JPS636113Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet reversal/non-reversal transport device for a double-sided copying machine.

Double-sided copying machines are equipped with a sheet reversing device because the reverse side of the copy paper that has already been copied on one side is copied again, but this sheet reversing device handles the copy paper after it has passed through the fixing device. Therefore, it may not move smoothly due to the influence of the curl.

FIG. 1 shows an example of the sheet reversing device. Reference numeral 1 denotes a first conveyance roller, and a second conveyance roller 2 and a third conveyance roller 3 are in rolling contact with this, respectively. Each of the conveyance rollers 1, 2, and 3 rotates in the directions of arrows a, b, and c, respectively. The second conveying roller 2 can switch its position from the non-reversing mode shown by the solid line to the reversing mode shown by the chain line as shown by the arrow d, and in conjunction with this, the third carrying roller 3 also changes to the reversing mode shown by the chain line by the arrow e. The position can be changed as shown in .

In the non-reversing mode, the sheet 7 guided by the guide plate 4 and sent between the first and second transport rollers 1 and 2 is immediately baton-touched to be transported by the first and third transport rollers 1 and 3. Then, it is discharged as shown by arrow g without being reversed.

In the reversal mode, the second and third conveyance rollers 2 and 3 are at the positions indicated by the chain lines, so the first and second
The sheet 7 that has passed between the transport rollers 1 and 2 comes into contact with the guide plate 5 at its leading end, and is guided by the guide plate 5 and advances upward. The sheet 7 is the guide plate 5,
After being conveyed upward between 6 and 6, it descends with the original rear end at the beginning. This original rear end is bent to the right by the rotation of the first conveyance roller 1, is pinched by the first and third conveyance rollers 1 and 3, and is discharged in the direction of arrow g. As a result, the original rear end of the sheet 7 becomes the leading edge, and the surface, which was originally upward, becomes downward. That is, an inversion is performed.

By the way, the sheet 7 is
It approaches as shown by arrow f in FIG. 2, and the approach angle θ needs to be about 50° or less. If the angle θ is larger than that, the sheet 7 will be supported at the position where it contacts the guide plate 5, and a jam will occur. However, if the sheet 7 undergoing reversal is curled downward,
As shown in FIG. 3, the effective angle of approach θ' increases. As a result, the curled sheet 7 will jam.

The present invention aims to solve the above-mentioned problems, and FIG. 4 shows an embodiment thereof.

The configuration and operation of each conveyance roller 1, 2, 3 are the same as those shown in FIG. 1, and the guide plates 4, 5,
The same applies to 6. Reference numerals 8 and 9 indicate reversing rollers provided above the guide plates 5 and 6. The reversing roller 9 moves from the solid line position to the operating position shown by the chain line by the energization of the solenoid 10, and rolls into contact with the reversing roller 8. The plunger 11 of the solenoid 10 operates the reversing roller 9 via the arm 12a of the two-pronged lever 12, and also operates the lever 14 via the arm 12b. The lever 14 rotates around a shaft 15,
Operate the auxiliary guide plate 16. Auxiliary guide plate 16
protrudes from the tip of the guide plate 4 and provides a guide surface following it, but when the lever 14 rotates in the direction of the arrow h, it goes below the circumferential surface of the first conveyance roller 1.

In the non-reversing mode in which the sheet 7 ejected from the fixing device 17 is ejected without reversing, the second and third conveying rollers 2 and 3 are in positions close to each other and overlapping each other, as shown by solid lines, and , solenoid 10 is in an energized state.

Therefore, the arm 12b rotates in the direction of arrow j,
The lever 14 is rotated in the direction of the arrow h to make the auxiliary guide plate 16 go under the circumferential surface of the first conveyance roller 1.
As a result, the sheet 7 is discharged in the direction of arrow g without being subjected to a reversing action.

When reversing the sheet 7, the second and third conveying rollers move to the positions indicated by the chain lines, and the solenoid 10 is deenergized. As a result, arm 12b,
The lever 14 and the auxiliary guide plate 16 return to the illustrated positions, and the reversing roller 9 separates from the reversing roller 8.
The auxiliary guide plate 16 continues to guide the sheet 7 that has been guided by the guide plate 4 and has passed the first and second conveyance rollers 1 and 2, leading it between the guide plates 5 and 6. The tip of this auxiliary guide plate 16 approaches the guide plate 5 and gives a sharp approach angle θ to it, so even if the sheet 7 is curled, the effective approach angle θ' cannot be increased beyond the limit. There is no.

In this way, the sheet 7 that has entered between the guide plates 5 and 6 rises therein, but the solenoid 10 is energized at the appropriate timing. solenoid 1
Although the auxiliary guide plate 16 goes under the circumferential surface of the first conveyance roller 1 due to the bias of 0, no problem occurs because its role as a guide has been completed. After the rear end of the sheet 7 passes between the first and second conveying rollers 1 and 2, the reversing roller 9 rolls into contact with the reversing roller 8 due to the urging of the solenoid 10, pinching the sheet 7, and pressing the sheet 7.
descend. Due to the rotation of the first conveyance roller 1, the rear end of the sheet 7 advances to the rolling contact area between it and the third conveyance roller 3, and the sheet 7 is discharged in the direction of arrow g in an inverted state with the original rear end at the beginning. Ru.

In the present invention, a second conveyance roller and a third conveyance roller are disposed so as to be able to move and contact the first conveyance roller in a fixed position to a non-reversal position and a reverse position, and the first conveyance roller
A mechanism in which a guide plate that guides the sheet is arranged and fixed between the conveyance roller and the second conveyance roller, and the sheet is transferred in a non-inverted manner or guided to a side path and switched by shifting the second and third conveyance rollers to the non-reversing position and the reversing position. In a sheet reversing/non-reversing conveyance device that reversely transports a sheet, an auxiliary guide plate is provided between the first and second conveyance rollers, and the auxiliary guide plate is operated in conjunction with a switchback mechanism to perform reversal and non-reverse conveyance. At the time of switchback, the sheet can be moved to a position where it does not obstruct the sheet facing the second and third conveyance rollers, or a position where the approach angle of the sheet facing the side path is less than a predetermined value, so that the sheet does not curl. Even if the tip is guided by the auxiliary guide plate, the tip moves smoothly and jams can be reliably prevented.

[Brief explanation of the drawing]

Figure 1 is a front view of the main parts of a conventional sheet reversing device, Figures 2 and 3 are front views for explaining the approach angle, and Figure 4 is a front view of the first embodiment of the present invention. be. 1...First conveyance roller, 2...Second conveyance roller, 3...Third conveyance roller, 4, 5, 6...Guide plate, 8, 9...Reverse roller, 10...Solenoid, 16... Auxiliary guide plate, θ... Approach angle.

Claims (1)

[Scope of utility model registration request] A second conveyance roller and a third conveyance roller are disposed so as to be able to move and contact the first conveyance roller in a fixed position to a non-reversal position and a reversal position, and guide the sheet between the first conveyance roller and the second conveyance roller. A sheet reversing device in which a guide plate is arranged and fixed, and the sheet is transported in a non-reversing manner by changing the non-reversing position and the reversing position of the second and third conveyance rollers, or the sheet is reversely transported by a mechanism that guides the sheet to a side path and switches it.
In the non-reversing transfer device, an auxiliary guide plate is provided between the first and second transport rollers, and the auxiliary guide plate is directed toward the second and third transport rollers in non-reversing and switchback states in conjunction with a switchback mechanism. A sheet reversing/non-reversing transport device capable of being displaced to a position where the sheet is not obstructed or a position where the approach angle of the sheet toward a side path is less than or equal to a predetermined value.