JPS6041568Y2 - Sheet conveyance device in electronic copying machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sheet conveying device in an electronic copying machine.

2. Description of the Related Art A so-called cheno-delivery type sheet conveyance device, in which the leading edge of a sheet is gripped and conveyed by a sheet gripper, is already known.

The above-mentioned sheet conveying device will be explained by taking an electronic copying machine equipped with this as an example. In FIG. 1, reference numeral 1 indicates a photosensitive drum that rotates in the direction of the arrow.

Around the photoreceptor drum 1, a charging device 2, an exposure device 3,
A developing device 4, a transfer device 5, and a static eliminator 6 are respectively arranged.

A reciprocating document table 7 is disposed at the top of the copying machine, and a sheet cassette 8 is disposed on the right side.

A sheet conveying device 9 is provided obliquely closest to the toner image transfer position A of the photosensitive drum 1 .

As shown in FIG. 2, the sheet conveying device 9 has a drive shaft 10.
a sprocket 11.11 fixedly attached to the driven shaft 12, a sprocket 13°13 attached to the driven shaft 12, and a pair of chinos 14, 1 wound around these sprockets 11.13.
4, and a sheet gripper 15 whose both ends are fixed to the cenograph 14 and 14.

The sheet conveyance device 9 is configured such that the sheet gripper 15 shown in FIG. 1 is at its starting position, and rotates once and stops at the same position.

Further, a chino 14 is provided in the left half of the sheet conveying device 9.
A fixing device 16 is disposed to sandwich this on the tension side.

A roller 17 (see FIG. 3) is fixed to the drive shaft 1o, and a paper discharge roller 18 is in contact with the roller.

Now, when a print button (not shown) is pressed, the photosensitive drum 1 rotates in the direction of the arrow, its surface is charged by the charging device 2, and then an original image (not shown) on the document table 7 is formed by the exposure device 3. is irradiated to form an electrostatic latent image.

This electrostatic latent image becomes a toner image by the developing device 4 and is brought to the transfer position.

At this time, the sheet S previously stored in the sheet cassette 8 is sent out by the sheet feeding roller 19, its leading end is gripped by the sheet gripper 15, and brought to the same position.

The sheet S conveyed by the sheet gripper 15 is brought into contact with the photosensitive drum 1 at the transfer position A, and the toner image is transferred by the action of the transfer position 5.

The toner image on the sheet is transported in the direction of arrow a and is melted and fixed onto the sheet while passing through the fixing device 16.

The sheet that has been fixed is released from the sheet gripper 15 in the sheet discharge section B, and is discharged to the outside of the machine by the discharge rollers 20.

Incidentally, the toner image formed on the surface of the photoreceptor drum 1 is transferred by contacting the sheet S that is gripped and conveyed by the sheet gripper 15 of the sheet conveyance device 9 that rotates in synchronization with the drum. As already mentioned.

During the transfer, the sheet S is brought into close contact with the surface of the photoreceptor drum 1, and the rotating checker 714
When the toner image is vibrated, the adhesion is not uniformly affected, resulting in uneven toner image transfer, or the toner image is disturbed during transfer or after transfer and before fixing.

The present invention solves the above-mentioned problems by providing a tightener in the check 7 that supports the sheet gripper and providing a vibration isolating member in the sheet transport path so as not to apply longitudinal vibrations to the sheet at least during sheet transport. An object of the present invention is to provide a sheet conveying device for an electronic copying machine.

The object of the present invention is to provide a pair of chains 7 that support and rotate both ends of a sheet gripper, a drive shaft and a driven shaft around which the chains 7 are wound, and that rotate at fixed positions, and these drive shafts. A cam is provided at the sheet gripping position and the sheet ejection position, respectively, to open and close the sheet holding pawl of the sheet gripper in cooperation with the driven shaft or its sprocket, and a cam is provided at the lower side of the tension side of the checker 7 that conveys the sheet. A sheet conveying device having a vibration isolating member extending along the belt and preventing vibration of the check 7 during sheet conveyance, and a tightener provided on the slack side of the check 7 to absorb the slack of the check 7. achieved by.

According to the present invention having such a configuration, the elongation of the checker 7 is not absorbed by increasing the distance between the drive shaft and the driven shaft, so the sheet gripping position and the sheet ejection position are always kept stationary. be able to.

For example, if the driven shaft is oriented toward and away from the drive shaft to absorb the slack of the chain 7, the tension of the chain 7 will be kept constant, but the sheet gripping position will be changes as the checker 7 becomes slack, and the relative position of the cam that opens and closes the sheet presser claw of the sheet gripper and other members shifts, making it impossible to accurately open and close the sheet presser claw. The effects will be understood.

In addition, by extending the vibration isolating member along the lower part of the tension side of the chain 7, vibration of the chain is prevented, so that the mutual position of the sheet conveyed using the tension side and the surface of the photoreceptor drum is is kept constant and good transfer can be performed.

The present invention will be explained below with reference to illustrated embodiments.

In the following description, members having the same functions as those of the conventional device will be designated by the same reference numerals, and detailed description of each will be omitted.

In FIG. 3, the sheet gripper 15 placed at the starting position is stopped with the cam follower 15a in contact with the cam 21 and the sheet holding claw 15b opened.

In the sheet gripper 15 in the so-called sheet gripping position where the claws 15b are open, when the cam follower 15a is swung, the entire gripper tends to oscillate, but this action is prevented by a cam (not shown) provided on the driven shaft 12. ) or blocked by sprocket 13.

At the paper discharge position B, a sheet release cam 22 is arranged on the rotational trajectory of the cam follower 15a.

Further, at the lower part of the tension side of the check 714, a vibration isolating member 23 is fixedly disposed on a stationary member (not shown) over a considerable length.

A tightener 30 is provided on the loose side of the chain 714.

The tightener 30 includes a roller 25 rotatably supported by a fixed shaft 24 mounted on a stationary member (not shown), a base end rotatably attached to the fixed shaft 24, and a spring 26. Arm 27 is given a counterclockwise rotational habit by
and a roller 28 rotatably pivoted to the free end of this arm 27, and each roller is wrapped around a chain 714 to apply tension as shown in the figure.

A heat insulating plate 29 of the sheet fall prevention/fixing device 16 is disposed below the sheet conveying device 9.

According to the sheet conveying device of the present invention configured as described above, when the sheet gripper 15 grips and moves the sheet, the check 714 that supports and rotates the sheet along the vibration isolating member 23. Since it rotates and is given tension by the tightener 30, it does not vibrate.

Therefore, the sheet being conveyed does not vibrate, so even if the image on the sheet conveyed to the fixing device 16 during transfer and after transfer is a powder image, the toner image formed on it will not be disturbed. .

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing an example of an electronic copying machine equipped with a sheet conveying device, FIG. 2 is a perspective view schematically showing the sheet conveying device, and FIG. 3 is a front sectional view showing an embodiment of the present invention. It is a diagram. DESCRIPTION OF SYMBOLS 1... Photosensitive drum, 9... Sheet conveyance device, 10... Drive shaft, 12... Driven shaft, 14... Cheno, 15... Seat gripper, 21, 22... Cam, 23...
...Vibration isolation member, 30...Tightener.

Claims (1)

[Scope of utility model registration request] A pair of chains that rotate while supporting both ends of the sheet gripper; a drive shaft and a driven shaft around which the chains are wound, which rotate at fixed positions, respectively; A cam is installed at the sheet gripping position and the sheet ejecting position to open and close the sheet presser claw of the sheet gripper, and a cam is fixed to the lower part of the tensioning side ceno where the sheet is conveyed, and the cam is attached to the ceno. In an electronic copying machine, the electronic copying machine has a vibration isolating member extending close to the belt to prevent vibration of the chino during sheet conveyance, and a tightener provided on the slack side of the chino to absorb the slack of the chino. Sheet conveyance device.