AN IMPROVED LIQUID METER
Year: 1870

page_text: LETTERS PATENT to John Reid, Engineer and Manager of the
Edinburgh and Leith Gas Light Company, of Leith, in the County
of Mid Lothian, North Britain, for the Invention of "AN IMPROVED
LIQUID METER,”
Sealed the 16th June 1871, and dated the 20th December 1870.
PROVISIONAL SPECIFICATION left by the said John Reid at the Office
of the Commissioners of Patents, with his Petition, on the 20th
December 1870.
I, JOHN REID, Engineer and Manager of the Edinburgh and Leith
Gas Light Company, of Leith, in the County of Mid Lothian, North
Britain, do hereby declare the nature of the said Invention for "AN
IMPROVED LIQUID METER," to be as follows, that is to say :-
This Invention relates to an improved liquid meter which from the
simplicity of its construction and action is at once economical in cost,
and not liable to get out of order whilst it measures in a positive and
accurate manner. The measuring chamber of the meter is in the form
of a cylindrical segment, the end of which is rather larger than the half
of a circle, and it may be of any convenient length axially or at right
angles to the plane of such segment. The usual counting wheels and
indexes are provided, and are acted upon by a spindle which passes
through a stuffing box, and is concentric with the segment circle. The

page_text: measuring chamber contains a piston of a rectangular form which is
connected to the spindle either by passing through a slot in an enlarge-
ment formed on the part of it inside the chamber, or by being itself
formed with a slot through which a flattened part of the spindle passes.
The piston is of a thickness equal to twice the excess of the segment
beyond the half circle, and its sides radially exceeds the radius of the
segment circle by a certain amount. One edge of the piston works
in contact or nearly so with the outer circular or cylindrical side of the
chamber, whilst the other edge works in contact or nearly so with a circular
or cylindrical concentric cavity of small radius formed in what may be
termed the chord side of the chamber. The chamber is placed with
this chord side in a vertical or somewhat inclined position, and the inlet
for the liquid is formed in it below its central cavity, whilst the outlet
is above that cavity. If the piston is at right angles to the chord side
the liquid entering under it lifts it up and turns it until it becomes
parallel with the chord side. The piston having reached this position
next slides by gravitation down the chord side, its then lowest part
covering the inlet as its upper part uncovers the outlet from the chamber.
Then the edge of the piston which was previously in contact with the
small cavity in the chord side comes into contact with the outer cylin-
drical surface, and vice versa, the piston changing its axis from near one
edge to near the other, crossing through or on the spindle and being
guided thereby. The liquid continuing to enter causes the piston to turn
on its new axis until half a revolution is performed, which brings it against
the chord side, when it again slides down, and changing its axis and
contacts proceeds to perform another half revolution, and so on, the
motion consisting of a series of semi-revolutions separated by the sliding
down of the piston after each. The motions of the piston resemble those
which take place on turning a card over on one edge on a table, sliding
back the card to its starting position, turning it again in the same
direction as before, and again sliding it back, and so on repeatedly.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Reid in the Great Seal Patent Office on the
19th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN 3
RELD, Manager of the Edinburgh and Leith Gas Light Coy., of Leith,
in the County of Mid Lothian, North Britain, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of December, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Reid, Her special
licence that I, the said John Reid, my executors, administrators, and
assigns, or such others as I, the said John Reid, my executors, admi-
nistrators, 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 "AN IMPROVED LIQUID METER,"
upon the condition (amongst others) that I, the said John Reid, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 I, the said John Reid, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement in writing, reference being had to the accom-
panying Drawings, that is to say :—
My said Invention relates to an improved liquid meter which from the
simplicity of its construction and action is at once economical in cost
and not liable to get out of order, whilst it measures in a positive and
accurate manner.
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append a Sheet of
explanatory Drawings to be hercin-after referred to and representing two
modifications of my improved meter.
Figures 1 and 2 are vertical sections as at right angles to each other
of one modification, and Figure 3 is a transverse vertical section of the
second modification, which does not differ from the first in any essential
particular. The same reference numerals are used to mark the same or
like parts wherever they are repeated.

page_text: The measuring chamber or space 1, 2, of the meter is in the form of a
cylindrical segment, the end of which is a plane circular segment rather
larger than the half of a circle, and this chamber may be of any con-
venient length axially or at right angles to the plane of the segment.
The usual counting wheels and indexes are provided in a glass-fronted
compartment or box 3, and are acted upon by a spindle 4 placed con-
centrically with the segment circle of the measuring chamber. The
measuring chamber contains a piston 5 of a rectangular form, which is
connected to the spindle 4 either by being formed as shown in Figures
1 and 2 with a slot 6, through which a flattened part of the spindle 4
passes, or as shown in Figure 3 by passing itself through a slot in
an enlargement 7 formed on the part of the spindle 4 inside the
measuring chamber. The piston 5 is of a thickness equal to twice the
excess of the segment beyond the half circle, and its size radially exceeds
the radius of the segment circle by a certain amount. One edge of the
piston 5 works in contact or nearly so with the outer internal cylindrical
side of the chamber 1, 2, whilst the other edge works in contact or
nearly so with a cylindrical concentric cavity 8 of small radius formed
in what may be termed the chord side 9, 10, of the chamber. The
chamber 1, 2, is placed with this chord side in a vertical, or, as I prefer it,
in a somewhat inclined position as shown, and the inlet or inlets 11 for
the liquid are formed in it below its central cavity 8, whilst the outlet or
outlets 12 are above that cavity. The piston 5 is shown as near the
middle of its stroke, and when in this position liquid entering below lifts
it up, turning it in the direction shown by the arrow until it attains the
position indicated by dotted lines parallel to the chord side 9, 10, of
the chamber. The piston then slides down by gravitation until the edge
which has just come out of the central cavity 8 reaches the outer
cylindrical surface at the bottom (where a strip 13 of wood, rubber, or
other suitable material may be inserted to prevent injurious effects from
concussion). The other edge then enters and works round and down-
wards through the cavity 8, whilst the edge now outermost works
upwards round the outer internal cylindrical surface as the piston makes its
next semi-revolution. The piston 5 is made with its faces parallel to each
other excepting at the opposite corners 14, each of which in turn comes
to the bottom corner of the cavity 8, and each of these corners 14 is
slightly bevilled so that the piston may be free from the corner of the
cavity 8 just before it comes to be quite against or parallel to the chord
side 9, 10, of the chamber. This provision permits the piston to begin

page_text: to fall a little sooner than it otherwise would do, and so facilitates its
action. The same result is obtainable by cutting away or bevilling the
bottom corner of the cavity 8, as shown in Figure 3. A small cavity 15
is formed along the bottom of the chamber as a receptacle for sediment,
and a screw plug 16 is provided for clearing out this cavity and thus
cleansing the meter when required.
As it does not appear to be necessary to make what has been called
the chord side 9, 10, of the measuring chamber continuous and complete,
from the central cavity 8 to the outer cylinder portions may be as it
were cut away, as shown in Figure 3, or in other words the inlet 11 and
outlet 12 may be enlarged, leaving merely narrow guiding surfaces 9, 10,
on each side of the cavity 8, but in this case I prefer to introduce
an antifriction roller 17 to be encountered by the upper part of the
piston 5 and to prevent the piston from bearing with leverage upon the
surface 9.
My improved liquid meter may be made with the chamber or casing
of cast iron, the spindle of wrought iron, and the piston of brass, but other
suitable materials may be employed if preferred.
Having thus particularly described my said Invention, and the
manner in which the same is to be performed, I have to state that
what I believe to be novel and original, and claim as the Invention
secured to me the herein-before in part recited Letters Patent is, the
constructing of a liquid meter with a segmental cylindrical chamber
having in it a piston making semi-revolutions alternately with
diametrical sliding movements, substantially as herein-before described.
In witness whereof, I, the said John Reid, have hereunto set my
hand and scal, this Sixteenth day of June, in the year of our
Lord One thousand eight hundred and seventy-one.