Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 1 of 23 PageID #: 3781
`Case 6:12—cv—00799—JRG Document 124-6 Filed 03/07/14 Page 1 of 23 Page|D #: 3781
`
`EXHIBIT 6
`
`EXHIBIT 6
`
`
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 2 of 23 PageID #: 3782
`
`United States Patent [t9J
`Smith
`
`[54} METHOD AND STRUCfURE FOR FLOW
`MEASUREMENT
`Inventor:
`James E. Smith, Boulder, Colo.
`
`(75]
`[73] Assignee: Micro Motion, Inc., Boulder, Colo.
`
`[21] Appl. No.: 348,071
`Feb. 11, 1982
`[22] Filed:
`
`Related U.S. Patent Documents
`
`Reissue of:
`Patent No.:
`(64]
`Issued:
`Appl. No.:
`Filed:
`
`4,187,721
`Feb. 12, 1980
`926,468
`Jul. 20, 1978
`
`[56]
`
`. U.S. Applications:
`(63] Continuation-in-part of Ser. No. 818,475, Jul. 25, 1977,
`abandoned.
`Int. CJ,l ................................................ GOlF 1/86
`[51]
`(52] U.S. CI. ................................ .... 73/861.38; 73/434
`(58] Field of Search .......... 73/32 A, 434, 505, 861.18,
`73/861.35, 861.37, 861.38
`References Cited
`U.S. PATENT DOCUMENTS
`2,624,198 1/1953 Pearson .
`2,635,462 4/1953 Poole et al. ............................. 73/32
`2,753,173 7/1956 Barnaby et al. ........................ 264/1
`2,754,676 7/1956 Poole et al. ............................. 73/32
`2,804,771 9/1957 Brown ................................... 73/228
`2,811,854 11/1957 Powers .
`2,813,423 11/1957 Altfillisch et al ..
`2,821,084 1/1958 Altfillisch et al ..
`2,831,349 4/1958 Altfillisch et al. .
`2,834,209 5/1958 Jones et al. .
`2,865,201 12/1958 Roth .
`2,877,649 3/1959 Powers .
`2,889,702 6/1959 Brooking ................................ 73/32
`2,897,672 8/1959 Glasbrenner et al. ................ 73/228
`2,914,945 12/1959 Cleveland .
`2,923,154 2/1960 Powers et al .
`2,934,951 5/1960 Li .
`2,943,476 7/1960 Bernstein ................................ 73/32
`2,943,487 7/1960 Potter .
`2,956,431 10/1960 Westerheim ............................ 'Z3/32
`3,039,310 6/1962 Copland et al. ...................... 73/434
`
`.
`
`Re. 31,450
`(II) E
`(45) Reissued Nov. 29, 1983
`
`3,044,302 7/1962 .Knauth .................................. 73/434
`3,049,917 8/1962 Alspach et al. .
`3,049,919 8/1962 Roth ...................................... 73/228
`3,080,750 3/ 1963 Wiley et al ..
`3,087,325 4/1963 Roth .......................................... 73/ 3
`3,096,646 7/1963 Peirce .................................... 73!228
`3,108,475 10/1963 Henderson .
`3,132,512 5/1964 Roth .
`3,138,955 6/1964 Uttley .
`3,164,017 1/1965 Karlby et al. .
`3,167,691 1/1965 Halista ................................. 317/157
`3,218,851 11/1965 Sipin .
`3,232,110 2/1966 Li .
`3,251,226 5/1966 Cushing ....................... 73/ 861.63 X
`3,261,205 7/1966 Sipin .
`3,276,257 10/1966 Roth .
`3,276,258 10/1966 Rowley .
`3,298,221 1/1967 Miller et a1 ............................. 73/32
`3,303,705 2/ 1967 Dostal ... .................................. 73/ 505
`3,320,791 5/1967 Banks ...................................... 73/32
`3,329,019 7/1967 Sipin .
`3,339,400 9/1967 Banks ...................................... 73/32
`3,344,666 10/ 1967 Rilett .
`3,349,604 10/1967 Banks ...................................... 73/32
`3,350,936 11/1967 Li .
`3,355,944 12/1967 Sipin .
`3,385,104 5/1968 Banks .
`3,396,579 8/1968 Saurian .
`3,449,940 6/1969 Banks ...................................... 73/32
`3,449,941 6/1969 Banks ...................................... 73/ 32
`3,456,491 7/1969 Brockhaus .............................. 73/32
`3,481,509 12/1969 Marhauer .
`3,485,098 12/ 1969 Sipin .
`3,533,285 10/1970 Dee .
`3,555,900 1/1971 Bauer et al. .
`3,575,052 4/1971 Lenker .
`3,584,508 6/1971 Shiba .
`3,589,178 6/1971 Germann .
`3,608,374 9/197l Miller .
`3,613,451 10/1971 Scott .
`3,625,055 12/1971 LaFourcade .
`3,677,086 7/ 1977 Corey .
`3,688,574 9/1972 Arutunian et al. .
`3, 728,893 4/1973 Janssen .................................... 73/32
`3,740,586 6/1973 Banks et al. .
`3,762,217 10/1973 Hagen .
`3,839,915 10/1974 Schlitt .
`3,842,681 10/1974 Mumme .
`3,876,927 4/1975 Gee et al ..
`3,897,766 8/1975 Pratt, Jr. et al. .
`3,927,565 12/1975 Pav1in et al. .
`
`MM0634666
`
`

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`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 3 of 23 PageID #: 3783
`
`Re. 31,450
`
`Page 2
`
`3,955,401 5/1976 Catherall ............................ 73/ 32 A
`4,051,723 10/ 1977 Head eta! ..
`4,056,976 11/1977 Hildebrand .
`4,109,524 8/1978 Smith .
`4,127,028 11!1978 Cox et al .......................... 73/861.38
`
`FOREIGN PATENT DOCUMENTS
`2249269 4/1974 Fed. Rep. of Germany .
`2145387 2/1975 France .
`32-6595 8/1957 Japan .
`44-18531 8/1969 Japan .
`46-19~27 6/1971 Japan .
`117091 5/1958 U.S.S.R.
`146982 4/1961 U.S.S.R.
`149900 11/ 1961 U.S.S.R.
`159678 12/1963 U.S.S.R.
`171651 5/1965 U.S.S.R.
`400838 10/1973 U.S.S.R ..
`426170 4/1974 U.S.S.R ..
`486247 9/ 1975 U.S.S.R . .
`
`OTHER PUBLICATIONS
`A. Treatise; Continuous Measurement of Unsteady Flow,
`by G. P. Katys, translated from the Russian by D. P.
`Barrett, MacMillan Company, New York, 1964.
`Primary Examiner-Jerry W. Myracle
`Attorney, Agent, or Firm-Irons & Sears
`
`ABSTRACT
`[57]
`Apparatus and method for mass flow measurement
`utilizing a substantially "U" shaped conduit mounted in
`a cantilever manner at the legs thereof, [means for
`oscillating the conduit, and means for measuring] so
`that, when the conduit is oscillated, sensors mounted on the
`conduit can measure the Coriolis force by measurement
`of the force moment or the angular motion of the con(cid:173)
`duit around an axis substantially symmetrical to the legs
`of the conduit. The force moment is measured by sens(cid:173)
`ing incipient movement around the axis, and generating
`and measuring a nulling force. In preferred embodi(cid:173)
`ments, the oscillating means are mounted on a spring
`arm having a natural frequency substantially equal to
`that of the "U" shaped conduit, and in a particularly
`preferred [displacement] embodiment the measuring
`(means are sensors] sensors are mounted on the "U"
`shaped conduit and adapted to measure, with proper
`direction sense, the time differential between the lead(cid:173)
`ing and trailing portions of the "U" shaped conduit
`passing through the plane of the "U" shaped conduit at
`substantially midpoint of the oscillation thereof.
`
`55 Claims, 14 Drawing Figures
`
`MM0634667
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 4 of 23 PageID #: 3784
`
`U.S. Patent
`
`Nov. 29, 1983
`
`Sheet 1 of 4
`
`Re. 31,450
`
`10
`
`/w
`
`/
`
`DRIVE
`CIRCUIT
`
`27
`
`9 E. i
`
`+E-
`
`Fig. 2
`
`:::-14
`
`----?+19
`
`READOUT
`CIRCUIT
`
`33
`
`Fig. 4
`
`MM0634668
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 5 of 23 PageID #: 3785
`
`U.S. Patent
`
`Nov. 29, 1983
`
`Sheet 2 of 4
`
`Re. 31,450
`
`r--------- ---- ------- --- ------ -- - - --- - --.,
`
`,..---t-=-f' 24
`
`--------- T--- - -- -- -- -- ----------- - - - - - - -- -~
`Fig. 5
`27 _ _,
`
`I
`
`19
`
`s -.,.
`A~~A
`
`0
`r - -
`I
`
`44 0
`:~
`- - - - - - - - - - - -
`-
`- -
`
`- - - - - - - -
`67
`
`-
`
`33--·1
`- - - - - - - - -
`
`- - - -
`
`- - .-
`
`- - - - ..
`
`92
`
`SENSOR 43--' I
`
`SENSOR 44
`
`I
`
`DOWNCOUNT-x
`UP COUNT
`
`SENSOR 43 __J
`
`SENSOR 44
`
`OOWNCOUNT __J
`
`UP COUNT
`
`I I
`
`II
`I
`
`I I
`
`I g.
`
`.
`
`I
`
`Fig. 8
`
`IL_
`rt FT7 * T *=
`ll-
`.
`L
`L * I *
`
`I I'
`.
`
`I I I
`.
`
`II
`
`I
`
`I
`
`I
`
`I
`
`MM0634669
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 6 of 23 PageID #: 3786
`
`U.S. Patent
`
`Nov. 29, 1983
`
`Sheet 3 of 4
`
`Re. 31,450
`
`162
`
`120
`
`SYNCHRONOlJS
`DEMODULATOR
`
`D.C. OUTPUT
`PROPORTIONAL TO MASS
`FLOW RATE
`
`157
`
`I~
`
`155
`
`SERVO.
`COMP.
`
`Fig. 10
`
`141
`
`MM0634670
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 7 of 23 PageID #: 3787
`
`U.S. Patent
`
`Nov. 29, 1983
`
`Sheet 4 of 4
`
`Re. 31,450
`
`188
`
`200
`
`B
`
`FiQ. II
`
`-
`
`Pipe
`~--...;__--(A
`Velocity
`
`211
`
`Fig. 12
`
`Fig.
`
`225
`Fig. 14
`
`.....__~Pi~pe::-:-----i A
`Velocity
`
`,
`
`--162
`
`235
`
`I
`I
`L -
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`.-.- - _j
`
`MM0634671
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 8 of 23 PageID #: 3788
`
`1
`
`Re. 31,450
`
`METHOD AND STRUCI'URE FOR FLOW
`MEASUREMENT
`
`Matter enclosed in heavy brackets [ ] appears in the 5
`original patent but forn:.s no part of this reissue specifica(cid:173)
`tion; matter printed in italics indicates the additions made
`by reissue.
`
`2
`Coriolis forces are quite small compared to the driving
`forces and, accordingly, it is quite difficult to accurately
`measure such small forces in the context of the large
`driving force.
`Still another measurement means is described by
`Sipin at column 7, lines [I through 23] 1/ through
`Column 8, line 16 of U.S. Letters Pat. No. 3,485,098. In
`this arrangement velocity sensors independent of the
`driving means are mounted to measure the velocity of
`10 the conduit as a result of the distortion of the conduit
`BACKGROUND OF THE INVENTION
`caused by Coriolis forces. While there may be worth-
`1. Field of the Invention
`while information obtained by such measurements, ve-
`The present invention relates generally to a flow
`measuring device, and more particularly to a flow mea-
`locity sensors require measurement of a minute differen-
`tial velocity superimposed upon the very large pipe
`suring device in the form of a "U" shaped conduit
`mounted in beamlike, cantilevered, fashion and ar-
`IS oscillation velocities. Thus an entirely accurate [deter-
`minate] determination of the gyroscopic force must
`ranged to determine the density of a fluid material in the
`deal with velocity measurements under limited and
`conduit, the mass flow rate therethrough, and accord-
`ingly other dependent flow parameters.
`specialized conditions as discussed below. Mathemati-
`cal analysis confirms that velocity measurements pro-
`2. Description of the Prior Art
`Heretofore, flow meters of the general type with 20 vide at best marginal results.
`which the present invention is concerned have been
`If the Coriolis force is not to produce movements of
`known as gyroscopic mass flow meters, or Coriolis
`great amplitude, clearly, as a basic precept of physics, a
`force mass flow meters. In essence, the function of both
`reactive force, or forces, must oppose the Coriolis
`types of flow meters is based upon the same [princi-
`force. Put simply, the Coriolis force, particularly in the
`pal] principle.
`flow meter arrangements permitting distortion of the
`Viewed in a simplified manner, Coriolis forces in-
`conduit (a qualification which will be explained below),
`volve the radial movement of mass from a first point on
`is opposed by, stated simply, the spring resistance of the
`a rotating body to a second point. As a result of such
`conduit itself as it distorts, plus velocity forces resulting
`movement, the peripheral velocity of the mass changes, 30 from movement of the conduit, i.e., air drag, etc. -usu(cid:173)
`i.e., the mass is accelerated. The acceleration of the
`ally a small component -and an inertial component
`mass generates a force in the plane of rotation and per-
`resulting from the acceleration of the mass of the con-
`pendicular to the instantaneous radial movement. Such
`duit. It is a complex endeavor to concurrently measure
`forces are responsible for precession in gyroscopes.
`Several approaches have been taken in utilizing Cori-
`and sum all three of these opposing forces. Accord-
`otis forces to measure mass flow. For instance, the early 35 ingly, it is understandable that Sipin measures but one of
`Roth U.S. Letters Pat. Nos. 2,865,201 and [3,312,512]
`the forces, i.e., velocity[, forces] . Given the rather
`3,132,512 disclose gyroscopic flow meters employing a
`involved and marginally accurate conventional mass
`full loop which is continuously rotated (DC type) or
`flow measuring devices utilizing, for instance, indepen-
`oscillated (AC type).
`dent densities and flow [velocities] velocity sensors, it
`Another flow meter utilizing substantially the same 40 is understandable that measurement of a single opposing
`force such as velocity by Sipin would produce useful
`forces but avoiding reversal of flow by utilizing a Jess
`than 180" "loop" is described in Sipin U.S. Letters Pat.
`though compromised information. If only velocity re-
`No. 3,485,098. In both instances, the devices are of the
`lated reactive forces are to be measured, the other nor-
`so called AC type, i.e., the conduit is oscillated around
`mally more substantially reactive forces should be mini-
`an axis and fluid flowing through the conduit flows first 45 mized. This is not the case in the apparatus illustrated by
`Sipin. No discussion of this critical consideration is to
`away from the center of rotation and then towards the
`center of rotation thus generating Coriolis forces as a
`be found.
`function of the fluid mass flow rate through the loop.
`Another approach to the problem of measuring the
`Since there is but one means of generating Coriolis
`small Coriolis forces is described in my U.S. Letters
`forces, all of the prior art devices of the gyroscopic and 50 Patent Application Ser. No. 591,907, for "METHOD
`Coriolis force configurations generate the same force,
`AND APPARATUS FOR MASS FLOW MEA-
`but specify various means for measuring such forces.
`SUREMENT", filed June 30, 1975 now U.S. Pat. No.
`Thus, though the concept is simple and straightforward,
`[ 4,109,529] 4, 109,524.
`practical results in the way of accurate flow measure-
`In an embodiment of my prior approach, rather than
`ment have proven elusive.
`55 attempting to measure the opposing forces to the Corio-
`For instance, the Roth flow meters utilize transducers
`lis forces, all of which are dependent upon displacement
`or gyroscopic coupling as readout means. The gyro-
`of the conduit, I describe an arrangement in which a
`scopic coupling is described in Roth as being complex,
`mechanical nulling force, i.e., an opposing force which
`and transducers are defined as requiring highly flexible
`precludes displacement, is produced. Accordingly, any
`conduits, such as bellows. The latter mentioned Roth 60 infinitesimal incremental displacement of the conduit is
`patent is primarily concerned with the arrangement of
`sensed and opposing force generated. By measuring the
`such flexible bellows.
`opposing force, which replaces the inherent opposing
`Another classical approach for measuring the force
`forces described above, an accurate measurement of the
`proportional to mass flow involve first driving or oscil-
`mass flow may be made, though at the complication of
`lating a conduit structure through a rotational move- 65 avoiding spurious measurements of forces resulting
`ment around an axis, and then measuring the additional
`from driving the conduit. My application described two
`energy required to drive such conduit as fluid [is
`independent means for avoiding such complicating
`flowed] flows through the conduit. Unfortunately, the
`forces, i.e., balancing the forces on opposite sides of a
`
`25
`
`MM0634672
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`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 9 of 23 PageID #: 3789
`
`Re. 31,450
`
`3
`beam to cancel the forces and measuring the Coriolis
`force at maximum angular velocity when driving accel(cid:173)
`eration forces and bellows spring forces are zero. The
`balancing approach in conjunction with nulling re(cid:173)
`quired relatively slow operation to accomodate the 5
`response time of the mechanical beam.
`In summary, numerous attempts have heretofore
`been made to measure mass flow as a function of the
`Coriolis forces generated by mass flow through an os(cid:173)
`cillating conduit. However, accurate measurements
`have been possible only when the conduit displacement
`is nulled while balancing [theacceleration] the accel(cid:173)
`eration forces due to driving the conduit, and only ap(cid:173)
`proximate measurements made when the conduit is
`allowed to distort against inherent restoration forces
`such as spring resistance in the conduit, velocity drag
`factors and inertia while making such measurements.
`
`4
`Accordingly, it is an object of the present invention
`to provide a new and improved apparatus and method
`for measuring mass flow which provides highly accu(cid:173)
`rate measurement with simple, low cost construction.
`Another object of the present invention is to provide
`a new and improved apparatus for measuring mass flow
`which is substantially insensitive to pressure difference
`between ambient pressure and the fluid being measured.
`Yet another object of the present invention is to pro-
`10 vide a new and improved apparatus and method for
`measuring mass flow which measures substantially all of
`the displacement forces generated by Coriolis forces.
`Still another object of the present invention is to
`provide a new and improved apparatus and method for
`15 measuring fluid mass flow which is capable of accurate
`measurement of the mass flow of gases.
`Yet still another object of the present invention is to
`provide a new and improved apparatus and method for
`measuring mass flow which is capable of accurately
`determining the mass flow of fluidized mixtures of
`solids and gases.
`Still yet another object of the present invention is to
`provide a new and improved apparatus and method for
`measuring fluid flow substantially independent of pres(cid:173)
`sure, temperature and viscosity variations.
`
`SUMMARY OF THE INVENTION
`The present invention, which provides a heretofore 20
`unavailable improvement over previous mass flow mea(cid:173)
`suring devices, comprises a substantially continuous
`"U" shaped tube mounted in beam-like fashion, i.e.,
`without flexible or separate pivoting sections, means for
`oscillating the conduit and means for measuring the 25
`resulting Coriolis force by measuring the force moment
`due to the Coriolis forces, or the angular distortion of
`the conduit as a result of such Coriolis forces. Prefera(cid:173)
`bly, the [oscillatiogn] oscillation means are mounted
`on a separate arm having a natural frequency substan- 30
`tially that of the "U" shaped tube. Accordingly, the two
`members oscillate in opposite phase similar to the man(cid:173)
`ner in which the tines of a tuning fork oscillate and like
`a tuning fork, cancel vibrations at the support. In a
`particularly preferred embodiment, the distortion of the 35
`"U" shaped conduit is measured by sensors positioned
`adjacent the intersections of the base and legs of the
`conduit which measure the time lag between the lead(cid:173)
`ing and trailing edges of the conduit passing through the
`nominal central point of oscillation as a result of distor- 40
`tion by the Coriolis forces. This arrangement avoids the
`need to control the frequency and/or amplitude of os(cid:173)
`cillation.
`The cantilevered beam-like mounting of the "U"
`shaped conduit is of more than passing significance. In 45
`the instance in which distortion is measured, such
`mounting provides for the distortion resulting from the
`Coriolis forces to be offset substantially entirely by
`resilient deformation forces within the conduit free of
`mechanical pivot means other than flexing of the con- 50
`duit. By minimizing [draft] drag and inertial inputs,
`measurement of but one of the three opposing forces
`generates highly accurate determinations. Thus rather
`than compromising the accuracy of the flow meters by
`measuring but one of the opposing forces, the method 55
`and apparatus of the present invention is specifically
`structured to minimize or obviate the forces generated
`by the two non-measured opposing forces, i.e., velocity
`drag and acceleration of mass. This effort has been
`successful to the point where such forces are present in 60
`cumulative quantities of less than 0.2% of the torsional
`spring force. Also, by mounting the conduit in a beam(cid:173)
`like fashion, which pivots by beam bending, the need
`for bellows and other such devices which are reactive
`to the differences in pressure between the conduit and 65
`ambient pressure are entirely avoided. Pivoting is ac(cid:173)
`complished free of pressure sensitive, separate pivot
`means.
`
`BRIEF DESCRIPTION OF THE ORA WINGS
`In the drawings:
`FIG. 1 is a perspective view of a fluid flow meter
`according to one embodiment of the present invention;
`FIG. 2 is an end view of the flow meter of FIG. 1
`illustrating oscillation at midpoint under no flow condi(cid:173)
`tions;
`FIG. 3 is an end view of the flow meter of FIG. 1
`illustrating oscillation at midpoint in the up direction
`under flow conditions;
`FIG. 4 is an end view of the flow meter of FIG. 1
`illustrating oscillation at midpoint in the down direction
`under flow conditions;
`FIG. 5 is a block diagram drawing of the drive circuit
`of the flow meter of FIG. 1;
`FIG. 6 is a logic diagram of the readout circuit of the
`flow meter of FIG. 1;
`FIG. 7 is a timing diagram of the readout signals of
`the flow meter of FIG. 1 under no flow conditions;
`FIG. 8 is a timing diagram of the readout signal of the
`flow meter of FIG. 1 with flow through the conduit;
`FIG. 9 is a simplified perspective view of a fluid flow
`meter according to another embodiment of the present
`invention.
`FIG. 10 is a circuit diagram of the drive and readout
`portion of the flow meter of FIG. 9, with the exception
`of the distortion sensing portion of the circuit;
`FIG. 11 is a circuit diagram of one distortion sensing
`arrangement suitable to generate the signal labeled B in
`FIG. 10;
`FIG. 12 is another circuit diagram for a purpose
`identical to that of FIG. 11;
`FIG. 13 is yet another circuit diagram for a purpose
`identical to that of FIG. 11; and
`FIG. 14 is a typical circuit diagram of the synchro(cid:173)
`nous demodulator of FIGS. 10, 12 and 13.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`Turning now to the drawings, wherein like compo(cid:173)
`nents are designated by
`like
`reference numerals
`throughout the various figures, a flow meter device
`
`MM0634673
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`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 10 of 23 PageID #: 3790
`
`Re. 31,450
`
`5
`according to a first embodiment of the present invention
`is illustrated in FIG. 1 and generally designated by
`reference numeral 10. Flow meter 10 includes fixed
`support 12 having "U" shaped conduit 14 mounted
`thereto in a cantilever, beam-like fashion. "U" shaped 5
`conduit 14 is preferably of a tubular material having
`resiliency such as is normally found in such materials
`such as beryllium, copper, tempered aluminum, steel,
`plastics, etc. Though described as "U shaped", conduit
`14 may have legs which converge, diverge, or are 10
`skewed substantially. A continuous curve is contem(cid:173)
`plated. Preferably, "U" shaped conduit 14 includes inlet
`15 and outlet 16 which in turn are connected by inlet leg
`18, base leg 19 and outlet leg 20. Most preferably, inlet
`leg 18 and outlet leg 20 are parallel, and base leg 19 is 15
`perpendicular to both; but, as mentioned above, sub(cid:173)
`stantial deviations from the ideal configuration, i.e., 5o
`convergence or divergence do not appreciably compro(cid:173)
`mise results. Operable results may be obtained with
`even gross deviations on the order of 30° or 40°, but, 20
`since little is gained from such deviations in the embodi(cid:173)
`ment of concern, it is generally preferred to maintain
`inlet leg 18 and outlet leg 20 in a substantially parallel
`relationship. Conduit 14 may be in the form of a contin(cid:173)
`uous or partial curve as is convenient.
`Though the physical configuration of "U" shaped
`conduit 14 is not critical, the frequency characteristics
`are important. It is critical in the embodiment of FIG. 1
`which permits distortion that the [resonent] resonant
`frequency around axis W-W be different than that 30
`around axis 0-0, and most preferably that the reso(cid:173)
`nant frequency [abut] about axis W-W be the lower
`resonant frequency.
`Spring arm 22 is mounted to inlet and outlet legs 18
`and 20, and carries force coil 24 and sensor coil23 at the 35
`end thereof adjacent base leg 19. Magnet 25, which fits
`within force coil 24 and sensor coil 23, is carried by base
`leg 19, Drive circuit 27, which will be discussed in more
`detail below, is provided to generate an amplified force
`in response to sensor coil 23 to drive "U" shaped con- 40
`duit 14 at its natural frequency around axis W-W in an
`oscillating manner. Though "U" shaped conduit 14 is
`mounted in a beamlike fashion to [supports] support
`12, the fact that it is oscillated at resonant frequency
`permits appreciable amplitude to be attained in the 45
`"beam" oscillation mode around axis W-W. "U"
`shaped conduit 14 essentially pivots around axis W-W
`at inlet 15 and outlet 16.
`As a preferable embodiment, first sensor [32] 43 and
`second sensor 44 are supported at the intersections of 50
`base leg 19 and inlet leg 18 and outlet leg 20, respec(cid:173)
`tively. Sensors 43 and 44 which are preferably optical
`sensors, but generally proximity or center crossing sen(cid:173)
`sors, are activated as "U" shaped conduit 14 passes
`through a nominal reference plane at approximately the 55
`mid-point of the "beam" oscillation. Readout circuit 33,
`as will be described below, is provided to indicate mass
`flow measurements as a function of the time differential
`of the signals generated by sensors 44 and 43.
`Operation of flow meter 10 will be more readily un- 60
`derstood with reference to FIGS. 2, 3 and 4, which, in
`a simplified manner, illustrate the basic [principal]
`principle of the instant invention. When conduit 14 is
`oscillated in a no flow condition, inlet leg 18 and outlet
`leg 20 bend at axis W-W essentially in a pure beam 65
`mode, i.e., without torsion. Accordingly, as shown in
`FIG. 2, base leg 19 maintains a constant angular position
`around axis 0-0 throughout the oscillation. However,
`
`6
`when flow is initiated, fluid moving radially from axis
`W-W through inlet leg 18 generates a first Coriolis
`force perpendicular to the direction of flow and perpen-
`dicular to axis W-W while flow in the outlet leg 20
`generates a second Coriolis force again perpendicular to
`the radial direction of flow, but in an opposite direction
`to that of the first Coriolis force since flow is in the
`opposite direction. Accordingly, as shown in FIG. 3, as
`base leg 19 passes through the mid-point of the oscilla(cid:173)
`tion. the Coriolis forces generated in inlet leg 18 and
`outleg leg 20 impose a force couple on "U" shaped
`conduit 14 thereby rotating base leg 19 angularly
`around axis 0-0. The distortion is both a beam bend(cid:173)
`ing distortion and a torsional distortion essentially in
`inlet leg 18 and outlet leg 20. As a result of the choice of
`frequencies and the configuration of "U" shaped con-
`duit 14, essentially all of the resistive force to the Corio(cid:173)
`lis force couple is in the nature of a resilient spring
`distortion, thereby obviating the need to and complica(cid:173)
`tion of measuring velocity drag restorative forces and
`inertial opposing forces. Given a [sustantially] sub-
`stantially constant frequency and amplitude, measure(cid:173)
`ment of the angular distortion of base leg 19 around axis
`0-0 at the nominal midpoint of the oscillation, pro-
`25 vi des an accurate indication of mass flow. This provides
`a substantial improvement over the prior art. However,
`as a most significant aspect of the present invention,
`determination of the distortion of base leg 19 relative to
`the nominal undistorted mid-point plane around axis
`0-0 in terms of the time difference between the in(cid:173)
`stant the leading leg, i.e., the inlet leg in the case of FIG.
`3, passes through the midpoint plane and the trailing
`leg, i.e., the outlet leg in the case of FIG. 3, passes such
`plane, avoids the necessity of maintaining constant fre(cid:173)
`quency and amplitude since variations in amplitude are
`accompanied by compensating variations in the veloc-
`ity of base leg 19. Accordingly, by merely driving "U"
`shaped conduit 14 at its resonant frequency, time mea(cid:173)
`surements may be made in a manner which will be
`discussed in further detail below, without concern for
`[conccurrent] concurrent regulation [or] of frequency
`and amplitude. However, if measurements are made in
`but one direction, i.e., the up direction in FIG. 3, it
`would be necessary to maintain an accurate alignment
`of base leg 19 relative to the nominal midpoint plane.
`Even this requirement may be avoided by, in essence,
`subtracting the time measurements in the up direc tion
`shown in FIG. 3, and in the down direction shown in
`FIG. 4. As is readily recognized by one skilled in the
`art, movement in the down direction, as in FIG. 4,
`reverses the direction of the Coriolis force couple and
`accordingly, as shown in FIG. 4, reverses the direction
`of distortion as a result of the Corio lis force couple.
`Summarily, stated broadly, "U" shaped conduit 14,
`having specified frequency characteristics though only
`general physical configuration characteristics, is merely
`oscillated around axis W-W. Flow through "U"
`shaped conduit 14 induces spring distortion in "U"
`shaped conduit 14 resulting, as a convenient means of
`measurement, in angular movement of base leg 19
`around axis 0-0 initially in a first angular direction
`during one phase of the oscillation, and, then in the
`opposite direction during the other phase of oscillation.
`Though, by controlling amplitude, flow measurements
`may be made by direct measurement of distortion, i.e.,
`strobe lighting the base leg 19 at the midpoint of oscilla-
`tion with, for instance, an analogue scale fixed adjacent
`to end portions and a pointer carried by base leg 19. a
`
`MM0634674
`
`

`
`Case 6:12-cv-00799-JRG Document 124-6 Filed 03/07/14 Page 11 of 23 PageID #: 3791
`
`Re. 31,450
`
`7
`8
`flop 60. Thus, flip-flop 60 would be set upon the output
`preferred mode of measurement involves determining
`of a negative signal from sensor 43, and reset upon the
`the time difference between the [instance] instants in
`subsequent output of a negative signal from sensor 44.
`which the leading and trailing edges of the base leg 19
`The output of flip-flop 54 is connected through line 63
`move through the midpoint plane. This avoids the need
`to control amplitude. Further, by measuring the up 5 to a logic gate such as AND gate 64. AND gates 64 and
`oscillation distortions and the down oscillation distor-
`66 are both connected to the output of oscillator 67 and,
`tions in the time measurement mode, anomalies result-
`accordingly, upon output from flip-flop 54, the signal
`ing from physical misalignment of "U" shaped conduit
`from oscillator 67 is gated through AND gate 64, to line
`14 relative to the midpoint plane are cancelled from the
`68 and thus to the downcount side of up-down counter
`to 70. Similarly, upon the output of a signal from flip-flop
`measurement results.
`The essentially conventional -given the above dis-
`60, the output of oscillator 67 is gated through AND
`cussion of the purposes of the invention -electronic
`gate 66 to line 69 connected to the upcount side of
`aspects of the invention will be more readily understood
`updown counter 70.
`with reference to FIGS. 5 through 8.
`Thus, in function, readout circuit 33 provides a
`As shown in FIG. 5, drive circuit 27 is a simple means IS downcount signal at the frequency of oscillator 67 to
`updown counter 70 for the period during which sensor
`for detecting the signal generated by movement of mag~
`net 25 in sensor coil 23. Detector 39 compares the volt-
`44 is activated prior to activation of sensor 43 during the
`age provided by sensor coil 23 with reference voltage
`down motion of "U" shaped conduit 14, while an up-
`37. As a result, the gain of force coil amplifier 41 is a
`count signal is provided to up-down counter 70 for the
`function of the velocity of magnet 25 within sensor coil 20 period during which sensor 43 is activated prior to
`23. Thus, the amplitude of the oscillation of "U" shaped
`activation of sensor 44 during the up motion of "U"
`conduit 14 is readily controlled. Since "U" shaped con-
`shaped conduit 14.
`duit 14 and spring arm 22 are permitted to oscillate at
`The significance of readout circuit 33 will be more
`their resonant frequencies, frequency control is not
`readily appreciated with reference to the timing dia-
`required.
`25 gram of FIG. 7 and FIG. 8. In FIG. 7, wave forms are
`The circuitry of FIG. 5 provides additional informa-
`illustrated for the condition in which "U" shaped con-
`lion. The output of force coil amplifier 41 is a sinusoidal
`duit 14 is oscillated in a no-flow condition, but in which
`signal at the resonant frequency of "U" shaped conduit
`flags 44 and 46 a