US3597818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rectifier roll
Assignee: Beloit Corp
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Filing: 1969-04-10
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Granted: 1971-08-10
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Expires: 1989-04-10
Abstract
Abstract A tubular rectifier roll for use in a paper machine headbox is provided with tapered radial perforations of streamlined contour which impart essentially uniform and nonturbulent rectilinear flow to the paper stock emerging from the downstream side of the roll and entering the headbox slice, thereby insuring uniform deposition of the paper stock onto a paper-forming surface.
Inventors
- 👤 Ralph A Beck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:59
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
111 words
A papermaking machine rectifier roll comprising a cylindrical tubular shell including surface means defining therein a repetitive pattern of similar holes extending through said shell, said holes being inversely tapered outwardly toward the exterior of said shell and streamlined at their extremities such that fluid emerging from the interior of said shell through laterally adjacent ones of said holes is combined into a substantially nonturbulent flow pattern of relatively uniform velocity extending along the length of said roll, said holes being disposed at uniform intervals along uniformly spaced parallel rows of such holes extending lengthwise of said roll, said holes further being staggered from row to row in a repetitive pattern.
Claim 2
Dependent Claim
111 words
A papermaking machine rectifier roll comprising a cylindrical tubular shell including surface means defining therein a repetitive pattern of similar holes extending through said shell, said holes being inversely tapered outwardly toward the exterior of said shell and streamlined at their extremities such that fluid emerging from the interior of said shell through laterally adjacent ones of said holes is combined into a substantially nonturbulent flow pattern of relatively uniform velocity extending along the length of said roll, said holes being disposed at uniform intervals along uniformly spaced parallel rows of such holes extending lengthwise of said roll, said holes further being staggered from row to row in a repetitive pattern.
Claim 3
Dependent Claim
24 words
A rectifier roll according to claim 1 in which said holes are disposed in generally radial relation to the axis of said tubular shell.
Claim 4
Dependent Claim
53 words
A rectifier roll according to claim 2 in which said holes are disposed at substantially uniform distances from adjacent ones thereof, each adjacent pair of said holes defining therebetween a shell ligament which is of generally teardrop shaped cross-sectional profile along a cutting plane generally normal to the exterior surface of said 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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |