IMPROVEMENTS IN DRY AND WET GAS METERS
Year: 1868

page_text: LETTERS PATENT to William Smith and George Browne Smith, both
of Kennington Park Road, in the County of Surrey, Gas Meter
Manufacturers, for the Invention of "IMPROVEMENTS IN DRY AND WET
GAS METERS."
PROVISIONAL SPECIFICATION left by the said William Smith and
George Browne Smith at the Office of the Commissioners of Patents,
with their Petition, on the 15th May 1868.
We, WILLIAM SMITH and GEORGE BROWNE SMITH, both of Kennington
Park Road, in the County of Surrey, Gas Meter Manufacturers, do hereby
declare the, nature of the said Invention for "IMPROVEMENTS IN DRY AND
WET GAS METERS," to be as follows:-
The first part of our Invention consists in forming the diaphragm of dry
gas meters as hereafter described, and in such manner that it is capable
of holding twice the quantity of gas that a diaphragm of the ordinary
construction will hold. We form the bottom rim to which one side of
the diaphragm is attached larger than the rim carrying the disc,
whereby the disc is enabled to pass through the larger rim. By this

page_text: means the whole of the gas contained in the diaphragm is expelled at
each stroke of the disc, a longer throw is given to the arms, the
meter itself works with less friction, and is much less in size than when
made as heretoforc.
The second part of our improvements are intended to facilitate the
registration of dry gas meters, and so to render it only necessary to once
prove the meter. Heretofore a pin has been free to slide on the tangent
bar fastened in position by back nuts. Now according to our Invention
we tap the tangent pin to which the arms are attached, so that the pin
itself turns on the bar; a given number of threads will determine the
number of revolutions the pin must make to render the registration of
the meter as perfeet as may be, for it is only necessary to know the
value of a thread to ascertain how many revolutions the pin ought to
make backwards or forwards to make the meter perfect, and this
determined a key or peg may be passed through the threaded part of
the pin to hold it firm and steady on the tangent bar.
The third part of our improvements consists in the employment of an
eccentric valve for dry gas meters constructed in such manner that the
face of the top or cover of the valve never leaves its seat, and con-
sequently always bears on all parts alike, and is further so constructed
that while rotating the inlet and outlet passages are at all times equal.
We attach a rod to one end or side of the valve cover, and this rod passes
through a loop on the valve plate; as a rotary motion is communicated
to the valve in the ordinary way the valve travels round and over the
ports, and as the rod on the end is loose in the loop the valve works
eccentrically over the ports. The ports of the valve may be curved or
triangular as desired. The shape of the valve cover is regulated by the
distance the loop on the valve plate is placed from the valve seat.
The fourth part of our improvements relate to those kind of wet
meters known as the compensating wet meters. The improvements
consist in materially simplyfying the method of keeping the water at
its proper level. We insert a bent pin in the end of the shaft of
the measuring drum or wheel, and through the plate or separating
chamber we place a stuffing box, through which a cranked rod passes,
and against which the bent pin passing through the shaft of the
measuring drum acts, causing the cranked rod to revolve. On the
outer end of the cranked rod we fit two or more hollow buckets or
arms, so formed that at each revolution of the measuring drum a

page_text: small quantity of water is carried up and discharged into the measuring
part of the meter, and which will ensure the water in the meter being
at all times at its proper level.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
by the said William Smith and George Browne Smith in the Great
Seal Patent Office on the 13th November 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, WILLIAM
SMITH and GEORGE BROWNE SMITH, both of Kennington Park Road, in
the County of Surrey, Gas Meter Manufacturers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of May, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said William Smith and George Browne Smith,
Her special licence that we, the said William Smith and George Browne
Smith, our executors, administrators, and assigns, or such others as we,
the said William Smith and George Browne Smith, our executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
DRY AND WET GAS METERS," upon the condition (amongst others) that we,
the said William Smith and George Browne Smith, our executors or
administrators, by an instrument in writing under our, or their, or one
of their hands and scals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said William Smith and George Browne
Smith, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to

page_text: "the accompanying Drawings, and to the letters of reference marked
¡thereon, that is to say
こ
The first part of our Invention consists in forming the diaphragm of
dry gas meters as hereafter described, and in such manner that it is
capable of holding twice the quantity of gas that a diaphragm of the
ordinary construction will hold. We form the bottom rim to which one
side of the diaphragm is attached larger than the rim carrying the disc,
whereby the disc is enabled to pass through the larger rim. By this
means the whole of the gas contained in the diaphragm is expelled at
each stroke of the disc, a longer throw is given to the arms, the meter
itself works with less friction, and is much less in size than when made
as heretofore.
Figure 1 of the accompanying Drawings is a front elevation, and
Figure 2 a side view of a diaphragm constructed according to our
Invention. a is the bottom rim, and 6 is the ring carrying the
diaphragm disc g; c is the leather forming the diaphragm, a detached
view of which is given at Figure 3; it is by preference formed in
three or more parts, each portion or part forming the segment of a
circle. To complete the diaphragm the three parts, if three are used,
are stitched together. In some cases the leather is made in one piece
or in two, four, or more pieces, or in fact in any number of picces
as desired or required. This leather is made of or about the same
width as the bottom rim; for example, if the bottom rim is two inches
deep the working portion of the leather will be two inches, and
will therefore advance and recede at least three inches at each throw,
and by which arrangement the leather can neither "bag" or tighten on
the rims.
Figure 4 shows in section the diaphragm open; and Figure 5 is a
similar view showing it closed. It will be there seen that as the disc
moves it at each stroke passes into and through the bottom rim, which
is accomplished by the leather forming the diaphragm being of or about
the same breadth as that of the said rim, and by this means it expels
as nearly as may be double the quantity of gas that a diaphragm of any
known construction and of similar dimensions has heretofore been
capable of doing.
Figure 6 is a front view, Figure 7 is a plan, and Figure 8 a side
elevation of a portion of a dry gas meter, showing how the disc is placed
in connection with the registration apparatus. d is an arm hinged to

page_text: the disc g by a double hinge h. Through the outer end of the arm a
vertical rod fpasses; this rod is stepped at bottom in the block f¹, and
at top it is united to the arms, which are themselves jointed to the
tangent pin and valve as hercafter described. i is a bent rod passing
through guides as shown for regulating the to-and-fro motion of the
diaphragm disc g.
The second part of our improvements are intended to facilitate
the registration of dry gas meters, and so to render it only necessary
to once prove them. Heretofore a pin has been free to slide on the
tangent bar fastened in position by back nuts. Now according to our
Invention we tap the tangent pin to which the arms are attached so that
the pin itself turns on the bar. A given number of threads will determine
the number of revolutions the pin must make to render the registration
of the meter as perfect as may be, for it is only necessary to know
the value of a thread to ascertain how many revolutions the pin ought
to make backwards or forwards to make the meter perfect, and this
determined a key or peg may be passed through the threaded part of the
pin to hold it firm and steady on the tangent bar.
Figure 9 is a side view, and Figure. 10 is a plan of this tangent
bar and pin; Figure 11 is a detached view of the pin.
The third part of our improvements consists in the employment of an
eccentric valve for dry gas meters so constructed that while rotating the
inlet and outlet passages are at all times equal. We attach a rod to
one end or side of the valve cover, and this rod passes through a loop
on the valve plate. We employ steel or cast steel facings for the valve
cover.
Figures 12, 13, and 14, are views of this valve (see also Figures 6
and 7). is the rod attached to the valve cover k¹ passing through a
loop on the valve plate.
At Figures 12 and 13 the ports are shown curved, but they may be
made of other shapes, for example, as shown at Figures 15 and 10, or
as practice may dictate. We prefer to make the ports curved because
the gas is thereby caused to be cut off and admitted gradually instead
of suddenly, as is the case with ordinary slide valves. With curved or
circular ports we use strait covers, and vice versa. As a rotary motion
is communicated to the valve cover ¹ in the ordinary way, it travels
round and over the ports as best seen at Figure 12, and as the rod k on
the end is loose in the loop 1, the valve works eccentrically over the

page_text: ports. The shape of the valve cover is regulated by the disctance the
loop on the valve plate is placed from the valve seat.
The fourth part of our improvements relate to those kind of wet
meters known as the compensating wet meters. The improvement
consists in materially simplyfying the method of keeping the water at
its proper level. We insert a bent pin in the end of the shaft of the
measuring drum or wheel, and through the plate or separating chamber
we place a stuffing box, through which a cranked rod passes, and against
which the bent pin passing through the shaft of the measuring drum acts,
causing the cranked rod to revolve. On the outer end of the cranked
rod we fit two or more hollow buckets or arms so formed that at each
revolution of the measuring drum a small quantity of water is carried
up and discharged into the measuring part of the meter and which will
insure the water in the meter being at all times at its proper level.
Figure 17 is a side view, Figure 18 is an end view, and Figure 19 is a
plan of this apparatus. o is the cranked rod passing through the
separating chamber p, and carrying arms q, q, q, with buckets q', 1', 1',
at the outer ends. As these arms revolve, motion being communicated
from the measuring drum, the buckets dip into the water and at each
revolution tako up water and discharge their contents into a reservoir r,
from whence it flows into the measuring part of the meter by the
aperture 8.
And having now described the nature of our said Invention, and in
what manner the same is to be performed, we declare that we lay no
claim whatever simply to the employment of diaphragms where one rim
passes into the other, neither do we claim any of the parts herein-before
described, in so far as the construction of the diaphragm is concerned,
when taken separately or alone, but we do claim as our improvements
in dry and wet gas meters,--
First. The employment in the construction of the diaphragms of dry
gas meters of a broad bottom rim of or about the same width as the
working portion of the leather composing the diaphragm, into and
through which the disc is free to pass, in combination with the par-
ticular method or methods for the construction or formation of the
diaphragm of dry gas meters, whereby the leather neither bags nor
tightens on the rims, all substantially in manner and for the purposes
herein-before described and illustrated by the accompanying Drawings.

page_text: Second. The improving of the registration of dry gas meters in and
by the employment of apparatus constructed and acting substantially
as described and illustrated at Figures 6, 7, and 8 of the accompanying
Drawings.
Third. The construction, arrangement, and method of action of
eccentric valves for dry gas meters, substantially as described and
illustrated in the accompanying Drawings.
Fourth. The method of and apparatus for keeping water at its proper
level in compensating wet meters, as hercin-before described and illus-
trated at Figures 14 and 15 of the accompanying Drawings.
In witness whereof, we, the said William Smith and George Browne
Smith, have hereunto set our hands and seals, this Tenth day
of November, in the year of our Lord One thousand eight
hundred and sixty-eight.