Patent US3984918A successfully refreshed from Google Patents.
US3984918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inclinometer
Assignee: Sperry Sun Inc
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Filing: 1974-10-02
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Granted: 1976-10-12
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Expires: 1994-10-02
Abstract
Abstract Disclosed is an inclinometer particularly adapted for use as a top-hole indicator in drilling operations. The inclinometer employs a ferrofluid in a closed tube; the fluid serves as an angle-sensitive movable core of a differential transformer. The secondary coils of the transformer are wrapped around the tube; the primary coil is wrapped around a core piece or the tube. Equipment is provided for comparing the outputs of the secondary coils to produce an angle signal. A sturdy construction for downhole use is disclosed.
Inventors
- 👤 Preston E. Chaney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:12
CPC Classifications
G; G01; G01C; G01C9/00; G01C9/18; G01C9/20; G01C9/22; E; E21; E21B; E21B47/00; E21B47/02; E21B47/022; G01C9/02; G01C9/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
122 words
An inclinometer for use as a top-hole indicator comprising: a dough-nut shaped loop piece having a circular trench formed therein that is concentric with the loop piece, said loop piece having a bar extending thereacross with a slot formed therein; a ferrofluid partially filling said trench; a core piece positioned in said slot; exciter coil windings wrapped around said bar; a loop piece lid on said loop piece, said lid having two pairs of arcuate slots therein adjacent major and minor circumferences of said loop piece; detector coil windings wrapped around said loop piece and through said arcuate slots; and an outer case comprising a pan-shaped base member and a cover piece containing and enclosing said loop piece and loop piece lid.
Claim 2
Dependent Claim
122 words
An inclinometer for use as a top-hole indicator comprising: a dough-nut shaped loop piece having a circular trench formed therein that is concentric with the loop piece, said loop piece having a bar extending thereacross with a slot formed therein; a ferrofluid partially filling said trench; a core piece positioned in said slot; exciter coil windings wrapped around said bar; a loop piece lid on said loop piece, said lid having two pairs of arcuate slots therein adjacent major and minor circumferences of said loop piece; detector coil windings wrapped around said loop piece and through said arcuate slots; and an outer case comprising a pan-shaped base member and a cover piece containing and enclosing said loop piece and loop piece lid.
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) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |