US4551256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slurry excavating method
Assignee: Ohbayashi Gumi Ltd
•
Filing: 1982-06-02
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Granted: 1985-11-05
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Expires: 2002-06-02
Abstract
Abstract A slurry excavating method for excavating the ground or drilling a hole using excavating slurry containing a powder of water absorbing resin. This method makes it easy to prevent the slurry from flowing into gaps in the ground or cracks in fractured shale layer or fissile layer while excavating the ground.
Inventors
- 👤 Daizo Kita
- 👤 Tsutomu Nakamura
- 👤 Takeshi Kawachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:06
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24; E; E21; E21B; E21B21/00; E21B21/003; Y; Y10; Y10S; Y10S507/00; Y10S507/903
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
102 words
A slurry excavating method for excavating ground or drilling a hole by means comprising introducing onto the ground or into the hole a slurry containing a powder of a water absorbing resin which is capable of absorbing at least 10 times its own weight in water and retaining its shape without dissolving when swollen by water, said water absorbing resin being a crosslinked copolymer of an α-olefin and a maleic acid compound selected from the group consisting of maleic acid, maleic acid anhydride, maleinamic acid and maleinimide, whereby loss of water from said slurry employed in said slurry excavating method is prevented.
Claim 2
Dependent Claim
102 words
A slurry excavating method for excavating ground or drilling a hole by means comprising introducing onto the ground or into the hole a slurry containing a powder of a water absorbing resin which is capable of absorbing at least 10 times its own weight in water and retaining its shape without dissolving when swollen by water, said water absorbing resin being a crosslinked copolymer of an α-olefin and a maleic acid compound selected from the group consisting of maleic acid, maleic acid anhydride, maleinamic acid and maleinimide, whereby loss of water from said slurry employed in said slurry excavating method is prevented.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the water absorbing resin is a crosslinked copolymer of an α-olefin and maleic acid anhydride.
Claim 4
Dependent Claim
11 words
A method according to claim 1 wherein the α-olefin is isobutylene.
Claim 5
Dependent Claim
37 words
A method according to claim 1 wherein the water absorbing resin is used as a composite of the water absorbing resin and inorganic powder particles to prevent the resin from floating to the surface of the slurry.
Claim 6
Dependent Claim
25 words
A method according to claim 4 wherein the composite is one in which the inorganic powder particles are entirely covered with the water absorbing resin.
Claim 7
Dependent Claim
25 words
A method according to claim 4 wherein the specific gravity of the composite after having absorbed water is in the range of 1.02 to 1.25.
Claim 8
Dependent Claim
61 words
A method according to claim 4 wherein the composite is obtained by adding the inorganic powder particles to an aqueous solution of the copolymer and a crosslinking agent for the copolymer, in a ratio of 0.1 to 10 wt % of the inorganic powder particles with respect to the weight of the copolymer, and dehydrating and heat treating the resultant mixture.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |