Ultrasonic tire testing apparatus

Claim 2

An electronic system for use in ultrasonic inspection apparatus comprising: (a) a plurality of transmitters for producing directional beams of pulsed ultrasonic energy, the transmitters being physically arranged so that the beams focus on a predetermined area of the product to be inspected; (b) a plurality of receiving channels, each having

Claim 3

an ultrasonic receiver transducer adapted to receive ultrasonic energy transmitted through said product from at least one of said plurality of transmitters and producing an electrical signal characteristic of said received ultrasonic energy; 2. a bandpass filter coupled to said receiver transducer for attenuating frequency components of said electrical signal above and below a predetermined center frequency; 3. demodulator means coupled to the output of said bandpass filter; 4. an integrate and hold circuit means for periodically integrating the electrical output from said demodulator during a predetermined time interval and holding said integrated, signal; (c) multiplexer means having a plurality of input lines, an output line and a control line, the output from said integrate and hold circuits of said plurality of receiving channels being coupled individually to said plurality of input lines of said multiplexer means; (d) an analogue-to-digital converter circuit having its input coupled to said output line of said multiplexer means; and (e) a stored program digital computing means having input means and output means, said input means being coupled to the output of said analogue-to-digital converter circuit, said output means being coupled to said transmitter means, said integrate and hold circuit means and said control line of said multiplexer means.

Claim 4

an ultrasonic receiver transducer adapted to receive ultrasonic energy transmitted through said product from at least one of said plurality of transmitters and producing an electrical signal characteristic of said received ultrasonic energy; 2. a bandpass filter coupled to said receiver transducer for attenuating frequency components of said electrical signal above and below a predetermined center frequency; 3. demodulator means coupled to the output of said bandpass filter; 4. an integrate and hold circuit means for periodically integrating the electrical output from said demodulator during a predetermined time interval and holding said integrated, signal; (c) multiplexer means having a plurality of input lines, an output line and a control line, the output from said integrate and hold circuits of said plurality of receiving channels being coupled individually to said plurality of input lines of said multiplexer means; (d) an analogue-to-digital converter circuit having its input coupled to said output line of said multiplexer means; and (e) a stored program digital computing means having input means and output means, said input means being coupled to the output of said analogue-to-digital converter circuit, said output means being coupled to said transmitter means, said integrate and hold circuit means and said control line of said multiplexer means.

Claim 5

The system as in claim 1 wherein said stored program digital computing means controls the pulse repetition rate of said pulsed ultrasonic energy from said plurality of transmitters, the sampling rate of said integrate and hold circuit means and the connection of said plurality of input lines of said multiplexer means to its output line.

Claim 6

Apparatus as in claim 2 wherein said digital computing means further includes storage means coupled to said input means and said output means for storing digital signal representations of the sampled values of said electrical output from said demodulator means of each of said plurality of receiving channels.

Claim 7

The apparatus as in claim 3 wherein said digital computing means includes an arithmetic logic unit for performing computations on digital information entered from said storage means in accordance with instructions comprising a stored program, whereby said electrical signals characteristic of said received ultrasonic energy may be classified.

Claim 8

Apparatus as in claim 4 and further including a display device connected to said output means of said digital computing means for providing an indication of the classification into which said electrical signals characteristic of received ultrasonic energy fall.

Claim 9

Apparatus as in claim 1 wherein said plurality of transmitters comprise: (a) an array of piezoelectric crystal transducers; (b) oscillator means coupled to said output means of said digital computing means for receiving triggering pulses at times determined by said digital computing means and producing pulses of a predetermined frequency at an output; (c) a monostable multivibrator circuit having an input connected to the output of said oscillator means and an output; (d) power amplifier means connected to the output of said oscillator means and said monostable multivibrator circuit means for producing pulsed bursts of electrical signals of said predetermined frequency; and (e) means coupling said pulsed bursts of electrical signals from said power amplifier means to said piezoelectric transducers.

Claim 10

An electronic system as in claim 1 wherein said digital computing means is coupled to receive said electrical signals characteristic of said received ultrasonic energy and programmed for performing a finite sampled data filter function on said discrete signals, the length of said filter being determined, either adaptively or nonadaptively, by the periodicity of irregularities in said product being inspected.