therein and the bell is raised so as to partially close
the valve and reduce the flow, the movement continuing until the bell again
reaches the position shewn in Figure 1. to maintain in the pipe A the normal day
pressure.
The bell may have more than one contraction in diameter so as to effect an
increase of pressure and then hold this increase for a time prior to a further
increase, for instance in Figures 3 and 4 I have shewn a bell with three contrac-
tions and on the other hand the bell may if desired be made in the form of
a frustrum of a cone as shewn in Figure 5 so as to effect a gradual increase
of pressure as the bell falls, or the bell may be made with a swell, more or less.
gradual, as shewn by full and dotted lines in Figure 6.
In apparatus of the class to which this Invention relates, it is advisable to
provide means for governing the flow of gas into the main independently of the
automatic regulation due to the movement of the valve under the influence of the
rise and fall of the bell float for instance, the demand for gas during the Summer
months is not as beavy as during the Winter months so that in order to supply the
heaviest demand during each Summer period the valve would not perhaps, require
to be more than half opened at any time, hence there could not be a high pressure
maintained in the main, as the bell would not fall to the same extent as when a
full movement of the valve was necessary in order to maintain the supply.

page_text: For this reason I combine with the valve or valve casing an adjustable shield or
guard by which the area of the ports may be increased or diminished longitudinally
so as to accord with the variation in demand upon the main.
The shield shown in Figures 1 and 2 is in the form of a sleeve J surrounding the
valve casing and having ports corresponding with those of said casing.
This shield can be turned by means of a rack and pinion as shewn or by other
means so as to partially obstruct the ports of the casing as in Figure 8. for instance
thus necessitating the same full extent of movement of the valve to meet the
variations in a limited demand upon the main as would be required to meet the
variations in a full demand if the ports retained their full area, so that there will
be the same changes of pressure upon the gas in the main in the one case as in the
other.
The ports may be of uniform width throughout as shown in Figures 7 and 8 or
the port in the casing may be tapered the port in the shield in this case being
preferably formed as shewn in Figures 9 and 10 so as to provide for the proper
contraction of the port in the casing as in the latter figure.
The shield may be applied to a ported valve as well as to a ported valve casing.
Thus, as shewn in Figure 11 a ported valve works through a partition separating
the inlet and outlet chambers of the valve casing, and the regulating shield is on
the inside of the valve, and has ports similar to those of said valve, a rack on the
shield gearing into an operating pinion the stem of which projects through the
casing of the valve.
I am aware that a conical bell float has been heretofore used in connection with
the valve of a gas regulator, but the coning of the bell in this case was intended
simply to counteract the loss of pressure exerted by the bell, as it descended, owing
to the increase in displacement or to compensate for the increase of friction due to
the increased flow of gas, the object being to maintain a uniform pressure upon the
gas in the distributing pipe, whereas in carrying out my Invention the taper of
the bell must be such that there will be an increase in the normal pressure as the
bell descends, & result essentially different from that contemplated in the devices
referred to.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First. The combination with gas supply and distributing pipes of a valve
controlling the flow from one to the other, a bell connected to the said valve
and having a chamber presenting differential areas, and a communication between
the said chamber and the distributing pipe, the differential areas of the bell
chamber being such that as the said bell changes its position there will be a
change in the normal pressure of gas in the distributing pipe as hereinbefore
set forth.
Second. In apparatus for automatically regulating the flow of gas, the com-
bination of the ported valve or valve casing with an adjustable shield or guard
whereby the area of the ports of the valve or casing may be increased or
diminished, and the flow of gas be thereby governed independently of the
regulation due to the movement of the valve.
Dated thin 97th ce
1007