Typewriting machines – Sheet or web – Including programmed-control-system for record-medium feed
Reexamination Certificate
2000-03-14
2001-04-10
Hilten, John S. (Department: 2854)
Typewriting machines
Sheet or web
Including programmed-control-system for record-medium feed
C400S630000
Reexamination Certificate
active
06213658
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet supply apparatus for supplying record sheet to an image forming apparatus, and more particularly to a sheet supply machine having a vertically movable sheet supplying table supporting a plurality of record sheets stacked thereon in which an image forming position to the record sheet can be adjusted by moving the sheet supplying table right and left.
2. Description of the Related Art
An image forming apparatus for forming an image on record sheets, for example, record sheets for general use, uses the record sheets by loading the record sheets on a sheet supply table. Particularly, in the case of a stencil printing machine, high-speed printing can be carried out since printing operation is carried out by mounting a stencil sheet on a printing drum situated inside the machine and rotating the printing drum. In correspondence therewith, there is constructed a constitution in which a fairly large number of record sheets is loaded on the sheet supply table and the large number of the record sheets can be continuously supplied in a short period of time in correspondence with printing speed.
The sheet supply table is constituted such that the topmost record sheet disposed at sheet supply position is supplied to a print section situated inside the printing machine one by one. A scraper roller (sheet supply roller) of the sheet supply section is provided at the sheet supply position and record sheet can be continuously supplied to the inside of the apparatus by rotating the scraper roller.
Further, there is constructed a constitution in which the sheet supply table is controlled to elevate in correspondence with supply of the record sheet and the topmost record sheet is always brought into contact with the scraper roller.
According to the record sheet, a position thereof in the left and right direction (width direction orthogonal to a transfer direction) is made variable in supplying the record sheet from the sheet supply table to the print section to thereby enable to move an image forming position in the left and right direction on the record sheet. For example, in the case of a stencil printing machine, by making variable a transfer position in the left and right direction of the record sheet relative to the printing drum, a contact position of the record sheet relative to an image position of stencil sheet mounted to the printing drum can be made variable in the left and right direction, so that the image forming position on the record sheet can be moved in the left and right direction.
FIG. 9
is a perspective view showing a sheet supply apparatus. A sheet supply table
50
loaded with the record sheets is provided with a dial
51
for moving the sheet supply table
50
in the left and right direction. By manually adjusting the dial
51
, a screw shaft
52
is rotated, a nut portion
53
fixed to the sheet supply table
50
is moved in the left and right direction, thereby moving the sheet supply table
50
in the same direction. Thus, an image forming position on a record sheet P can be adjusted to move in the left and right direction.
The topmost one of the record sheets P loaded on the sheet supply table
50
is brought into contact with a scraper roller
57
a
of sheet supply means
57
provided above the sheet supply table
50
and the record sheet is supplied one by one from the topmost sheet to a print section by rotating the scraper roller
57
a.
The sheet supply table
50
is constituted such that the sheet supply table
50
is controlled to elevate gradually in compliance with supply of the record sheet P and the topmost record sheet P is always brought into contact with the scraper roller
57
a
and can be supplied to the print section.
However, according to the above-described constitution, if the sheet supply table
50
is moved while the scraper roller
57
a
contacts the record sheet P for adjusting the image forming position on the record sheet P in the left and right direction, the record sheet P is supplied in an oblique direction by being rubbed with the scraper roller
57
a
, thereby causing sheet supply jamming in next printing operation. Further, the scraper roller
57
a
is also damaged. This accelerates deterioration in printing performance of the sheet supply apparatus.
Further, a conventional printer is constituted such that the left and right movement can be conducted regardless of printing operation. Therefore, if the sheet supply table is moved in the left and right direction during printing, conveying force may be exerted in an oblique direction on the record sheet, thereby causing record sheet jamming.
Then, it is possible that the sheet supply table is electrically moved in the left and right direction by means such as a motor instead of the manual operation stated above. However, the above-mentioned problems cannot be solved at all merely by adopting such constitution that the sheet supply table is moved in the left and right direction by motor power. Additionally, if the motor is energized while the scraper roller contacts the record sheet; excessive electric power is consumed due to friction between the scraper roller and the record sheet in comparison with the case where no friction occurs therebetween. This deteriorates electrical efficiency and leads to overheating and life-time deterioration of the motor
SUMMARY OF THE INVENTION
The present invention has been carried out in order to resolve the above-described problems and it is an object of the present invention to provide a sheet supply apparatus capable of keeping printing quality by avoiding occurrence of the record sheet rubbing when the image forming position is adjusted in the left and right direction. Additionally, it is another object of the present invention to provide a sheet supply apparatus capable of stably supplying the record sheets by controlling the left and right movement of the sheet supply table in accordance with sheet supplying operation.
According to a first aspect of the present invention, there is provided a sheet supply apparatus for supplying record sheets to an image forming apparatus, the sheet supply apparatus includes a sheet supply table for supporting the record sheets stacked thereon; vertically moving device for vertically moving the sheet supply table; sheet supply device provided above the sheet supply table and contacting a topmost one of the record sheets for supplying the record sheets one by one from the topmost record sheet to the image forming apparatus; left and right movement instructing device for giving an instruction to move the sheet supply table in a direction orthogonal to a transfer direction of the record sheet; left and right moving device for moving the sheet supply table in response to an instruction from the left and right movement instructing means; and control device for executing a control of moving the sheet supply table downward by the vertically moving device when the left and right movement instructing device gives the instruction.
According to a second aspect of the present invention, there is provided a sheet supply apparatus for supplying record sheets to an image forming apparatus, the sheet supply apparatus includes a sheet supply table for supporting the record sheets stacked thereon; vertically moving device for vertically moving the sheet supply table; sheet supply device provided above the sheet supply table and contacting a topmost one of the record sheets for supplying the record sheets one by one from the topmost record sheet to the image forming apparatus; sheet supply position detecting device for detecting whether the topmost record sheet is situated to a sheet supply position where the topmost record sheet is contacted with the sheet supply device; left and right movement instructing device for giving an instruction to move the sheet supply table in a direction orthogonal to a transfer direction of the record sheet; left and right moving device for moving the sheet supply table in response to an instruction from the le
Cone Darius N.
Hilten John S.
Kanesaka & Takeuchi
Riso Kagaku Corporation
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