US3808879A
Expired / Lapsed
US
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Ultrasonic wall thickness measurement
Assignee: YUBOSCOPE Inc
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Filing: 1972-08-03
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Granted: 1974-05-07
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Expires: 1992-08-03
Abstract
Abstract Method and apparatus for ultrasonic measurement of average wall thickness. Only true and accurate wall thickness measurements are averaged, and average thickness of wall is indicated in continuous, accurate manner. Invention is particularly useful where there is continuous relative motion with respect to measured wall, and where surface of wall is irregular.
Inventors
- 👤 P Rogers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:41
CPC Classifications
G; G01; G01N; G01N29/00; G01N29/04; G01N29/07; G01B; G01B17/00; G01B17/02; G01N2291/00; G01N2291/02; G01N2291/028; G01N2291/02854
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
208 words
In a method of making an average wall thickness measurement of a walled member, the steps comprising directing ultrasonic energy from an ultrasonic transducer means onto and through a front surface of said member, starting a timing period at a time representing the time of incidence of said energy at the front surface of said member, concluding said timing period in response to receiving at said transducer means a reflection of ultrasonic energy from the back wall of the member, thereby to represent the propagation time of ultrasonic energy through the member, or alternatively concluding said timing period at a predetermined maximum time if reflected energy has not been received at the transducer means from said back wall, producing a set pulse when the timing period concludes before said predetermined maximum time, preventing the production of a set pulse if reflected energy from the back wall has not been received at the transducer before said predetermined maximum time, producing regularly occurring clock pulses, repeating the above steps to produce a predetermined number of set pulses, providing a coded digital signal representing the total of the number of clock pulses that occurred only in timing periods that are associated with the production of said predetermined number of set pulses.
Claim 2
Dependent Claim
208 words
In a method of making an average wall thickness measurement of a walled member, the steps comprising directing ultrasonic energy from an ultrasonic transducer means onto and through a front surface of said member, starting a timing period at a time representing the time of incidence of said energy at the front surface of said member, concluding said timing period in response to receiving at said transducer means a reflection of ultrasonic energy from the back wall of the member, thereby to represent the propagation time of ultrasonic energy through the member, or alternatively concluding said timing period at a predetermined maximum time if reflected energy has not been received at the transducer means from said back wall, producing a set pulse when the timing period concludes before said predetermined maximum time, preventing the production of a set pulse if reflected energy from the back wall has not been received at the transducer before said predetermined maximum time, producing regularly occurring clock pulses, repeating the above steps to produce a predetermined number of set pulses, providing a coded digital signal representing the total of the number of clock pulses that occurred only in timing periods that are associated with the production of said predetermined number of set pulses.
Claim 3
Dependent Claim
41 words
The method of claim 1 and further including the step converting said coded signal to an indication or read out of an average of the number of pulses received during the time periods associated with the production of a set pulse.
Claim 4
Dependent Claim
49 words
The method of claim 1 and further including the steps establishing substantially continuous relative motion between the ultrasonic transducer means and said member, and continuing said recited steps to provide a continuous succession of said coded signals and a continuous and persisting indication of said average number of pulses.
Claim 5
Independent Claim
255 words
A method of making an average wall thickness measurement comprising the steps from a region adjacent a front surface of a member whose average wall thickness is to be measured, directing a beam of ultrasonic energy onto and through said front surface, producing a first signal which represents the propagation time of a portion of said energy which is reflected from the front surface and received back at said region, producing a second signal which represents the propagation time of another portion of the energy which is reflected from a back surface of the member and received back at said region, starting a timing period in response to the first signal, concluding the timing period in response to the second signal or at the conclusion of a predetermined time after the first signal, whichever is first to occur, producing a set pulse when the second signal occurs before said predetermined time after the first signal, preventing the production of said set pulse when said predetermined time expires before the occurrence of said second signal, producing repetitively occurring clock pulses, counting the number of clock pulses that occur during said timing period, repeating the above steps to produce a succession of timing periods, providing a coded signal representing the total of the number of pulses counted only in a given number of said timing periods that are associated with the production of a set pulse, in response to said last named coded signal, providing an indication or read out representing average wall thickness of said member.
Claim 6
Independent Claim
255 words
A method of making an average wall thickness measurement comprising the steps from a region adjacent a front surface of a member whose average wall thickness is to be measured, directing a beam of ultrasonic energy onto and through said front surface, producing a first signal which represents the propagation time of a portion of said energy which is reflected from the front surface and received back at said region, producing a second signal which represents the propagation time of another portion of the energy which is reflected from a back surface of the member and received back at said region, starting a timing period in response to the first signal, concluding the timing period in response to the second signal or at the conclusion of a predetermined time after the first signal, whichever is first to occur, producing a set pulse when the second signal occurs before said predetermined time after the first signal, preventing the production of said set pulse when said predetermined time expires before the occurrence of said second signal, producing repetitively occurring clock pulses, counting the number of clock pulses that occur during said timing period, repeating the above steps to produce a succession of timing periods, providing a coded signal representing the total of the number of pulses counted only in a given number of said timing periods that are associated with the production of a set pulse, in response to said last named coded signal, providing an indication or read out representing average wall thickness of said member.
Claim 7
Dependent Claim
36 words
The method claimed in claim 4 and including the step establishing relative motion between said front surface and a means for directing said ultrasonic energy, whereby said succession of timing periods occur during said relative motion.
Claim 8
Dependent Claim
107 words
The method claimed in claim 4 wherein the step of providing a coded signal includes the steps upon command of each set pulse, presetting into a backward counter A coded number representing the number of said clock pulses counted during the corresponding timing period that concluded with the production of a respective set pulse, coupling clock pulses to the backward counter each time it is preset to cause it to count backward to some predetermined count, and counting the total number of clock pulses coupled to the backward counter during said given number of times that it is preset and then counts backward to the predetermined count.
Claim 9
Dependent Claim
59 words
The method claimed in claim 6 and further including the steps repeating during each of a succession of said given number of times the counting of the total number of clock pulses coupled to the backward counter to provide a succession of said second coded signals and a corresponding succession of indications or read outs representing average wall thickness.
Claim 10
Dependent Claim
47 words
The method claimed in claim 7 wherein the step of providing an indication or read out includes the steps converting said coded signals to corresponding persisting analog signals, and coupling said persisting analog signals to means for providing said indications or read outs representing average wall thickness.
Claim 11
Dependent Claim
188 words
Apparatus for making an average wall thickness measurement of a walled member, comprising ultrasonic transducer means for directing repetitive ultrasonic energy pulses onto and through a front surface of said member, means for starting each of a plurality of repetitive timing periods at a time representing the time of incidence of a respective ultrasonic pulse at said front surface, means for concluding each timing period at a time corresponding to the receipt at the transducer means of a reflection of a corresponding pulse from the back wall of said member, means for terminating a timing period if a reflection of a corresponding pulse is not received at the transducer within a predetermined time after start of the time period, means for producing a succession of clock pulses, means for counting the total number of clock pulses that occur during a predetermined number of timing periods that are concluded only by the receipt of a reflection from the back surface, and means providing a representation of the average of the number of pulses counted during said timing periods that are concluded only by a reflection from the back surface.
Claim 12
Dependent Claim
188 words
Apparatus for making an average wall thickness measurement of a walled member, comprising ultrasonic transducer means for directing repetitive ultrasonic energy pulses onto and through a front surface of said member, means for starting each of a plurality of repetitive timing periods at a time representing the time of incidence of a respective ultrasonic pulse at said front surface, means for concluding each timing period at a time corresponding to the receipt at the transducer means of a reflection of a corresponding pulse from the back wall of said member, means for terminating a timing period if a reflection of a corresponding pulse is not received at the transducer within a predetermined time after start of the time period, means for producing a succession of clock pulses, means for counting the total number of clock pulses that occur during a predetermined number of timing periods that are concluded only by the receipt of a reflection from the back surface, and means providing a representation of the average of the number of pulses counted during said timing periods that are concluded only by a reflection from the back surface.
Claim 13
Dependent Claim
221 words
Ultrasonic inspection apparatus, comprising ultrasonic transducer means for directing repetitive ultrasonic energy pulses onto and through a front surface of a walled member whose average wall thickness is to be measured, means for producing a succession of first signals in response to the receipt at said transducer means of respective reflected pulses from said front surface, means for producing a succession of second signals in response to the receipt at said transducer means of respective reflected pulses from the back surface of said member, means for starting a respective timing period in response to each of said first signals, means for stopping each of said timing periods a predetermined maximum time after its start, or alternatively, in response to a respective second signal occurring before said predetermined maximum time, whichever is first to occur, means for providing clock pulses, means for counting the total number of clock pulses that occur during each occurrence of a predetermined number of timing periods that are concluded only by a respective second signal, means for providing a succession of coded signals representing, respectively, said total number of pulses counted in each predetermined number of timing periods, and means responsive to said coded signals for providing an indication or read out representing the average number of pulses counted during each timing period in said predetermined number.
Claim 14
Dependent Claim
221 words
Ultrasonic inspection apparatus, comprising ultrasonic transducer means for directing repetitive ultrasonic energy pulses onto and through a front surface of a walled member whose average wall thickness is to be measured, means for producing a succession of first signals in response to the receipt at said transducer means of respective reflected pulses from said front surface, means for producing a succession of second signals in response to the receipt at said transducer means of respective reflected pulses from the back surface of said member, means for starting a respective timing period in response to each of said first signals, means for stopping each of said timing periods a predetermined maximum time after its start, or alternatively, in response to a respective second signal occurring before said predetermined maximum time, whichever is first to occur, means for providing clock pulses, means for counting the total number of clock pulses that occur during each occurrence of a predetermined number of timing periods that are concluded only by a respective second signal, means for providing a succession of coded signals representing, respectively, said total number of pulses counted in each predetermined number of timing periods, and means responsive to said coded signals for providing an indication or read out representing the average number of pulses counted during each timing period in said predetermined number.
Claim 15
Dependent Claim
50 words
Apparatus claimed in claim 10 wherein the means for providing an indication or read out includes, digital to analog converter means responsive to said coDed signals for providing corresponding analog signals, each of said analog signals persisting at its corresponding analog value until the occurrence of the next coded signal.
Claim 16
Dependent Claim
127 words
The combination claimed in claim 10 wherein said means for counting the total number of clock pulses that occur during each occurrence of a predetermined number of timing periods that are concluded only by a respective second signal comprises, counting means for counting clock pulses during each timing period, means for producing a set pulse each time a timing period is concluded by a second signal, means responsive to a set pulse for transferring the count from said counting means only at the conclusion of a timing period associated with a respective set pulse, and means for producing a total count of the counts transferred from the counting means in a predetermined number of timing periods that are associated with the production of a respective set pulse.
Claim 17
Dependent Claim
224 words
In a method of making an average wall thickness measurement of a walled member, the steps comprising directing ultrasonic energy from an ultrasonic transducer means onto and through a front surface of said member, starting a timing period at a time representing the time of incidence of said energy at the front surface of said member, concluding said timing period in response to receiving at said transducer means a reflection of ultrasonic energy from the back wall of the member, thereby to represent the propagation time of ultrasonic energy through the member, or alternatively concluding said timing period at a predetermined maximum time if reflected energy has not been received at the transducer means from said back wall, producing a set pulse when the timing period concludes before said predetermined maximum time, preventing the production of a set pulse if reflected energy from the back wall has not been received at the transducer before said predetermined maximum time, producing regularly occurring clock pulses, producing a coded signal representing the number of clock pulses that occur during a timing period, repeating the above steps to produce a plurality of set pulses and a plurality of coded signals, and gating respective ones of the coded signals to further signal processing means only when a set pulse is produced at the conclusion of the corresponding timing period.
Claim 18
Dependent Claim
224 words
In a method of making an average wall thickness measurement of a walled member, the steps comprising directing ultrasonic energy from an ultrasonic transducer means onto and through a front surface of said member, starting a timing period at a time representing the time of incidence of said energy at the front surface of said member, concluding said timing period in response to receiving at said transducer means a reflection of ultrasonic energy from the back wall of the member, thereby to represent the propagation time of ultrasonic energy through the member, or alternatively concluding said timing period at a predetermined maximum time if reflected energy has not been received at the transducer means from said back wall, producing a set pulse when the timing period concludes before said predetermined maximum time, preventing the production of a set pulse if reflected energy from the back wall has not been received at the transducer before said predetermined maximum time, producing regularly occurring clock pulses, producing a coded signal representing the number of clock pulses that occur during a timing period, repeating the above steps to produce a plurality of set pulses and a plurality of coded signals, and gating respective ones of the coded signals to further signal processing means only when a set pulse is produced at the conclusion of the corresponding timing period.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |