JP2532074B2 - Sheet reversing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sheet reversing device, and more particularly to a sheet reversing device in a copying machine having a double-sided copying function.

(Prior Art) It is convenient for a copying machine to have a so-called double-sided copying function in which a copy sheet copied on one side is reversed and fed again to the copying machine to perform copying on the back side. .

Conventionally, in a general copying machine, a double-sided copying function can be provided by forming an inverted sheet re-feeding path for a discharged sheet at a sheet discharge port. A sheet reversing device is provided in the passage for re-feeding the sheet.

An example of a reversing device for reversing the ejected copy sheet provided in the sheet ejecting section of the copying machine in the copying machine having the double-sided copying function will be described with reference to FIG. In the figure, reference numeral 1 indicates a heat fixing roller pair in the copying machine. A sheet conveying path 2 for guiding the discharged sheet is provided from the discharge port of the nip portion of the heating and fixing roller pair to the sheet reversing portion 10. A sheet re-feeding path 3 for feeding the sheet to a sheet re-feeding section in the copying machine branched from the path and a sheet discharging path 15 for discharging the sheet to the outside are provided in the middle of the sheet conveying path 2. There is. Between the sheet conveying path 2 and the re-feeding path 3, a conveying roller 5 is provided, a part of the peripheral surface of which faces each other and rotates in the arrow direction. A roller 4 lightly pressed to the peripheral surface of the roller 5 on the sheet conveying path side is provided, and a roller 6 lightly pressed to the peripheral surface is provided on the peripheral surface of the sheet re-feeding path 3 side. Has been. The branch portion 2a of the sheet conveying passage 2 is provided with a switching claw 7 for switching the sheet traveling direction from the sheet conveying passage side to the re-feeding passage 3 side and the sheet discharging passage 15 side.

Inside the sheet conveying path 2, the roller 5 and the roller 4
A sheet detecting member 8 for detecting that the rear end of the sheet advancing in the sheet conveying passage has passed the nip portion is provided in the nip portion of and.

The paper discharge path 15 is provided with a pair of paper discharge rollers 9 for discharging the sheet to the outside.

A part of the sheet conveying passage 2 faces between the sheet conveying passage 2 and the sheet reversing portion 10, and the reverse roller 11 always rotates in a direction opposite to the traveling direction of the sheet in the sheet conveying passage 2. Is provided. When the sheet detection member 8 detects the passage of the trailing edge of the sheet, the detection signal energizes the solenoid 12 so that the pressure contact roller 13 abutting against the peripheral surface 11a of the reverse roller 11 faces the reverse roller 11. Is provided.

As the sheet advances in the sheet conveying path 2, the roller 5
When the sheet detection member 8 detects that the rear end of the roller 4 has passed through the nip portion, the solenoid 12 is excited by the detection signal of the detection member 8 and the pressure contact roller 13 moves to the position indicated by the chain line. , The peripheral surface 13a of the roller is pressed against the peripheral surface 11a of the reverse roller 11 with the sheet interposed, and the rotational force of the reverse roller 11 causes the sheet to be fed in the direction opposite to the sheet advancing direction. At the same time, when the sheet detecting member 8 detects that the rear end of the sheet has passed the nip portion of the rollers 5 and 6, the switching claw 7 also receives the sheet detection signal and is not shown at a predetermined timing. Swing to the position shown by the chain line in Fig. 3 with a solenoid. The sheet S fed back by the reverse roller 11 and the pressure contact roller 13 is nipped by the switching claw 7 in the nip portion between the roller 5 and the roller 6 of the re-feeding path 3 and guided to the re-feeding path 3.

By the way, as shown in FIG. 4, the reverse roller 11 and the pressure contact roller 13 which is in pressure contact with the reverse roller 11 are configured by supporting a roller-shaped chopping roller on a support shaft.
No. 13 was made of EPDM (ethylene propylene rubber) as its rubber material, and its rubber hardness was 30 ° ± 5 °.

In such a reversing device, when the sheet S that has entered the reversing portion is thicker than a postcard and has a large size, the pressing roller 13 has a roller shape and the rubber of the roller is formed. If EDPM is used for the material and the rubber hardness of the roller is 30 ° ± 5 °, the pressure contact roller 13
When the sheet S is not brought into contact with the sheet S with a too strong force, the pressure roller 13 cannot be brought into pressure contact with the reverse roller 11 with a force sufficient to convey the sheet S, and the sheet S slips in the sheet conveying path. There is a problem that it will cause a jam.

In order to solve this problem, it is conceivable to use a large-capacity solenoid to bring the pressing roller 13 into contact with a strong force, but this is disadvantageous in terms of cost and layout.

(Object) The present invention has been made in view of the problems of the above-described conventional reversing device, and provides a sheet reversing device that increases the pressing force of a pressing roller to reliably reverse any kind of sheet. With the goal.

(Structure) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 11 indicates a reverse roller. A pressure roller 23 is provided which contacts the peripheral surface 11a of the reverse roller 11. The section 23a of the pressure contact roller 23, which is in contact with the peripheral surface of the reverse roller, has a sharp cross-section when cut along a plane including the rotation axis. Hokushin Kogyo's trade name) is composed. Murubber (trade name of Hokushin Kogyo) is a rubber material that is mixed with EPDM to soften the rubber hardness of the portion in contact with the peripheral surface 11a of the reverse roller 11 to 25 ° ± 5. By mixing murubber, the rubber hardness can be reduced compared to that made of EPDM alone, and the hardness of the rubber material in the same part is reduced to 25 ° ± 5 °.

Now, when the solenoid (see FIG. 3) is excited, as shown in FIG. 2, the leading end portion 23b of the pressure contact roller comes into contact with the peripheral surface 11a of the reverse roller 11 while sandwiching the sheet S, and the leading end portion is moved. It will be crushed. It has a sharp tip and has a rubber hardness of 25 ° ± 5 °.
Because it has been lowered to. Circumferential surface 11 of reverse roller 11
In a, the tip portion 23b is curved due to the pressing force of the entire pressure contact roller 23, and the elastic force of the curved portion becomes positive, which is a unit smaller than that of the roller-shaped pressure contact roller. The pressure per area becomes stronger.

By configuring the sheet reversing device in this way, the pressing roller 23 can reverse the reverse roller with a pressing force for sufficiently reversing and feeding even if the sheet that has advanced in the sheet conveying path is thick and large in size. Since the sheet S abuts on the sheet 11, the sheet S rotates around with the rotation of the reverse roller 11 and is reliably sent to the sheet re-feeding path 3 (see FIG. 3).

(Effect) According to the present invention, the portion of the pressure contact roller that comes into contact with the peripheral surface of the reverse roller is formed by mixing EPDM with a rubber material that softens the rubber hardness, and the rubber hardness is set to 25 ° ± 5 °. In addition, since the cross-sectional shape is sharp, the pressing force per unit area of the sheet can be increased to a sufficient pressing force for feeding the sheet when the pressing roller contacts the reverse roller. Therefore, a solenoid having a small capacity can be sufficiently used, and any sheet can be surely inverted.

[Brief description of drawings]

FIG. 1 is a front view of a sheet reversing device showing an embodiment of the present invention, FIG. 2 is a partial cross-sectional view for explaining the operation of the same, and FIG. 3 is a sheet discharge section of a copying machine having a built-in sheet reversing device. FIG. 4 is a front view of a conventional sheet reversing device. 2 ... Sheet transport passage, 11 ... Reverse roller, 11a ...
… Reverse roller circumferential surface, 12 …… Solenoid, 23 …… Pressing roller, 23a …… Abutting section on reverse roller circumferential surface.

Claims (1)

(57) [Claims] 1. A sheet conveying passage for guiding a sheet, and a part of a peripheral surface of the sheet conveying passage is exposed, and the exposed portion moves in a direction opposite to a traveling direction of the sheet. No. 1 between the roller and the sheet conveying path
Is provided corresponding to the first roller and is movably supported at a first position in contact with the peripheral surface of the first roller and a second position distant from the peripheral surface of the first roller. 1
And a second roller which cooperates with the first roller to convey the sheet in a direction opposite to the sheet conveying direction when the position is set to the first position and the second position. In a sheet reversing device having a second roller moving unit that moves to and, a portion of the second roller that comes into contact with the first roller when the second roller is cut along a plane including the rotation axis is A rubber material is added to soften the rubber hardness of the portion of the second roller that comes into contact with the peripheral surface of the first roller to 25 ° ± 5 °.
The rubber hardness of the part that comes into contact with the peripheral surface of the roller is 25 ° ± 5 °
And a sheet reversing device having a sharp cross-section.