JP2002120945A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent tip folding of paper, occurrence of wrinkles or jam by feeding the paper by flatly pressing down the paper fed from a paper feeding part, and smoothly feeding the feeding paper in a paper carrying passage. SOLUTION: An upper surface of the feeding paper 6 is pressed down by a paper feeding roller 12 and disks 33 positioned on both outsides of a lateral width of the paper feeding roller 12 on the paper feeding directional rear side of the paper 6 more than the paper feeding roller 12. Thus, a wide range of the upper surface of the feeding paper 6 can be flatly pressed down to prevent the feeding paper 6 from becoming a wavy state and the lateral width directional both end sides orthogonal to the paper feeding direction from curling upward, and a collision of the waved and curled paper 6 with an inlet part of a paper carrying passage can be prevented so that folding of a tip part of the paper 6, the wrinkles of the paper 6 and the occurrence of the jam by such a collision can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder used in an image forming apparatus such as a printing machine, a printer, a copying machine, and the like.

[0002]

2. Description of the Related Art Conventionally, a paper feeding device of an image forming apparatus is driven to rotate in the paper feeding direction by contacting the upper surface of the paper loaded on the paper loading tray and the uppermost sheet loaded on the paper feeding tray. Pickup roller, separation paper feed roller, and the like. In addition, there is a sheet feeding apparatus having a structure in which sheet feeding is performed only by a separation sheet feeding roller without using a pickup roller. Here, a typical structure of a conventional sheet feeding device will be described.

FIG. 7 is a side view showing a sheet feeding device that feeds sheets 102 stacked on a sheet feeding table 101 only by a separation sheet feeding roller 103. Sheets 102 stacked on the sheet supply table 101 are guided by sheet side fences 104 at both ends in the width direction orthogonal to the sheet supply direction. The separation paper feed roller 103 is located at the center in the width direction orthogonal to the paper feed direction.

FIG. 8 shows a state in which the paper 102 loaded on the paper feed table 101 is fed by the pickup roller 105 and the separation paper feed roller 103, and further, it is positioned on both sides of the separation paper feed roller 103. This is a sheet feeding device in which a disk 107 is fixed on a rotation center shaft 106 of the separation sheet feeding roller 103. The disk 107 rotates while being in contact with the upper surface at both ends in the width direction orthogonal to the paper feeding direction of the paper to be fed, and prevents both ends of the paper from warping upward.

FIG. 9 shows a state in which the paper 102 stacked on the paper feed table 101 is fed by a pickup roller 105 and a separation paper feed roller 103, and a paper pressing guide is provided on both sides of the separation paper feed roller 103. 108 is provided. The paper holding guide 108 is formed of a plate-shaped member or a rod-shaped member, and is in contact with the upper surface of both ends of the paper to be fed in the width direction orthogonal to the paper feeding direction, thereby preventing the both ends of the paper from curling upward. are doing.

As described in Japanese Patent Application Laid-Open No. 56-149929, a paper pressing roller is provided at a position forward of the separation paper feeding roller in the paper feeding direction, and the paper is fed by the paper pressing roller. There is also known a sheet feeding device configured to press upper surfaces of both ends of a sheet.

[0007]

[0007] As shown in FIG.
The paper is fed only by the separation paper feed roller 103 located at the center in the width direction orthogonal to the paper feeding direction, or
In a paper feeding device in which a pickup roller and a separation paper feeding roller are located at the center in the width direction perpendicular to the paper feeding direction and are located back and forth along the paper feeding direction, the paper feeding direction is orthogonal to the paper feeding direction. Both ends in the width direction are not pressed,
The paper 102 stacked on the paper feed table becomes wavy or both ends curl upward. In particular,
When the paper is thin paper, the waving or curling due to moisture absorption becomes large.

When such waving or curling occurs, it is difficult for the paper fed by the separation paper feed roller 103 to properly enter the paper transport path, and the paper fed to the entrance of the paper transport path causes the leading edge of the paper to fall. The paper is broken, the paper is wrinkled, or a paper jam occurs.

[0009] As shown in FIG.
According to the sheet feeding device in which the discs 107 are arranged on both sides of the sheet 3, the discs 107 can hold both ends orthogonal to the sheet feeding direction. However, since the pressing portion is located on the same line as the position where the separation paper feed roller 103 presses the paper 102, the paper 102 cannot be pressed flat in a wide range, and as shown in FIG. Paper 10
2 wrinkles are easier.

Further, since the disk 107 is fixed on the rotation center axis 106, the distance between the outer peripheral surface of the disk 107 and the upper surface of the uppermost sheet 102 is determined.
It is not possible to adjust the pressing force on the paper 102 by adjusting the position of the disk 107 in the vertical direction in accordance with the degree of curl of 02, the type of paper, and the like.

As shown in FIG. 9, in a sheet feeding apparatus provided with a sheet pressing guide 108 formed of a sheet metal or a rod-like member,
When the paper holding guide 108 comes into contact with the paper 102, the paper holding guide 108 becomes a resistance of the fed paper 102, and may cause the paper 102 to wrinkle. Further, when the printing apparatus performs overprinting using inks of different colors, the paper pressing guide 108 rubs an image already formed on the paper 102, and thus image stains are likely to occur.

As described in JP-A-56-149929, in a paper feeder provided with a paper pressing roller located forward of the separation paper feed roller in the paper feed direction, a paper feeder is provided on a paper feed table. Since the paper is not structured to press the top surface of the paper, the paper fed from the paper feed table by the separation paper feed roller may hit the paper press roller. Wrinkles, jams, etc. occur.

An object of the present invention is to flatly press a sheet fed from a sheet feeding table and feed the sheet, so that the fed sheet is smoothly fed into a sheet conveying path, and the leading end of the sheet is bent and wrinkles are formed. To prevent the occurrence of jams and jams.

[0014]

According to a first aspect of the present invention, there is provided a sheet feeding device which contacts a sheet feeding unit on which sheets are stacked and an upper surface of the uppermost sheet of the sheets stacked on the sheet feeding unit. A paper feed roller that rotates and feeds the paper in the paper feed direction; and a paper feed roller located rearward of the paper feed roller in the paper feed direction and on both outer sides of the width of the paper feed roller. A disk rotatably supported about an axis parallel to the rotation center axis of the roller and rotating in a direction of feeding the sheet by contacting the upper surface of the uppermost sheet of the sheets stacked on the sheet feeding unit; And

Therefore, the uppermost sheet of the sheets stacked in the sheet feeding section is fed by the sheet feeding roller rotating in contact with the upper surface of the sheet. At the time of this paper feeding, the disk rotatably supported around an axis parallel to the rotation center axis of the paper feeding roller contacts the upper surface of the paper to be fed and rotates in the paper feeding direction. The paper to be fed is fed in a state where the upper surface is pressed by the disk and the feed roller. Since the disk is located rearward of the paper feed roller in the paper feed direction and on both outer sides of the width of the paper feed roller,
A wide range of the upper surface of the paper can be pressed flat by the disk and the paper feed roller, and the paper to be fed becomes wavy or both ends in the width direction orthogonal to the paper feeding direction curl upward. Is prevented.

According to a second aspect of the present invention, in the paper feeder according to the first aspect, the disk is arranged such that a peripheral speed of an outer peripheral portion of the disk is substantially equal to a peripheral speed of an outer peripheral portion of the paper feed roller. And a driving mechanism for driving the rotation.

Therefore, the disk in contact with the sheet does not become a resistance when the sheet is fed, and further, a conveying force can be applied to the sheet from the disk, so that the sheet can be fed smoothly. Done.

According to a third aspect of the present invention, in the paper feeder according to the first or second aspect, there is provided a vertical position adjusting mechanism for adjusting a vertical position of the disk.

Therefore, if necessary, for example, by adjusting the position of the disk in the vertical direction in accordance with the thickness and type of the paper, and the likelihood of curling and waving, the waving and curling of the paper can be reduced. The upper surface of the sheet can be pressed with a pressing force that is optimal for prevention.

The invention described in claim 4 is the first to third aspects of the present invention.
In the sheet feeding device according to any one of the above, a plurality of the disks are provided on both outer sides of the sheet feeding roller.

Therefore, even when sheets of various sizes having different widths in the direction perpendicular to the sheet feeding direction are fed,
One of the disks can press the paper flat without adjusting the position of the disk in the width direction of the paper according to the size of the paper.

The fifth aspect of the present invention provides the first to fourth aspects.
In the sheet feeding device according to any one of the above, on the rotation center axis of the sheet feeding roller, the sheet contacting the upper surface of the uppermost sheet of the sheets stacked in the sheet feeding unit and integrally with the sheet feeding roller. The rotating disk is fixed.

Accordingly, the disk for pressing the upper surface of the sheet is located before and after along the sheet feeding direction, and the number of points for pressing the upper surface of the sheet is increased, so that the sheet is pressed more flatly.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, the disk is located rearward of the paper feeding roller in the paper feeding direction, and is fixed on a rotation center axis of the paper feeding roller. The disc is disposed at a position where the position in the direction orthogonal to the sheet feeding direction does not overlap with the disc.

Therefore, the number of points for pressing the upper surface of the sheet increases in the width direction orthogonal to the sheet feeding direction, and the sheet is pressed more flatly.

According to a seventh aspect of the present invention, in the paper feeding apparatus, the paper is rotated while contacting the upper surface of the uppermost paper stacked on the paper feeding unit and the uppermost paper stacked on the paper feeding unit. A feed roller for feeding in the feed direction; at least a pair of drive pulleys fixed on both sides of the feed roller on the rotation center axis of the feed roller; A support shaft located on the rear side in the paper direction and arranged in parallel with the rotation center axis, at least a pair of driven pulleys supported by the support shaft, and between the drive pulley and the driven pulley. And a belt that rotates in a direction to feed the sheet by contacting the upper surface of the uppermost sheet of the sheets stacked and stacked on the sheet feeding unit.

Therefore, the uppermost sheet of the sheets stacked in the sheet feeding section is fed by the sheet feeding roller rotating in contact with the upper surface of the sheet. At the time of this paper feeding, the driving pulley fixed to the rotation center axis of the paper feeding roller rotates together with the paper feeding roller, so that the belt stretched between the driving pulley and the driven pulley is fed. As the paper rotates in contact with the top surface of the paper to be fed,
Paper is fed while the upper surface is pressed by the paper feed roller and the belt. The belt is located on both outer sides of the width of the sheet feeding roller and between the sheet feeding roller and the rear side in the sheet feeding direction of the sheet with respect to the sheet feeding roller. Because of the contact, the belt and paper feed roller can flatly press the wide area of the top surface of the paper, and the paper to be fed becomes wavy or both ends in the width direction orthogonal to the paper feed direction are upward. Or curling is prevented.

[0028]

FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. FIG. 1 is a vertical sectional front view showing the entire structure of a stencil printing apparatus which is one of image forming apparatuses. Since the basic structure of the stencil printing apparatus is well known, the basic structure will be briefly described. The stencil printing apparatus includes an image reading device 1 for reading an image of a document placed on a contact glass, a plate making section 2 for making a master according to image data read by the image reading device 1, and a plate cylinder for printing a master made by the plate. A printing unit 4 wrapped around the outer peripheral surface of the printing unit 3 for printing, a plate discharging unit 5 for discarding a master used for printing and peeled from the plate cylinder 3, and a sheet 6 fed to the printing unit 4 are supplied. The printing apparatus 4 includes a paper feeding device 7 for feeding paper, and a paper discharging device 8 for discharging the paper 6 fed from the paper feeding device 7 and printed in the printing unit 4.

FIG. 2 is a plan view showing details of the sheet feeding device 7, and FIG. 3 is a side view thereof. The sheet feeding device 7 is provided with a sheet feeding table 9 that is a sheet feeding unit that is supported by a guide device (not shown) so as to be able to move up and down and is moved up and down by a lifting mechanism (not shown). Paper 6 fed to the printing unit 4 is stacked. The paper feed tray 9 is slidable in the width direction of the paper 6 orthogonal to the paper feed direction of the paper 6 and can be stopped at an arbitrary sliding position. A side fence 10 that guides an end and a discharge fan 11 that is attached to the outside of the side fence 10 and discharges air are provided. When the air discharged from the discharge fan 11 hits the edge of the paper 6 stacked on the paper feed table 9, several upper papers 6 among the stacked papers 6 are separated, Double feeding during paper feeding is prevented.

Above the paper feed table 9, a separation paper feed roller 12 and a pickup roller 13, which are paper feed rollers, are arranged. The separation paper feed roller 12 and the pickup roller 13 form the paper 6 fed from the paper feed table 9.
The separation paper feed roller 12 is located on the front side in the paper feeding direction, and the pickup roller 13 is located on the rear side, and the separation paper feed roller 12 and the pickup roller 13 are orthogonal to the paper feeding direction of the paper 6. It is arranged at the center position in the width direction. Separation paper feed roller 12 and pickup roller 1
3 is set to the same outer diameter. A separation pad 14 for preventing double feeding of the paper 6 to be fed is in contact with the outer peripheral surface on the lower end side of the separation paper feed roller 12.

The separation paper feed roller 12 has a rotation center shaft 15 extending in the width direction of the paper 6 orthogonal to the paper feed direction.
The rotation center shaft 15 is rotatably provided around the axis together with the rotation center shaft 15, and both ends of the rotation center shaft 15 are supported by body side plates 16 of the stencil printing machine via bearings 17. A pulley 18 is fixed to one end of the rotation center shaft 15, and a timing belt 21 is stretched between the pulley 18 and a pulley 20 fixed to a motor shaft 19 a of a motor 19.

A support shaft 22 having an axis parallel to the rotation center shaft 15 is disposed forward of the rotation center shaft 15 in the sheet feeding direction of the paper 6, and both ends of the support shaft 22 are fixed to the main body side plate 16. Have been. One end of a pair of arms 24 is supported on the support shaft 22 via a bearing 23, and the other end of the arm 24 is connected to the rotating shaft 1 of the pickup roller 13 via a bearing 25.
3a is supported. A pulley 26 is fixed to the rotating shaft 13a, and a timing belt 28 is stretched between the pulley 26 and a pulley 27 fixed to the rotation center shaft 15. The number of teeth of the pulleys 26 and 27 is set to be the same.

The separation paper feed roller 12 is mounted on the rotation center shaft 15.
One end side of each of two arms 29 (a total of four arms 27) located on both sides of is supported via a bearing 30,
A rotating shaft 32 is rotatably supported via bearings 31 on the other ends of the two arms 29 located on both sides of the separation sheet feeding roller 12. The rotation axis 32 is the rotation center axis 15
, And three disks 33 are fixed to each of the rotating shafts 32. In addition, the rotating shaft 32
Are arranged at positions where the position in the direction along the paper feeding direction of the paper 6 is between the separation paper feeding roller 12 and the pickup roller 13. The outer diameter of the disk 33 is set to be equal to or slightly smaller than the outer diameter of the separation / feed roller 12. A pulley 34 is provided at one end of each rotating shaft 32.
Is fixed, and a timing belt 36 is stretched between the pulley 34 and a pulley 35 fixed to the rotation center shaft 15. The number of teeth of the pulleys 34 and 35 is set to be the same. The pulleys 34 and 35 and the timing belt 36 actuate a driving mechanism 37 for rotating the disk 33 so that the peripheral speed of the outer peripheral portion of the disk 33 and the outer peripheral portion of the separation paper feed roller 12 become substantially the same. It is configured.

The three disks 33 are fixed at positions corresponding to various types of paper 6 of different sizes fed from the paper feed table 9. For example, out of the three disks 33, the outermost disk 33 is arranged at a position 20 mm inward from the widthwise end of the A6 size paper 6 when the A6 size paper 6 is fed vertically, The central disk 33 is arranged at a position 20 mm inward from the end of the paper 6 in the width direction when the paper 6 of B4 size is fed in a portrait orientation.

As shown in FIG. 3, the arm 29 has a protruding portion 29a protruding upward. A spring 39 is provided between the protruding portion 29a and the main body fixing portion 38a of the stencil printing apparatus, for urging the disk 33 in a direction for rotating the disk 33 downward around the axis of the rotation center shaft 15. Further, an adjustment screw 40 having a tip portion abutting on the protruding portion 29a is provided on the main body fixing portion 38b of the stencil printing apparatus. The adjustment of the adjustment screw 40 causes the disk 33 to rotate around the axis of the rotation center shaft 15. It can be turned up and down. Then, these protrusions 29a, springs 39,
The adjusting screw 40 constitutes a vertical position adjusting mechanism 41 that adjusts the position of the disk 33 in the vertical direction.

Separated paper feed roller 1 on rotation center shaft 15
Two disks 42 are fixed to both sides of the disk 2, respectively. The outer diameter of these disks 42 is the same as that of the disks 33 described above.
Similarly to the above, the outer diameter of the separation sheet feeding roller 12 is set to be equal to or slightly smaller than the outer diameter. These disks 42 and the above-mentioned disks 33 are arranged so as to be shifted from each other so that the positions in the direction orthogonal to the paper feeding direction of the paper 6 do not overlap.

In such a configuration, the paper feed table 9 on which the paper 6 is loaded is moved up and down by a drive mechanism, and the upper surface of the uppermost paper 6 of the loaded paper 6 is separated by the separation paper feed roller 12, the pickup roller 13, and the like. It comes into contact with the disks 33 and 42.

The paper 6 loaded on the paper feed table 9 is fed
The operation starts when the motor 19 is driven. At the time of this paper feeding, the driving force of the motor 19 is transmitted to the rotation center shaft 15 via the timing belt 21, and the separation paper feed roller 12 fixed on the rotation center shaft 15 and the disk 4
2 are driven to rotate in the paper feeding direction of the paper 6. Further, the rotation of the rotation center shaft 15 is transmitted to the rotation shaft 13 a via the timing belt 28 and to the rotation shaft 32 via the timing belt 36, and
Are driven to rotate in the direction of picking up and feeding the uppermost sheet 6, and the disk 33 is driven to rotate in the direction of feeding. The separation paper feed roller 12, the pickup roller 13, and the disks 33 and 42 are driven to rotate so that the peripheral speeds of the respective outer peripheral portions are substantially the same.

Then, for the paper 6 to be fed, the separation paper feed roller 12, the pickup roller 13, and the disks 33, 4
2 provides a conveying force, and furthermore, these separation paper feed roller 12, pickup roller 13, and disks 33, 4
2 is rotated so that its outer peripheral portion has substantially the same peripheral speed, so that the paper 6 can be fed smoothly.

The paper 6 to be fed has its upper surface separated from the paper feed roller 12, the pickup roller 13, and the disk 3.
3 and 42. The separation paper feed roller 12 and the pickup roller 13 are located at the center in the width direction of the paper 6 in the front-back direction along the paper feed direction. The disk 33 is located between the separation sheet feeding roller 12 and the pickup roller 13, and is located on both outer sides of the horizontal width of the separation sheet feeding roller 12 and the pickup roller 13. Further, the disk 42 is located on the same axis as the separation sheet feeding roller 12 and on both outer sides of the separation sheet feeding roller 12. Further, the disk 42 and the disk 33 are located at positions where the positions in the direction orthogonal to the paper feeding direction of the paper 6 do not overlap. For this reason, the uppermost sheet 6 to be fed is composed of the separation sheet feeding roller 12, the pickup roller 13, and the disks 33 and 42.
As a result, the wide area of the upper surface of the paper 6 can be pressed flat at many points, so that the paper 6 to be fed is wavy or both ends in the width direction orthogonal to the feeding direction curl upward. Is prevented. As a result, it is possible to prevent the wavy or curled paper 6 from hitting the entrance portion of the paper transport path, and to prevent the leading end of the paper 6 from breaking due to such bumping, and to prevent the paper 6 from wrinkling or jamming. Is done.

The position of the disk 33 is adjusted in the vertical direction by operating the adjusting screw 40 in accordance with the thickness and type of the paper 6 to be fed or the likelihood of the paper 6 curling or waving. can do. Accordingly, the upper surface of the paper 6 can be pressed with a pressing force that is optimal for preventing the paper 6 from waving or curling, and the paper 6 can be prevented from waving or curling during paper feeding. It is possible to prevent the leading end of the sheet 6 from being bent, wrinkled or jammed due to such waving or curling.

In the present embodiment, an example in which three disks 33 are fixed to each rotating shaft 32 and two disks 42 are fixed to the rotation center shaft 15 on one side of the separation feed roller 12 respectively. As described above, the number of these disks 33 and 42 can be increased or decreased from the number in the embodiment.

Next, a second embodiment of the present invention will be described with reference to FIG.
A description will be given based on FIG. The same parts as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments).

In this embodiment, the rotating shaft 3 serving as a support shaft
2, three driven pulleys 43 are fixed, and the rotation center shaft 1
5, five drive-side pulleys 44 are fixed. The driving pulley 44 and the driven pulley 43 are disposed at front and rear positions along the paper feeding direction of the paper 6, and a rubber, which is a belt, is formed between the driving pulley 44 and the driven pulley 43 forming a pair in front and rear. Round belt 45 made of stainless steel. The round belt 45 is arranged so as to contact the upper surface of the uppermost sheet 6 of the sheets 6 stacked on the sheet feeding table 9.

The outer diameter of the driving pulley 44 is set so that the peripheral speed of the outer peripheral portion of the separation paper feed roller 12 and the peripheral speed of the outer peripheral portion of the round belt 45 are substantially the same.

Also in this embodiment, a vertical position adjusting mechanism 41 having the same structure as that of the first embodiment is provided.
By adjusting the adjusting screw 40 of the vertical position adjusting mechanism 41, the round belt 45 can be rotated vertically around the axis of the rotation center shaft 15, and the pressing force of the round belt 45 against the paper 6 is adjusted. can do.

In such a configuration, the paper feed table 9 on which the paper 6 is loaded is moved up and down by a driving mechanism, and the upper surface of the uppermost paper 6 of the loaded paper 6 is separated by the separation paper feed roller 12, the pickup roller 13, and the like. It comes into contact with the round belt 45.

The paper 6 loaded on the paper feed table 9 is fed
The operation starts when the motor 19 is driven. At the time of this paper feeding, the driving force of the motor 19 is transmitted to the rotation center shaft 15 via the timing belt 21, and the separation paper feed roller 12 fixed on the rotation center shaft 15 and the driving pulley 44 are separated by a paper. 6 in the paper feeding direction. Then, the rotation of the rotation center shaft 15 is transmitted to the rotation shaft 13 a via the timing belt 28 and the pickup roller 1
3 is driven to rotate in the direction of picking up and feeding the uppermost sheet 6. Further, as the driving pulley 44 rotates, the round belt 45 stretched between the driving pulley 44 and the driven pulley 43 is driven to rotate in the paper feeding direction of the paper 6. The separation paper feed roller 12, the pickup roller 13, and the round belt 45 are driven to rotate so that the peripheral speeds of the respective outer peripheral portions are substantially the same.

Then, for the paper 6 to be fed, the separation paper feed roller 12, the pickup roller 13, and the round belt 45 are provided.
The separation paper feed roller 12, the pickup roller 13, and the round belt 45 are driven to rotate so that the outer peripheral portions thereof have substantially the same peripheral speed. Is performed smoothly.

Here, the upper surface of the paper 6 to be fed is pressed by the separation feeding roller 12, the pickup roller 13, and the round belt 45. The separation paper feed roller 12 and the pickup roller 13 are located at the center in the width direction of the paper 6 in the front-back direction along the paper feed direction. Further, the round belt 45 is an area between the separation sheet feeding roller 12 and the pickup roller 13 and
2 and on both outer sides of the width of the pickup roller 13. Further, the round belt 45 makes line contact or surface contact with the upper surface of the paper 6 in a long range along the paper feeding direction. For this reason, the uppermost sheet 6 to be fed is the separation sheet feed roller 12, the pickup roller 13, and the round belt 45.
As a result, the wide area of the upper surface of the paper 6 can be pressed flat, so that the paper 6 to be fed becomes wavy,
Both ends in the width direction orthogonal to the sheet feeding direction are prevented from curling upward. As a result, it is possible to prevent the wavy or curled paper 6 from hitting the entrance portion of the paper transport path, and to prevent the leading end of the paper 6 from breaking due to such bumping, and to prevent the paper 6 from wrinkling or jamming. Is done.

By operating the adjusting screw 40 in accordance with the thickness and type of the paper 6 to be fed or the likelihood of curl or waving of the paper 6, the round belt 45 is operated.
Can be vertically rotated about the axis of the rotation center shaft 15, and the pressing force of the round belt 45 against the paper 6 can be adjusted. Accordingly, the upper surface of the paper 6 can be pressed with a pressing force that is optimal for preventing the paper 6 from waving or curling, and the paper 6 can be prevented from waving or curling during paper feeding. It is possible to prevent the leading end of the sheet 6 from being bent, wrinkled or jammed due to such waving or curling.

Next, a third embodiment of the present invention will be described with reference to FIG.
It will be described based on. The basic structure of this embodiment is the second structure.
Is the same as that of the second embodiment, but in the second embodiment,
Three drive pulleys 44, three driven pulleys 43, and three round belts 4 are provided on both sides of the separation paper feed roller 12, respectively.
In contrast, in this embodiment, one wide driving pulley 46, one wide driven pulley 47, and one wide pulley 4 are provided on both sides of the separation feed roller 12 in this embodiment.
A wide belt-like belt 48 is provided between the belts 6 and 47. The driving pulley 46 is connected to the rotation center shaft 15.
, And the driven pulley 47 is fixed to the rotating shaft 32.

On the outer peripheral surface of the belt 48, irregularities for increasing the frictional force of the paper 6 are formed.

The outer diameter of the driving pulley 46 is set so that the peripheral speed of the outer peripheral portion of the separation sheet feeding roller 12 and the peripheral speed of the outer peripheral portion of the belt 48 are substantially the same.

In such a configuration, at the time of feeding the paper 6, the separation paper feed roller 12, the pickup roller 13 and the belt 48 are driven by the driving force from the motor 19.
In the paper feeding direction. For the paper 6, these separation paper feed roller 12 and pickup roller 1
3 and the belt 48, a conveying force is applied, and the separation paper feed roller 12, the pickup roller 13, and the belt 48 are driven to rotate so that their outer peripheral portions have substantially the same peripheral speed. Paper is fed smoothly.

The upper surface of the paper 6 to be fed is separated from the paper feed roller 12, the pickup roller 13, and the belt 4.
8 and is held down. Then, the separation paper feed roller 1
The pickup roller 2 and the pickup roller 13 are located at the center in the width direction of the sheet 6 in the front-back direction along the sheet feeding direction. The belt 48 is located between the separation sheet feeding roller 12 and the pickup roller 13 and on both outer sides of the width of the separation sheet feeding roller 12 and the pickup roller 13.
The belt 48 is in wide surface contact with the upper surface of the paper 6 in a long range along the paper feeding direction. For this reason, the uppermost sheet 6 to be fed is separated from the separation sheet feeding roller 12.
, The pickup roller 13 and the belt 48, the second
A wider range can be pressed flat than when the round belt 45 described in the embodiment is used. Accordingly, the fed paper 6 is further prevented from waving or curling upward at both ends in the width direction orthogonal to the feeding direction, and the wavy or curled paper 6 is transported. It is further prevented from hitting the entrance of the route,
Breakage of the leading end of the paper 6 due to such collision, wrinkling of the paper 6 and occurrence of jam are further prevented.

[0057]

According to the paper feeding apparatus of the first aspect of the present invention, the upper surface of the paper to be fed is located between the paper feeding roller and the paper feeding roller behind the paper feeding roller, and The paper can be pressed by the disks located on both outer sides of the width of the paper feed roller, and thereby a wide range of the upper surface of the paper to be fed can be pressed flat, and the paper to be fed becomes wavy. And prevents the curled paper from hitting the entrance of the paper transport path by preventing the paper from curling upward at both ends in the width direction perpendicular to the paper feeding direction. It is possible to prevent the leading end of the sheet from being bent, from wrinkling the sheet, and from jamming.

According to the second aspect of the present invention, in the paper feeder according to the first aspect, the disk is rotated such that the peripheral speed of the outer peripheral portion of the disk is substantially equal to the peripheral speed of the outer peripheral portion of the paper feed roller. Since the drive mechanism for rotating the paper is provided, the disk in contact with the paper does not become a resistance when the paper is fed, and the disk can apply a conveying force to the paper, and the paper can be fed. Paper can be made smooth.

According to the third aspect of the present invention, in the paper feeder according to the first or second aspect, a vertical position adjusting mechanism for adjusting a vertical position of the disk is provided. By adjusting the position of the disk in the vertical direction according to the thickness and type of the paper and the likelihood of curling or waving, the top surface of the paper is pressed with an optimal pressing force to prevent the paper from waving or curling. Can be held down,
It is possible to prevent waving and curling of various types of paper during paper feeding.

According to the fourth aspect of the present invention, in the paper feeder according to any one of the first to third aspects, the disk is
Since a plurality of papers are provided on both outer sides of the paper feed roller, even if paper of various sizes with different widths in the direction perpendicular to the paper feed direction is fed, the disk is The paper can be pressed flat by any of the disks without adjusting the position in the width direction.

According to a fifth aspect of the present invention, in the paper feeder according to any one of the first to fourth aspects, the uppermost one of the sheets stacked in the paper feed unit is provided on the rotation center axis of the paper feed roller. The disk that rotates integrally with the paper feed roller in contact with the upper surface of the paper is fixed, so the disk that presses the upper surface of the paper is located before and after along the paper feeding direction, and the upper surface of the paper Since the number of points for pressing is increased, the paper can be pressed even more flatly.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the disk is located on the rear side in the sheet feeding direction with respect to the sheet feeding roller, and is fixed on the rotation center axis of the sheet feeding roller. The disc is positioned so that its position in the direction perpendicular to the paper feed direction does not overlap, so that the number of points for pressing the top surface of the paper in the width direction perpendicular to the paper feed direction can be increased. Thus, the paper can be pressed more evenly.

According to the paper feeder of the invention described in claim 7,
The upper surface of the paper to be fed is formed by a paper feed roller and a belt positioned on both outer sides of the width of the paper feed roller and between the paper feed roller and the paper feed direction rear side of the paper feed roller. Can be pressed, and the belt makes line contact or surface contact with the top surface of the paper, so that the top surface of the paper can be pressed flat in a wide range, and the paper to be fed may be wavy or in the paper feeding direction. Can be prevented from curling upward at both ends in the width direction perpendicular to the paper, thereby preventing the paper having the wavy or curled from colliding with the entrance of the paper transport path. Breakage of the leading end, wrinkling of paper, and occurrence of jam can be prevented.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing the entire structure of a stencil printing apparatus provided with a sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a sheet feeding device.

FIG. 3 is a front view thereof.

FIG. 4 is a plan view illustrating a sheet feeding device according to a second embodiment of the present invention.

FIG. 5 is a front view thereof.

FIG. 6 is a plan view illustrating a sheet feeding device according to a third embodiment of the present invention.

FIG. 7 is a side view showing a conventional sheet feeding device.

FIG. 8 is a perspective view showing another conventional sheet feeding apparatus.

FIG. 9 is a front view showing another conventional sheet feeding apparatus.

[Description of Signs] 6 Paper 9 Paper feed unit 12 Paper feed roller 15 Rotation center shaft 32 Support shaft 33 Disk 37 Drive mechanism 41 Vertical position adjustment mechanism 42 Disk 43, 47 Driven pulley 44, 46 Drive pulley 45, 48 Belt

Claims (7)

[Claims] A sheet feeding unit on which sheets are stacked; and a sheet feeding roller for rotating the sheet stacked on the sheet feeding unit and feeding the sheet in the sheet feeding direction while rotating while contacting an upper surface of the uppermost sheet. The paper feed roller is positioned on the rear side in the paper feed direction with respect to the paper feed roller and on both outer sides of the width of the paper feed roller, and is rotatably supported around an axis parallel to a rotation center axis of the paper feed roller. And a disk that rotates in a direction in which the uppermost sheet of the sheets stacked on the sheet feeding unit is fed to feed the sheet. 2. The paper feeder according to claim 1, further comprising a drive mechanism for rotating the disk so that a peripheral speed of an outer peripheral portion of the disk is substantially equal to a peripheral speed of an outer peripheral portion of the paper feed roller. . 3. The paper feeding device according to claim 1, further comprising a vertical position adjusting mechanism for adjusting a vertical position of the disk. 4. The paper feeder according to claim 1, wherein a plurality of said disks are provided on both outer sides of said paper feed roller. 5. On the rotation center axis of the paper feed roller,
The paper feeder according to any one of claims 1 to 4, wherein a disk that rotates integrally with the paper feed roller in contact with the upper surface of the uppermost paper stacked on the paper feeder is fixed. 6. A disk positioned rearward of the paper feed roller in the paper feed direction and the disk fixed on a rotation center axis of the paper feed roller is orthogonal to the paper feed direction. 6. The paper feeding device according to claim 5, wherein the paper feeding devices are arranged at positions where they do not overlap with each other. 7. A paper feed unit on which paper is stacked, and a paper feed roller which rotates while contacting the upper surface of the uppermost paper stacked on the paper feed unit and feeds the paper in a paper feed direction; At least a pair of drive-side pulleys fixed on both sides of the paper feed roller on the rotation center axis of the paper feed roller; and A support shaft disposed in parallel with a central axis; at least a pair of driven pulleys supported by the support shaft; and a bridge between the drive pulley and the driven pulley and loaded on the paper feeding unit. And a belt that rotates in a direction to feed the sheet by contacting the upper surface of the uppermost sheet of the selected sheets.