Improvements in Dry Gas Meters.
Year: 1890

page_text: Date of Application. 13th Jan., 1890-Accepted, 15th Feb., 1890
COMPLETE SPECIFICATION.
Improvements in Dry Gas Meters.
We, JOHN THOMAS WYNNE, Gas Engineer, and ALEXANDER CHARLES MORRISON,
Meter Maker both of the Metropolitan Gas Works Queen's Wharf, Melbourne in the
Colony of Victoria 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 has been devised for the purpose of simplifying the construction of
dry gas meters so as to reduce their first cost, lessen their wear and tear, and facilitate
their repair.
In accomplishing these objects we dispense with the ordinary valve box together
with the stuffing box through which the valve spindle usually passes to the parallel
motion, which parallel motion we have superseded by an improved motion.
We have
also invented an improved slide valve and an improved grating for such slide valve.
These two latter improvements namely, those relating to the valves and to the gratings
being the most essential part of our improvements.
66
In constructing our meters we proceed in many respects upon the lines already
laid down by previous inventors of similar apparatus, that is to say, we provide an
outer casing which is divided into an upper and a lower part by means of a horizontal
dividing plate, the upper and smaller compartment containing the valves and their
gratings together with the devices by which they are worked, whilst the lower and
larger part is sub-divided by a vertical partition into two compartments or chambers
each of which contains an alternately expanding and contracting chamber or
diaphragm." The movable disc forming the outer side of each of these expanding
and contracting chambers is guided by a flag piece attached to a vertical rod which
passes through a stuffing box into the upper chamber in exactly the same way as in
the well known Glover meter, but our slide valves and their gratings are constructed
differently to anything before devised for this purpose, and our contrivance for
communicating motion from the vertical flag rods connected to the discs of the
expanding chambers is different to that which has hitherto been used for this
purpose. One noticeable difference between our invention and those previously
devised consists also in the arrangement of the passages by which the ports on one
side of the meter communicate with the expanding and contracting chamber on the
opposite side thereof instead of with that on the same side as has hitherto been the
With regard to the slide valves themselves, they have hitherto been made
with a single port at or about their centre whereas we make them with an additional
port surrounding three sides of the original one. And with regard to the gratings
upon which such slide valves work, they have hitherto been made with three ports
arranged parallel with each other. Now we make such gratings with an additional
port arranged transversely and opposite to the ends of the three ports now in
common use. The mechanical arrangements by which motion is communicated to
the slide valves is quite new and will be understood together with the other parts of
our invention on reference to the drawings hereto attached, in which,
case.
Figure 1 is a front elevation, and,
Figure 2 a side elevation of a dry gas meter constructed according to our
invention.
Figure 3 is a plan of the upper part of said meter shewing the slide valves and
the gear operating same.
Figure 4 is a plan of the plate which divides the upper from the lower part of the
meter. This view is drawn to a larger scale than the preceding figures the better to
illustrate the arrangement of the passages leading from the different ports in the slide
valve gratings to the two main chambers of the meter and to the expanding and
contracting chamber or bellows arrangement working therein.
ID 077

page_text: Figure 6 is a view of the underside of one of our slide valves.
Figure 7 is a horizontal section on line a Figure 1, that is a section taken through
the horizontally arranged passages which are situated immediately below the herein-
before mentioned plate which divides the upper compartment from the two lower
compartments or chambers of our meter.
Figures 8 and 9 are vertical longitudinal sections on the lines У у and zz respectively
of Figure 7, and
Figures 10 and 11 are diagrams illustrating the passage of the gas through the
different ports and passages in our improved dry gas meter.
Similar letters of reference indicate the same parts throughout the different
figures.
A B and C represent, the three compartments or chambers into which as herein-
before mentioned our improved dry gas meter is divided, the horizontal plate D
serving to divide the upper chamber A from the lower ones B and (whilst the
vertical partition E serves to divide the two lower chambers or compartments B and C
from each other.
Within each of these latter is arranged as ordinarily an expanding and contracting
chamber or diaphragm F and G adapted to operate the slide valves a and b through
the medium of flags H flag wire I and the following mechanism.
To the upper end of each of the flag wires I is secured a crank arm c having a
slot through which passes a set screw or pin c² which projects downwardly to
between a pair of transversely arranged guides c³ provided on the upper surface of
each of the slide valves a and b. The outer ends of these crank arms c are connected
each by a rod or link c to another crank or radius arm secured upon the upper
end of a vertical spindle e upon which is secured a worm e', this latter being provided
for the purpose of communicating motion through a worm wheel and spindle to the
usual index dial of the meter in a way that will be understood by any person skilled
in the art to which our invention relates.
The construction of slide valve which we employ will be readily understood on
reference to figure 6 it being seen that we employ two ports as hereinbefore mentioned
one a¹ being arranged in the centre of the valve as ordinarily whilst the other a² is
arranged around three sides of the first one.
The gratings upon which these valves a and slide are provided each with four
ports d d d d and e e¹ e² e³ respectively as clearly illustrated in Figures 4, 7, 10
and 11.
Of these ports d and e are both in communication with the inlet passage f whilst
the ports and d² are in communication with the outlet passage g. Of the other
four is in communication through the approximately triangular passage hand
downwardly projecting passage with the chamber Č. e³ is in communication
through the passage i and downwardly projecting passage with the expanding and
contracting chamber G. The port d³ is in communication through the approximately
triangular passage ; and short downwardly projecting passage with the expanding
and contracting chamber F, and the port d' is in communication through the
passage k and the downwardly projecting passage k¹ with the chamber B.
The operation of our invention is as follows:
Assuming the slide valves a and b to be at the outer extremity of their stroke as
illustrated in figure 10, the expanding and contracting chamber G full of gas and the
chamber F empty then the progress of the gas through the meter will be as indicated
by the arrows in said figure, that is, as follows:-Passing along the inlet passage f
it flows through the ports d a² d³ into the triangular passage j and from thence
through the passage into the chamber F. At the same time the gas will pass
through the ports e b² e¹ into the triangular passage h and from thence through
passage into the chamber C. During all this time the chamber B is in
communication through the passages ¹ and k and ports d¹ a¹ d² with the exit passage g
whilst the chamber & is in communication through the passages ¹ i and ports e³ b¹³
with the exit g.

page_text: When these slide valves a and b are in the positions indicated in figure 11 that is at
the inner end of their stroke the expanding and contracting chamber F and the
chamber C will be in communication with the exit g whilst the chambers G and B
will be in communication with the inlet f as clearly illustrated by the arrows in said
figure the flow of gas being as follows: From the inlet fit passes through the
ports d, a', d, along the passages k k into the chamber B and through ports e, 62, es
along the passages i, i¹ into the chamber G, whilst the gas which is contained in the
chamber F will pass through the passages ¹ i ports d³, a', d, to the exit g and the
gas from the chamber will pass through the passages h¹h ports e¹, b¹, e³, to
the exit 9 as clearly illustrated by the arrows in said figure.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
First. In a dry gas meter wherein the gas is measured by alternately expanding
and contracting chambers the employment of slide valves having two ports such as a
and a², in each one (a¹) being placed transversely in the centre of the valve as
ordinarily and the other (a2) being arranged around three sides of the former,
substantially as and for the purpose specified and as illustrated in figure 6 of our
drawings.
Second. In a dry gas meter in which the gas is measured by alternately expanding
and contracting chambers the employment of a slide valve grating having four ports
such as d d d d³ arranged substantially as and for the purpose specified and as
illustrated in figure 4.
Third. In a dry gas meter in which the gas is measured by alternately expanding
and contracting chambers the combination with a pair of slide valves such as a b of a
radius or crank arm such as c and a pair of crank arms such as c c connected to
said radius arm by a pair of links the whole being arranged constructed and operated
substantially as and for the purpose specified and as illustrated in figures 1, 2, and 3
of our drawings.
Fourth. In a dry gas meter wherein the gas is measured by alternately expanding
and contracting chambers the employment of a pair of slide valves such as a b
together with the gratings upon which they are arranged to slide in combination
with a series of suitably arranged passages such as are herein described for connecting
the ports in the slide valve on one side of the meter with the measuring chambers
on the opposite side thereof, substantially as and for the purposes herein described
and explained and as illustrated in our drawings.
Dated this Second day of December One thousand eight hundred and eighty-
JOHN THOMAS WYNNE.
ALEXANDER CHARLES MORRISON.