AN IMPROVED LIQUID METER
Year: 1885

page_text: I, EDWIN TATHAM of Balmain near Sydney in the Colony of New South Wales,
Plumber, do hereby declare the nature of my invention for "AN IMPROVED LIQUID
METER "and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention has been devised for the purpose of producing an apparatus which
will measure and record the quantity of water or other liquid passing through it
no matter what is the pressure of such liquid and which will discharge the liquid
at practically. the same pressure at which it receives it.
My improved Liquid Meter is so constructed that the filling of one of two equal
stationary chambers or measures with water or other liquid will float or lift the
lower end of an oscillating lever upwards to such a position that a moving body
will pass from such lifted end to the other end and oscillate the said lever so as to
cause the said filled chamber to empty and the other said chamber to fill.
"
22
This improved Liquid Meter consists essentially of an airtight receiving vessel
containing two equal chambers or measures having independent openings to the
supply and independent openings to the discharge which latter openings must be
trapped " '-an oscillating lever within such airtight receiving chamber either side
of which is connected to the induction valves or openings and the eduction valves
or openings of each chamber or measure and registering mechanism preferably
contained in the airtight receiving vessel and connected with the oscillating lever so
as to record each movement or each two movements of said lever. Although I have
stated that the discharge openings must be "trapped I prefer-and more
especially when it is desired to supply the measured water at an elevation above
the meter or against a pressure-to add an airtight discharging vessel or chamber
which communicates with said airtight receiving chamber and from which the
trapped discharge opening or pipe is led-in such discharge opening or pipe I also
prefer to construct an adjustable check valve-so as to "trap" or retain within
such discharging vessel a sufficient quantity of air which when compressed will
counterbalance the pressure or weight of the column of water in the discharge pipe.
The said equal chambers or measures are constructed preferably separately of
cast metal with one half or portion of a discharging vessel attached to each and
are bolted together to an inverted-T-piece or frame so as to form the whole Meter
in one piece. The journals or bearings for the spindle or fulcrum pin of the

page_text: "
oscillating lever are supported by the upright divisional metal between the chambers
and the necessary valve boxes are bolted to said inverted-T-piece on either side and
within its angles. Said oscillating lever termed a "water balance consists
preferably of an oblong chamber nearly equal in area to the area of the Meter in
cross section but relatively very shallow in which is hermetically sealed a small
quantity of water mercury or other fluid. Said lever has on its underside and on.
its centre line lugs or hinges to form a fulcrum joint and to said underside on
either end of said lever is attached an air vessel or float. Connecting rods having
slotted eyes reach from convenient studs or pintles on the side of said lever to the
spindles of the valves. The registering mechanism may be of any well-known
description so long as it records the number of times the valves are opened and
closed by the oscillation of the lever.
But in order that this invention may be clearly understood reference will now be
made to the drawings herewith in which Figure 1 shows a front elevation and
Figure 2 a plan respectively of an improved Liquid Meter constructed according
thereto. Figure 3 is an internal elevation showing the casing or meter-casting the
induction valves and the discharge pipe or orifice in section. Figure 4 an internal
plan showing the casing in section. Figure 5 a vertical section on line a a in
Figure 3. Figure 6 a horizontal section on line bb in Figures 3 and 5. Figure 7 is
an internal elevation in a plane at right angles to the planes of Figures 1 3 and 5
the casing and the induction pipe or orifice being shown in section and Figure 8 is
a plan of the underside of the oscillating lever or "water balance."
A is the airtight receiving vessel B and B¹ two equal chambers or measures
C the oscillating lever or "water balance" D the induction valve box or casing
and E the eduction valve box or frame F the airtight discharging vessel and
G the registering mechanism. A¹ is inverted-T-piece partition A journals
A³ flanges A bolts A³ reading opening for dials A glass front A7 attaching
flange or frame A³ hinged cover B2 is maximum water line in chambers B and B₁
C¹ is water or other fluid C lugs C³ fulcrum pin C+ air vessels or floats
C³ buffers or stops D¹ and E¹ are ports D2 and E2 slide valves D3 and E³ spindles
D and E guides D³ and E³ connecting rods joined at bottom by a transverse
rod De is.supply orifice E° discharge opening to vessel F F1 is discharge orifice
having bend reaching downwards in which is check valve F³ provided with
weighted float F4 F5 is connecting pipe to vessel A reaching above the water line
Gis pawl lever whose weighted end G2 is allowed to fall a certain distance G³ is
ratchet wheel G4 pawl lever and G³ ratchet wheel on the first spindle of registering
mechanism whose construction is well understood.
The mode of operation is as follows:-The water or other liquid to be measured
flows in through orifice D° to valve box D and through one of the ports D¹ to
chamber B or Bas the case may be (as shown in the drawing the water would flow
into chamber B) and filling it lifts or floats the air vessel C and lever C until said
lever or "water balance" is horizontal and until the water in the chamber B reaches
line B' when the water or fluid C¹ instantly moves to the other end of the lever C
causing that "other" end to overweigh or overbalance the end which was previously
the lower and thereby to "oscillate" said lever to the reverse position to that
shown on the drawing which movement by means of connecting rods D³ and E
closes port D¹ and opens port E¹ of chamber B and at the same time opens port D¹
and closes port E¹ of chamber B' which latter chamber commences to fill and the
liquid rising lifts the lower end of the lever C with the opposite effect to that just
described. The slotted eyes of the connecting rods D and E allow the rising
liquid in the chambers B or B¹ to lift or float the weight alone of the lower end of
lever C and such weight to be freely lifted while they also cause no movement of
the valves until the oscillation of the lever takes place.
The weight G² keeps the pawl lever G₁ against a stop in any convenient position
ready to actuate ratchet wheel G³ upon the upward movement of that end of
lever C above chamber B¹ which movement of the ratchet wheel is multiplied as
required by gearing pawl lever G and ratchet G³. The capacity of the chambers B

page_text: and B¹ to the water line B2 being known, it is multiplied by the ratio of such
gearing and by the number of movements registered by the dials of mechanism G
and the product is the quantity of liquid measured.
When the liquid first enters the chamber B or B' as the case may be it displaces
and compresses the air therein to a certain limit at which a check valve or a trapped
discharge is set and upon the other chamber B or B¹ filling the air is locked within
the upper portion of the receiving vessel forming a cushion which assists to force
the liquid from out of each of such chambers in turn. But when as I prefer the
air-tight discharging vessel is used the air is compressed at the outset to the pressure
at which the check valve F³ is set to discharge at and the back pressure head or
column of liquid in the discharge pipe further compresses the air within the meter
(when the water in the vessel F keeps the float F up and such check valve open)
and such compressed air passes up through pipe F5 to supplement the cushion
forined by the air from the measuring chambers and the pressure thereof is felt by
the liquid filling into and discharging from measuring chambers B and B'
respectively and by the liquid which is being discharged through pipe F¹ and which
may be discharged at practically the same pressure at which it is supplied through
pipe D by adjusting the check valve and weighted float F* at the proper distance
from the fulcrum.
It is clearly to be seen that any cut off and supply mechanism such as taps
lift-valves &c. might be substituted for the slide valves shown without departing
from the nature of my invention also that it is not essential that the "water
balance" should be oblong or have parallel sides nor that any particular sizes or
materials are necessary to the success of the operations of my improved liquid
meter although I prefer when such meter is used to measure water supplied in a
pipe say one inch or less in diameter to make each measuring chamber of a capacity
of two and a-half gallons.
Having thus particularly described and ascertained the nature of my said
invention and the manner in which the same is to be performed I would have it
understood that what I believe to be novel and therefore claim as of my
invention is―
First. An improved liquid meter so constructed that the filling of one of two
equal stationary chambers or measures will float or lift the lower end of a
lever upwards causing said lever to oscillate and reverse the supply and
discharge valves of each such chamber or measure respectively substantially
as herein described and explained.
Second. The combination and arrangement of the chambers B and B within the
air-tight vessel A with an oscillating lever C for opening and closing valves
cocks or entrances to such chambers and mechanism for recording the
movements of such lever substantially as herein described and explained and
as illustrated in the drawings.
Third. The hollow oscillating lever in which is hermetically sealed a small
quantity of water inercury or other fluid and whether or not provided with air
vessels or floats substantially as herein described and explained.
Fourth. The combination and arrangement of the air-tight discharging vessel F
baving discharging check valve F³ and communicating pipe F with the
air-tight receiving vessel A substantially as herein described and explained
and as illustrated in the drawings.
Dated this twenty fourth day of November One thousand eight hundred and