Patent US3840430A successfully refreshed from Google Patents.
US3840430A
Expired / Lapsed
US
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Twin-wire papermaking machine wherein the forming wires pass through the slice chamber which contains flexible trailing elements
Assignee: Beloit Corp
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Filing: 1972-06-30
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Granted: 1974-10-08
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Expires: 1992-06-30
Abstract
Abstract A twin-wire papermaking machine wherein the forming wires are guided into and through an elongate tapered slice chamber prior to entering a dewatering run. The slice chamber is formed in part by imperforate plates over which the wires move, and non-porous backing belts are guided to pass with the forming wires over the plates to control dewatering. Within the slice chamber are located flexible elements in sheet or filament form to control large scale turbulence. Clear or white water is supplied between the forming wires and the outermost elements in the slice chamber for lubrication purposes.
Inventors
- 👤 D Ely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:16
CPC Classifications
D; D21; D21F; D21F9/00; D21F9/003
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
144 words
In a machine for forming a web from a slurry of stock, the combination comprising, a headbox with a main chamber for discharging stock and having a tapered slice chamber immediately downstream of the headbox chamber, a pair of traveling forming wires guided to form the walls of said tapered slice chamber and leading into a pressure forming throat followed by a dewatering forming zone, means for preventing the flow of liquid through the wires in said slice zone, a plurality of flexible trailing elements in the slice chamber anchored at their upstream ends to a support means within their downstream ends free of attachment and self-positionable from stock flowing through said slice chamber, and means for supplying sheets of water at the upstream ends of the trailing elements between the outermost elements and the forming wires to form a layer of water therebetween.
Claim 2
Dependent Claim
144 words
In a machine for forming a web from a slurry of stock, the combination comprising, a headbox with a main chamber for discharging stock and having a tapered slice chamber immediately downstream of the headbox chamber, a pair of traveling forming wires guided to form the walls of said tapered slice chamber and leading into a pressure forming throat followed by a dewatering forming zone, means for preventing the flow of liquid through the wires in said slice zone, a plurality of flexible trailing elements in the slice chamber anchored at their upstream ends to a support means within their downstream ends free of attachment and self-positionable from stock flowing through said slice chamber, and means for supplying sheets of water at the upstream ends of the trailing elements between the outermost elements and the forming wires to form a layer of water therebetween.
Claim 3
Dependent Claim
39 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 1 wherein said trailing members are in the form of sheets extending in a cross-machine direction parallel to the wires.
Claim 4
Dependent Claim
33 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 1, the combination wherein said trailing members are in the form of individual filaments.
Claim 5
Dependent Claim
48 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 1, the combination including a plurality of passages in the headbox in advance of the slice zone extending parallel to the flow of the stock toward the slice zone.
Claim 6
Dependent Claim
61 words
In a machine for forming a web from a slurry of stock, the combination in accordance with claim 1 wherein said means for preventing the flow of liquid through the wires is in the form of firsT and second nonporous support belts positioned outside of said wires opposite said tapered slice chamber preventing flow from the slice chamber through the wires.
Claim 7
Dependent Claim
50 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 5 wherein said support belts are supported on rolls positioned at the upstream end and downstream end of said slice chamber and the rolls at the downstream end define said throat.
Claim 8
Dependent Claim
48 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 5 wherein at least one of said belts diverges in an acute angle from the wire downstream of the throat aiding in dewatering of the web through the wire.
Claim 9
Dependent Claim
40 words
In a paper making machine for making a web from a slurry of stock constructed in accordance with claim 5 wherein one of said belts extends parallel to the dewatering zone along the wire for a distance following the throat.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |