Sheet feeding or delivering – Feeding – With means to align sheet
Reexamination Certificate
1999-05-13
2001-04-24
Bollinger, David H. (Department: 3651)
Sheet feeding or delivering
Feeding
With means to align sheet
C271S178000, C271S220000, C270S058120, C270S058160, C270S058270
Reexamination Certificate
active
06220592
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sheet processing apparatus and, more particularly, to a sheet processing apparatus sequentially fetching inside sheets such as copy papers conveyed from an image forming apparatus such as photocopiers, printers, facsimile machines, and the like and executing selectively operations such as folding, sorting, stapling, and so of to the sheets.
2. Description of Related Art
Image forming apparatuses such as photocopiers are conventionally structured, for rendering easy processing work such as photocopying, to have an original document automatic feeding apparatus for feeding automatically original documents and a sheet processing apparatus such as, a so-called finisher and stitcher for selectively doing operations such as sorting operation for arranging or classifying sheets on which images are formed, a staple operation for selectively stapling a bundle made of plural sheets, a folding operation for selectively folding a bundle made of plural sheets, a stack operation for stacking the sheets or sheet bundles in stacking them, and so on. An image forming apparatus is constituted by connecting with those apparatuses.
The sheet processing apparatus has a rocking guide rocked by a drive mechanism composed of a motor and a gear series, and the rocking guide has a pulling means rotatively provided for pulling in a direction opposite to the delivery direction the delivered sheets on the temporarily stacking tray for temporarily stacking sheets. The pulling means rotates in a direction opposite to the sheet delivery direction at every delivery of a single sheet on the temporarily stacking means, is transformed elastically when contacting with the rear end of the sheets on the temporarily stacking means, and pulls back the sheets by the frictional force created between the sheet and the means.
However, if the pulling means pulls back the sheets at every sheet delivery while the rocking guide is held at a fixed position upon rocking in a separating direction from the temporarily stacking means, the sheet height of the topmost sheet on the temporarily stacking means changes because the sheets are delivered one by one on the temporarily stacking means, and therefore, the contact area and contact pressure of the pulling means in contact with the topmost sheet are changed, thereby possibly causing over returning of the sheets.
It is an object of the invention to provide a sheet processing apparatus to prevent the sheets from being excessively returned due to changes of the contact area and contact pressure of the pulling means with respect to the topmost sheet on the temporarily stacking means.
SUMMARY OF THE INVENTION
A representative structure of the invention to accomplish the above object is characterized in having: temporarily stacking means for stacking a sheet temporarily; upstream delivering means for delivering the sheet to the temporarily stacking means; and pulling means for pulling in a direction opposite to a delivery direction the sheet delivered to the temporarily stacking means, wherein the pulling means is structured to keep approximately constant a contract pressure exerted to the topmost sheet delivered on the temporarily stacking means.
According to the above structure, since the pulling means is structured to keep approximately constant a contract pressure exerted to the topmost sheet delivered on the temporarily stacking means, stable returning force is obtained notwithstanding the stacked number of the sheets, and durability can be improved. The pulling means can be formed in, e.g., a tapered shape whose one end is narrower. Moreover, stepwise portions are formed on opposite sides of a tip of pulling means to render the paddle in the tapered shape, or a stepwise portion is formed on either a sheet contacting surface side or a sheet noncontacting surface side of a tip of the pulling means to render the paddle in the tapered shape.
Furthermore, it is characterized in that the pulling means is a flexible paddle and that the multiple paddles are arranged at a round edge of a rotary body and radially separated from each other to perform a pulling operation multiple times with respect to a single sheet per one rotation of the rotary body.
In accordance with the above structure, since the pulling means is a flexible paddle and since multiple paddles are arranged in the rotational direction to perform the pulling operation multiple times with respect to a single sheet per one rotation, the processing time can be shortened in comparison with a case that a sole paddle is rotated twice because the pulling operation can be performed twice in a single rotation where the two flexible paddles are arranged in the rotational direction.
In another aspect, the apparatus includes: temporarily stacking means for stacking a sheet temporarily; upstream delivering means for delivering the sheet to the temporarily stacking means; and pulling means for pulling in a direction opposite to a delivery direction the sheet delivered to the temporarily stacking means; and a rocking guide rotatively supporting the pulling means, capable of rocking in directions for coming closer to and going away from the temporarily stacking means, wherein a contract area of the pulling means to the topmost sheet is kept constant according to changes of a height of the topmost sheet delivered on the temporarily stacking means.
According to this structure, since the rocking guide is rocked toward the separating direction according to increase of of the delivery number of the sheets to the temporarily stacking means as to keep constant a contract area of the pulling means to the topmost sheet according to changes of a height of the topmost sheet delivered on the temporarily stacking means, the contract area of the pulling means to the topmost sheet is kept constant regardless the number of the stacked sheets, and thereby the sheets can be prevented from being overly returned due to changes in the contact area of the pulling means to the topmost sheet.
The rotation number of the rotary body to which the flexible paddles are mounted is changed according to the sheet size, and more particularly, according to a length of the sheet in a conveyance direction, to increase when the length is long and to decrease when the length is short, a smooth pulling work can be done corresponding to the mass of the stacked sheets.
Furthermore, when the above sheet processing apparatus is formed with an image forming means for forming images on a sheet, an image forming apparatus having the same effect can be formed.
REFERENCES:
patent: 3847388 (1974-11-01), Lynch
patent: 4084809 (1978-04-01), Looney
patent: 5033731 (1991-07-01), Looney
patent: 60-56766 (1985-04-01), None
patent: 18160 (1989-01-01), None
Hayashi Ken-ichi
Morishige Yuji
Onodera Kazuo
Watanabe Tomoyuki
Yamada Tsuyoshi
Bollinger David H.
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
LandOfFree
Sheet processing apparatus and image forming apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sheet processing apparatus and image forming apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sheet processing apparatus and image forming apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474763