JPH03200663A - Sheet turning-over device - Google Patents

Abstract

PURPOSE:To switch back even a curled sheet without being bent by mounting a press member to press other part than a pressed part when the sheet is pressed by a sheet press means to a given spot of the press means. CONSTITUTION:A turn-over roller 2 is mounted to an arm 1 serving as a sheet press means. When the rear end part of a sheet X fed through a conveyance passage 16 is separated away from a conveyance roller 9, the arm 1 is moved downward, and the sheet X is reversely fed in a pressed state to a reverse feed route B. A plateform resilient guide 3 is mounted to the under side on the free end side of the arm 1. The plateform resilient guide 3 has a notch formed in its central part, in which a spring 33 is suspended, and a turn-over roller 2 is rotatably supported on the spring 33 serving as a shaft. Thus, when the sheet X is positioned in a turn-over position Y, it is pressed by the turn-over roller 2 and the rear end part of the sheet X is also pressed by means of the resilient guide 3. Even when the rear end part thereof is curled, the curl is straightened, and the occurrence of a jam due to collision of the sheet with the conveyance roller 9 during reverse feed is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a sheet reversing device used in a copying machine or the like, for reversing a sheet.

[Prior Art] Conventionally, a sheet reversing device has the following structure, as shown in the cross-sectional view of FIG.
A conveyance path 16 and a conveyance roller 9 are provided at the bottom thereof,
Further, a reversing arm 1 having a reversing roller 2 is rotatably provided at a location where the sheet X falls from the conveying roller 9. The operation is performed from the input direction to the conveyance path 16.
After the rear end of the sheet X that has been conveyed through the (reversed) and conveyed in direction B.

[Problem B to be solved by the invention] However, the conventional sheet reversing device assumes that the sheet is straight and not curved, and as shown in FIG. When the sheet is being conveyed, even if the sheet is separated from the conveyance roller 9, the curled trailing edge will be lifted up. In this state, when the reversing roller 2 presses the reversing roller 6 and conveys the paper X in the direction B,
There was a problem in that the sheet collided with the azure O-ra 9t and the sheet folded. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the conventional sheet reversing device, and an object of the present invention is to provide a sheet reversing device that does not cause sheet folding even if the sheet is curled.

[Means for Solving the Problems] The present invention provides C! - a transport path for sending the to the reversal location;
a sheet presser that is located at a first position remote from the reversing location when the sheet is not being fed, and is movable to a second position that can press the sheet when the sheet is being fed; In the sheet reversing device, the sheet reversing device is attached to a predetermined location of the sheet pressing means, and when the sheet pressing means presses the sheet, the sheet reversing device presses other parts of the sheet other than the pressed part. It is characterized by comprising a presser member for.

[Function] According to the above configuration, the present invention provides the sheet pressing means with a pressing member for pressing other parts other than the portion pressed by the sheet pressing means, so that even a curled sheet can be pressed. In response to the movement of the presser means, the presser member presses the sheet, allowing the sheet to be switched back and forwarded without folding.

[Examples] The present invention will be described below based on drawings showing examples thereof. Incidentally, the same members as in the conventional figure 5.6 are given the same reference numerals.

FIG. 1 is a schematic sectional view showing the main parts of an image forming apparatus using a sheet reversing device according to the present invention. Figure 2 shows
FIG. 3 is a plan view of a reversing arm as sheet pressing means.

In FIG. 1, paper (sheet) x separated from the image carrier 20 after undergoing the charging, exposure, development, and transfer steps for copying.
The toner image on the paper X is thermally melted and fixed by a thermal fixing device 22 through a conveyor belt (21). In the case of single-sided copying, paper X is ejected from ejection rollers 14 and 15. In the case of double-sided copying, sheet X will proceed to the sheet inversion device of the present invention. Also, in the case of composite copying, the ejection roller 14
．． 15, but is transported to an intermediate tray by switching claws 12 and 13, which will be described later. Ejection roller 14.150
In the front, there is a switching claw 13 that selects whether the paper X is to be ejected to the outside or to proceed toward the intermediate tray, and also in the transport path 16, which selects whether or not the paper X is to be reversed. A switching claw 12 is provided. When the paper X is not reversed (in the case of composite copying), the switching claw 12 is at the position indicated by the two-dot chain line, and the paper X passes through the conveyance roller 10 and advances downstream. On the other hand, when paper X is to be reversed (in the case of double-sided copying), the switching claw 13 is located at the position indicated by the two-dot chain line, and the switching claw 12 is located at the position indicated by the solid line. A progressive roller 9 is arranged at the rear end ("F end") of the conveyance path 16 in the case of double-sided copying with reversal, and the paper X passes through the Ha roller 9 and is guided to the reversal location Y. In this case, the reversing arm 1 serving as the sheet holding means is normally placed at the first position remote from the reversing location Y.
It is located at the position indicated by the solid line above. Further, when the rear end of the paper X is sent out from the conveyance roller 9, the reversing arm 1 moves to the second position that presses the paper
It is designed to be rotated to the position.

Two arms l serving as sheet holding means are arranged in the left and right direction. As shown in FIG. 2, plate-shaped elastic guides 3 as holding members are attached to the lower side of the free end of the reversing arm l. This plate-shaped elastic kite 3 has a notch in the center, and a spring 33 is suspended therefrom.

The reversing roller 2 is rotatably supported around the spring 33 as an axis. The material of this elastic guide 3 is P.
An elastic material such as ET film (polyethylene terephthalate) is suitable.

This is because the curled paper X can be reliably held down.

A reversing roller 6 and a roller 30 are located below the reversing arm l.
A conveyor belt 4 rotated by a conveyor belt 4 is arranged. Even if paper
The rib 31 located slightly toward the E side of the root 4
It's starting to get boring. Therefore, when "C paper xh" is conveyed, the paper X moves to the right on the rift 311 by inertia and does not come into contact with the conveyance heald 4, so there is no problem because it will not be pushed back by reason. Reversing arm 1 The rift 31 secures a large gap below the reversing roller 2 so that the reversing roller 2 attached to the paper X can rotate downward and contact the conveyance heald 4.
is located between the reversing roller U: 12 and the decoy held 4, and when the reversing roller 2 rotates in the F direction and pushes down the paper a little, the paper X comes into contact with the conveyor belt 4, and the conveying force causes the paper to be reversed. It is designed to be sent to the left from location Y.

The conveyance roller 8 transfers the fed paper X to the conveyance roller 9.
It is also a means for sending out the kite to the semicircular kite plate 11.

The lower end of the guide plate 11 faces the lower left side of the rib 31. On the other hand, conveyance rollers 25, 26, and 27 are brought into contact with the lower side of the conveyance heald 4. If the paper X is large, for example an A3 size paper, the right switching claw 28 of the reversing roller 6 is rotated upward as shown by the imaginary line, and the paper X is guided below the switching claw 28. Intermediate tray 17
In the case of paper of size 84 etc., the next switching claw 29 of the transport roller 26 is guided below the switching claw 29 which cannot be rotated upwards as shown by the imaginary line, and the paper is transferred to the intermediate tray. 1
It is scheduled to be introduced in 7. That is, intermediate tray 1
In order to align the leading edge of the paper X at step 7, the larger paper X is moved away from the conveyance nozzle 4 sooner.

Furthermore, small sheets of paper, such as A4 and B5 size sheets, are introduced into the intermediate tray 17 from the conveyance roller 27 closest to the intermediate tray 17.

Next, the operation of the sheet reversing device will be explained with reference to FIG. 3.4.

FIG. 3 is a sectional view of a main part of the sheet reversing device when the trailing edge of the paper X is curled.

First, it is assumed that a sheet X is conveyed in the incoming direction along the day feed path 16, passes through the conveyance rollers 9, and is conveyed to the reversal location Y, but the trailing edge of the sheet X is curled as shown in FIG. When the reversing arm 1 rotates downward, the elastic guide 3 provided at the lower free end of the reversing arm 1 also rotates downward, and the curled portion of the paper X is brushed off (Fig. 4, point 2). As shown in the figure, the paper X is transported in the direction B by the transport heald 4 passing through the reversing roller 6 and the transport roller 8 without being caught. Then, the paper X is introduced into the intermediate tray 17 via the lower side of the transport heald 4.

Furthermore, the sheet reversing device according to the present invention is not limited to those used in copying machines, but can also be applied to sheet reversing devices used in other devices capable of reversing sheets.

Note that the location of the sheet pressing means to which the pressing member is attached is not limited to the lower side of the tip of the reversing arm, but may be any other location above the tip.

[Effects of the Invention] The present invention has the effect that even if the sheet is curled, the sheet will not be folded during the folding and reversing operation, by providing a pressing member at a predetermined location of the sheet pressing means for pressing the sheet.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing the main parts of an image forming apparatus using an embodiment of a sheet reversing device according to the present invention, and FIG. A plan view of the arm, FIG. 3 is a sectional view of the main part of the sheet reversing device of the same embodiment when the trailing edge of the paper is curled, and FIG. 4 is a diagram of the same embodiment when the paper is knocked off. FIG. 5 is a cross-sectional view of the main parts of a conventional sheet reversing device, and FIG. 6 is a cross-sectional view of the main parts of the conventional sheet reversing device when paper is curled. be.

Claims (2)

[Claims] (1) A conveyance path for sending the sheet to a reversing place; when the sheet is not being fed, the conveyance path is located at a first position away from the reversing place, and when the sheet is being fed, the conveyance path is located at the In a sheet reversing device, the sheet reversing device includes sheet pressing means movable to a second position capable of pressing the sheet, which is attached to a predetermined location of the sheet pressing means, and when the sheet pressing means presses the sheet, the sheet A sheet reversing device comprising a pressing member for pressing a portion other than the pressed portion of the sheet. (2) The sheet reversing device according to claim 1, wherein the pressing member is made of an elastic material.