Improvements in Prepayment Gas Meters.
Year: 1894

page_text: Date of Application, 15th May, 1894
Complete Specification Left, 15th Feb., 1895-Accepted, 15th May, 1895
Improvements in Prepayment Gas Meters.
We, WILLIAM COWAN and WILLIAM HENRY COWAN both of Buccleuch
Street Works, Edinburgh, in the County of Midlothian, North Britain, Gas
Meter Manufacturers, etc., do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in prepayment gas meters and has for its
object to provide an efficient wet gas meter having prepayment mechanism and
stops attached.
In carrying out our said invention we employ a wet gas meter in which the area
or surface of the water exposed to the inlet pressure is more or less considerably in
excess of the area or surface of water exposed to the outlet pressure, thus always
ensuring an efficient seal of water at the centre opening of the drum, by reason of
which this form of meter is more applicable to wet prepayment meters in which
stops are used, than other forms of wet meters hitherto employed. The kind of
drum we prefer to use is constructed on the Warner and Cowan principle which
enables a deeper seal to be given to the centre opening of the drum, without
affecting the measurement.
The prepayment mechanism and stop arrangement which we prefer to combine
with the above form of meter is practically that which is described in the
Specification of the former application for Patent No. 24490 dated 20th December
1893 made by the above named William Cowan and our former application for
Patent No. 7988 dated 23rd April 1894 respectively, except with regard to the
following.
According to the present invention, we employ the stop which was described as
the "second line of defence," not as such, but as a stop to enable the prepayment
or supplementary valve to be dispensed with, and to ensure the more efficient
working of this stop, we form the front or bent end of the stop as a sliding rod
working in a slot or opening formed in the end of the pivoted weighted lever, said
rod being suitably guided.
Also according to the present invention, we employ the vertical stop and pawl
shaped lever arrangement for shutting off the supply of gas, in the event of the
prepayment pawl and wheel being left in gear, that is, when the coin carrier has
not been returned to its normal position. Also in some cases if desired we may
mount the disc or cam, having the projections against which the stops act, on an
auxiliary shaft in lieu of on the upright shaft and suitably gear the said shaft with
the upright shaft.
The foregoing use of the stop to the exclusion of a valve and the improved
construction of same is equally applicable to dry gas meters.
Dated this 12th day of May 1894.

page_text: 030
We, WILLIAM COWAN and WILLIAM HENRY COWAN both of Buccleuch
Street Works, Edinburgh, in the County of Midlothian, North Britain, Gas
Meter Manufacturers, etc., 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 improvements in prepayment gas meters and has for its
object to provide an efficient prepayment gas meter having prepayment mechanism
and stops attached said stops being employed to the exclusion of a valve:
But in order that our present invention may be more readily understood and'
easily carried into effect, we will describe the same with reference to the
accompanying drawings.
'
Figures. 1 and 2 are part front elevation and part side elevation of a form of wet
gas meter which we prefer to employ.
Figure 3 is a-front elevation of part of an index. case of a wet gas meter having
our improvements attached..
Figure 4 is a.similar view of. a modification.
Referring to Figures.land. 2 of the said. drawings, we prefer to employ a wet
gas.meter, of a similar kind. to the meters described, in the Specifications of the
Letters Patent granted, to James Pinchbeck,. No.. 979 of 20th April 1861 and
James Urquhart and William Ward Andrews No. 104 of 8th January 1876, in
which the area. or surface of the water exposed to the inlet pressure is more or less.
considerably in excess of the area or surface of water: exposed: to the ontlet
pressure,, thus always ensuring an efficient seal of water at the centre opening W.
of the drum,, by reason of which this form of meter is more: applicable to wet:
prepayment meters in, which stops, are used; than other forms of wet meters:
hitherto employed. That. is. to say, that the gas after passing down the inlet
pipe B enters the chamber B' through the valve B, thence through the opening B³
into the drum's case B', through the drum and thence out through the pipe Brin
the central opening, W and out by the outlet pipe: W..
The kind of drum we prefer, to. use is constructed: on the Warner and Cowan
principle, as described in the Specification of William Warner and William Cowan
No. 1698 of 15th May 1874, which enables. a deeper seal to be given to the centre.
opening of the drum,,without,affecting the measurement.
The prepayment mechanism and stop arrangement which we prefer to combine.
with the above form of meter is practically that which is described in the
Specifications of the former application for Patent No: 24490 dated: 20th December
1893 made by the, above: named William Cowan and our former application for
Patent No. 7988 dated, 23rd. April 1894 respectively, except with regard to the
following
"
According to the present invention,, we employ the stop which was describedi ass
the "second line of defence not as such, but as a stop to enable the prepayment
or supplementary, valve to be dispensed with, we arrange the parts. as shown in
Figure 3, that is to say we employ the: pawl shaped leven N and depending rod.
arrangement N¹ for the purpose of shutting off, the supply of gas.in the event of
the pawl J not being returned to its normal position, and we also employ a
modification of the speciali stopy consisting of the pivoted lever Q having slotted
end depending rod or stop pin g which would be moved into gear with the
cam on the upright shaft S of the meter by the prepayment or plain wheels
projecting pin q'; said stop pin g' working in one or more guides 9. The other.
end q of this lever Q is provided with a balance weight gas before and the stop
pin q is lifted up out of gear with the cams by the carrier's depending rod Qas

page_text: already described in the before-mentioned Specifications. In this. invention the
projections s' on the disc S, do not effect the closing, of a valve, but are used for
the purpose of enabling stops to arrest the mechanism of the meter,
"
Or as a modification of the foregoing we may arrange the said "second line of
defence as shown in Figure 4, that is to say, we form the lever Q as shown and
mount the depending rod or stop pin on the end q in lieu of on, the end
which in this case is provided with a projection or tooth q which when in its
Dormal position engages with a notch or recess q° formed in the periphery of the
plain wheel K' which attached to the prepayment wheel as hitherto. The stop
pin q is in this case lifted out of gear with the cams every time the eccentric
carrier E is moved forward by the depending arm Q' the lower end of which
works against the surface of an angled arm or lever q' which is connected to the
front end of the said lever Q as shown. This arrangement enables a quicker and
more efficient action being given to the stop pin q' than is the case in the
arrangement shown in Figure 3.
Also according to the present invention, we employ the vertical stop and pawl
shaped lever arrangement for shutting off the supply of gas, in the event of the
prepayment pawl and wheel' being left in gear, that is when the coin carrier has
not been returned to its normal position. This may be effected as shown in
Figure 3, that is to say, we pivot to the front end of the eccentric carrier E a pawl
shaped lever N which is provided with a normal rest or support n formed on or
attached to the carriers track D.
The said lever N is formed with a slot or opening n¹ through which passes a
depending rod N¹ having an enlarged head and provided with one or more
guide brackets n. The arrangement is such that on the eccentric carrier E being
moved forward the pawl shaped lever N will leave its rest or support n and so lower
the rod N' into the path of the projections on the discs of the meter's upright
shaft S in a wet meter, and into the path of the ordinary tangent in a dry meter.
Or as a modification we may employ the pawl shaped lever arrangement, as is
shown in Figure 4, so as to enable the index being more readily lifted clear of the
prepayment mechanism.
That is to say, we pivot the lever N to a small bracket e near the back of the
carrier E which, in the example shown, has its coin slot arranged so as to permit of
the coin being dropped in from the roof of the index case C¹. The other parts
being as before described with the exception of the guide bracket n³ which in this
case is soldered, screwed or otherwise attached, to the index frame so as to enable
the bracket n being lifted out with the index; the said bracket m may also be
provided with a support or steadying pin n. The lifting out of the index being
effected by means of one or more slotted brackets and screws c, formed in or
attached to the index frame, and the driving shaft S' of the index is connected to
the upright shaft S of the meter by means of a cross pin or bar and slots §³.
Also in accordance with this invention, in some cases if desired we may mount
the disc or cam s having the projections against which the stops act, on an
auxiliary shaft in lieu of on the upright shaft S and suitably gear the said shaft
with the upright shaft S. The ridges or projections s' on the disc or cam s may in
some cases be dispensed with and a series of holes formed in the discs, at or near
the circumference of the disc s, may be employed and into which the ends of the
stop pins q' and N¹ would drop.
The foregoing use of the stop to the exclusion of a valve and the improved
construction of same is equally applicable to dry gas meters.
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:
1st. In prepayment wet gas meters, the combination of a prepayment mechanism,
having stops to the exclusion of a valve, with a wet gas meter having a larger area
of water exposed to inlet pressure than is exposed to outlet pressure, whereby an

page_text: efficient seal at centre opening of drum is obtained, substantially as hereinbefore
described and shewn in the accompanying drawings.
2nd. In prepayment gas meters, the arrangement and combination with the parts
forming a prepayment mechanism of the stops g' and N' and disc s, in wet meters,
or stops q and N' and tangent in dry meters, substantially as and for the purposes
hereinbefore described and shewn in Figure 3 of the accompanying drawings.
3rd. In prepayment gas meters, the modification of the arrangement and
combination with the parts forming a prepayment mechanism of the stops q¹ and N'
and disc s, in wet meters, or stops q' and N and tangent in dry meters, substantially
as and for the purposes herein before described and shewn in Figure 4 of the
accompanying drawings.
Dated this 14th day of February 1895.
JOHNSONS,
115, St. Vincent Street, Glasgow, Applicants' Agents.