Patent US3743249A successfully refreshed from Google Patents.
US3743249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heave compensator
Assignee: Shell USA Inc
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Filing: 1971-04-20
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Granted: 1973-07-03
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Expires: 1991-04-20
Abstract
Abstract The dead end of a drilling cable is attached to a cable drum operably connected to a cylinder/piston assembly, the cable drum being spirally shaped to keep the tension in the drilling cable independent of the position of the piston.
Inventors
- 👤 Daalen F Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:49
CPC Classifications
E; E21; E21B; E21B19/00; E21B19/08; E21B19/09; B; B63; B63B; B63B35/00; B63B35/44; B63B35/4413; Y; Y10; Y10S; Y10S254/00; Y10S254/90
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a cylinder/piston assembly supplied with energy from an external source; a cable drum, said drum being mounted for rotation about a central axis and having a supporting surface for the cable, said surface having a non-constant radius, one end of the cable being connected to the drum and the part of the cable adjacent to said end passing over the supporting surface of the drum; and a transmission means connecting said piston to the cable drum, said transmission means being suitable to convert longitudinal displacements of the piston into rotation of the cable drum about its central axis.
Claim 2
Independent Claim
111 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a cylinder/piston assembly supplied with energy from an external source; a cable drum, said drum being mounted for rotation about a central axis and having a supporting surface for the cable, said surface having a non-constant radius, one end of the cable being connected to the drum and the part of the cable adjacent to said end passing over the supporting surface of the drum; and a transmission means connecting said piston to the cable drum, said transmission means being suitable to convert longitudinal displacements of the piston into rotation of the cable drum about its central axis.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein the supporting surface is in the shape of a spiral.
Claim 4
Dependent Claim
13 words
The apparatus of claim 1 wherein the energy source is high pressure gas.
Claim 5
Dependent Claim
42 words
The apparatus of claim 1 wherein said apparatus is mounted on a floating structure that moves vertically in response to wave action and said cable extends from said floating structure to a position that does not move in response to wave action.
Claim 6
Independent Claim
99 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a first drum having suitable means for connecting one end of the cable thereto, said first drum having a cable supporting surface having a non-constant radius; a cylinder/piston assembly supplied with energy from an external source; a transmission means connecting the first drum and piston of said cylinder/piston assembly, said transmission means comprising a second drum coupled to the first drum to rotate in combination therewith; and a cable coupled between the piston and the second drum to rotate said second drum when said piston moves.
Claim 7
Independent Claim
99 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a first drum having suitable means for connecting one end of the cable thereto, said first drum having a cable supporting surface having a non-constant radius; a cylinder/piston assembly supplied with energy from an external source; a transmission means connecting the first drum and piston of said cylinder/piston assembly, said transmission means comprising a second drum coupled to the first drum to rotate in combination therewith; and a cable coupled between the piston and the second drum to rotate said second drum when said piston moves.
Claim 8
Dependent Claim
16 words
The apparatus of claim 5 wherein the supporting surface is in the shape of a spiral.
Claim 9
Dependent Claim
13 words
The apparatus of claim 5 wherein the energy source is high pressure gas.
Claim 10
Independent Claim
155 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a travelling block; a pair of cylinder/piston assemblies suitably connected by a bridge piece, said assemblies moving in unison with each other through said bridge piece, said assemblies being supplied with energy from an external source; a pair of connecting members for connecting said travelling block to said cylinder/piston assemblies; a first drum, said drum being mounted for rotation on said pair of connecting members, said first drum having suitable means for connecting one end of the cable thereto, and said first drum having a cable supporting surface having a non-constant radius; and a transmission means connecting the first drum to said bridge piece, said transmission means including a second drum coupled to the first drum to rotate in combination therewith and a cable coupled between the bridge piece and the second drum to rotate said second drum when said pistons move.
Claim 11
Independent Claim
155 words
An apparatus for maintaining a constant tension in a cable, said apparatus comprising: a travelling block; a pair of cylinder/piston assemblies suitably connected by a bridge piece, said assemblies moving in unison with each other through said bridge piece, said assemblies being supplied with energy from an external source; a pair of connecting members for connecting said travelling block to said cylinder/piston assemblies; a first drum, said drum being mounted for rotation on said pair of connecting members, said first drum having suitable means for connecting one end of the cable thereto, and said first drum having a cable supporting surface having a non-constant radius; and a transmission means connecting the first drum to said bridge piece, said transmission means including a second drum coupled to the first drum to rotate in combination therewith and a cable coupled between the bridge piece and the second drum to rotate said second drum when said pistons move.
Claim 12
Dependent Claim
16 words
The apparatus of claim 8 wherein the supporting surface is in the shape of a spiral.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |