IMPROVEMENTS IN GAS METERS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by William Cowan at the Office
of the Commissioners of Patents, with his Petition, on the 26th April
. 1861.
I, WILLIAM COWAN, of Edinburgh, in the County of Mid Lothian, Gas
Meter Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN GAS METERS," to be as follows, that is to say:-
This Invention relates to the arrangement and construction of gas meters
either of the wet or dry class in such manner as to admit of the indicating
mechanism being sealed or stamped by the inspector or official appointed for
purpose, so as to prevent subsequent alteration of the adjustment, or render
it at once evident that the instrument had been tampered with.
the
Under one modification, as applied to a meter of the ordinary kind, the
drum shaft carries on its front extremity an eccentric, the rotatory motion of
which imparts a vertical oscillating movement to the rod through which the
indicating mechanism is actuated. This rod passes up through the usual
pendent seal tube into the index box; the lower extremity of the rod is bent
and curved upwards and then in a horizontal direction, which part rests
upon the drum shaft eccentric, and it has a vertical wire soldered to it
which passes through a guide eye above. The object of bending the lower"
portion of the rod in this way is to admit of the mouth of the seal tube
being brought well down below the water line. The upper extremity of the
rod is connected to a flag wire, which is a small rod made with a laterally
projecting part at the upper end and working up and down in guides on the
back part of the index frame. As the flag wire rises and falls with the
motion of the eccentric, the projection both in its upward and downward

page_text: movement gives motion to a pallet arranged at the side of the flag wire.
The pallet is made with duplex detents, which alternately take into the teeth
of a crown or ratchet wheel arranged in proximity to the pallet. The spindle
of the crown wheel is carried in the front part of the index frame and in
a supplementary bearing piece which is screwed to the back of the main
frame. The outer screw of this piece also secures a cupped disc to receive
the inspector's seal or other means of preventing this part of the mechanism
being removed to alter the arrangement of the indicating train. The spindle
of the crown wheel which is actuated by the pallet is formed of pinion wire,
the leaves of which give motion to the ordinary train of indicating mechanism;
thus the rising motion of the flag wire causes the pallet to move the crown
wheel a certain distance forward, and the descent of the wire completes the
movement equal to one, tooth of the wheel, so that whether the drum is
moved forwards or backwards the motion of the indicating mechanism is
always in the forward direction, and thus preventing fraud on the part of the
consumer. 'Another mode of arranging the drum shaft in lieu of the
eccentric is to form the front end of the shaft with a crank, the pin of which
passes through an eye formed for the purpose in the end of the rod which
actuates the flag wire. In meters of some kinds the front extremity of the
drum shaft is carried in a bearing which is fitted in the front box, inside
the drum this bearing is bent at a right angle to receive the end of the drum
shaft. This arrangement admits of the bearing being arranged out of tho
centre of the opening, so that the spout passes in at the centre and this allows
of the aperture being reduced in size. As the end of the drum shaft rests
upon the bearing which is carried inside the drum other means are required
for the necessary movement to the vertical actuating rod. This is done by
means of a pin fixed in the margin of the central aperture of the drum; as
the drum rotates, this pin raises the arm of the bent rod, which is com
municated to the pallet movement above. This actuating pin being fixed
in the margin of the central aperture admits of its traversing round the
bearing and spout, which, as before explained, pass through the opening. In
applying these improvements to meters of the dry class, an eccentric; which
actuates the pallet movement, is employed in lieu of the worm and wheel now
used for imparting motion to the index mechanism of this class of meters
The minor details of this Invention may be variously modified without
departing from the essential features of the improvements.