US4430210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen
Assignee: Repola Oy
•
Filing: 1981-03-12
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Granted: 1984-02-07
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Expires: 2001-03-12
Abstract
Abstract A screen intended for screening pulp chips or equivalent, wherein two or more screen baskets are fitted one above the other. At least one of these baskets consists of two or more screw spirals journalled to the screen basket, the spiral wings of said spirals being fitted as interlocking in between each other. The outer circumference of each wing extends to the proximity of the mantle face of the core part of the adjoining spiral. The adjoining spirals are opposite-handed and have opposite directions of rotation, their rotation being synchronized in relation to each other, and the distance of the interlocking parts of the wings from each other corresponds to the maximum acceptable thickness of the chips. Two screen baskets fitted one above the other are supported by the frame, and they are connected to each other by units that permit free movement of vibration of one or both of the screen baskets. The movement of vibration is produced by transferring a cam shaft movement from one basket to the other.
Inventors
- 👤 Rolf Tuuha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:00
CPC Classifications
B; B07; B07B; B07B1/00; B07B1/28; B07B1/12; B07B1/14; B07B1/15; B07B1/42; B07B1/46; B07B9/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
129 words
A screen for the separation of an oversize fraction from pulp chips on the basis of the thickness of the chips, comprising a screen face having at least two synchronously driven screw spirals, each of said screw spirals includes a core part having a mantle face and a spiral wing secured around the core part, said spiral wings are arranged to interlock in between each other, an outer circumference of each wing extends to the proximity of the mantle face of the core part of the adjoining spiral, adjoining spirals are opposite-handed and have opposite directions of rotation, and the distance between the interlocking portions of the wings being less than the distance between mantle faces of adjoining spirals and corresponding to the maximum acceptable thickness of the chips.
Claim 2
Dependent Claim
129 words
A screen for the separation of an oversize fraction from pulp chips on the basis of the thickness of the chips, comprising a screen face having at least two synchronously driven screw spirals, each of said screw spirals includes a core part having a mantle face and a spiral wing secured around the core part, said spiral wings are arranged to interlock in between each other, an outer circumference of each wing extends to the proximity of the mantle face of the core part of the adjoining spiral, adjoining spirals are opposite-handed and have opposite directions of rotation, and the distance between the interlocking portions of the wings being less than the distance between mantle faces of adjoining spirals and corresponding to the maximum acceptable thickness of the chips.
Claim 3
Dependent Claim
21 words
The apparatus as claimed in claim 1, further comprising means for vibrating the screen face to assist movement of the chips.
Claim 4
Dependent Claim
73 words
A screen as claimed in claim 1, wherein the screen basket consisting of the spirals is supported on the frame by rolling units and is connected to a frame by a support pin substantially perpendicular to the bottom of the screen basket, the screen basket being permitted to turn about the pin by the effect of the vibration, said pin is placed in the proximity of the output end of the screen basket.
Claim 5
Dependent Claim
87 words
The apparatus as claimed in claim 1, further comprising at least one additional screen face fitted in a screen basket in addition to the screen face comprised of the eccentric spirals, the screen basket is connected to a stationary frame by units which permit movement of the screen basket by the effect of the force that results from the eccentrically rotating spirals, the eccentrically rotating spirals intensifying the screening movement of the spiral screen face and at the same time producing a vibrating movement of the basket.
Claim 6
Dependent Claim
58 words
The apparatus as claimed in claim 4, wherein a central axis of each spiral is parallel to the axis of rotation of the spiral and at a distance from same, the spirals being arranged so that the central axes of two adjoining spirals are located in opposite directions as viewed from the axis of rotation of each spiral.
Claim 7
Dependent Claim
97 words
The apparatus as claimed in claim 1, further comprising a vibrating screen fitted underneath the screen face comprised of the spirals and including two screen planes placed one above the other, said vibrating screen having a hole size in the upper plane which hole size is larger than a hole size of the lower plane, a desired quantity of cooking chips being passed to the lower plane from the upper plane through an adjustable opening, the size of the adjustable opening being such that the main portion of the cooking chips remain retained on the upper plane.
Claim 8
Independent Claim
121 words
A method for screening chips for pulp which have a thickness substantially smaller than their length and width, comprising the steps of permitting the chips to pass through slots the side walls of which are formed by surfaces partially overlapping and rotating around at least two parallel shafts, the distance between two adjacent side wall surfaces on two adjacent shafts being less than the distance between the adjacent shafts and corresponding to the maximum acceptable thickness of the chips, forming the surfaces of the slot side walls by an assembly of screw spirals, extending the circumference of each spiral to the proximity of a mantle surface of the shaft of an adjacent spiral, and rotating the adjacent spirals in opposite directions.
Claim 9
Independent Claim
121 words
A method for screening chips for pulp which have a thickness substantially smaller than their length and width, comprising the steps of permitting the chips to pass through slots the side walls of which are formed by surfaces partially overlapping and rotating around at least two parallel shafts, the distance between two adjacent side wall surfaces on two adjacent shafts being less than the distance between the adjacent shafts and corresponding to the maximum acceptable thickness of the chips, forming the surfaces of the slot side walls by an assembly of screw spirals, extending the circumference of each spiral to the proximity of a mantle surface of the shaft of an adjacent spiral, and rotating the adjacent spirals in opposite directions.
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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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |