US3649991A - Doctors for paper making machines - Google Patents
Doctors for paper making machines Download PDFInfo
- Publication number
- US3649991A US3649991A US861409A US3649991DA US3649991A US 3649991 A US3649991 A US 3649991A US 861409 A US861409 A US 861409A US 3649991D A US3649991D A US 3649991DA US 3649991 A US3649991 A US 3649991A
- Authority
- US
- United States
- Prior art keywords
- holder
- pressure
- plate
- blade
- edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
- D21G3/00—Doctors
- D21G3/005—Doctor knifes
Definitions
- ABSTRACT Primary Examiner-Leon G. Machlin Attorney-Watson, Cole, Grindle & Watson [5 7] ABSTRACT
- the invention provides a doctor for a paper making machine in which the holder for the doctor blade carries a series of spaced members which are individually adjustable, without any distortion of the blade holder itself, to vary the doctoring pressure applied by the blade at different zones along its length.
- PATENTEDMARZI m2 SHEET 2 [IF 2 Q l I DOCTORS FOR PAPER MAKING MACHINES it is essential that the doctor blade should be in even contact with the roll surface over its whole length. Furthermore, it is desirable that the contact pressure should not vary unduly along the roll face.
- Some rolls are cambered, that is to say the diameter increases from the ends towards the center.
- Other rolls, and particularly cylinders, are heated with the result that the diameter tends to increase unevenly as the cylinder expands.
- the roll may deflect under its own weight since it is only supported at the ends.
- the doctor support has uneven surfaces and/or deflects in the center. All .these factors militate against a consistent doctor blade contact pressure along the whole length of the roll.
- the invention provides a doctor for a papermaking machine in which the holder for the doctor blade carries a series of spaced members which are individually adjustable, without any distortion of the blade holder itself, to vary the doctoring pressure applied by the blade at different zones along its length.
- the blade holder may carry a series of spaced adjusting screws which are individually adjustable to effect variation of the level at different points along its length either of the rear end of the doctor blade itself or of the rear end of a pressure plate, mounted in the blade holder, which applies pressure to the doctor blade.
- FIG. 1 is a perspective view of part of one form of doctor according to the invention
- FIG. 2 is a cross-sectional view of the doctor shown in FIG. I.
- FIGS. 3-6 are cross-sectional views similar to that of FIG. 2 showing alternative forms of doctor.
- the doctor includes a doctor blade 10, a pressure plate 11, and a blade holder made of two parts 12, 13 suitably secured together.
- Screws 14 are screwed at intervals, for example of 3 inches, into the upper part 12 of the blade holder and have at their lower ends heads 15, accommodated in a recess 16 in the lower part 13, which bear against the undersurface of the rear end of the pressure plate 11.
- the screws 14 are individually adjustable and when any screw is raised it will cause the adjacent portion of the pressure plate 11 to rock about the nose 17 of the blade holder to increase the local pressure applied by the pressure plate to the doctor blade and therefore the doctoring pressure applied to the roll 18.
- the screws 14 are provided with any convenient form of thread lock to ensure their retention in adjusted position, e.g., a longitudinal strip of nylon inserted into the threads which will ensure firm engagement with the corresponding threads in the blade holder.
- FIG. 4 shows a very similar construction, the screws 14 again being fitted into the lower part of the blade holder, but in this case the screws bear against the undersurface of the pressure plate 11.
- the screws can engage a deforma le bar 20 extending longitudinally of the doctor and interposed between the screws 14 and the pressure plate 13.
- the deformable bar may be arranged to bear against the doctor blade. Such a deformable bar provides for more even distribution of the distortion of the blade 10 resulting from adjustment of the screws 14.
- FIG. 6 shows a doctor in which, as described in U.S. application No. 728,727, now U.S. Pat. No. 3,596,305, issued Aug. 3, 1971, the pressure plate 11 applies pressure to the side of the doctor blade 10 facing the roll and the screws 14 bear against the upper surface of the pressure plate.
- Structure for doctoring a roll of a papermaking machine comprising:
- an elongated, generally planar doctor blade having a Iongitudinally extending face and a longitudinal doctoring edge disposed generally in line contact with said roll;
- an elongated, generally planar pressure plate having a longitudinally extending face and a longitudinal pressure edge disposed generally in line contact with the face of the blade;
- a holder for the blade and the plate said holder having an elongated abutment nose presenting a longitudinally extending fulcrum edge disposed generally in line contact with the face of the plate, said plate having a rear edge spaced from the pressure edge, said fulcrum edge contacting the plate at a location intermediate the rear edge and pressure edge thereof;
- a doctor for a roll of a papennaking machine comprising a blade holder, a doctor blade accommodated in said holder for pivotal movement about its rear end with respect to the holder and adapted to bear at its front end against said roll, a pressure plate accommodated in the holder for pivotal movement about a nose on the holder which bears against the pressure plate at a location intermediate its front and rear ends, said pressure plate bearing at its front end against the doctor blade to press said doctor blade against the roll, and a plurality of spaced adjusting members on said holder disposed to bear against the rear end of said pressure plate, said adjusting members being individually adjustable to cause pivotal movement of adjacent parts of the pressure plate about said nose and thereby to effect variations in the pressure applied by the pressure plate to the doctor blade at different points along its length and consequent variation in the doctoring pressure applied to the roll.
- a doctor as claimed in claim 4 which includes a deformable longitudinal bar disposed within the blade holder and interposed between the adjusting members and the rear end of the pressure plate.
Landscapes
- Paper (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4658868 | 1968-10-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3649991A true US3649991A (en) | 1972-03-21 |
Family
ID=10441846
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US861409A Expired - Lifetime US3649991A (en) | 1968-10-01 | 1969-09-26 | Doctors for paper making machines |
Country Status (5)
Country | Link |
---|---|
US (1) | US3649991A (enrdf_load_stackoverflow) |
BR (1) | BR6912871D0 (enrdf_load_stackoverflow) |
DE (1) | DE1948112A1 (enrdf_load_stackoverflow) |
GB (1) | GB1226160A (enrdf_load_stackoverflow) |
SE (1) | SE359875B (enrdf_load_stackoverflow) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3884145A (en) * | 1972-09-19 | 1975-05-20 | Daetwyler & Co M | Doctor blade for photogravure printing machine |
US4803752A (en) * | 1982-08-23 | 1989-02-14 | Canon Kabushiki Kaisha | Cleaning device |
US5279710A (en) * | 1988-11-16 | 1994-01-18 | Aikawa Iron Works, Co., Ltd. | Doctor blade supporting structure |
CN109675871A (zh) * | 2018-12-26 | 2019-04-26 | 江苏理文造纸有限公司 | 一种纸机的烘缸缸面清洁机构 |
US12226062B1 (en) * | 2023-01-11 | 2025-02-18 | Transition Automation, Inc. | Squeegee holder with an integrated clamp bar |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4151797A (en) * | 1977-05-04 | 1979-05-01 | Mid America Tag And Label Company, Inc. | Doctor blade apparatus |
US5230775A (en) * | 1990-06-05 | 1993-07-27 | Thermo Electron Web Systems, Inc. | Blade edge loading control for doctoring apparatus |
DE9214884U1 (de) * | 1992-10-28 | 1994-03-03 | Zimmer, Johannes, Klagenfurt | Rakeleinrichtung |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US767933A (en) * | 1903-11-27 | 1904-08-16 | Joseph Lawrence Galleciez | Guard-board. |
US1803927A (en) * | 1930-09-26 | 1931-05-05 | Rice Barton & Fales Inc | Flexible doctor or scraper blade |
US2477339A (en) * | 1945-02-14 | 1949-07-26 | Lodding Engineering Corp | Doctor mechanism for rolls and cylinders |
GB656812A (en) * | 1947-11-12 | 1951-09-05 | Gen Am Transport | Scraper blade |
US2664792A (en) * | 1949-09-27 | 1954-01-05 | Brown Co | Multilength continuous doctor blade |
-
1968
- 1968-10-01 GB GB4658868A patent/GB1226160A/en not_active Expired
-
1969
- 1969-09-23 DE DE19691948112 patent/DE1948112A1/de active Pending
- 1969-09-23 SE SE13060/69A patent/SE359875B/xx unknown
- 1969-09-26 US US861409A patent/US3649991A/en not_active Expired - Lifetime
- 1969-09-30 BR BR212871/69A patent/BR6912871D0/pt unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US767933A (en) * | 1903-11-27 | 1904-08-16 | Joseph Lawrence Galleciez | Guard-board. |
US1803927A (en) * | 1930-09-26 | 1931-05-05 | Rice Barton & Fales Inc | Flexible doctor or scraper blade |
US2477339A (en) * | 1945-02-14 | 1949-07-26 | Lodding Engineering Corp | Doctor mechanism for rolls and cylinders |
GB656812A (en) * | 1947-11-12 | 1951-09-05 | Gen Am Transport | Scraper blade |
US2664792A (en) * | 1949-09-27 | 1954-01-05 | Brown Co | Multilength continuous doctor blade |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3884145A (en) * | 1972-09-19 | 1975-05-20 | Daetwyler & Co M | Doctor blade for photogravure printing machine |
US4803752A (en) * | 1982-08-23 | 1989-02-14 | Canon Kabushiki Kaisha | Cleaning device |
US5279710A (en) * | 1988-11-16 | 1994-01-18 | Aikawa Iron Works, Co., Ltd. | Doctor blade supporting structure |
CN109675871A (zh) * | 2018-12-26 | 2019-04-26 | 江苏理文造纸有限公司 | 一种纸机的烘缸缸面清洁机构 |
CN109675871B (zh) * | 2018-12-26 | 2021-06-18 | 江苏理文造纸有限公司 | 一种纸机的烘缸缸面清洁机构 |
US12226062B1 (en) * | 2023-01-11 | 2025-02-18 | Transition Automation, Inc. | Squeegee holder with an integrated clamp bar |
Also Published As
Publication number | Publication date |
---|---|
SE359875B (enrdf_load_stackoverflow) | 1973-09-10 |
BR6912871D0 (pt) | 1973-01-09 |
DE1948112A1 (de) | 1970-04-09 |
GB1226160A (enrdf_load_stackoverflow) | 1971-03-24 |
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