Turbine meter for bi-directional measurement of fluid flow

A multi-bladed turbine meter is in a fluid flow line and has two magnetic pick-ups at the periphery of its blade tips positioned to be pulsed at different times by each blade as each blade passes the pick-ups. A circuit is connected to both pick-ups to determine which pick-up is pulsed first and to register the volume of fluid which is passed through the meter in each direction.

BACKGROUND OF THE INVENTION 
Turbine meters are steadily improving. These basically simple, 
multi-bladed, measuring devices have steadily gained in acceptance by 
industry. 
Turbine meters have been used to measure fluid as it fills a reservoir a 
predetermined amount. Turbine meters have been used to measure fluid as 
the fluid is withdrawn from the reservoir inventory. To the non-inventive 
mind, a meter is required to measure the fluid flow in each direction of 
the same path. Economics demand only one meter be used for measuring the 
fluid flow in both directions of a single flow path. Further, convenience 
and time demand the bi-directional flow be differentially measured, i.e. 
the single registration of volume be that of the inventory of the 
reservoir. These demands must be met by invention over the prior art. 
Next, consider closely the meter mechanism which must be used in solving 
the problem. A multi-bladed rotor has its shaft parallel with the fluid 
flow. The blades radiate from the shaft and are at an angle to the flow to 
develop a force which rotates the blades and shaft. 
Electro-magnetic pick-up units are positioned about the periphery of the 
blades. The magnetic lines of force generated by these pick-up units are 
cut by each rotating blade to generate an electrical pulse. The number of 
pulses generated within a predetermined time span establishes the rate of 
fluid flow through the meter. 
The prior art provides a single well in the meter casing in which a single 
pick-up unit is mounted. Can the single, conventional pick-up well be 
utilized to mount more than one pick-up unit as needed to provide signals 
which will establish the one of two directions fluid flows through the 
meter? Can a plurality of pick-up units be mounted at the periphery of the 
blades to establish which direction fluid flows through the meter and add 
or subtract from a single registration to manifest the inventory supplied 
through the meter? These two questions underline the problems solved by 
the present invention. 
SUMMARY OF THE INVENTION 
The present invention contemplates aligning two magnetic pick-up units at 
the periphery of turbine meter blades. Each blade of the meter is directed 
to rotate and slice the line of the two units at an angle. The arrangement 
insures that one of the pick-up units is actuated before the other. Which 
pick-up is actuated first depends upon which direction the fluid flows 
through the meter. In either direction of rotation, the pick-up units are 
nested in the same well of the meter body and are actuated in sequence by 
each blade of the turbine. The circuit receiving these pulses is arranged 
to detect in which of the two directions flow occurs and to manifest the 
quantity of fluid flowing in that direction. 
Other objects, advantages and features of the invention will become 
apparent to those skilled in this art as the description, appended claims 
and drawings are considered.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Structuring definitions of the inventive concepts in the disclosure is 
difficult to couch in robust language within this particular art. As novel 
as the concepts are, they are embodied in structure which must be 
described in limited and simplistic terms such as meter body, turbine 
blades, pick-up units, fluid flow path, and manifestation of direction and 
quantity. This is hardly a dramatic arsenal from which to select telling 
descriptions that will ring out the solid advances this invention makes in 
the art. However, if words with a persuasive bite are unavailable, the 
words and phrases selected will be clear and definite as the periphery of 
the scope of the present invention is carefully traced in the following 
description of the drawing. 
In FIG. 1 a conduit 1 defines the path along which fluids flow into and out 
of a reservoir which need not be shown. Flow arrow 2 is double-headed to 
establish that the flow of fluids through the conduit 1 can be in either 
of the two directions. 
A more or less conventional, multi-bladed rotor 3 is disclosed as 
positioned in conduit 1 for the fluids to contact as a primary element. 
Spider supports 4 and 5 are in exploded positions relative to the shaft of 
rotor 3. The spider supports are moved to these exploded positions to 
avoid a clutter of such auxiliary structure about the rotor 3. 
It is well established that a magnetic pick-up unit is conventionally 
mounted at the periphery of the tips of the blades of rotor 3. The pick-up 
establishes magnetic lines of force which are cut by each rotating blade 
of rotor 3. As each blade cuts the magnetic lines of force, the pick-up 
generates an output pulse. 
The blades of rotor 3 rotate in a plane which is normal to the fluid flow 
path. Further, each blade is shaped, and positioned on the hub of rotor 3, 
so that its cross-section is at an angle to the plane or rotation. Each 
blade cross-section is also at an angle to the axis of hub rotation. 
Therefore, the impact of fluid flowing along the conduit 1 exerts force on 
the face of the blades with a vector which rotates the blades and their 
rotor 3. This structure and function is elementary to one skilled in the 
art, but it is reviewed to emphasize the angle at which the blades slice 
the magnetic field of the pick-up unit. It is this angle which the present 
invention utilizes in producing its new result. 
The present invention is embodied in two magnetic pick-up units mounted at 
the periphery of the blade tips of rotor 3 so that each blade will cause 
the pick-up units to generate output pulses in sequence. A crude 
description of the relationship between pick-up units and blade is that 
one unit is pulsed before the other. With the alignment of the pick-up 
units and the blade angle known, the direction of rotor rotation will be 
known when the sequence in which the pick-up units are actuated is 
detected. 
Now pick-up units 6 and 7 are aligned in the direction which will give a 
definite time between their actuations, or pulsing, by each blade. They 
could be arranged in the plane of rotor 3 rotation. However, aligning the 
units with the axis of rotor 3 brings them closer to the blade tips and 
generates stronger pulses. 
However the units 6 and 7 are aligned, it is important that they do not 
require variations in the dimensions of single well, or bore, 8. Units 6 
and 7 are sized to fit into the cavity, or well, already provided for a 
single pick-up unit. Thus, no change is required in this standard mounting 
provision. 
The remaining problem is provision of a circuit which will respond, as 
desired, to the output pulses generated by 6 and 7. In general, electronic 
gates are readily designed to connect to both pick-up units and receive 
their trains of pulses. Further, a sensing circuit responds to the two 
pulse trains and controls the gates to fix the sequence in which the gates 
will pass the pulses. Two outputs will then be estabished from the gates. 
One of the outputs will be a train of pulses representative of the pulses 
generated by one of the pick-up units when the flow is in a first 
direction through the conduit 1. The other of the outputs will be a second 
train of pulses representative of the pulses generated by the second of 
the pick-up units when the flow is in the second direction through the 
conduit. Each of the pulse trains can alternately actuate a counter or 
each train can actuate a separate counter. 
In FIG. 1, the gates, and phase sensing circuit is represented as embodied 
in 9. The separate pulse trains alternately flow outward as indicated by 
arrows 10 and 11. Both pulse trains are indicated as actuating the single 
counter 12. 
ELECTRICAL CIRCUIT 
In FIG. 2, the relation between the pick-up units 6 and 7, the elements of 
the lead/lag phase sensing and gates of 9 and the scalers and register 12 
are shown in more detail to insure the disclosure is complete. In FIG. 2 
the pick-up units are represented by small coils at 6 and 7. The 
connections and electronic units which are required in a workable system 
have been abbreviated. However, enough is disclosed to make the operation 
understandable to one skilled in this art. 
Imagination is depended upon to coordinate how coils 6 and 7 of FIG. 2 
operate with the blades of rotor 3. The final result of each blade cutting 
the lines of magnetic force of the coils 6 and 7 is the generation of 
pulses of voltage. One pulse is generated a finite time before the other 
pulse. 
There is much electronic gear to shape and size the pulses 15 and 16. 
However, the pulses are represented just above lines 17 and 18 in more or 
less their final, processed form. They are abruptly generated, of uniform 
and consistent magnitude and terminated abruptly. They may be termed 
"square wave" pulses. A time, base line, 20 is vertically drawn to give 
positive emphasis that one pulse is generated before the other. 
Those skilled in the art are familiar with the basic circuit arrangement. 
Electronic gates 21, 22 are disclosed within circuit 9. Line 17 routes the 
pulses, represented by pulse 15, directly from pick-up coil 6 to one of 
the two inputs of each of gates 21 and 22. Meanwhile, the pulses, 
represented by pulse 16, from pick-up coil 7, are routed to the 2-bit 
shift register 23. 
Pulse 16 is inverted by electronic unit 24. To be absolutely sure of being 
understood, pulse 15a and pulse 16a are disclosed in relation to time, 
base line 20a. Pulse 16a is inverted by unit 24 but is otherwise fixed in 
its relation to 15a. 
The pulses represented by 16a are routed into 2-bit shift register 23. 
Oscillator, or clock 25 is connected to the register 23. The clock 25 
scans the pulses routed to the register and passes them to the gates 
21,22. As pulse 16a is inverted relative to pulse 15a, the read-out of 
register 23 by clock 25 will determine which of gates 21,22 the pulses 
will pass to the scaler which are connected to the gates by lines 10 and 
11. 
One scaler, or the other, will receive the pulse train from the gates 
21,22. Which pulse leads the other pulse determines whether gate 10 or 
gate 11 will pass a pulse train to register 12. The lead/lag relation of 
the pulses will be established by the direction rotor 3 turns. The 
lead/lag of the pulses will determine which gate passes the pulse trains 
to register 12. The register 12 will be actuated in one direction by gate 
10 pulses and in the other direction by gate 11 pulses. Therefore, the 
flow in one direction will add to the reading of register 12 and the flow 
in the other direction will subtract from the register 12 reading. 
CONCLUSION 
The disclosed system measures the flow of fluid in a path. The system 
determines which direction the fluid flows in the path and the quantity of 
fluid that flows in each direction. A turbine meter responds to the flow 
and two magnetic pick-up units are mounted so each blade will generate a 
pair of pulses with the two pick-up units. The two pulses will be 
generated at different times. The system will determine which pulse is 
generated first and therefore which direction the fluid flows. A pair of 
electronic gates is connected to both pick-up units. A sensing circuit 
inverts the pulses of one pick-up unit and uses a clock to read out these 
pulses from a 2-bit shift register to the electronic gates. This control 
thereby routes the pulse train of the pick-up units through the gate which 
is related to one of the two directions of flow. The alternate flow will 
be evidenced by the change in the lead/lag relation of the pulses and the 
read-out of inverted pulses will be routed through the second of the 
gates. 
The end result is two different pulse trains to the same register. The one 
pulse train actuates the register in one direction, and the other pulse 
train actuates the register in the other direction. 
From the foregoing, it will be seen that this invention is one well adapted 
to attain all of the ends and objects hereinabove set forth, together with 
other advantages which are obvious and inherent to the apparatus. 
It will be understood that certain features and subcombinations are of 
utility and may be employed without reference to other features and 
subcombinations. This is contemplated by and is within the scope of the 
invention. 
As many possible embodiments may be made of the invention without departing 
from the scope thereof, it is to be understood that all matter herein set 
forth or shown in the accompanying drawings is to be interpreted in an 
illustrative and not in a limiting sense.