Patent US3600779A successfully refreshed from Google Patents.
US3600779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Press roll with tapered grooves
Assignee: Allis Chalmers Corp
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Filing: 1969-12-12
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Granted: 1971-08-24
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Expires: 1989-12-12
Abstract
Abstract A grooved press roll shell is disclosed for dewatering a newly formed web of paper. The shell may be grooved with a continuous helical groove in its periphery. The groove presents a continuous radially inward converging taper from the outer cylindrical surface of the roll to the bottom of the groove. The bottom of the groove is defined by a cylindrical surface concentric to the outer cylindrical surface of the roll. The groove tapers inwardly for a distance which is preferably more than twice the width of the groove at the outer periphery of the roll, to define an included angle preferably in a range of from 8* to 10* and a bottom surface between one-half and two-thirds of the width of the groove at the outer periphery of the roll. The continuous taper of the flat bottom groove from the roll surface radially inward to such depth provides desired dewatering without an undesired counter pressure of water trapped in the groove and without the groove become clogged or plugged with felt hair or fiber.
Inventors
- 👤 Donald B Denoyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:15
CPC Classifications
D; D21; D21F; D21F3/00; D21F3/02; D21F3/08; D21F3/086; Y; Y10; Y10S; Y10S162/00; Y10S162/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
164 words
In a generally cylindrical press roll shell adapted to be mounted for rotation about its centroidal axis and to present to a pressure nip a peripheral rotary surface portion, said surface portion having alternating generally circumferentially aligned grooves and ridges, the ridges having an outer periphery presenting a cylindrical surface concentric to the centroidal axis, and the grooves having a radially inner portion projecting radially inward of the adjacent outer cylindrical surfaces of adjacent ridges by a distance greater than the distance between the adjacent outer cylindrical surfaces of adjacent ridges, the improvement comprising: each said groove having a pair of sidewalls presenting a continuous radially inward converging taper from the adjacent outer cylindrical surfaces of adjacent ridges to the radially inner portion of each said groove and with said continuous taper converging for a distance greater than the distance between the adjacent outer cylindrical surfaces of adjacent ridges; and said sidewalls convergingly tapering to define an included angle from about 5* to 15*.
Claim 2
Dependent Claim
164 words
In a generally cylindrical press roll shell adapted to be mounted for rotation about its centroidal axis and to present to a pressure nip a peripheral rotary surface portion, said surface portion having alternating generally circumferentially aligned grooves and ridges, the ridges having an outer periphery presenting a cylindrical surface concentric to the centroidal axis, and the grooves having a radially inner portion projecting radially inward of the adjacent outer cylindrical surfaces of adjacent ridges by a distance greater than the distance between the adjacent outer cylindrical surfaces of adjacent ridges, the improvement comprising: each said groove having a pair of sidewalls presenting a continuous radially inward converging taper from the adjacent outer cylindrical surfaces of adjacent ridges to the radially inner portion of each said groove and with said continuous taper converging for a distance greater than the distance between the adjacent outer cylindrical surfaces of adjacent ridges; and said sidewalls convergingly tapering to define an included angle from about 5* to 15*.
Claim 3
Dependent Claim
67 words
In a roll shell according to claim 1, said radially inner portion of said grooves presenting an inner cylindrical groove surface concentric to the outer periphery of the ridges and the centroidal axis; and said inner cylindrical groove surface having a width, measured along a line parallel to the centroidal axis, that measures between one-half and two-thirds the distance between adjacent outer cylindrical surfaces of adjacent ridges.
Claim 4
Dependent Claim
38 words
In a roll shell according to claim 1, the taper presented by the pair of sidewalls converging continuously and radially inward for a distance at least twice the distance between the adjacent outer cylindrical surfaces of adjacent ridges.
Claim 5
Dependent Claim
22 words
In a roll shell according to claim 2 said sidewalls convergingly tapering to define an included angle from about 8* to 10*.
Claim 6
Dependent Claim
36 words
In a roll shell according to claim 3 and in which the grooves in said surface portion presented to a pressure nip, are all portions of a single cOntinuous spiral groove about the cylindrical roll shell.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |