Sheet-material associating – Associating and folding – Stapling or stitching
Reexamination Certificate
1999-05-13
2001-04-17
Skaggs, H. Grant (Department: 3651)
Sheet-material associating
Associating and folding
Stapling or stitching
C270S045000, C493S444000, C493S445000, C399S410000
Reexamination Certificate
active
06217016
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sheet processing apparatus for fetching sequentially sheets on which images are formed by an image forming apparatus such as, e.g., photocopiers, printers, and so on, stapling the plural sheets with a stapling means, and folding the sheets in folio and an image forming apparatus.
2. Description of Related Art
Some image forming apparatus such as photocopiers or the like today can do bookbinding by stapling plural sheets and folding the sheets in folio where connected with a sheet processing apparatus. Such a sheet processing apparatus capable of bookbinding fetches sequentially the sheets on which images are formed at the image forming apparatus body, staples the sheets at about the center of the sheet bundle upon driving the stapler unit, and folds the sheets in folio where the sheets are conveyed to a folding means.
As a structure for folding the sheets in folio, it is structured by a folding roller means made of a roller pair, and a projecting means made of a projecting plate and so on. The projecting plate folds the sheet bundle upon projecting the stapled position of the sheet bundle between the nip portions, and the folded sheet bundle is pressed and conveyed by the roller pair to fold the bundle in folio. Therefore, the sheet bundles delivered to the delivery tray are delivered in a state that the sheet bundles are folded in folio and bound in a book form at the center stapled position of the sheets.
However, in the folding roller means, at least one roller is movable to change the distance to the nip position according to the thickness of the sheet bundle. If the projecting position by the projecting plate is constant, the plate cannot hit the center of the distance between the nips of the roller pair when the thickness of the sheets is deviated. That is, if the sheet bundle becomes thick, the projecting plate hits the center between the nips until the sheet bundle is nipped by the folding roller, but when the folding roller nips the sheet bundle to change the distance between the nips, the plate may hit a position shifted from the center of the distance between the nips, and therefore, the folding position may be shifted due to differentials in loads given to upstream and downstream of the sheet bundles, or wrinkles may occur on the sheet and may cause tears in sheets.
This invention is made with respect to the above viewpoint, and it is an object to provide a sheet processing apparatus in which the projecting means can always hit the center of the distance between the nips as the projecting position even where the distance between the nips of the folding roller is changed.
SUMMARY OF THE INVENTION
A representative structure of the invention to accomplish the above object is characterized in a sheet processing apparatus for stapling multiple sheets with a stapling means and delivering the sheets in folio, including: two rollers for folding the sheets in folio; and projecting means for projecting between the two rollers to fold the sheets in sandwiching the sheets between the two rollers, wherein at least one roller of the two rollers is made movable, and a cam member is further provided capable of correcting a projecting position by the projecting means according to traveling of the roller.
In another representative structure of the invention, a sheet processing means for folding sheets in folio includes: a first roller having a fixed rotational position; a second roller having a rotational position movable; projecting means for projecting between the first roller and the second roller to fold the sheets in sandwiching the sheets between the two rollers; and a cam member for moving the projecting position by pushing the projecting means in the traveling direction of the second roller in association with travel of the second roller.
With the above structure, even where the distance between the nips of the two rollers is changed, the cam member operative according to changes of the distance between the nips of the two rollers corrects the projecting position of the projecting means, and therefore, the projecting means always hits the center of the distance between the nips of the two rollers, so that work for folding sheets in folio can be done with high quality.
In the above sheet processing apparatus, the movable roller (the second roller) may have a structure to travel according to the thickness of plural sheets, thereby performing work for folding sheets in folio according to the number of sheets to be processed. The cam member may be pivotally mounted around a roller shaft, as a center, of one roller between the two rollers, and include a cam groove capable of engaging with the other roller shaft, and a guide portion capable of pressing the projecting means. From this simple structure, the projecting position of the projecting means can be moved surely in accordance with the travel of the roller.
Moreover, in the above sheet processing apparatus, the projecting means, after projecting operation, returns to a home position, thereby being capable of preventing wrinkles from occurring inside due to frictional force between the projecting means and the folded sheets. Particularly, the projecting means returns to the home position after at least one roller rotates in a prescribed amount, so that the sheets are surely nipped by two rollers.
The above sheet processing apparatus can have an image forming means body to form images on sheets to structure an image forming apparatus having substantially the same advantages.
REFERENCES:
patent: 4338088 (1982-07-01), Buss et al.
patent: 5007891 (1991-04-01), Hein
patent: 5316280 (1994-05-01), Watkiss
patent: 6004254 (1999-12-01), Murata
patent: 6022011 (2000-02-01), Hirose
Adachi Seiichiro
Honmochi Hiroki
Murata Mitsushige
Sasa Kazunori
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Skaggs H. Grant
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