IMPROVEMENTS IN GAS METER INDICATORS
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by James Thomas at the Office of
the Commissioners of Patents, with bis Petition, on the 24th October
1868.
I, JAMES THOMAS, of No. 54, Great Bolton Street, Kennington Park, in the
County of Surrey, Gas Meter Indicator Maker, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN GAS METER INDICATORS," to be as
follows:-
The object of my Invention is to guard against fraud by preventing the
dials of an indicator from being turned back and thereby representing a less
number of feet of gas than has actually passed through the meter, and at the
same time allow the quantity of gas registered to be read off in a simple
and unmistakeable manner.
The nature and description of my Invention consists in placing three dials
in a frame, one in the centre and one on each side, partly lapping over the
same, each dial being numbered round the edge with figures from 1 to 10,
representing respectively hundreds, thousands, and tens of thousands in the
usual manner. These dials are acted upon by spindles fixed in their centres
upon which are fixed the wheels that play into each other successively. One
wheel upon each spindle has ten notches on its periphery, and is acted upon
by another wheel having a single stud projecting from its rim on the adjoining
spindle, so that at every revolution of the studded wheel one-tenth of the
adjoining wheel is made to revolve, and so on to the next in rotation, and then
to the other wheel in succession.

page_text: Action is given to the several wheels by an endless screw formed on the
main spindle, and made to act upon a cog wheel fixed on a spindle near the
end of the frame. At the end of the latter spindle a snail eccentric is fixed,
which works a lever having a friction roller at one end to ride over the snail
and a spring at the other end to keep the lever in position. The object of the
lever is to discharge the dials when raised by the snail eccentric and give
them liberty to act, and upon the lever again falling to lock the several dials
and prevent their being reversed.
At the upper end of the main spindle is fixed a drum index, the edge of
which is divided into five parts, and a pointer is fixed on the frame to indicate
the number of feet of gas that has passed through the meter in a given time.
At the other end of the main spindle is fixed a spur wheel that is acted upon
by an endless screw worked by the shaft of the meter in the usual manner.
A click hinged to the outer case drops over the spur wheel and acts against
the spokes so as to prevent the wheel from going back.
The frame containing the apparatus and dials is fixed in a case and attached
to the meter and covered over by an enainelled or japanned plate and glass
front. Perforations are made in the plate over the upper centre figure of
each dial so as to indicate that figure only on the outside, the other figures
being covered by the plate. Two cyphers are enamelled or painted on the plate
and remain stationary so as to be read off' in connection with the single figure
in the last dial to indicate the number of hundreds of feet of gas that have
passed through the meter. The centre dial shows a figure for the number of
thousands, and the first dial a figure for the number of tens of thousands of
feet of gas that have passed through the meter, all of which said figures are
read off in a single line on the upper part of the face of the indicator.
A greater or less number of dials may be used if required, to act on the same
principle as herein described, but three dials are prefered for ordinary use.