IMPROVEMENTS IN GAS METERS
Year: 1876

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 19th December 1876, and dated the 1st July 1876.
PROVISIONAL SPECIFICATION left by the said Alexander Gibb Henderson at
the Office of the Commissioners of Patents on the 1st July 1870.
ALEXANDER GIBB HENDERSON, of Edinburgh, in the County of Mid Lothian,
North Britain. "IMPROVEMENTS IN GAS METERS."
The object of this Invention is to secure uniform registration independent of the
liquid level, which may by these improvements be varied within extensive limits.
This improved wheel is identical to the ordinary wheel, in so far that it
revolves in a chamber partly filled with water and gas upon an axis, and in
having four hollow chambers, which fitted in their respective positions completely
surround the axis; and also in that gas and water alternately pass through these
hollow chambers as the wheel revolves. Here, however, its identity with the ordi-
nary drum ceases. It has no cover on the front end forming the fifth chamber of
the ordinary drum. It has but one fixed central shield of large diameter supporting
the four chambers, and which also serves to separate from the main body of mea-
sured gas passing through cach chamber a small portion of gas which is expelled
outside the wheel into unmeasured gas contained within the external case of the
meter, and from whence it passes through the chambers of the wheel a second time.
No portion of the measuring parts of the chambers traverses through what is
called the dead water centre. The inlets of the chambers as they successively rise
out of the water are open to, and each chamber obtains its proper supply of gas
dependant upon the height of the water-line from that contained within the
external case of the meter, and which again is supplied from the gas company's
mains. As the chambers fill with gas the wheel revolves, and not until the inlet
is sealed in water do the outlets [for there are two] discharge the gas contained in
the chamber. The gas inlet of each chamber extends outside and over the wheel,
and at the larger end of the chamber from the level of the water in front over the
rim and to the level of the water at the back. The gas outlet of the main body of
the gas is at the other and smaller end of the chamber and extends inside from the
height of the water level at front over part of the rim of the succeeding chamber.
The small portion of gas left behind in the chamber travels from the discharge port
[Price Gd.]

page_text: of the main body of gas a not less distance than an arc of a circle of 45° or there-
abouts, when it is discharged at the second discharge port, which extends over half
the breadth of the rim and over the back of the wheel to the height of the water.
The first discharge port is in communication with the spout which leads the now
measured gas on to the burners. The gas from the second port is discharged at the
back into unmeasured gas, and from whence it passes a second time through the
wheel. The water travels through the drum by the same ports as the gas.
Each chamber is made mainly of three pieces, viz., two hoods or sides, and a
tapered baud or partition of the same metal, which answers to that portion of the
rim or cylinder over one chamber of the ordinary drum, and the band or partition
is differently extended. That portion of the band of metal answering to the rim
or cylinder, and to the partition of the ordinary wheel, is extended about half its
breadth, and to a suitable length, and their inner edges are soldered to the large
central shield supporting the chambers. To a certain extent these chambers out-
wardly resemble the buckets of an elevator or dredge. The chambers when fitted
together into their proper position around the axis form their own inlets and outlets
for the passage of both the water and gas, as well as being the measure.
The wheel has its inlets extended back and front from the surface of the water
and across its outer diameter; the gas therefore exerts great power over the wheel
as it bears constantly on the greatest leverage of the wheel, the action of the wheel
is consequently steady. The outlets are placed within the wheel and are situated
at less than half the radii of the wheel. As the inlets rise out of the water the
measured gas is first discharged by the ports for its passage, which ports rise out
of the water on the side where the bent pipe is situated earlier than the ports on
the other side of the supporting shield. The bent pipe carries off said gas to the
burners. The volume of gas detached from the main body by said shield is dis-
charged into the unmeasured. gas chamber.
It will be seen that the gas in passing through each chamber of the wheel divides
itself into two portions in a direct and natural manner, the larger portion is dis-
charged measured before reaching the extreme end of the chamber, and from thence
it is conveyed through the bent tube (the spout) and on to the burners; the smaller
portion travels the entire length of the chamber before it is discharged from the
second outlet into the measured gas contained within the external case of the meter.
The outlets of cach chamber are of equal area, and therefore when the' water-line
lowers an equally large quantity of gas is discharged at both outlets. The converse
holding good, that is to say, when the water-line is raised the quantities of gas
discharged from the outlet of the chambers is lessened in equal proportion. There
is therefore perfect reciprocity with the outlets, hence a fixed volume of gas is
discharged to the burners.
The four chambers around the axis of the wheel may be fitted in their positions
in different ways. It may be done without bringing the chambers into direct con-
tact one with the other, their relative positions each to each may be made with
strips of metal and solder so that a space from one-eighth to four-eighths of an
inch, more or less, will intervene between each chamber; or the chambers may
come into contact one with the other at different points, and soldered one to the
other.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
Baid Alexander Gibb Henderson in the Great Seal Patent Office on the 1st
January 1877.
ALEXANDER GIBB HENDERSON, of Edinburgh, in the County of Mid Lothian, 5
North Britain. IMPROVEMENTS IN GAS METERS."
The object of this Invention is to secure uniform registration independent of
the liquid level, which may by these improvements be varied within extensive

page_text: limits and without materially increasing the loss of pressure over that absorbed
by the ordinary wheel.
This improved wheel is identical to the ordinary wheel, in so far that it revolves
in a chamber partly filled with water and gas upon an axis, and in having four
hollow chambers, which fitted in their respective positions completely surround the
axis; and also in that gas and water alternately pass through these hollow
chambers as the wheel revolves. Here, however, its identity with the ordinary
drum ceases. It has no cover on the front end forming the fifth chamber of the
ordinary drum. It has but one fixed central shield of large diameter supporting
the four chambers, and which also serves to separate from the main body of
measured gas passing through each chamber a small portion of gas which is expelled
outside the wheel into unmeasured gas contained within the external case of the
meter, and from whence it passes through the measuring chamber of the wheel a
second time.
The inlets of the chambers as they successively rise out of the water are open
to, and each chamber obtains its proper supply of gas dependent upon the height
of the water-line from that contained within the external case of the meter, and
which again is supplied from the gas company's mains. As the chamber fills with
gas the wheel revolves, and not until the inlet is sealed in water do the outlets
(for there are two) discharge the gas contained in the chamber. The gas inlet of
each chamber may extend outside and over the wheel, and at the larger end of the
chamber from the level of the water in front over the rim and to the level of
the water at the back. The gas outlet of the main body of the gas is at the other
and smaller end of the chamber and extends inside from the height of the water
level at front over part of the rim of the preceding chamber. The small portion
of gas left behind in the chamber travels from the discharge port of the main body
of gas a not less distance than an are of a circle of forty-five degrees or thereabouts,
when it is discharged at the second discharge port, which extends over half the
breadth of the rim and over the back of the wheel to the height of the water.
The first discharge port is in communication with the spout which leads the now
measured gas on to the burners. The gas from the second port is discharged at
the back of the wheel into unmeasured gas, and from whence it passes a second
time through the wheel. The water travels through the drum by the same ports
as the gas.
Each chamber is made mainly of three pieces, namely, two hoods or sides, and a
tapered band of the same metal, which answers to that portion of the rim or
cylinder over one chamber of the ordinary drum, and the quarter or partition, but
differently extended. That portion of the band of metal answering to the rim or
cylinder, and to the partition [of the ordinary wheel], is extended about half its
breadth or more to a suitable length, and their inner edges are soldered to the
large central shield supporting the chambers. To a certain extent these chambers
outwardly resemble the buckets of an elevator or dredger. The chambers when
fitted together into their proper positions around the axis form their own inlets and
outlets for the passage of both the water and gas, as well as being the measure.
The wheel has its inlets extended back and front from the surface of the water
and across its outer diameter; the gas therefore exerts great power over the wheel
as it bears constantly on the greatest leverage of the wheel, the action of the wheel
is consequently steady. The gas inlets may also be limited to the slits in the hoods,
both in front and back, and the periphery of the wheel may then be a continuous
band of metal, as shown on the Drawings. The outlets are placed within the wheel,
and are situated at less than half the radii of the wheel. As the outlets rise out
of the water the measured gas is first discharged by the ports for its passage, which
ports rise out of the water on the side where the bent pipe is situated earlier than
the ports on the other side of the supporting shield. The bent pipe carries off the
said gas to the burners. The volume of gas detached from the main body by the
said shield is discharged into the unmeasured gas chamber.
It will be seen that the gas in passing through each chamber of the wheel

page_text: divides itself into two portions in a direct and natural manner, the larger portion
is discharged measured before reaching the extreme end of the chamber, and from
thence it is conveyed through the bent tube (the spout) and on to the burners ;
the smaller portion travels the entire length of the chamber before it is discharged
from the second outlet into the unmeasured gas contained within the external
caso of the meter. The outlets of each chamber are of equal area, and therefore
when the water-line lowers an equally larger quantity of gas is discharged at both
outlets. The converse holding good, that is to say, when the water-line is raised
the quantities of gas discharged from the outlet of the chamber is lessened in equal
proportion. There is therefore perfect reciprocity with the outlets, hence a fixed
volume of gas is discharged to the burners.
The four chambers around the axis of the wheel may be fitted in their positions
in different ways. It may be done without bringing the chambers into direct
contact one with the other, their relative positions cach to each may be made
with strips of metal and solder so that a space from one to four-eighths of an
incli, more or less, will intervene between each chamber; or the chambers may
come into contact one with the other at different points, and soldered one to
the other.
In order that the foregoing may be more easily understood Drawings are
attached hereto, of which the following is a description.
Fig. 1 is a side sectional elevation of a meter showing the general measuring and
the compensating chambers, the bent tube, or what is generally called the "spout,"
forming the general outlet for the gas.
Fig. 2 is a section of the wheel looking from the front, the hoods being removed
in order to show the shape of the measuring chambers and the position of the
partitions or quarters.
Fig. 3 is a front view of the wheel exhibiting the hoods attached.
Fig. 4 is a section of the wheel looking froin the back, with the hoods removed,
and shows the shape of the compensating chambers with their partitions, together
forming the inner wheel.
Fig. 5 is a back view of the wheel with the hoods both of the measuring
cliambers and the compensating chambers in proper position, the direction of the
partitions being shown in dotted lines. In all these five views the arrangement is
such as is adopted when the spout is used as the general outlet for the gas.
In Figures 6, 7, and 8 the arrangement is the one adopted when the gas is
admitted by the spout, as is usual, and is discharged from the slits in the hoods
into the space between the external case and the wheel.
Fig. 6 is a section of the wheel looking from the front, and from which the
loods have been removed in order to depict the shape and arrangement of both
ineasuring chambers and compensating chambers.
Fig. 7 is a front view of the wheel with the hoods in their proper place, the
position of the partitions being drawn in dotted lines.
Fig. 8 is a side sectional elevation of the meter similar to that of Fig. 1, the
difference between the two being occasioned by the necessary alteration of arrange-
ment of the chambers to suit the direction in which the gas flows, namely, from
the spout through the wheel to the space between it and the external case. In all
the views the large arrows indicate the direction in which the wheel revolves, and
the small arrows the direction in which the gas flows. In each of the Figures
similar letters refer to the same parts.
In Fig. 1A is the external case of the meter; B, the inlet to the meter; C, C,
the gas inlets to the measuring chambers; and D, D, the outlets thereof; E, E, are
the gas inlets to the compensating chambers; and F, F, their outlets; G being the
spout or general gas outlet from the wheel. H is the waste water box, through
the upper part of which the gas passes from the spout to the outlet of the meter.
In Fig. 2 A is the external case; I, the centre opening; G, the spout; and J, J,
the four measuring chambers, the partitions being marked K, and the outlets D.
In Fig: 3 the hoods are marked L, the partitions K being dotted in.

page_text: In Fig. 4 the compensating chambers are lettered DI, their partitions being
denoted as N.
In Fig. 5 the hoods of the compensating chambers are shown as O, the hoods of
the measuring chambers L, while the partitions of the measuring chambers are
dotted in at K, and the partitions of the compensating chambers at N.
In Fig. 8, which is a side sectional elevation similar to Fig. 1, it must be
observed that the spout forms the general gas inlet to the wheel, the gas being intro-
duced into the body of each measuring chamber J as it rises at Q, the outlets of
the chambers being marked P. The inlets of the compensating chambers M are
shown at R, and their outlets at S, the gas issuing therefrom being discharged
direct into the body of a succeeding measuring chamber. In this arrangement the
measured gas surrounds the wheel, and the general gas outlet from the ineter may
therefore be placed in any convenient part of the case.
In Fig. 6, which is a front view, the measuring chambers are shown at J, and
the compensating chambers at M, with their partitions K and N.
Fig. 7 is also a front view, in which the hoods of the measuring chambers are
marked L, and, the hoods of the compensating chambers O.
The action of the apparatus is as follows, reference being had to the arrangement
where the spout forms the outlet:-Gas, being admitted to the meter by the
general inlet B it flows into the measuring chambers by the inlets C, and from
thence a portion will also pass into the compensating chambers by the inlets E,
being ejected from the measuring chambers by the outlets D, and from the
compensating chambers by the outlets or slits F in their hoods, consequently as
each chamber comes into position any excess of gas taken up by the ineasuring
chambers consequent upon the depression of the surface of the water will be
discharged in equal proportions, one portion direct to the burners, and the other
re-admitted to the compensating chamber and measured anew.
In the case where the gas is admitted in the usual way by the spout the gas is.
received into the body of the measuring chambers direct, and at the same time a
portion enters the compensating chambers by the inlet slits in the rim of the
chamber, any excess of gas, however, that is taken up by the small chambers is
ejected direct into a succeeding measuring chamber and there measured anew, this
action being ensured by the different times at which the measuring and com-
pensating chambers seal, the properly measured quantity only being allowed to
pass out of the measuring chambers to the measured gas space, or that between
the wheel and the external case.
It will be noticed that all the openings, slits, or valves of the wheel are con-
structed or so placed as to admit of both volumes of water and gas to flow
in direct and in uninterrupted currents through the wheel; also that the
curvilinear form of the chambers admit of less obstruction by the water as the
wheel revolves than is the case with the ordinary wheel, and that both volumes
of gas and water have less distance of travel between the inlet and outlet ports in
this wheel than in the ordinary wheel.
It will be observed that the usual raised cover forming the fifth chamber of the
ordinary wheel is dispensed with. The dimensions of this wheel is not increased,
nor is the distance between the bearings increased, nor does it carry so large a
body of water as the ordinary wheel necessarily does with its raised cover or fifth
chamber.
In consequence of these conditions it has been found in actual practice that there
is no increase of friction or pressure required beyond what is necessary to drive
the ordinary wheel. Deprived of its compensating chambers the improved wheel
may be used as a rival to the ordinary wheel in efficiency.
A meter wheel with curved chambers is not new, but a wheel with curvilinear
chambers and open hooded back and front of wheel, to which is also attached
compensating chambers of a curvilinear form, as depicted in the Drawings, is new.
The introduction of the gas to the measuring chambers by the slits in the hoods and
its ejection through the spout is not new, but the adaptation of this arrangement

page_text: to meters made upon the principle herein-before described, namely, compensating
meters made with curvilinear chambers of the form shown, is new.
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 which I have described or referred to, as 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 herein-before in part recited Letters Patent
is_
Firstly. The construction of compensating gas meters in which both the
incasuring and compensating chambers of the wheel are made of the curvilinear
open hooded form herein-before described and shown on the Drawings.
And, Secondly. The construction of compensating gas meters with wheels of the
form herein described, having the inlets and outlets of both the measuring and
compensating chambers so arranged as to allow of gas being introduced to the
measuring chambers by the slits in their hoods and its ejection by the spout, as
herein-before described and shown on the Drawings.
In witness whereof, I, the said Alexander Gibb Henderson, have hereunto set
my hand and seal, this Thirtieth day of December, in the year of our Lord
One thousand eight hundred and seventy-six.
A. G. HENDERSON. (L.S.)