IMPROVEMENTS IN GAS METERS
Year: 1879

page_text: LETTERS PATENT to Alexander Gibb Henderson, of Edinburgh, in the County
of Mid Lothian, North Britain, for the Invention of "IMPROVEMENTS IN GAS
METERS."
Sealed the 6th April 1880, and dated the 9th October 1879.
PROVISIONAL SPECIFICATION left by the said Alexander Gibb Henderson
at the Office of the Commissioners of Patents on the 9th October 1879.
ALEXANDER GIBB HENDERSON, of Edinburgh, in the County of Mid Lothian,
North Britain. "IMPROVEMENTS IN GAS METERS."
The object of this Invention is to provide means for compensating for the loss of
water due to evaporation or otherwise, and so maintain an uniform height of water
in the measuring chambers of wet gas meters, and thus ensure their correct registra-
tion, while what is technically known as flooding is prevented, and unsteadiness
of lights avoided when any sudden increase of pressure takes place.
The Invention consists in dividing vertically what is commonly called the front
chamber, without increasing its ordinary dimensions, into two unequal parts, the
vacant space in the larger one forming a reservoir for the storage of water, while
the smaller one serves for what is ordinarily known as the float chamber. The
reservoir part of the front is provided with the usual water filling tube, and at a
convenient point in the plate which forms the division between the float chamber
and the reservoir, or in the mid division between the front and wheel chamber,
there is an opening to which is attached a tube that descends into the reservoir,
and the bottom end of which is in a line or thereabouts with the true water level.
This tube, for its better distinction, I call the automatic controlling tube. At or
near the top of the reservoir, and open thereto, there is a tube called the reservoir
overflow tube, which descends into the wheel chamber below the water line, and
is sealed by the water therein. There is placed within the float chamber an over-
flow pipe that leads to the waste water box, which is below the float chamber and
reservoir; or the overflow pipe may be placed in the drum chamber, but in either
case it leads to the waste water box.
When charging the meter the water poured in through the filling tube will fall
into the front chamber, which fills first, and from which the water flows in bulk

page_text: into the wheel chamber by the reservoir overflow tube, and also through the centre
opening of the mid-division into the wheel chamber; but as soon as the centre
opening is sealed a continued supply of water will keep the reservoir full, and
continue to flow through the reservoir overflow tube into the drum chamber until
it has reached the true water level or justice line, which is coincident with the top
of the overflow pipe and the bottom of the automatic controlling tube, and any
excess of water will flow through the overflow pipe into the waste water box.
The meter being charged with liquid, gas on being admitted will flow in one or
the other of two courses, according to the arrangement of the meter. In the first
case it will flow from the inlet into the valve box, through the valve into the float
chamber, and from thence through an opening into the wheel chamber. It will
then pass into the drum through the slits in the backs of the hoods, and flow out
into the hollow cover, down the spout into the waste water box, and away to the
outlet; or in the second case it will flow from the inlet into the valve box, through
the valve, down the overflow pipe into the waste water box, and up through the
spout into the hollow cover, then through the quarters of the wheel and out of the
slits at the backs of the hoods into the case, and so on to the outlet. I prefer
however the first mentioned course.
Should water from any cause be abstracted from the wheel chamber, and in
proportion as the water evaporates the level sinks in the reservoir, and the vacuum
thus formed is filled with the gas which enters the automatic controlling tube and
rises in bubbles through the liquid, but the level in the measuring chambers
remains constantly the same. If however the whole of the water be drawn from
the reservoir the float will then fall and shut the valve, thus closing the passage
for gas.
In lieu of the automatic controlling tube as before described, modifications forming
its equivalent may be adopted. These consist, firstly, in making the vertical division
between the float chamber and the reservoir in two pieces, the one overlapping the
other, but with a space left between, and this space becomes virtually the automatic
controlling tube. Secondly, a further modification is made by forming the automatic
controlling tube into a bell shaped tube, within which is placed the float, and on the
top of which is attached the valve (enclosed howover in a valve box), and to this
bell shaped tube there is fixed at right angles a tube leading to and piercing the
mid-division.
A modification of the float and valve arrangement consists in placing the float
within the reservoir, thus removing it from the reach of pressure. By this plan no
range of float is necessary, as the float can be made to shut the valve before the
water in the reservoir is exhausted.
The positions of the automatic controlling tube, wheel chamber, filling tube, and
overflow pipe, may be varied to suit the convenience of manufacture.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Gibb Henderson in the Great Seal Patent Office on the
8th April 1880.
ALEXANDER GIBB HENDERSON, of Edinburgh, in the County of Mid Lothian,
North Britain. "IMPROVEMENTS IN GAS METERS."
The object of this Invention is to provide means for compensating for the loss of
water due to evaporation or otherwise, and so maintain an uniform height of water
in the measuring chambers of wet gas meters, and thus ensure their correct regis-
tration, while what is technically known as flooding is prevented, and unsteadiness
of lights avoided when any sudden increase of pressure takes place.
The Invention consists in dividing vertically what is commonly called the front
chamber, without increasing its ordinary dimensions, into two unequal parts, the
vacant space in the larger one forming a reservoir for the storage of water, while
the smaller one serves for what is ordinarily known as the float chamber. The
reservoir part of the front is provided with the usual water filling tube, and at a
convenient point in the plate which forms the division between the float chamber
and the reservoir, or in the mid-division between the front and wheel chamber,
there is an opening to which is attached a tube that descends into the reservoir,
and the bottom end of which is in a line, or thereabouts, with the truo water level.
This tube, for its better distinction, I call the automatic controlling tube. At or
Dear the top of the reservoir there is an opening leading to a tube called the
reservoir overflow tube, which descends into the wheel chamber below the water
line, and is sealed by the water therein. The vertical division of the front chamber
is not absolutely necessary as the meter may be constructed without it, as shown
in the Drawings attached. There is placed within the float chamber an overflow
pipe that leads to the waste water box, which is below the float chamber and
reservoir; or the overflow pipe may be placed in the drum chamber, but in either
case it leads to the waste water box.
In order that the foregoing may be more easily understood Drawings are attached
hereto, of which the following is a description:-Fig. 1 represents a front elevation
of the meter with the front plate and front of the valve box removed; Fig. 2 is a
back elevation of the meter with the back plate and drum removed; Fig. 3 is a
vertical transverse section of the meter, showing the arrangement of the valve box
and overflow pipe, and Fig. 4 is a sectional plan of the meter, in which is depicted
the valve seat and passage for gas, the automatic controlling tube, the reservoir
overflow tube, and the overflow pipe leading to the waste water box. In Fig. 1,
A is the body of the meter; B, the front chamber or reservoir; C, the valve box;
D, the valve and seat; and E, the waste water box; F is the automatic controlling
tube, the bottom of which is open and level with the justice water line, while the
top is also open to the drum chamber at G, Fig. 2; H is the reservoir overflow tube,
the top opening of which into the front chamber is shown at I; J is the spout, the
bottom of which is open to the waste water box; and K is the gas outlet pipe, also
open at bottom to the waste water box, the top leading to the outlet L; M is
the waste water overflow pipe leading to the waste water box, the top being open
and level with the justice water line; N, the filling tube; O, the float; and P, the
passage for the gas from the valve box to the drum chamber, as seen in Figs. 2, 3,
and 4. The dotted lines Q, R, show the true water level or justice line in the
wheel chamber. In each of the Figs. similar letters refer to the same parts.
When charging the meter the water poured in through the filling tube N will
fall into the front chamber B, which fills first, and from which the water flows in
bulk into the wheel chamber by the reservoir overflow tube H, and also through
the centre opening of the mid-division into the wheel chamber; but as soon as the

page_text: centre opening is sealed a continued supply of water will keep the reservoir
full, and continue to flow through the reservoir overflow into the drum chamber
until it has reached the true water level or justice line, which is coincident with
the top of the overflow pipe M and the bottom of the automatic controlling tube F,
and any excess of water will flow through the overflow pipe into the waste water
box E.
The meter being charged with liquid, gas on being admitted will flow in one or
the other of two courses, according to the arrangement of the meter. In the first
case it will flow from the inlet S into the valve box C, through the valve D and
passage P, into the wheel chamber. It will then pass into the drum through the
slits in the backs of the hoods and flow out into the hollow cover, down the spout
into the waste water box, and away to the outlet; or in the second case it will flow
from the inlet into the valve box, through the valve, down the overflow pipe into
the waste water box, and up through the spout into the hollow cover, then through
the quarters of the wheel and out of the slits at the backs of the hoods into the case,
and so on to the outlet. I prefer however the first mentioned course.
Should water from any cause be abstracted from the wheel chamber of the meter,
in the exact proportion, and just as the abstracted water is in process of evaporation,
the level of the water in the reservoir sinks, forming a vacuum therein, and while
the said vacuum is in process of forming, gas which enters the automatic controlling
tube rises in bubbles through the water and replaces the water abstracted from the
reservoir chamber; but the water in the mensuring chamber remains constantly at
the same level. In other words, while the meter is in use there is a constant stream
of water evaporating from the measuring chamber, and there is at the same instant
of time a constant stream of water corresponding in volume ting its place from
the reservoir chamber; and also at the same instant of time there is a constant
stream of gas corresponding in volume, drawn or sucked up through the reservo
water to take the place of the water as it flows from the reservoir chamber to the
measuring chamber, so that when the meter is at justice point the fluctuations of
water level are existent only in the reservoir chamber, instead of, as is the case in
other fountain meters, being in the reservoir chamber and likewise in the measuring
chamber. If, however, the whole of the water be drawn froin the reservoir the
float will then fall and shut the valve, thus closing the passage for gas.
In lieu of the automatic controlling tube as before described, modifications forming
its equivalent may be adopted. These consist, firstly, in making the vertical division
between the float chamber and the reservoir in two pieces, the one overlapping the
other, but with a space left between, and this space becomes virtually the automatic
controlling tube. Secondly, a further modification is made by formning the auto-
matic controlling tube into a bell shaped tube, within which is placed the float, and
on the top of which is attached the valve (enclosed however in a valve box), and to
this bell shaped tube there is fixed at right angles a tube leading to and piercing
the mid-division.
A modification of the float and valve arrangement consists in placing the float
within the reservoir, as shown in the Drawings, thus removing it from the reach of
pressure. By this plan no range of float is necessary, as the float can be made to
shut the valve before the water in the reservoir is exhausted.
The positions of the automatic controlling tube, wheel chamber, filling tube, and
overflow pipes, may be varied to suit the convenience of manufacture.
Having now described and particularly set forth the nature of this Invention, and
the manner in which the same is or may be used or carried into effect, I would
observe in conclusion that I do not confine or restrict myself to the precise details
or arrangements that I have described or referred to, ns variations may be made
therefrom without deviating from the principles or main features of this Invention,
but what I consider to be novel and original and therefore claim as the Invention
secured to me by the hereinbefore in part recited Letters Patent is,—
Firstly. The construction of meters with a pipe or conduit marked F, as arranged

page_text: and herein described and shown on the Drawings, or its equivalent in the modifi-
cations horein described.
Secondly. The construction of meters with a pipe or conduit'marked H, arranged
as herein described and shown on the Drawings.
Thirdly. The construction of meters with a pipe or conduit marked M, arranged
as herein described and shown on the Drawings.
In witness whereof, I, the said Alexander Gibb Henderson, have hereunto set
my hand and seal, this Seventh day of April, in the year of our Lord One
thousand eight hundred and eighty.
A. G. HENDERSON. (L.S.)