US3769154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressurized chambers for controlling deflection of papermaking machine headbox walls
Assignee: JM Voith GmbH
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Filing: 1970-12-02
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Granted: 1973-10-30
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Expires: 1990-12-02
Abstract
Abstract A closed, pressure operated, stock inlet box, especially for a papermaking machine, which has walls supporting the lips of the discharge nozzle. The lip supporting walls of the box are constructed as hollow girders and support for the walls is provided by supporting load relief girders adjacent the walls and confining therewith chambers which are pressurized. The load relief girders, according to the invention, are mounted inside the hollow girders of the walls to be supported thereby leading to a compact structure. Mechanical support elements, ribs, for example, disposed between the load relief girders and the supported walls transmit loads from the walls to the load relief girders in the event of loss of pressure in the pressure chambers.
Inventors
- 👤 K Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:27
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/02; D21F1/028
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
223 words
In a closed and pressure operated stock inlet box, especially for a papermaking machine, and having confining front, rear, and bottom walls and a laterally extending discharge nozzle, said nozzle comprising upper and lower lips, the upper lip of said nozzle extending from and supported by said front wall of said stock inlet box, and said lower lip extending from and supported by said bottom wall, hollow girder means extending transversely of the stock inlet box and connected to said lip supporting walls on the sides of said walls which face away from said stock inlet box from imparting stiffness to said lip supporting walls, at least one transversely extending load relief girder means disposed inside a respective hollow girder means and substantially coextensive therewith in the longitudinal direction, connecting means connected between the periphery of said load relief girder means and the respective said wall and confining a closed pressure chamber between the respective lip supporting wall and the side of the relief girder means facing the said wall, said connecting means permitting said relief girder means to flex relative to the respective said wall in the region of said relief girder means between the ends thereof, and means for supplying a pressure medium to said chamber for supporting the respective wall against deflection due to pressure inside said stock inlet box.
Claim 2
Dependent Claim
223 words
In a closed and pressure operated stock inlet box, especially for a papermaking machine, and having confining front, rear, and bottom walls and a laterally extending discharge nozzle, said nozzle comprising upper and lower lips, the upper lip of said nozzle extending from and supported by said front wall of said stock inlet box, and said lower lip extending from and supported by said bottom wall, hollow girder means extending transversely of the stock inlet box and connected to said lip supporting walls on the sides of said walls which face away from said stock inlet box from imparting stiffness to said lip supporting walls, at least one transversely extending load relief girder means disposed inside a respective hollow girder means and substantially coextensive therewith in the longitudinal direction, connecting means connected between the periphery of said load relief girder means and the respective said wall and confining a closed pressure chamber between the respective lip supporting wall and the side of the relief girder means facing the said wall, said connecting means permitting said relief girder means to flex relative to the respective said wall in the region of said relief girder means between the ends thereof, and means for supplying a pressure medium to said chamber for supporting the respective wall against deflection due to pressure inside said stock inlet box.
Claim 3
Dependent Claim
30 words
A stock inlet box according to claim 1 in which the connectioN of the ends of said load relief girder means to said hollow girder means comprises flexible inextensible elements.
Claim 4
Dependent Claim
47 words
A stock inlet box according to claim 2 in which said flexible elements seal said pressure chamber at the ends, and seal members along the sides of said chamber which are elongatable so as not to interfere with flexing of the respective said load relief girder means.
Claim 5
Dependent Claim
22 words
A stock inlet box according to claim 1 in which said hollow girder means are open at at least the ends thereof.
Claim 6
Dependent Claim
65 words
A stock inlet box according to claim 1 which includes spacer means disposed in said chamber between the respective lip supporting wall and the side of the load relief girder means facing the wall and free of at least one thereof and operable for transmitting loads from the said wall to the load relief girder means in the absence of pressure in said pressure chamber.
Claim 7
Dependent Claim
49 words
A stock inlet box according to claim 4 in which said spacer means are distributed in said pressure chamber and are dimensioned so as to engage both the said wall and the said load relief girder means when the said wall is free of pressure on both sides thereof.
Claim 8
Dependent Claim
35 words
A stock inlet box according to claim 1 which includes at least one said load relief girder means inside the hollow girder means for each of said lip supporting walls of the stock inlet box.
Claim 9
Dependent Claim
67 words
A stock inlet box accordng to claim 1 in which the stock inlet box wall supporting the lower lip of the nozzle forms the lower wall of the stock inlet box, said hollow girder means for said lower wall comprising a pair of hollow girders spaced longitudinally along the lower wall, and a said load relief girder means inside each said hollow girder of said lower wall.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |