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US4539075A Expired / Lapsed US ⏱️ 0.0 years remaining

Perforated sheet for the head box of a paper machine

Assignee: Tampella Oy AB
•
Filing: 1983-12-19
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Granted: 1985-09-03
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Expires: 2003-12-19
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Abstract

Abstract Perforated sheet for a head box of a paper machine, the perforated sheet being provided with a number of parallel flow passages starting from a common front face. The perforated sheet is provided with a set of feeding ducts which can be connected to a source of flushing liquid and which is connected, by means of flushing ducts, to the front face of the perforated sheet. The perforated sheet preferably consists of several rod elements, each of which is provided with a flow passage and which have been assembled as parallel to each other, side by side and one above the other, into an integrated package.

Inventors

  • 👤 Pekka Majaniemi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 22:02
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/02; D21F1/022; D21F1/026

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 126 words
A perforated sheet for a head box of a paper machine, comprising several rod elements each including a flow passage, said flow passages arranged in parallel into an integrated package and starting from a common front face of said perforated sheet and having inlet openings; said rod elements each being integrally formed with a feeding duct, said feeding ducts being substantially parallel to said front face of said perforated sheet and being connected to a source of flushing liquid to feed said flushing liquid through said feeding ducts; and said rod elements each being integrally formed with a flushing duct, said flushing ducts connecting said feeding ducts to said front face, and terminating in said front face at points between said inlet openings of said passages.
Claim 2
Dependent Claim 126 words
A perforated sheet for a head box of a paper machine, comprising several rod elements each including a flow passage, said flow passages arranged in parallel into an integrated package and starting from a common front face of said perforated sheet and having inlet openings; said rod elements each being integrally formed with a feeding duct, said feeding ducts being substantially parallel to said front face of said perforated sheet and being connected to a source of flushing liquid to feed said flushing liquid through said feeding ducts; and said rod elements each being integrally formed with a flushing duct, said flushing ducts connecting said feeding ducts to said front face, and terminating in said front face at points between said inlet openings of said passages.
Claim 3
Dependent Claim 25 words
Perforated sheet as claimed in claim 1, wherein said feeding duct in a rod element surrounds said flow passage annularly and is radially open outwards.
Claim 4
Dependent Claim 42 words
Perforated sheet as claimed in claim 2, wherein each rod element is provided with at least one flushing duct parallel to said flow passage and placed in the face of a portion of material between said feeding duct and said front face.
Claim 5
Dependent Claim 33 words
Perforated sheet as claimed in claim 1, wherein said rod elements have been assembled into a support frame and connected to said frame by means of fastening rods extending between said rod elements.
Claim 6
Dependent Claim 21 words
Perforated sheet as claimed in claim 4, wherein each rod element is provided with a locking groove for said fastening rods.
Claim 7
Dependent Claim 16 words
Perforated sheet as claimed in claim 1, wherein said rod elements have a rectangular cross-sectional shape.

References Cited (Backward Citations)

US2736247A Cited
US3791918A Cited
US3962031A Cited
US3970513A Cited
US4146427A Cited
US4198270A Cited
SE422091B Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-09-02 1989-03-04 1989-09-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-09-02 1993-03-04 1993-09-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-09-02 1997-03-04 1997-09-03 $7700.00 Window Closed / Lapsed

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