IMPROVEMENTS IN GAS METERS
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by Adam John Burr at the Office of
the Commissioners of Patents, with his Petition, on the 6th March
1855.
I, ADAM JOHN BURR, of 42, Alfred Road, Paddington, in the County of
Middlesex, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN GAS METERS " to be as follows:-
This Invention relates to the general construction and arrangement of wet
gas meters, and consists of an outside metallic casing, which is divided into
three compartments or chambers by vertical divisions, which, however, permit
the water in all the chambers to communicate, the two end chambers being of
equal size, & much larger than the central one, which contains within it
in proper sub-compartments the inlet, exit, & syphon pipes, herein-after
described. In each end chamber is placed a measuring cell, composed of metal
or other suitable material, which is inserted & has its mouth always immersed
in water. These cells rise and fall vertically through a certain given distance
comprehended between fixed points. It will thus be obvious, on reflection, that
as the cells rise and fall, there will always be the same capacity opened and
closed for the admission and expulsion of air, although the level of the water
may vary, and this capacity will depend of course on the amount of movement
of the cell. Beneath and within a four-way hydraulic valve, which governs

page_text: the flow of gas in connection with the measuring cells. These valves consist
each of a semi-cylindrical or nearly semi-cylindrical chamber, working in the
water with its mouth downwards, and they are divided longitudinally into
three chambers by vertical partitions, which are so arranged, that when one
edge of the valve is brought up to the top of its stroke, by turning it round on
its axis the mouth of the first chamber will be above the water line, and
consequently in communication with the interior of the inverted measuring
cell placed over it; at, the same time the, other two chambers in the valve, that
is, the second. or central one & the third chamber, will communicate with
each other by the raising of a portion of the partition between them above the
water level. The branches of the inlet pipe open respectively into the first
chamber of the valves, and the gas passes therefrom and fills the measuring
cell above it, thereby elevating it, and actuating the opposite valve, with which
it is connected, by means of levers and a connecting rod. This elevating of
the measuring cell in its chamber or enclosing compartment expels the air or
gas contained between the outside of the measuring cell, and the inside of the
compartment, and causes such air or gas to escape through a lateral opening
in the chamber, and enter one end of an inverted syphon, which opens at its
other end into the central chamber of the valve; and as this chamber is at
present in communication with the third chamber of the valve, the air or gas
passes therefrom into this third chamber, and thence into that branch of the
exit pipe which opens into it.
"
While the, ascent of a measuring cell is thus going on in one compartment
of the meter, access has been, provided for the gas into, the space. outside the
measuring cell in the opposite compartment; by reason of the communication
being opened between the. inlet pipe and the said outside. space through the
middle chamber of the valve and the inverted syphon, each valve being
constructed and worked in. a precisely similar manner, and having each the
same arrangement of pipes and chambers; and they are so constructed, and
worked that each valve establishes free communication, first and simul-
taneously, between the inlet pipe and the inside of the cell, and, between the
outside of the cell and the outlet pipe; and, secondly, and also simultaneously,
between the inlet pipe and the outside of the 'cell, and between the inside of
the cell and the outlet pipe, and that the changes, from the one condition to
the other is effected in each of the valves by the motion of the opposite.cell
through the intervention of levers and a connecting rod, as already stated, that
motion when in an upward direction, being due to the excess of pressure of
the gas on the inside of the cell, and when downwards to excess of pressure
on the outside. This movement is: transmitted from one of the cells, to 'the

page_text: index by two pins or studs on the valve actuating rod connected with it, which
studs, as the rod moves to and fro, actuate the tail of a short lever, which
carries a pall at its upper end, taking into the teeth of a ratchet wheel.
This wheel gives motion by means of an endless screw and toothed wheel or
other suitable arrangement to the index, which may be placed on the top of
the small-central chamber or compartment of the meter. For the purposes
of adjustment of this part of the mechanism, the tail of the pall lever is forked,
and may be thereby expanded or contracted, so as to be acted upon more or
less by the stud pins. The points which define the movements of the cells
may be all fixed, except one, which may consist of an adjusting screw, so
applied that the exact movement of one cell may be under precise controul for
the final adjustment of the registration. The float valve connected with the inlet
pipe is made so that it will adjust itself readily on to the top of the pipe. This
is effected by simply making the plate constituting the valve slightly loose or
free in its bearings. The float may be of the usual kind, or it may be composed
of cork or other buoyant substance, coated with gutta percha, to prevent
saturation. An overflow plug is fitted into the meter to regulate the level of
the water therein. The valves have their working centres placed below the
centre of gravity, so that they will have a tendency, after the centre of gravity
has passed over the pivots, to cause each cell to remain at the end of its stroke
(in either direction) until the other shall have completed its transit. The
absolute weight of the valve must be made sufficient to effect the purpose.
In order to counteract the weight of the measuring cells, the remote edge of
the valves may be weighted, or an air chamber may be attached to the cell, the
buoyancy of which in water shall counterpoise the weight of the cell.