JP3842317B2 - Sheet transport device - Google Patents

Description

[0001]
[Industrial application fields]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device in a copying machine or the like, and more particularly to a sheet feeding device provided on a copying machine main body and a conveying path that can be expanded and contracted in the conveying direction.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a sheet conveying apparatus in which a conveying path can be expanded and contracted, an apparatus using an endless belt is known (for example, Japanese Patent Laid-Open No. 2-265835). In this case, the idler pulley is moved perpendicularly to the sheet conveying direction to apparently change the length of the belt.
However, the belt type has a large number of parts and is difficult to assemble and maintain. Moreover, there is a drawback that the load torque of the belt increases when the conveying path becomes longer.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide a sheet conveying apparatus having a simpler structure.
[0004]
[Means for Solving the Problems]
The sheet conveying apparatus according to the present invention includes a plurality of flat, cylindrical sheet guides that are internally configured to be a sheet conveying path, and are connected to each other in a stretchable manner. Each sheet guide increases in thickness toward the upstream side, and it is preferable that the upstream side sheet guide is received in the downstream side sheet guide when contracted. A long hole is formed in both side surfaces of each sheet guide, a guide pin is provided on both sides of the front end, and the guide pin of the upstream sheet guide is engaged with the long hole of the downstream sheet guide. Can be connected to each other. Preferably, a conveyance roller for nipping and conveying the sheet to the sheet guide is provided.
[0005]
[Action]
The sheet is conveyed through a series of flat cylindrical sheet guides that are connected to be stretchable. By extending and retracting the series of sheet guides, the sheet conveyance distance can be changed. If a conveyance roller is provided in the sheet guide, the sheet is directly conveyed by this roller. If the thickness of the sheet guide is increased toward the upstream side, the upstream side sheet guide can be received in the downstream side sheet guide, so that the sheet guide can be contracted to a short length.
If long holes are drilled on both sides of each seat guide, and guide pins are provided on both sides of the leading end, the guide pins of the upstream sheet guide are engaged with the long holes of the downstream sheet guide. , The sheet guides expand and contract smoothly.
[0006]
【Example】
An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, this copying machine has two sheet feeding units for supplying sheets to an image forming apparatus 1, and one unit 2 is an image as usual. At the bottom of the forming apparatus 1, another unit 3 is at the top. Each of the sheet feeding units 2 and 3 is provided with a plurality of sheet feeding trays 5 and stores sheets 6 in each sheet feeding tray.
[0007]
The upper sheet feeding unit 3 is supported on the image forming apparatus so as to be movable up and down along a rail (not shown). The upper sheet feeding unit 3 is usually at a high position as shown by a solid line in FIG. 1 so as not to interfere with setting a copy document on the image forming apparatus 1. When replenishing a sheet or performing maintenance, as shown by a chain line in FIG. 1, the upper sheet feeding unit 3 is lowered to a low position to perform the work.
[0008]
The sheet conveying device 7 for conveying the sheet 6 from the upper sheet feeding unit 3 to the image forming apparatus 1 is composed of a series of (a total of five in the drawing) sheet guides 9. As shown in FIG. 2, each sheet guide 9 is a flat cylindrical body integrally formed of plastic, in other words, a flat box with the top and bottom open. Each of the sheet guides 9 is increased in thickness as it goes upward so that the upstream sheet guide can enter therein. Long holes 10 are formed in both sides of the sheet guide 9 in the vertical direction, guide pins 11 are provided on both sides of the tip, and the guide pins 11 of the upstream sheet guide are engaged with the long holes 10 of the downstream sheet guide. By connecting, the sheet guides are connected.
[0009]
Every other series of sheet guides 9 is provided with a conveying roller 12. That is, an ear 13 is provided on the sheet guide 9, and roller shafts 15 and 16 (one is a drive shaft and the other is a driven shaft) are rotatably supported on the front and back of the sheet guide, respectively. An electric motor 17 is attached to the drive shaft 15. The driven shaft 16 is biased toward the drive shaft 15 using a spring 19. Accordingly, the conveyance rollers (rubber rollers) 12 fixed to the shafts 15 and 16 are in close contact with each other, and when the motor 17 is driven, the sheet is conveyed downward while sandwiching the sheet.
[0010]
Reference numeral 20 denotes a window through which the conveying roller 12 enters the inside of the sheet guide 9, and reference numeral 21 denotes a notch provided so that the conveying roller 12 does not hit the lower part of the sheet guide. These cutouts are preferably sized so that the operator's finger can be inserted so that the sheet can be easily taken out when a sheet jam occurs in the sheet guide 9.
A sensor 23 for detecting the presence or absence of a sheet is attached to the seat guide base 22 and the motor is controlled by the output signal.
Of the series of sheet guides 9, the uppermost one is fixed to the upper sheet feeding unit 3 and the lowermost sheet guide is fixed to the image forming apparatus 1 detachably.
[0011]
The sheet conveying device 7 is configured as described above. When the upper sheet feeding unit 3 is raised, a series of sheet guides are fully extended as shown in FIG. The unit and the image forming apparatus are connected. When a paper feed command is issued, the sheet on the paper feed tray 5 is first fed into the uppermost sheet guide 9 by the paper feed roller 25. When this is detected by the sensor 23 of the uppermost sheet guide, the motor 17 is started and the conveying roller 12 starts to rotate, and is nipped by this to feed the sheet 6 downward. When the sheet passes through the second-stage sheet guide and the lower edge reaches the third-stage sheet guide, the third-stage sensor detects this time, and the third-stage conveyance roller starts to rotate. Sent to.
[0012]
Further, when the sheet reaches the fifth-stage sheet guide, the sheet is conveyed by the fifth-stage conveyance roller and sent to the image forming apparatus 1. The sheet sent to the image forming apparatus forms an image through an image forming process and is discharged out of the apparatus.
Note that the pitch of the conveying rollers 12 (the distance between the upper and lower conveying rollers) needs to be set smaller than the length of the minimum sheet to be conveyed.
[0013]
In the state where the upper sheet feeding unit 3 is lowered, as shown in FIG. 3B, the series of sheet guides contracts shortly so that the lower half of each sheet guide enters the lower sheet guide. In this state, sheet replenishment and maintenance are performed. In this state, the conveyance path is secured and the sheet can be conveyed.
[0014]
【The invention's effect】
As described above, the present invention has the following effects.
In the sheet conveying apparatus according to the first aspect, a plurality of flat cylindrical sheet guides that form a sheet conveying path are connected in a telescopic manner, so that the sheet conveying distance can be freely adjusted. is there. Further, each sheet guide is thicker toward the upstream side, and when contracted, the upstream side sheet guide is received in the downstream side sheet guide, so that the amount of expansion and contraction can be increased. .
[0015]
The apparatus according to claim 2 is provided with long holes on both side surfaces of each sheet guide, and provided with guide pins on both sides of the leading end, and the guide pins of the upstream sheet guide are engaged with the long holes of the downstream sheet guide. Since they are combined, there is an effect that can be expanded and contracted smoothly.
According to the third aspect of the present invention, since the conveyance roller for nipping and conveying the sheet is provided in the sheet guide, the structure becomes simple and maintenance is easy.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a copying machine.
FIG. 2 is an assembly drawing of a sheet guide.
FIGS. 3A and 3B are cross-sectional views of the sheet conveying apparatus, in which FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Upper sheet feeding unit 7 Sheet conveying apparatus 9 Sheet guide 10 Long hole 11 Guide pin 12 Conveying roller

Claims (3)

A plurality of flat cylindrical sheet guides (9) forming a sheet conveyance path inside are connected in a telescopic manner , and each sheet guide is thickened toward the upstream side, A sheet conveying apparatus configured to receive an upstream sheet guide into a downstream sheet guide when contracted .   Slots (10) are drilled on both sides of each seat guide, and guide pins (11) are provided on both sides of the tip, engaging the guide pins of the upstream seat guide with the slot of the downstream seat guide. The sheet conveying apparatus according to claim 1.   The sheet conveying apparatus according to claim 1 or 2, wherein the sheet guide is provided with a conveying roller (12) for nipping and conveying the sheet.

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