US4438754A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for sensing and remotely controlling a tool to workpiece spatial relationship
Assignee: Shell USA Inc
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Filing: 1981-09-11
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Granted: 1984-03-27
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Expires: 2001-09-11
Abstract
Abstract An electromagnetic system is provided for accurately sensing and remotely controlling a tool-to-workpiece spatial relationship. A typical application of the system may include a saw being sensor controlled through the process of removing a reinforced concrete covering from and about an underwater pipe or other metallic object that must be protected.
Inventors
- 👤 Walter C. Nanny
- 👤 Thomas L. Stewart
- 👤 Dean P. Hemphill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:30
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/023; Y; Y10; Y10S; Y10S83/00; Y10S83/924; Y10T; Y10T83/00; Y10T83/525; Y10T83/538
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
142 words
A method for cutting and removing concrete containing embedded reinforcement from about a pipe, said cutting being effected with a saw blade without cutting the pipe, comprising: disposing two magnetic field generating probes on opposite sides of the saw blade, each probe having a north and south pole face and the saw blade being magnetically insulated; generating a magnetic field extending between the north pole of each probe and the south pole of the other probe; sensing the massive disturbing effect of the pipe and the minimal disturbing effect of the reinforcement; distinguishing between the massive disturbing effect and the minimal disturbing effect to determine the distance between the saw blade and the pipe; and cutting and removing the concrete containing embedded reinforcement without cutting the pipe by maintaining not less than the determined distance between the pipe and the saw blade.
Claim 2
Independent Claim
142 words
A method for cutting and removing concrete containing embedded reinforcement from about a pipe, said cutting being effected with a saw blade without cutting the pipe, comprising: disposing two magnetic field generating probes on opposite sides of the saw blade, each probe having a north and south pole face and the saw blade being magnetically insulated; generating a magnetic field extending between the north pole of each probe and the south pole of the other probe; sensing the massive disturbing effect of the pipe and the minimal disturbing effect of the reinforcement; distinguishing between the massive disturbing effect and the minimal disturbing effect to determine the distance between the saw blade and the pipe; and cutting and removing the concrete containing embedded reinforcement without cutting the pipe by maintaining not less than the determined distance between the pipe and the saw blade.
Claim 3
Dependent Claim
51 words
The method of claim 1 wherein the probes and saw are moved along the surface of the concrete-covered pipe, and irregular disturbing effects of the magnetic field are sensed and correlated to verify the roundness and/or straightness of the pipe within the concrete cover and/or the structural integrity of the pipe.
Claim 4
Dependent Claim
31 words
The method of claim 2 wherein the probes and saw are remotely operated and are used to determine the relative spatial relationship of the concrete-covered pipe to the probes and saw.
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) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |