US4376042A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chip sizing process
Assignee: Weyerhaeuser Co
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Filing: 1981-05-11
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Granted: 1983-03-08
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Expires: 2001-05-11
Abstract
Abstract A chip screening system has a primary screening station for dividing an incoming flow of chips into a first acceptable fraction and a second fraction having acceptable chips and also both oversized and overthick chips. The second fraction is directed to a second screening station where the incoming flow will again be fractionated into an acceptable flow being screened primarily according to thickness and a second fraction being composed of oversized and overthick chips. The second fraction is then directed to a size reducing station.
Inventors
- 👤 Robert A. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:15
CPC Classifications
B; B07; B07B; B07B9/00; D; D21; D21B; D21B1/00; D21B1/02; D21B1/023
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
167 words
A process for fractionating and sizing a flow of incoming wood chips from a known source into an output flow of chips falling in a predetermined size range with substantially all of the chips in the output flow having a thickness falling within a predetermined thickness range, comprising the steps of: directing the incoming flow to a primary screening station where at least two fractions are generated with a first fraction containing chips falling substantially within the predetermined acceptable size and thickness range and a second fraction comprising at least 30% by weight of the incoming flow having a substantial majority of the oversize and overthick chips together with a substantial amount of chips falling within the acceptable size and thickness range, and directing the second fraction to a second screening station where at least two fractions are generated with a fourth fraction containing chips falling substantially within the predetermined acceptable size and thickness range and a fifth fraction containing chips substantially all of which are overthick.
Claim 2
Dependent Claim
167 words
A process for fractionating and sizing a flow of incoming wood chips from a known source into an output flow of chips falling in a predetermined size range with substantially all of the chips in the output flow having a thickness falling within a predetermined thickness range, comprising the steps of: directing the incoming flow to a primary screening station where at least two fractions are generated with a first fraction containing chips falling substantially within the predetermined acceptable size and thickness range and a second fraction comprising at least 30% by weight of the incoming flow having a substantial majority of the oversize and overthick chips together with a substantial amount of chips falling within the acceptable size and thickness range, and directing the second fraction to a second screening station where at least two fractions are generated with a fourth fraction containing chips falling substantially within the predetermined acceptable size and thickness range and a fifth fraction containing chips substantially all of which are overthick.
Claim 3
Dependent Claim
20 words
The process as in claim 1 further including the step of directing the fifth fraction to a size reducing means.
Claim 4
Dependent Claim
25 words
The process as in claim 2 in which the size reducing means is a chip slicer generating chips falling substantially within the acceptable thickness range.
Claim 5
Dependent Claim
37 words
The process as in claim 2 further including the step of directing the fifth fraction past a metal removal means in order to remove metal elements prior to directing the fifth flow to the size reducing means.
Claim 6
Dependent Claim
34 words
The process as in claim 2 further including the step of directing the output flow from the size reducing means back to the primary screening station where it is merged into the incoming flow.
Claim 7
Dependent Claim
24 words
The process as in claim 2 including the step of collecting all fractions containing chips falling within the predetermined acceptable size and thickness range.
Claim 8
Dependent Claim
25 words
The process as in claim 1 in which a third fraction is generated containing chips falling substantially in a size range below the acceptable range.
Claim 9
Dependent Claim
16 words
The process as in claim 1 in which the primary screening station is a gyratory screen.
Claim 10
Dependent Claim
16 words
The process as in claim 1 in which the second screening station is a disc screen.
References Cited (Backward Citations)
SU311669A1
Cited
DE624046C
Cited
US780349A
Cited
US1529970A
Cited
US2966267A
Cited
US3279597A
Cited
US3220546A
Cited
US3337139A
Cited
US3530986A
Cited
US4050980A
Cited
US4043901A
Cited
US4167438A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-07 | 1986-09-06 | 1987-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-07 | 1990-09-06 | 1991-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-07 | 1994-09-06 | 1995-03-08 | $7700.00 | Window Closed / Lapsed |