US4242002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Agitator means for tower type abrasion mills
Assignee: KUBOTA TOWER MILL Co Ltd A CORP OF JAPAN
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Filing: 1979-05-07
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Granted: 1980-12-30
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Expires: 1999-05-07
Abstract
Abstract An agitator for tower type abrasion mills has a screw blade assembly composed of an inner screw blade and a number of outer screw blade units each having a fixed size. The outer blade units are positioned side by side along the peripheral portions of the inner blade and are fixed thereto. This realizes a long life of the agitator, low repair costs, and a remarkably short work stoppage period for the repair.
Inventors
- 👤 Shigekatsu Kawabata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:46
CPC Classifications
B; B02; B02C; B02C17/00; B02C17/16; B02C17/163; B01; B01F; B01F27/00; B01F27/05; B01F27/11; B01F27/114; B01F27/1143; B01F27/051; B01F27/052
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
177 words
Agitator means, for tower type abrasion mills, comprising a continuous helical blade assembly, said helical blade assembly being composed of: (i) a center shaft, (ii) an inner helical blade of fixed pitch secured on the periphery of said center shaft (iii) a segmental outer helical blade of the same pitch as said inner helical blade, said outer helical blade being composed of a plurality of outer blade segments placed end to end, said outer blade segments being secured removably on said inner helical blade, said segmental outer helical blade having an inner circumferential periphery spaced radially from and coaxial with said center shaft, said segmental outer helical blade having its external diameter greater than the external diameter of said inner helical blade, said segmental outer helical blade having its external circumferential periphery coaxial with said center shaft, each of said outer blade segments including a radially inner portion and a radially outer portion, said radially outer portion being relatively axially thicker than said radially inner portion, each of said outer blade segments having the same angular extent.
Claim 2
Dependent Claim
177 words
Agitator means, for tower type abrasion mills, comprising a continuous helical blade assembly, said helical blade assembly being composed of: (i) a center shaft, (ii) an inner helical blade of fixed pitch secured on the periphery of said center shaft (iii) a segmental outer helical blade of the same pitch as said inner helical blade, said outer helical blade being composed of a plurality of outer blade segments placed end to end, said outer blade segments being secured removably on said inner helical blade, said segmental outer helical blade having an inner circumferential periphery spaced radially from and coaxial with said center shaft, said segmental outer helical blade having its external diameter greater than the external diameter of said inner helical blade, said segmental outer helical blade having its external circumferential periphery coaxial with said center shaft, each of said outer blade segments including a radially inner portion and a radially outer portion, said radially outer portion being relatively axially thicker than said radially inner portion, each of said outer blade segments having the same angular extent.
Claim 3
Dependent Claim
21 words
Agitator means, for tower type abrasion mills, as claimed in claim 7, wherein said angular extent does not exceed 180 degrees.
Claim 4
Dependent Claim
19 words
Agitator means, for tower type abrasion mills, as claimed in claim 2, wherein said angular extent is 180 degrees.
Claim 5
Dependent Claim
19 words
Agitator means, for tower type abrasion mills, as claimed in claim 2, wherein said angular extent is 120 degrees.
Claim 6
Dependent Claim
19 words
Agitator means, for tower type abrasion mills, as claimed in claim 2, wherein said angular extent is 90 degrees.
Claim 7
Dependent Claim
28 words
Agitator means, for tower type abrasion mills, as claimed in claim 1, wherein said outer blade segments are secured to said inner helical blade by bolts and nuts.
References Cited (Backward Citations)
US3469824A
Cited
US3770214A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-30 | 1984-06-30 | 1984-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-30 | 1988-06-30 | 1988-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-30 | 1992-06-30 | 1992-12-30 | $7700.00 | Window Closed / Lapsed |