Patent US4284247A successfully refreshed from Google Patents.
US4284247A
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US
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Apparatus for defibrating and conditioning nonflowable cellulosic material
Assignee: Metso Fiber Karlstad AB
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Filing: 1979-01-15
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Granted: 1981-08-18
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Expires: 1999-01-15
Abstract
Abstract An apparatus is provided for the defibration and conditioning of nonflowable cellulosic material, comprising a housing having an inlet and an outlet and a flow chamber for cellulose material therebetween; two screws disposed in the chamber and extending from the inlet to the outlet, the screws having interdigitating helical blades with opposed pitches, and helical grooves therebetween receiving the helical blades of the opposite screws; the screws being arranged for interdigitating rotational movement in opposite directions, so as to defibrate and condition cellulosic material in the bite therebetween while carrying the material through the flow chamber from the inlet towards the outlet; at least a portion of the outer periphery of each helical blade being undulating in a plurality of successive recesses and projections, intermeshing short of contact with a like plurality of projections and recesses defining a land area in the groove of the opposite blade of the other screw, so that within the land areas in the bite of the screws the intermeshing projections of one groove occupy at least part of the recesses in the blade of the other screw to extend the filled-in area of the blade surface along each screw, for improved screw efficiency in defibration and conditioning of the cellulosic material, and transport of the material through the flow chamber.
Inventors
- 👤 Erik F. Eriksson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:01
CPC Classifications
B; B30; B30B; B30B11/00; B30B11/22; B30B11/24; B30B11/243; B30B11/246; D; D21; D21B; D21B1/00; D21B1/04; D21B1/12; D21B1/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
214 words
Apparatus for the defibration and conditioning of nonflowable cellulosic material comprising a housing having an inlet and an outlet and a flow chamber for cellulose material therebetween; two screws disposed in the chamber and extending from the inlet to the outlet, the screws having interdigitating helical blades with opposed pitches, and helical grooves therebetween interdigitatingly receiving the helical blades of the opposite screws; the screws being arranged for interdigitating rotational movement in opposite directions, so as to defibrate and condition cellulosic material in the bite therebetween while carrying the material through the flow chamber from the inlet towards the outlet; at least a portion of the outer periphery of each helical blade being undulating in a plurality of successive recesses and projections, intermeshing short of contact with a like plurality of projections and recesses defining a land area in the groove of the opposite blade of the other screw, so that within the land areas in the bite of the screws the intermeshing projections of one groove occupy at least part of the recesses in the blade of the other screw, to extend the filled-in area of the blade surface along each screw, for improved screw efficiency in defibration and conditioning of the cellulosic material, and transport of the material through the flow chamber.
Claim 2
Dependent Claim
214 words
Apparatus for the defibration and conditioning of nonflowable cellulosic material comprising a housing having an inlet and an outlet and a flow chamber for cellulose material therebetween; two screws disposed in the chamber and extending from the inlet to the outlet, the screws having interdigitating helical blades with opposed pitches, and helical grooves therebetween interdigitatingly receiving the helical blades of the opposite screws; the screws being arranged for interdigitating rotational movement in opposite directions, so as to defibrate and condition cellulosic material in the bite therebetween while carrying the material through the flow chamber from the inlet towards the outlet; at least a portion of the outer periphery of each helical blade being undulating in a plurality of successive recesses and projections, intermeshing short of contact with a like plurality of projections and recesses defining a land area in the groove of the opposite blade of the other screw, so that within the land areas in the bite of the screws the intermeshing projections of one groove occupy at least part of the recesses in the blade of the other screw, to extend the filled-in area of the blade surface along each screw, for improved screw efficiency in defibration and conditioning of the cellulosic material, and transport of the material through the flow chamber.
Claim 3
Dependent Claim
48 words
Apparatus according to claim 1 in which the intermeshing of like projections and recesses in the helical blades and grooves of opposed screws is sufficiently complete to make possible an additional stage of radial compression at the peripheries of the blade between the intermeshing projections and recesses themselves.
Claim 4
Dependent Claim
52 words
Apparatus according to claim 1 in which the screws comprise rotatable screw shafts enclosed in cylinders rotatable therewith, and the intermeshing sets of recesses and projections in the helical grooves of each screw are provided at the base of the grooves by an undulating surface on the cylinder enclosing the screw shaft.
Claim 5
Dependent Claim
65 words
Apparatus according to claim 1 in which the intermeshing set of recesses and projections define a land area in the grooves that is spaced from the bottom of the grooves, and is in the form of rods extending axially between adjacent helical blade portions opposite the base of recessed portions of the blades, and serving as projections, and spaces between the rods serving as recesses.
Claim 6
Dependent Claim
58 words
Apparatus according to claim 1 in which the intermeshing set of recesses and projections define a land area in the grooves that is spaced from the bottom of the grooves, and is in the form of rods extending axially between projections on the adjacent helical blade portions and serving as projections, and spaced between the rods and recesses.
Claim 7
Dependent Claim
20 words
Apparatus according to claim 1 in which the projections are in the form of beads fixedly mounted in the grooves.
Claim 8
Dependent Claim
27 words
Apparatus according to claim 6 in which the beads are spaced radially from the base of the grooves and are fixedly mounted between adjacent helical blade portions.
Claim 9
Dependent Claim
31 words
Apparatus according to claim 6 in which the beads extend along the screw shaft the entire length of the helical blade portion in which the periphery of the blade is undulating.
Claim 10
Dependent Claim
22 words
Apparatus according to claim 6 in which the beads extend axially of the screw through openings in the adjacent helical blade portions.
Claim 11
Dependent Claim
21 words
Apparatus according to claim 6 in which the beads increase in size in the direction towards the outlet of the chamber.
Claim 12
Dependent Claim
21 words
Apparatus according to claim 6 in which the beads decrease in size in the direction towards the outlet of the chamber.
Claim 13
Dependent Claim
20 words
Apparatus according to claim 1 in which the projections and recesses themselves have undulating projections and recesses on their peripheries.
Claim 14
Dependent Claim
12 words
Apparatus according to claim 12 in which the undulating form constitutes serrations.
Claim 15
Dependent Claim
22 words
Apparatus according to claim 12 in which the undulating peripheral surfaces are arranged on removable elements mounted on the projections and recesses.
Claim 16
Dependent Claim
13 words
Appparatus according to claim 14 in which the adjacent elements abut one another.
Claim 17
Dependent Claim
15 words
Apparatus according to claim 1 in which the projections are removably mounted in the grooves.
Claim 18
Dependent Claim
26 words
Apparatus according to claim 1 in which the projections defining land areas in the groove of the opposite blade extend all the way across the groove.
Claim 19
Dependent Claim
28 words
Apparatus according to claim 1 in which the projections defining land areas in the groove of the opposite blade extend only part of the way across the groove.
Claim 20
Dependent Claim
27 words
Apparatus according to claim 1 in which the projections defining land areas in the groove of the opposite blade extend upwardly from the bottom of the groove.
Claim 21
Dependent Claim
27 words
Apparatus according to claim 1 in which the projections defining land areas in the groove of the opposite blade extend into the groove from the helical blade.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |