Patent US3835374A successfully refreshed from Google Patents.
US3835374A
Expired / Lapsed
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Method and apparatus for providing speed compensation for information containing signals in which the threshold level of the detector is varied proportional to speed
Assignee: INTERNATIONAL PIPELINE ENGINEERING Ltd
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Filing: 1973-02-20
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Granted: 1974-09-10
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Expires: 1993-02-20
Abstract
Abstract Certain types of equipment, for example, certain types of instrument pigs used for detecting flaws in or other characteristics of pipelines, employ sensing devices that derive information-containing signals having an amplitude that varies in response to a characteristic of the device being scanned by the scanning device and undesirably in response to the speed of movement of the sensing device through the device being scanned. In order to speed compensate the information-containing signal so that it can be properly interpreted, a speed responsive signal that varies in amplitude in response to the speed of movement of the sensing device is derived and is used to vary the threshold level of the information-containing signal to permit portions of the information-containing signal that exceed in amplitude the amplitude of the speed responsive signal to be recorded and to prevent portions of the information-containing signal that are lesser in amplitude than the amplitude of the speed responsive signal from being recorded.
Inventors
- 👤 D Frost
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:10
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01N27/82; G01N27/90; G01N27/9046; G01N27/906
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
281 words
In combination with apparatus including a sensing device for deriving information-containing signals having an amplitude that varies both in response to the speed of movement of said sensing device and in response to a characteristic of the device being scanned by said sensing device, means for deriving a second signal that varies in amplitude in response to said speed of movement of said sensing device, means for recording said information-containing signals, switching means connected between said sensing device and said recording means, said switching means having first and second states, in said first state said switching means permitting said information-containing signal to be supplied to said recording means and recorded thereby, in said second state said switching means preventing said informationcontaining signal from being recorded by said recording means, a signal amplitude comparator for comparing said amplitude of said information-containing signal and said amplitude of said second signal, said signal amplitude comparator having an output terminal and providing at said output terminal an output signal when said amplitude of said information-containing signal exceeds a predetermined level related to said amplitude of said second signal, said output signal thus having a variable, speedresponsive threshold level, means for supplying said informationcontaining signal and second signal to said signal amplitude comparator for amplitude comparison and means connecting said output terminal and said switching means for supplying said output signal to said switching means to change the state thereof from said second state to said first state when said amplitude of said information-containing signal exceeds said predetermined level and for changing the state thereof from said first state to said second state when said amplitude of said informationcontaining signal is less than said predetermined level.
Claim 2
Dependent Claim
281 words
In combination with apparatus including a sensing device for deriving information-containing signals having an amplitude that varies both in response to the speed of movement of said sensing device and in response to a characteristic of the device being scanned by said sensing device, means for deriving a second signal that varies in amplitude in response to said speed of movement of said sensing device, means for recording said information-containing signals, switching means connected between said sensing device and said recording means, said switching means having first and second states, in said first state said switching means permitting said information-containing signal to be supplied to said recording means and recorded thereby, in said second state said switching means preventing said informationcontaining signal from being recorded by said recording means, a signal amplitude comparator for comparing said amplitude of said information-containing signal and said amplitude of said second signal, said signal amplitude comparator having an output terminal and providing at said output terminal an output signal when said amplitude of said information-containing signal exceeds a predetermined level related to said amplitude of said second signal, said output signal thus having a variable, speedresponsive threshold level, means for supplying said informationcontaining signal and second signal to said signal amplitude comparator for amplitude comparison and means connecting said output terminal and said switching means for supplying said output signal to said switching means to change the state thereof from said second state to said first state when said amplitude of said information-containing signal exceeds said predetermined level and for changing the state thereof from said first state to said second state when said amplitude of said informationcontaining signal is less than said predetermined level.
Claim 3
Dependent Claim
17 words
The combination according to claim 1 wherein said predetermined level is said amplitude of said second signal.
Claim 4
Dependent Claim
14 words
The combination according to claim 2 wherein said apparatus is a pipeline instrument pig.
Claim 5
Dependent Claim
53 words
The combination according to claim 2 wherein said means for supplying said information-containing signal to said amplitude comparator include a full wave rectifier and means connecting said rectifier between said sensing device and said amplitude comparator for full wave rectifying said information-containing signal before it is compared in amplitude with said second signal.
Claim 6
Dependent Claim
53 words
The invention according to claim 2 wherein said means for deriving said second signal comprise means for generating a signal having a frequency directly proportional to the speed of said sensing device and means for converting said signal so generated into a signal having an amplitude that varies directly proportional to said frequency.
Claim 7
Independent Claim
239 words
A method for compensating an information-containing signal derived from a moving sensing device and that varies in amplitude both in response to the speed of movement of said sensing device and in response to a characteristic of the device being scanned for variations in said speed of movement of said sensing device in a system which includes an output terminal at which the speed compensated information-containing signal is obtained which comprises deriving a second signal that varies in amplitude in response to said speed of movement of said sensing device, comparing the amplitudes of said information-containing signal and said second signal to generate an output signal when said amplitude of said information-containing signal exceeds a predetermined level related to said amplitude of said second signal and supplying said output signal to switching means having first and second states and connected in said system between said sensing device and said output terminal to change the state thereof from said second staTe to said first state when said amplitude of said information-containing signal exceeds said predetermined level and to change the state thereof from said first state to said second state when said amplitude of said information-containing signal is less than said predetermined level, in said first state said switching means permitting said information-containing signal to be supplied to said output terminal and in said second state said switching means preventing said information-containing signal from being supplied to said output terminal.
Claim 8
Independent Claim
239 words
A method for compensating an information-containing signal derived from a moving sensing device and that varies in amplitude both in response to the speed of movement of said sensing device and in response to a characteristic of the device being scanned for variations in said speed of movement of said sensing device in a system which includes an output terminal at which the speed compensated information-containing signal is obtained which comprises deriving a second signal that varies in amplitude in response to said speed of movement of said sensing device, comparing the amplitudes of said information-containing signal and said second signal to generate an output signal when said amplitude of said information-containing signal exceeds a predetermined level related to said amplitude of said second signal and supplying said output signal to switching means having first and second states and connected in said system between said sensing device and said output terminal to change the state thereof from said second staTe to said first state when said amplitude of said information-containing signal exceeds said predetermined level and to change the state thereof from said first state to said second state when said amplitude of said information-containing signal is less than said predetermined level, in said first state said switching means permitting said information-containing signal to be supplied to said output terminal and in said second state said switching means preventing said information-containing signal from being supplied to said output terminal.
Claim 9
Dependent Claim
17 words
A method according to claim 6 wherein said predetermined level is said amplitude of said second signal.
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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |