JPS60122648A - Sheet reversing device of both-faces-copying machine - Google Patents

Abstract

PURPOSE:To prevent the edge of a sheet of paper from being folded by a V-groove, by forming the V-groove on the circumferential surface of one of a pair of conveying-rollers, which constitute a rotating and touching part to guide the sheet to a reversing section, and at that time, making the downstream-side inner wall of the V-groove as it meets specific conditions. CONSTITUTION:A sheet reversing device is constituted as guiding a sheet of paper 7, which has passed through a point of rolling contact between the first conveying-roller 1 and the second conveying-roller 2, to a side way, by means of a guide board set between the second conveying-roller 2 and the third conveying- roller 3, to be subjected to a switch turn. On this occasion, one inner wall surface BD of a V-groove 22, formed on the circumferential surface of the first conveying-roller 1, is formed as the relation among respective straight lines, a straight line AB between a point A and a point B on the bottom of the V-groove 22, a straight line AB' between a point A and a point B' on the surface BD, and a straight line AB'' between a point A and the other point B'' on the surface BD, becomes AB<AB'<AB''. In other words, the surface BD is formed as the distance between a point A on the periphery of a roller on the inner wall surface AB and each of the points B-B'' becomes longer in order as the point moves from a point B on the bottom of the V-groove 22 toward a point D on the periphery of the roller on the inner wall surface BD. In this way, it is prevented that the surface BD detains the edge of the sheet of copy paper 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a sheet reversing device for a double-sided copying machine.

(Prior art) In a double-sided copying machine, copying is performed again on the back side of the copy paper in the single-sided copying method, so the copy paper that has completed the process of copying on one side is fed to a sheet reversing device and turned over. and then return to the copying process again.

FIG. 1 shows an example of the sheet reversing device. '1 is a first conveyance roller, and a second conveyance roller 2 and a third conveyance roller 3 are in rolling contact with this, respectively. Each conveyance roller 1. , 2, and 3 rotate in the directions of arrows (1, b, and C, respectively.) The second conveying roller 2 and the third conveying roller 3 change from the non-reversing mode shown by the solid line to the reversing mode shown by the chain line by the arrows d and e, respectively. The position can be switched as shown in . This switching operation is performed by a mechanism not shown. Reference numeral 4 denotes a fixed guide plate, which is placed at the rolling contact between the first conveying roller 1 and the second conveying ports to 2. 16 is a movable guide plate, and is fixed to an arm 17 that is pivoted on a shaft 15. The arm 17 is integrated with a lever 14, and the lever 14 is connected to a shaft 18. The arm 12b of the lever 12 rotates around the lever 12.
is connected to the plunger 11 of the solenoid 10, and is rotated counterclockwise by its bias. Second. Guide plates 5 and 6 extending in the vertical direction are arranged between the third conveyance rollers 2 and 3. A reversing roller 8 and a pinch roller 9 are provided above the guide plates 5 and 6, sandwiching them therebetween. The pinch roller 9 is rotatably attached to the arm 12α of the lever 12, and the reversing roller 8 rotates in forward and reverse directions.

When the copy paper 7 discharged from the fixing device 19 as shown by the arrow f is to be discharged as it is, the second. The third conveying rollers 2 and 3 are switched to the non-reversing mode position shown by the solid line. Further, the solenoid 10 is in an energized state, the arm 1.2h of the lever 12 rotates in the direction of the arrow, and the arm 17 also rotates in the direction of the arrow, so the movable guide 16 is retracted downward. .

The copy paper 7 traveling as indicated by the arrow f is guided by the fixed guide plate 4 and sent to the rolling contact portion between the second conveyance roller 2 and the first conveyance roller 1 located at the solid line position. As a result, the copy paper 7 is the first one. It is sandwiched between the second conveyance rollers 1 and 2 and conveyed by them, and then it is baton-touched by the third conveyance roller 3 in the same posture, and is discharged by it and the first conveyance roller 1 as shown by the arrow g. Ru.

When copying is to be performed on the back side of the copy paper 7 discharged from the fixing device 19, the second. The third conveyance rollers 2 and 3 are switched to the reverse mode position shown by the chain line. The solenoid 10 is initially turned off. As a result, the movable guide plate 16 is raised to the position shown, and the pinch roller 9 is separated from the reversing roller 8.

The copy paper 7 traveling as shown by the arrow f is conveyed while being pinched by the second conveyance roller 2 located at the position indicated by the chain line and the first conveyance roller 1, but its tip is conveyed by the movable guide plate 1.
6 and rises along the guide plate 5. Then, the rear end of the copy paper 7 is placed on the second conveyance roller 2.
When the vehicle passes through, the solenoid 10 is energized. As a result, the pinch roller 9 comes into pressure contact with the reversing roller 8, and the copy paper 7 is pinched between both rollers 8 and 9. Reversing roller 8
Initially, the copy paper 7 is rotated counterclockwise, so that the copy paper 7 is advanced upward, but the rotation is reversed at the same time.

As a result, the copy paper 7 makes a switch turn and begins to descend. The lower end of the copy paper 7 once leaves the first conveyance roller 21, but as it descends, it comes into contact with the first conveyance roller 1 again, and as it rotates, it moves toward the rolling contact portion with the third conveyance roller 3. As a result, the copy paper 7 is placed in the third position shown by the chain line.
It is conveyed while being pinched by the conveyance roller 3 and the first conveyance roller 1, and is conveyed as shown by the arrow! The paper is discharged as shown in , and then goes to the second copying process. In this state, the copy paper 7 is attached to the fixing device 1.
Compared to when it was ejected from 9, its leading edge and trailing edge are swapped, and its top and bottom surfaces are swapped, making it upside down.

By the way, on the circumferential surface of the first conveyance roller 1, there are guide plates 5,
In order to ensure that the lower end of the copy paper 7, which is descending by making a switch turn between 6 and 6, is directed in the direction of the third conveyance roller 3, a V-groove 20 is provided parallel to the axis of the copy paper 7, as shown in FIG. However, this causes a fold 21 at the leading edge of the copy paper 7 as shown in FIG. In other words, when the leading edge of the copy paper 7 traveling in the direction of the arrow f enters the V-groove 20, it is held in place by the restrained roller and the rolling contact portion with the second conveyance roller 2, as shown in FIG. , and pressure is applied at rolling contact A.

As a result, a bending force is applied to the leading edge of the copy paper 7, causing the leading edge to fold 21.

The present invention aims to eliminate the above-mentioned drawbacks, that is, to prevent the occurrence of folding of the sheet due to the V-groove of the first conveying roller.

(Structure) In order to achieve the above object, the present invention is structured as follows. That is, a first conveying roller and a second conveying roller that rolls into contact with the first conveying roller at different positions. each of the third conveyance rollers;
．． The sheet that has passed through the rolling contact portion of the second conveyance roller is guided to a side path by a guide plate provided between the second conveyance roller and the third conveyance roller, and the sheet that has been switched in the side path is transferred to the first conveyance roller. ．． In the sheet reversing device configured to advance the sheet toward the rolling contact portion of the third conveyance roller, a V groove parallel to the axis thereof is provided on the circumferential surface of the first conveyance roller, and an inner wall on the downstream side of the groove is provided. It is characterized in that the distance between it and a point on the roller outer periphery of the upstream inner wall increases as it approaches the roller outer periphery.

FIG. 5 shows an embodiment of the invention.

Of the two inner wall openings of the V-groove 22 provided on the circumferential surface of the first conveyance roller 1, the upstream inner wall i is connected to the guide plates 5 and 6.
Because it is necessary to push the lower end of the copy paper 7 that has descended between the spaces and direct it toward the third transport roller 3, the inclination of the copy paper 7, that is, the gap between the circumferential surface of the transport roller 1 and the inner wall AB The angle θ of is selected to a predetermined value. On the other hand, the inner wall BD on the downstream side is not subject to the above-mentioned restrictions. However, in the past, it was formed symmetrically with the inner wall AB,
The washed edge of the copy paper 7 is unnecessarily restrained, resulting in the tip being folded 2.
1 was generated.

The present invention has been made in consideration of this problem, and is designed to prevent the inner wall BD from restricting the leading edge of the copy paper 7. In order for the inner wall Bl) to satisfy this condition, point A and
Each point B on the inner wall n.

A straight line A B' that connects B/ B//...
, AB'.

π1" to A B (A B' (A B"),
In other words, from point B at the bottom of the V-groove 22 to the point on the outer circumference of inner 1BDO roller, the distance between point A on the outer circumference of roller 1 on the inner wall and point (B...B'') on the inner wall BD. The purpose is to make the values gradually increase.

If these conditions are satisfied, as shown in Figure 6,
Copy paper 7 is the first. Even if it is pinched by the second conveying roller 1.2 and pressurized at the entrance point A of the groove 22,
The leading end 7α of the copy paper 7 in the groove 22 can be rotated as shown by the arrow from the bottom point B of the groove 22, and is not bent because it is not restrained.

The above conditions for the inner wall BD are equivalent to making 1ABD a right angle or an obtuse angle if it is made of a plane, and if it is made of a curved surface, the curve P has a radius of 1 and the center point A It is equivalent to being outside the arc of .

(Effects) As described above, the present invention has the shape of the V-groove provided on the circumferential surface of the first conveyance roller such that the distance between the downstream inner wall thereof and a point on the upstream inner wall on the outer circumference of the roller is Since it is formed so that it becomes larger as it approaches the outer periphery, the sheet whose tip is pushed into the (1) groove is not restrained at the bottom of the (2) groove. When pressurized by the third conveyance roller and the first conveyance roller, bending force is no longer applied to the leading edge of the sheet. Therefore, it is possible to prevent the sheet from being folded, and the occurrence of a jam due to this can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of a sheet reversing device, Figs. 2 and 3 are front views showing how a sheet is folded by a conventional device, and Fig. 4 is a perspective view of copy paper with a fold. It is a diagram. FIG. 5 is a front view of the main parts of the embodiment of the present invention, and FIG.
The figure is a front view of the main parts showing the operation of the device of the present invention. 1...First conveyance roller, 2...Second conveyance roller, 3
...Third conveyance roller, 5, 6...Guide plate, 7...
・Copy paper, 22...V groove, AB...upstream inner wall,
BD: Downstream inner wall, A, D: Points on the outer circumference of the roller. Patent applicant Rico Co., Ltd. - Figure 1 Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A first conveying roller, and a second conveying roller that rolls into contact with the first conveying roller at a different position.
and a third conveyance roller, the sheet passing through the rolling contact portion of the first and second conveyance rollers is guided to a side path by a guide plate provided between the second conveyance roller and the third conveyance roller; The seat that was made a switch turn on the side road was placed in the first. In the sheet reversing device that allows the sheet to advance toward the rolling contact portion of the third conveyance roller, a V groove parallel to the axis of the first conveyance roller is provided on the circumferential surface of the first conveyance roller, and an inner wall on the downstream side of the groove is formed. A sheet reversing device for a double-sided copying machine, characterized in that the distance between the upstream inner wall and a point on the outer circumference of the roller increases as the distance approaches the outer circumference of the roller.