Volume gas meter

Claim 2

Volume meter for producing more accurate representations of the volume flow rate of a metered compressible fluid, comprising a first shaft for rotating at a first speed representative of volume flow rate of the metered fluid, a second shaft, slip connecting means between the first shaft and the second shaft for causing the second shaft to rotate at a second speed functionally related to the first speed, and means for braking the second shaft, the slip connecting means and the braking means being such that the second speed varies in reverse to the temperature of the metered fluid to compensate for any variation of the first speed as a result of a temperature caused density variation of the metered fluid, whereby the second speed provides a representation of the flow rate of the metered fluid which is corrected for variations of density thereof with temperature changes.

Claim 3

Volume meter according to claim 1, wherein the slip connecting means comprises at least one rotatable permanent magnet which is mechanically coupled to one of said shafts to create a rotatable magnetic field and a metallic disk which is mechanically coupled to the other of said shafts and is disposed in the magnetic field so that currents may be induced therein upon rotation of said first shaft.

Claim 4

Volume meter according to claim 2 wherein the permanent magnet is rigidly secured to the first shaft.

Claim 5

Volume meter according to claim 2 wherein the metallic disk has a resistivity whose temperature coefficient is equal to the temperature coefficient of the fluid.

Claim 6

Volume meter according to claim 2 wherein the disk is made of a non-ferromagnetic metal.

Claim 7

Volume meter according to claim 1 wherein the braking means comprises a permanent magnet and a metallic disk which is secured to the second shaft, a circular portion of the disk rotating between the poles of the permanent magnet.

Claim 8

Volume meter according to claim 6 wherein the disk is made of a non-ferromagnetic metal.

Claim 9

Volume meter according to claim 1 wherein the braking means and slip connecting means are enclosed in an envelope adapted for communicating with the fluid.

Claim 10

A volume meter of a compressible fluid having an output shaft rotating at a speed omega 1 proportional to the volume flow rate of the fluid and further comprising a second shaft rotating at a speed omega 2, magnetic slip connecting means coupliNg the output shaft to the second shaft, eddy current magnetic means for braking the second shaft, the magnetic slip connecting means comprising first permanent magnet means providing a flux phi 1 secured to one of said shafts and a first non-ferromagnetic metal circular member of resistivity Rho 1 which is secured to the other of said shafts and is in magnetic relationship with said first permanent magnet means, the eddy current magnetic means comprising a second non-ferromagnetic metal circular member of resistivity Rho 2 and second permanent magnet means of flux phi 2, one of said second circular member and permanent magnet means mounted to said second shaft and movable with respect to the other, the permanent magnet means of the magnetic slip connecting means and of the eddy current magnetic means including one or more thermomagnetic shunts which, in combination with the values of the resistivities Rho 1 and Rho 2 are chosen such that ( phi 1/ phi 2)2( Rho 2/ Rho 1) varies inversely proportional to the absolute temperature.

Claim 11

A volume meter of a compressible fluid having an output shaft rotating at a speed omega 1 proportional to the volume flow rate of the fluid and further comprising a second shaft rotating at a speed omega 2, magnetic slip connecting means coupliNg the output shaft to the second shaft, eddy current magnetic means for braking the second shaft, the magnetic slip connecting means comprising first permanent magnet means providing a flux phi 1 secured to one of said shafts and a first non-ferromagnetic metal circular member of resistivity Rho 1 which is secured to the other of said shafts and is in magnetic relationship with said first permanent magnet means, the eddy current magnetic means comprising a second non-ferromagnetic metal circular member of resistivity Rho 2 and second permanent magnet means of flux phi 2, one of said second circular member and permanent magnet means mounted to said second shaft and movable with respect to the other, the permanent magnet means of the magnetic slip connecting means and of the eddy current magnetic means including one or more thermomagnetic shunts which, in combination with the values of the resistivities Rho 1 and Rho 2 are chosen such that ( phi 1/ phi 2)2( Rho 2/ Rho 1) varies inversely proportional to the absolute temperature.

Claim 12

Volume meter of a compressible fluid having an output shaft for rotating at a first speed representative of the volume flow of the fluid and further comprising a second shaft, magnetic driving means coupling the output shaft to the second shaft to drive the second shaft at a second speed, magnetic means for braking the second shaft, the magnetic and electrical characteristics of said driving and braking means being selected so that the ratio of the second speed to the first speed varies with temperature of the fluid as a reciprocal function of the temperature according to a law which compensates for variation of the density of the fluid with the temperature thereof, whereby the speed of said second shaft may provide a representation of the volume flow of a compressible fluid corrected for variations of fluid density with temperature.

Claim 13

Volume meter of a compressible fluid having an output shaft for rotating at a first speed representative of the volume flow of the fluid and further comprising a second shaft, magnetic driving means coupling the output shaft to the second shaft to drive the second shaft at a second speed, magnetic means for braking the second shaft, the magnetic and electrical characteristics of said driving and braking means being selected so that the ratio of the second speed to the first speed varies with temperature of the fluid as a reciprocal function of the temperature according to a law which compensates for variation of the density of the fluid with the temperature thereof, whereby the speed of said second shaft may provide a representation of the volume flow of a compressible fluid corrected for variations of fluid density with temperature.

Claim 14

Volume meter according to claim 10, wherein the magnetic driving means comprises first permanent magnet means coupled to one of said shafts so as to create a rotatable magnetic field and a first non-ferromagnetic metal circular member coupled to the other of said shafts and in space relationship with said first permanent magnet means so that currents may be induced by the magnetic rotatable field in said first circular member upon rotation of the output shaft, and wherein the magnetic braking means comprises second permanent magnet means and a second non-ferromagnetic metal circular member, one of the second permanent means and of the second circular member being coupled to the second shaft and movably mounted with respect to the other so that the magnetic flux of the second permanent magnet means induces eddy current in the second circular member upon rotation of the second shaft.

Claim 15

Volume meter according to claim 11, wherein at least one of the permanent magnet means of the magnetic driving means and of the magnetic braking means includes a thermomagnetic shunt.

Claim 16

Volume meter according to claim 12, wherein the ratio of the resistivity of the second circular member to the resistivity of the first circular member varies in inversely proportional relationship with respect to the absolute temperature of the fluid.

Claim 17

Volume meter according to claim 11, wherein the first and second circular members are made of the same material.

Claim 18

Volume meter according to claim 11, wherein the first and second circular members are separate disks secured to said second shaft.

Claim 19

Volume meter according to claim 11, wherein the first and second circular members are respective portions of a single disk.

Claim 20

Volume meter according to claim 10 further comprising a first totalizer coupled to the second shaft.

Claim 21

Volume meter according to claim 17 further comprising a second totalizer coupled to the output shaft.

Claim 22

Volume meter according to claim 11, wherein said first and second permanent magnet means have respectivE flux phi 1, and phi 2 and said first and second circular members have respective resistivity values Rho 1 and Rho 2, phi 1 phi 2, Rho 1 and Rho 2 being selected so that ( phi 1/ phi 2)2 ( Rho 2/ Rho 1) is substantially inversely proportional function of the absolute temperature.