Claims
- 1. A tractor for moving within a borehole, comprising:an elongated body defining a longitudinal axis; and an inflatable bladder longitudinally movably engaged with said body, said bladder formed from an elastomeric material reinforced by fibers arranged in a cross-ply arrangement, said bladder having an inflated position in which said bladder limits movement of said bladder relative to an inner surface of said borehole, and a deflated position in which said bladder permits substantially free relative movement between said bladder and said inner surface.
- 2. The tractor of claim 1, wherein said fibers are oriented in two general directions crossing one another at an angle of between 7° and 30°.
- 3. The tractor of claim 1, wherein each of said two general directions are within 30° of said logitudinal axis.
- 4. The tractor of claim 1, wherein said fibers comprise S-glass fibers.
- 5. The tractor of claim 1, wherein said elastomeric material comprises one of nitrile butadiene rubber or tetra-fluor-ethylene rubber.
- 6. The tractor of claim 1, further comprising a plurality of longitudinally oriented flexible beams on said radial exterior of said bladder, said beams having first ends at a first end of said bladder and second ends at a second end of said bladder, said beams configured to flex radially outward and grip onto said inner surface of said borehole when said bladder is inflated.
- 7. The tractor of claim 6, further comprising an elongated mandrel longitudinally movably engaged with said body, said bladder being secured onto a radial exterior of said mandrel, said first ends of said beams being pivotably secured and longitudinally fixed with respect to said mandrel, said second ends of said beams being pivotably secured and longitudinally movable with respect to said mandrel.
- 8. An inflatable engagement bladder for use in a tractor for moving within a borehole, said bladder comprising an elastomeric material reinforced by fibers oriented in two general directions crossing one another at an angle of between 0° and 60°, said bladder having an inflated position in which said bladder limits movement of said bladder relative to an inner surface of said borehole, and a deflated position in which said bladder permits substantially free relative movement between said bladder and said inner surface.
Parent Case Info
This application is a continuation of application Ser. No. 09/453,996, filed Dec. 3, 1999, now U.S. Pat. No. 6,347,674, which claims priority from abandoned Provisional Application Ser. No. 60/112,733, filed Dec. 18, 1998, abandoned provisional Application Ser. No. 60/129,503, filed Apr. 15, 1999, and abandoned Provisional Application Ser. No. 60/168,790, filed Dec. 2, 1999.
US Referenced Citations (59)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0 257 744 |
Jan 1995 |
EP |
WO 9427022 |
Nov 1994 |
WO |
Non-Patent Literature Citations (1)
Entry |
“Kolibomac to Challenge Tradition.” Norwegian Oil Review, 1988, pp. 50 & 52. |
Provisional Applications (3)
|
Number |
Date |
Country |
|
60/112733 |
Dec 1998 |
US |
|
60/129503 |
Apr 1999 |
US |
|
60/168790 |
Dec 1999 |
US |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09/453996 |
Dec 1999 |
US |
Child |
09/916478 |
|
US |