US3661706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air loaded headbox for a papermaking machine having vertically aligned vanes therein
Assignee: Allis Chalmers Corp
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Filing: 1970-11-06
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Granted: 1972-05-09
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Expires: 1990-11-06
Abstract
Abstract An airloaded headbox for a papermaking machine having an air chamber above vertical rectangular guide vanes defining horizontally extending channels between adjacent vanes for the flow of dilute paper stock toward a slice opening over a Fourdrinier wire. The guide vanes are provided with keys projecting vertically upward from each of the upper corners of each vane and with keys projecting horizontally from each of the four corners of each vane. The keys project into keyways defined by lands and shelves projecting toward the guide vanes from vertical front and rear wall assemblies of the headbox. Three spacers are arranged between each pair of adjacent vanes, with a first of the spacers providing a channel floor and a second and third of the spacers horizontally spaced apart and adjacent the upper corners of each vane and defining therebetween a channel top open to the air chamber for air loading stock flowing horizontally through the channels. The first spacer has a horizontally extending key on each end. The second and third spacers each have a vertical key projecting upwardly and a horizontal key projecting toward the adjacent vertical end wall. Each of the keys of both the vanes and the spacers, in side abutting and alternating arrangement, project into keyways in register therewith. The keyways support the vanes and spacers, with the vanes and channel floor spacers between front and rear wall assemblies providing for cross-machine deflection of the floor of the flow passages, due pressure of pulp stock therein, which is both minimized and made independent of headbox width. The vertical keys of the vanes provide for the vanes to tie together the front and rear wall assemblies to minimize deflection of the front wall assembly and slice defining structure toward the slice opening.
Inventors
- 👤 Donald B De Noyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:11
CPC Classifications
D; D21; D21F; D21F1/00; D21F1/02; D21F1/024; D21F1/026; D21F1/028
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
348 words
In an air loaded headbox for a papermaking machine having a stock flow chamber defined by a vertical front wall assembly, a vertical rear wall assembly, and a horizontal structure defining a floor between the front and rear wall assemblies; a structure defining a stock inlet chamber communicating through an opening defined in the rear wall assembly, structure defining a stock outlet chamber with a slice opening and communicating through an opening defined in the front wall assembly, and a plurality of parallel and vertical guide vanes projecting upwardly from the floor and means defining stock flow channels therebetween with each vane projecting on one end thereof to the opening in the rear wall assembly and on the other end thereof to the opening in the front wall assembly, each said vanes being generally rectangular and having an upper horizontal edge, with the upper horizontal edge of adjacent vanes providing the channels with top portions open upwardly thereof, the improvement comprising: a. each vane having a first key projecting vertically upward from each vane and adjacent the end of the vane projecting to the front wall opening; b. each vane having a second key projecting vertically upward from each vane and adjacent the end of the vane projecting to the rear wall opening; c. a first land connected to the front wall assembly and projecting vertically downward and spaced from the front wall assembly on the channel side thereof and defining a first vertically extending keyway in the front wall assembly above the opening therethrough; d. a second land connected to the rear wall assembly and projecting vertically downward and spaced from the rear wall asSembly on the channel side thereof and defining a second vertically extending keyway in the rear wall assembly above the opening therethrough; and e. the first key projecting into the first keyway and the second key projecting into the second keyway to thereby utilize the vanes to tie together the front and rear vertical wall assemblies above the openings therethrough and minimize deflection of the front vertical wall assembly and slice defining structure.
Claim 2
Dependent Claim
348 words
In an air loaded headbox for a papermaking machine having a stock flow chamber defined by a vertical front wall assembly, a vertical rear wall assembly, and a horizontal structure defining a floor between the front and rear wall assemblies; a structure defining a stock inlet chamber communicating through an opening defined in the rear wall assembly, structure defining a stock outlet chamber with a slice opening and communicating through an opening defined in the front wall assembly, and a plurality of parallel and vertical guide vanes projecting upwardly from the floor and means defining stock flow channels therebetween with each vane projecting on one end thereof to the opening in the rear wall assembly and on the other end thereof to the opening in the front wall assembly, each said vanes being generally rectangular and having an upper horizontal edge, with the upper horizontal edge of adjacent vanes providing the channels with top portions open upwardly thereof, the improvement comprising: a. each vane having a first key projecting vertically upward from each vane and adjacent the end of the vane projecting to the front wall opening; b. each vane having a second key projecting vertically upward from each vane and adjacent the end of the vane projecting to the rear wall opening; c. a first land connected to the front wall assembly and projecting vertically downward and spaced from the front wall assembly on the channel side thereof and defining a first vertically extending keyway in the front wall assembly above the opening therethrough; d. a second land connected to the rear wall assembly and projecting vertically downward and spaced from the rear wall asSembly on the channel side thereof and defining a second vertically extending keyway in the rear wall assembly above the opening therethrough; and e. the first key projecting into the first keyway and the second key projecting into the second keyway to thereby utilize the vanes to tie together the front and rear vertical wall assemblies above the openings therethrough and minimize deflection of the front vertical wall assembly and slice defining structure.
Claim 3
Dependent Claim
99 words
In a headbox according to claim 1, wherein said means defining stock flow channels between said guide vanes includes three spacers between adjacent vanes, a first of the spacers being adjacent a lower horizontal edge of the vanes and extending horizontally between the front and rear wall openings and upwardly a predetermined distance to provide a stock flow channel floor, and a second and third of the spacers being horizontally spaced apart and adjacent the vane first and second keys respectively in side abutting relation therewith, the second and third of the spacers defining therebetween a channel top opening.
Claim 4
Dependent Claim
68 words
In a headbox according to claim 2, the second and third spacers each having a key projecting upwardly and into one of the keyways and between keys of adjacent vanes. 4 In a headbox according to claim 2, horizontal structure spaced above the vanes and the second and third spacers defining an enclosed chamber for containing pressurized air for loading paper stock flowing through the open top channels.
Claim 5
Dependent Claim
139 words
In a headbox according to claim 1, a. a third keyway defined by a first horizontal shelf connected to the front wall assembly above the front wall opening and projecting toward the stock flow channels to define the third keyway below the first keyway and on the stock outlet chamber side of the first keyway; b. a fourth keyway defined by a second horizontal shelf connected to the rear wall assembly above the rear wall opening and projecting toward the first shelf to define the fourth keyway below the second keyway and on the stock inlet chamber side of the second keyway; and c. each vane having a third key projecting into the third keyway and a fourth key projecting into the fourth keyway to support each vane of the vanes between the front and rear vertical wall assemblies.
Claim 6
Dependent Claim
123 words
In a headbox according to claim 5, a. a fifth keyway defined by a third horizontal shelf connected to the front wall assembly below the front wall opening and projecting toward the stock flow channels to define the fifth keyway above the floor of the stock flow chamber; b. a sixth keyway defined by a fourth horizontal shelf connected to the rear wall assembly below the rear wall opening and projecting toward the stock floor channels to define the sixth keyway above the floor of the stock flow chamber; and c. each vane having a fifth key projecting into the fifth keyway and a sixth key projecting into the sixth keyway to support each vane between the front and rear vertical wall assemblies.
Claim 7
Dependent Claim
148 words
In a headbox according to claim 6, the first shelf being connected to the front wall by an upper front wall member movable upwardly relative to the first land and first keyway, a first screw operatively connected to the movable upper front wall member for raising the first shelf to clamp the third key in the third keyway and place the vanes in vertical tension between the third and fifth vane keys when the headbox is pressurized, the second shelf being connected to the rear wall by an upper rear wall member movable upwardly relative to the second land and second keyway, and a second screw operatively connected to the movable upper rear wall member for raising the second shelf to clamp the fourth key in the fourth keyway and place the vanes in vertical tension between the fourth and sixth vane keys when the headbox is pressurized.
Claim 8
Dependent Claim
150 words
In a headbox according to claim 7, the third shelf being connected to the front wall by a lower front wall member movable downwardly relative to the stock flow chamber floor and fifth keyway, a third screw operatively connected to the movable lower front wall member for lowering the third shelf to clamp the fifth key in the fifth keyway to hold the vanes in vertical tension between the third and fifth keys when the headbox is pressurized, the fourth shelf being connected to the rear wall by a lower rear wall member movable downwardly relative to the stock flow chamber floor and sixth keyway, and a fourth screw operatively connected to the lower movable rear wall member for lowering the fourth shelf to clamp the sixth key in the sixth keyway to hold the vanes in vertical tension between the fourth and sixth keys when the headbox is pressurized.
Claim 9
Dependent Claim
193 words
In a headbox according to claim 6, three spacers between adjacent vanes, a first of the spacers being adjacent a lower horizontal edge of the vanes and extending horizontally between the front and rear wall openings and upwardly a predetermined distance to provide a stock flow channel floor, and a second and third of the spacers being horizontally spaced apart and adjacent the vane first and second keys respectively in side abutting relation therewith, the second and third of the spacers defining therebetween a channel top opening, the first spacer having a key on the front wall end thereof projecting into the fifth keyway between adjacent fifth keys of adjacent vanes and the first spacer having a key on the rear wall end thereof projecting into the sixth keyway between adjacent sixth keys of adjacent vanes, the second spacer having a key projecting into the first keyway and a key projecting into the third keyway between first and third keys respectively of adjacent vanes, and the third spacer having a key projecting into the second keyway and a key projecting into the fourth keyway between second and fourth keys respectively of adjacent vanes.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |