Patent US3702934A successfully refreshed from Google Patents.
US3702934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling equipment on a crawler displaceable inside a pipe
Assignee: Picker Andrex X Ray AS
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Filing: 1970-09-28
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Granted: 1972-11-14
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Expires: 1990-09-28
Abstract
Abstract Means for controlling the operation of a crawler adapted to move inside a pipeline and comprising a radiation source, e.g., an Xray tube, for the inspection of welds in the pipe line. The operation is controlled by means of an AC-supplied electromagnet to be arranged on the outside of the pipe at a certain distance from the weld to be examined. The magnetic field from the electro-magnet is detected by a detector mounted on the crawler and comprising three coils spaced apart in the direction of movement of the crawler. The signals from the three coils are supplied to a logical unit generating control signals for the operation (start, stop, exposure etc.) of the crawler in response to the coil signals. Means may be incorporated for transforming the coil signals into binary DC-signals.
Inventors
- 👤 Niels Jakobsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:39
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/06; G01N23/18; G01N23/083; G01N27/00; G01N27/72; G01N27/82
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
205 words
A remote controlled inspection device for inspecting a pipe line from the interior thereof by means of radiation comprising a control device adapted to be arranged on the outside of the pipe line at a position adjacent to the area of the pipe line to be inspected, said device comprising an electro-magnet and an ACcurrent source for supplying an AC-current to the electro-magnet, a movable crawler adapted to be placed in the pipe line, driving means on the crawler for moving said crawler in the longitudinal direction of the pipe line, radiation means on said crawler, detector means on said crawler including three coils having iron cores spaced apart in the direction of movement of the crawler and arranged so that when the crawler passes the electro-magnet a signal is induced in each coil having an amplitude dependent on the relative position of the coil and the electro-magnet in the longitudinal direction of the pipe line, logic unit means on said crawler having inputs for receiving signals derived from said three coils, and outputs connected to the driving means and the radiation means to selectively activate the driving means and the radiation means in dependence on the combination of signals received from said three coils.
Claim 2
Dependent Claim
205 words
A remote controlled inspection device for inspecting a pipe line from the interior thereof by means of radiation comprising a control device adapted to be arranged on the outside of the pipe line at a position adjacent to the area of the pipe line to be inspected, said device comprising an electro-magnet and an ACcurrent source for supplying an AC-current to the electro-magnet, a movable crawler adapted to be placed in the pipe line, driving means on the crawler for moving said crawler in the longitudinal direction of the pipe line, radiation means on said crawler, detector means on said crawler including three coils having iron cores spaced apart in the direction of movement of the crawler and arranged so that when the crawler passes the electro-magnet a signal is induced in each coil having an amplitude dependent on the relative position of the coil and the electro-magnet in the longitudinal direction of the pipe line, logic unit means on said crawler having inputs for receiving signals derived from said three coils, and outputs connected to the driving means and the radiation means to selectively activate the driving means and the radiation means in dependence on the combination of signals received from said three coils.
Claim 3
Dependent Claim
37 words
A device as claimed in claim 1, wherein the cores of the coils are arranged with their axes substantially at right angles to the wall of the pipe line when the crawler is in the pipe line.
Claim 4
Dependent Claim
49 words
A device as claimed in claim 1, wherein three outputs of the logic unit means are connected to the driving means to bring about forward run, return run and stopping, respectively, when activated, and one output is connected to the radiation means to bring about an exposure when activated.
Claim 5
Dependent Claim
71 words
A device as claimed in claim 1, further comprising three signal channels, each extending from one of the coils to one of the inputs of the logic unit means, an amplifier in each of said channels to supply an output signal only when the input signal to the amplifier exceeds a predetermined threshold value, and a rectifier means in each of said channels intermediate said amplifier and said logic unit means.
Claim 6
Dependent Claim
40 words
A device as claimed in claim 4, further comprising a smoothing circuit in each of said channels with the smoothing circuit in the channel corresponding to the center coil having a lower time constant than the two other smoothing circuits.
References Cited (Backward Citations)
US3492477A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |