Current meter or flow meter

Claim 2

A current meter or flow meter comprising a conduit means through which a fluid to be measured flows, a vortex generating rod means immersed in the stream of said fluid for producing the Karman vortices, a vibrator means disposed on the downstream side of said vortex forming rod means and vibrated by said Karman vortices, an ultrasonic signal transmitter means disposed on said conduit means on the downstream side of said rod means for producing ultrasonic signals against said vibrator means, an ultrasonic signal receiver means disposed on said conduit means on the downstream side of said rod means for receiving the ultrasonic signal reflected by said vibrator means, an electronic circuit means of the so-called ''''sing-around'''' type for applying pulse signals to said ultrasonic signal transmitter means in response to the signals from said ultrasonic signal receiver means, FM demodulator means for demodulating the output of said electronic circuit means, and a counter means for counting the output signal of said FM demodulator means.

Claim 3

A current meter or flow meter as claimed in claim 1 in which said vortex generating rod means has provided therethrough a bore at the openings of which suction and shedding of said fluid occur.

Claim 4

A flow meter as claimed in claim 1 in which said vortex generating rod means has provided therein two cavities between which a partition wall is provided, said partition wall having a bore through which said two cavities intercommunicate with ach other and bores or slits, the openings of which are opened out in the surfacE of the vortex generating rod means at the positions from where the boundary layer of said fluid is substantially separated.

Claim 5

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flow of said fluid and also the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line, detector means connected to said receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid output; and further including a ''''sing-around'''' circuit for pulsing said ultrasonic signal at a frequency inversely proportional to the travel time of said ultrasonic signal in said fluid, said sing-around circuit applying said pulsed ultrasonic signal to said ultrasonic signal transmitter in response to signals from said ultrasonic signal receiver, said detector means comprises an FM signal demodulator for demodulating outputs from said sing-around circuit, and said counter means connected to said FM signal demodulator and counting output pulses to indicate the velocity of said fluid.

Claim 6

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flow of said fluid and also the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line, detector means connected to said receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid output; and further including a ''''sing-around'''' circuit for pulsing said ultrasonic signal at a frequency inversely proportional to the travel time of said ultrasonic signal in said fluid, said sing-around circuit applying said pulsed ultrasonic signal to said ultrasonic signal transmitter in response to signals from said ultrasonic signal receiver, said detector means comprises an FM signal demodulator for demodulating outputs from said sing-around circuit, and said counter means connected to said FM signal demodulator and counting output pulses to indicate the velocity of said fluid.

Claim 7

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flow of said fluid and also the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line, detector means connected to said receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid output; further including a vibrator means disposed on the downstream side of said vortex generating rod means and vibrated by said Karman vortices, said detector and counter means counting the number of interruptions of said ultrasonic signal by said vibrator; and in which said ultrasonic signal transmitter emits said ultrasonic signal against said vibrator means and said ultrasonic signal receiver receives said ultrasonic signal after it has been reflected by said vibrator means.

Claim 8

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flow of said fluid and also the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line, detector means connected to said receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid output; further including a vibrator means disposed on the downstream side of said vortex generating rod means and vibrated by said Karman vortices, said detector and counter means counting the number of interruptions of said ultrasonic signal by said vibrator; and in which said ultrasonic signal transmitter emits said ultrasonic signal against said vibrator means and said ultrasonic signal receiver receives said ultrasonic signal after it has been reflected by said vibrator means.

Claim 9

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flOw of said fluid and parallel to the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line; a vibrator means disposed on the downstream side of said vortex generating rod means and mounted on an axis parallel thereto and vibrated transversely of said conduit means by said Karman vortices; a detector means connected to said ultrasonic signal receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of the velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid; wherein the said vortex generating rod means has provided therein two cavities which are separated by a partition wall, said partition wall having a bore transverse to the direction of fluid flow in said conduit means through which said cavities intercommunicate with each other, and openings which open out to the surface of the vortex generating rod means at positions transverse to the direction of fluid flow in said conduit means from which the boundary layer of said fluid tends to separate from said surface; and in which said ultrasonic signal transmitter means emits said ultrasonic signal against said vibrator means and said ultrasonic signal receiver means receives said ultrasonic signal after it has been interrupted by said vibrator means.

Claim 10

A flow meter comprising: a conduit means through which a fluid to be measured flows; a vortex generating rod means immersed in the stream of said fluid in said conduit means for producing Karman vortices; an ultrasonic signal transmitter means and an ultrasonic signal receiver means mounted on said conduit means on the downstream side of said vortex generating rod means in such a manner that a line connecting said ultrasonic signal transmitter means and receiver means is substantially at right angles to the direction of flOw of said fluid and parallel to the axis of said vortex generating rod means, an ultrasonic signal emitted from said ultrasonic signal transmitter means travelling through said fluid to said ultrasonic signal receiver means over a path coincident with said connecting line; a vibrator means disposed on the downstream side of said vortex generating rod means and mounted on an axis parallel thereto and vibrated transversely of said conduit means by said Karman vortices; a detector means connected to said ultrasonic signal receiver means and receiving a signal therefrom and processing it to demodulate the intelligence on said signal indicative of the velocity of said fluid; a counter means receiving the output of said detector means to produce an output indicative of the velocity of said fluid; wherein the said vortex generating rod means has provided therein two cavities which are separated by a partition wall, said partition wall having a bore transverse to the direction of fluid flow in said conduit means through which said cavities intercommunicate with each other, and openings which open out to the surface of the vortex generating rod means at positions transverse to the direction of fluid flow in said conduit means from which the boundary layer of said fluid tends to separate from said surface; and in which said ultrasonic signal transmitter means emits said ultrasonic signal against said vibrator means and said ultrasonic signal receiver means receives said ultrasonic signal after it has been interrupted by said vibrator means.