JPS5922847A - Sheet inverter - Google Patents

Abstract

PURPOSE:To invert a sheet smoothly with high speed by providing a pair of sheet inverters comprising a sheet inverting guide and a sheet inverting means then feeding the sheets alternatively to each sheet inverter and inverting. CONSTITUTION:A sheet is fed in the arrow direction from central left on the drawing and the passing is detected by a sheet sensor 9 receiving the light from a light source 8, to feed the sheet to an inverter at the upper stage through a carry path exchanging mechanism 7. In other word, it is fed through a sheet inversion roll 12 to an upper stage inversion guide 11 where it is inverted then guided by an upper stage inversion guide 14 to the next process. The following sheet is applied with similar operation then fed to the lower stage inverter or a sheet inversion roll 12, sheet inversion guide 11' and sheet guide 14'. Consequently when assembling two sheet inverters and using alternatively, the sheet can be inverted smoothly with high speed without jamming.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for reversing a sheet, such as a transfer paper, in a copying machine or the like. More specifically, the present invention relates to a high-speed sheet reversing device.

In a conventional copying machine, when the transfer paper is fed to the reversing device at high speed with narrow intervals,
There is a drawback that the next transfer sheet enters the device before the previous transfer sheet is removed from the reversing device, causing a jam in the device. However, there is a demand for high-speed operation of copying machines, and along with the development of new models with higher speeds, increasing the speed of sheet reversing devices has become a new challenge.

The inventors of the present invention have completed the present invention after conducting various studies in order to speed up the operation of the sheet reversing device. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet reversing device with increased speed.

The object of the invention is achieved by using two sheet inversion devices for combined exchange. The present invention will be described in detail below with reference to the drawings.

Fig. 1 is a diagram showing a conventional sheet reversing device. A sheet fed from the left in the direction of the arrow passes through a pair of sheet feeding rolls 3, and then passes through three rolls (2°2', 2"). The upper pair (2, 2') of the sheet reversing rolls causes the sheet to reach the sheet reversing guide 1, and when the leading edge of the sheet reaches the innermost end point of the sheet reversing guide, the trailing edge of the sheet is The lower pair of sheet reversing rolls (2', 2"
) and then reversed and sent to the next process via a sheet guide 4'. However, when operating at high speeds, there was a drawback that the ↑ sheet could jam in the sheet reversal guide.

FIG. 2 is a diagram showing an embodiment of the present invention, and this sheet reversing device includes two sheet reversing guides 11 and 11', sheet reversing rolls 12 and 12' attached to these, and a sheet reversing guide 14. , 14'. The passage of the first sheet fed from the left in the direction of the arrow is detected by a sheet sensor 9 receiving light from a light source 8, and is sent to, for example, an upper reversing device by a sheet feeding path switching mechanism 7. The sheet passes through the sheet reversing roll 12, enters the upper reversing guide 11, is reversed, and then enters the upper reversing guide 14.
will be guided out of the reversing device in the direction of the arrow to the right.

When the next second sheet is fed, its passage is detected by the sheet sensor, the feeding path switching mechanism is activated, and the sheet is sent to the reversing device at the lower stage, and the sheet reversing roll 12'
, the sheet reversing guide 11' and the sheet reversing guide 14' to exit the reversing device.

Thereafter, the third sheet is sent to the upper reversing device, the fourth sheet is sent to the lower reversing device, and the sheets are sequentially reversed by alternately using the upper and lower reversing devices. In this embodiment, a sensor detects sheet feeding and operates the feeding path switching mechanism, but a signal from a sheet feeding section of the main body of the copying machine may also be used.

FIG. 3 is a view showing another embodiment of the present invention, in which the upper and lower sheet reversing guides 1'11, 11' are actuated by the sheet detection of the sheet sensor 9. is attached to. Each reversing guide is attached with an upper sheet feeding reversing roll 13 and a lower sheet feeding reversing roll 13'. When a sheet is fed in the direction of the left arrow, the sheet is sent to the reversing device by the sheet feed roll 3, and is detected by the sheet sensor 9 and a signal is sent to the reversing guide mounting shaft 10, and the upper sheet reversing guide 11 is rotated. It comes to a position where it can receive sheets, facing the guide 15 together with the upper sheet feeding and shuffling reversing roll 13 attached thereto. The roll 13 rotates in the direction to take in the sheet, so that the sheet enters the sheet reversing guide 11.

At this time, the sheet stored in the lower sheet reversing guide 12 passes through the sheet reversing guide 6 and leaves the sheet reversing device in the direction of the arrow to the right by the lower sheet feeding reversing roll 13'. When the next sheet is supplied to the reversing device, the reversing guide mounting shaft 10 rotates in response to a signal from the sheet sensor, and the upper sheet reversing guide 11 rotates upward together with the reversing roll 13 to face the upper sheet reversing guide. 1), the reversing rolls 13 are rotated in the opposite direction to take out the sheet in the reversing guide and leave the sheet reversing device via the upper guide 6. At this time, the lower sheet reversing guide 12 is located opposite the guide 15 together with the reversing roll 13', and the reversing roll 14 rotates in the opposite direction to supply the next sheet to the lower sheet reversing guide 12. Thereafter, each time a sheet is fed, the reversing guide mounting shaft 10 rotates so that the upper and lower sheet reversing guides alternately face the guide 5, and at the same time, the reversing roll 13 or 13' also changes its rotation direction to rotate the sheet. The sheet is fed and reversed so as to be stored in the sheet reversal guide 11 or 12 or discharged from there. To change the direction of rotation of the reversing roll, the sheet is fed into the sheet reversing guide, then the sheet is temporarily stopped with its trailing end held between the rolls, and when the reversing guide mounting shaft begins to rotate, the roll begins to rotate in the opposite direction, reversing the sheet. The sheet is then fed from the sheet reversing guide to the guide 6. The device in Figure 3 shows an example in which sheets are fed horizontally, but if the sheets are fed from the bottom to the top (the device in Figure 3 is placed upright with its left side facing down). Since the sheet is naturally guided between the rolls of the reversing rolls by gravity, once the sheet is fed from the reversing rolls, it can be moved between the reversing rolls without stopping while the sheet is being held between the rolls as described above. rotation can be performed. The above explanation ↑ describes the case where a sheet reversing roll is used, but the sheet may be guided to the reversing guide by means such as a belt or air blowing as the sheet reversing means.

According to the sheet reversing device of the present invention, it is possible to perform smooth copying without causing a jam when used in a high-speed copying machine and the feeding interval of transfer paper is small, and it can also be used in a normal-speed copying machine. Each paper has a point even when used.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional sheet reversing device, and FIGS. 2 and 3 are diagrams showing a sheet reversing device according to the present invention. Symbols 1, 11, 11' in the figure: Sheet reversal guide, 2.1
2... Sheet reversing roll, 3.13... Sea) feed o-ru, 4.4', 14.14', 5.6... Sheet guide, 7... Feeding route switching mechanism, 8 ...light source, 9
... Sheet sensor, 10... Reversing guide mounting shaft (and 3 others)

Claims (1)

[Claims] It consists of a pair of sheet reversing guides and a sheet reversing means provided opposite to each sheet reversing guide, and each sheet is alternately guided to the sheet reversing guides to perform sheet reversal. Characteristic sheet reversing device 1.