Patent US2175886A successfully refreshed from Google Patents.
US4704191A
Expired / Lapsed
US
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Electromagnetic extended nip press
Assignee: Beloit Technologies Inc
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Filing: 1986-05-06
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Granted: 1987-11-03
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Expires: 2006-05-06
Abstract
Abstract Extended nip presses for papermaking machines and the like are provided with electromagnets immediately adjacent the press nip to create or augment the nip pressures or loads. The electromagnets have massive, wide large areas, establishing a concentrated magnetic field between conforming opposite sides of the entire nip area eliminating gaps heretofore encountered in magnetic presses. Non-magnetic belts convey wet webs through the nips of dewatering presses and dry web calendering presses can have the webs directly engage a calender roll conveying the web through the nip.
Inventors
- 👤 Gregory L. Wedel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:40
CPC Classifications
D; D21; D21F; D21F3/00; D21F3/02; D21F3/0209; D21F3/0218; D21F3/06; D21F7/00; D21F7/06; Y; Y10; Y10S; Y10S100/00; Y10S100/917
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
216 words
An extending nip press for a papermaking machine through which a formed web passes comprising a non-magnetic impermeable belt, a felt, and an extended nip defined by a first nip member and a second nip member which conforms to the first nip member, mounting means for one of said nip members permitting movement toward and away from the other nip member, said press further comprising in combination electromagnetic means disposed within the first nip member for generating flux for electromagnetically cooperating with the second nip member, said electromagnetic means being coextensive with the extended nip in a direction transverse to the direction of movement of the web through the nip, a non-magnetic shoe supported by and covering said electromagnetic means disposed between said electromagnetic means and the belt to be urged against the belt upon excitation of said electromagnetic means for generating sufficient force between the second nip member and the felt to remove water from the web by pressure, and said shoe having a thickness selected for minimizing the distance between the electromagnetic means and the second nip member such that substantially all of said flux passes through said shoe to said second nip member with substantially no air gap therebetween for increasing the pressure exerted on the web during excitation of said electromagnetic means.
Claim 2
Dependent Claim
216 words
An extending nip press for a papermaking machine through which a formed web passes comprising a non-magnetic impermeable belt, a felt, and an extended nip defined by a first nip member and a second nip member which conforms to the first nip member, mounting means for one of said nip members permitting movement toward and away from the other nip member, said press further comprising in combination electromagnetic means disposed within the first nip member for generating flux for electromagnetically cooperating with the second nip member, said electromagnetic means being coextensive with the extended nip in a direction transverse to the direction of movement of the web through the nip, a non-magnetic shoe supported by and covering said electromagnetic means disposed between said electromagnetic means and the belt to be urged against the belt upon excitation of said electromagnetic means for generating sufficient force between the second nip member and the felt to remove water from the web by pressure, and said shoe having a thickness selected for minimizing the distance between the electromagnetic means and the second nip member such that substantially all of said flux passes through said shoe to said second nip member with substantially no air gap therebetween for increasing the pressure exerted on the web during excitation of said electromagnetic means.
Claim 3
Dependent Claim
26 words
The press of claim 1 wherein the second nip member is a ferromagnetic roll and the shoe has an arcuate configuration conforming with the roll periphery.
Claim 4
Dependent Claim
28 words
The press of claim 1 wherein the first and second nip members each have electromagnetic means disposed therein and a non-magnetic shoe is supported by each electromagnetic means.
Claim 5
Dependent Claim
49 words
The press of claim 1 wherein the electromagnetic means has a ferromagnetic core block traversing the full width of the formed web with an open top slot along the length thereof covered by the shoe, and an exciting coil of the electromagnetic means has a leg filling said slot.
Claim 6
Dependent Claim
34 words
The press of claim 4 wherein the core block has a pair of parallel open top slots along the length thereof covered by the shoe and the exciting coil has legs filling both slots.
Claim 7
Dependent Claim
33 words
The press of claim 1 wherein the electromagnetic means has a core composed of a row of side-by-side slidable blocks covered by the shoe and an exciting coil is wrapped around each block.
Claim 8
Dependent Claim
15 words
The press of claim 1 wherein the felt is interposed between the belt and web.
Claim 9
Dependent Claim
21 words
The press of claim 1 wherein the second nip member is a ferromagnetic roll and the electromagnetic means heats the roll.
Claim 10
Dependent Claim
22 words
The press of claim 8 wherein the ferromagnetic roll has circumferential grooves forming channels for flow of water out of the nip.
Claim 11
Dependent Claim
20 words
The press of claim 1 wherein the belt is longitudinally grooved to form channels draining water out of the nip.
Claim 12
Dependent Claim
40 words
The press of claim 1 wherein the electromagnetic means includes a housing, a core shiftable in the housing toward the second nip and means in the housing urge the core toward the second nip to create an initial nip load.
Claim 13
Dependent Claim
42 words
The press of claim 1 including a plurality of pairs of first and second nip members defining a plurality of successive extended nips and wherein the belt is trained through all of the nips to convey the web successively through the nips.
Claim 14
Dependent Claim
26 words
The press of claim 12 wherein the second nip member of each press has a separate felt trained therethrough to cover the web on the belt.
Claim 15
Dependent Claim
39 words
The press of claim 13 wherein the second nip member of each press is a ferromagnetic roll and a separate felt is trained around each roll to cover the web as the belt conveys the web through the nips.
Claim 16
Dependent Claim
58 words
The press of claim 1 wherein the second nip member is a roll having a ferromagnetic cylindrical core, a stack of thin washer laminates surround the core radiating therefrom and composed of a metal which does not develop eddy currents in the magnetic field generated by the electromagnetic means, and means on the core squeeze the laminates together.
Claim 17
Dependent Claim
31 words
The press of claim 1 wherein the shoe has a lip diverging from the belt entering the nip and means adjacent the lip to introduce lubricant between the shoe and belt.
Claim 18
Dependent Claim
51 words
The press of claim 1 wherein the electromagnet has a row of separate core blocks extending across the width of the papermaking machinery, a separate exciting coil wound around each block, and means for variably energizing each exciting coil to control the strength of the magnetic field across the papermaking machinery.
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) | 1990-11-02 | 1991-05-04 | 1991-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-02 | 1995-05-04 | 1995-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-02 | 1999-05-04 | 1999-11-03 | $7700.00 | Window Closed / Lapsed |