JPH0348111Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a conveying direction changing device for a sheet-like conveyed object that converts the feeding direction of a forwardly conveyed sheet-like object to a reverse direction and conveys the same.

BACKGROUND OF THE INVENTION It has been well known that a conveyance direction changing device of the above type is used in a copying machine or the like for the purpose of reversing a sheet-like conveyed object such as a copy paper or a manuscript. For example, in a double-sided copying machine, the copy paper that has been copied on one side must be reversed in order to perform copying on the other side. It is also well known to invert the copy paper after completion of copying and then discharge it out of the machine.

A conventional conveyance direction converting device has a return roller that is rotationally driven only in the direction in which the sheet-like conveyed object is conveyed in the opposite direction, and a contact/separation roller that approaches and separates from the return roller. When the sheet material enters between the two rollers, the contact/separate roller is moved away from the return roller, and when the sheet-like conveyed object is sent in the opposite direction, the contact/separate roller is brought into contact with the return roller, and the sheet between these rollers is moved away from the return roller. The conveyed object is conveyed in the opposite direction.

According to this configuration, when the sheet-like conveyed object is conveyed in the reverse direction, there is no need to reverse the return roller, so there is no need to use an expensive reversible motor as a drive motor for this roller, and costs can be reduced. However, since the return roller always rotates in a direction that transports the sheet-like object in the opposite direction, when the sheet-like object enters the return roller, its tip hits the return roller, causing transport problems. There is a fear.

Conversely, when the contact/separation roller is in contact with the return roller and the sheet-shaped conveyed object is being conveyed in the opposite direction, the conveyance force against the sheet-like conveyed object is reduced because the return roller is only being rotationally driven. weakened,
There is also a possibility that this cannot be transported reliably.

Purpose The purpose of the present invention is to provide a conveying direction changing device for sheet-like conveyed objects that can not only reduce costs, but also eliminate transportation troubles of sheet-like conveyed objects and reliably feed the sheet-like conveyed objects in the opposite direction. It is.

Configuration In order to achieve the above object, the present invention provides a sheet-like conveyance direction converting device that converts the feeding direction of a sheet-like conveyed object that is being conveyed forward to the opposite direction and conveys the sheet-like conveyed object. A return roller that is rotatably driven only in the direction of conveyance in the opposite direction and supports the conveyed sheet-like object, a rotating shaft that fixedly supports the return roller, and a rotation shaft that is provided above the return roller and that is connected to the return roller. A contact/separate roller supported so as to be able to approach and separate, a support shaft that fixedly supports the contact/separate roller, and a return roller and a contact/separate roller that are respectively fixed to the rotating shaft and the support shaft outside the range through which the sheet-like conveyed object passes. and transmission rollers that contact each other so as to transmit the rotation of the return roller to the contact/separation roller when the rollers contact each other, and cause the roller to follow the rotation, and when the contact/separation roller and the return roller are separated, the sheet The surface of the return roller is made of a low-friction material so that when the sheet-like conveyed object moves forward, the sheet-like conveyed object slides on the surface of the return roller. We propose a configuration in which the surface of the contact/separate roller is made of a high-friction material so that the conveyed object is conveyed in the opposite direction.

Embodiment Hereinafter, an embodiment in which the conveyance direction changing device according to the present invention is used in a double-sided copying machine will be described.

FIG. 1 is an explanatory diagram schematically showing a part of a double-sided copying machine, and first the overall structure of this copying machine will be explained. The copy paper (sheet-like conveyance material) 4 stored in the paper feed cassette 20 is transported by a paper feed roller 21, a separation roller 22, and a feed roller 2 paired with the paper feed roller 21.
3, the sheets are sent one by one from the cassette 20 to the pair of registration rollers 24 (arrow A ₁ ).

On the other hand, a toner image is formed on the photoreceptor 25, which is rotated clockwise, by an image forming means such as an exposure device and a developing device (not shown).

The copy paper 4 sent to the registration roller pair 24 is
The toner image is fed to the surface of the photoreceptor 25 in synchronization with the rotation of the photoreceptor 25, the toner image is transferred by the transfer charger 26, and the toner image is separated from the photoreceptor 25 by the separation charger 27 (arrow A ₂ ). Continue to arrow A ₃ for copy paper.
As shown in , it is conveyed by a conveyor belt 28,
The toner image passes through a pair of rollers 30 of the fixing device 29, and at this time the toner image is fixed on the surface of the copy paper. The copy paper with the copy image formed on one side in this manner is conveyed toward the reversing device 100 by the feed roller pair 31 (arrow A ₄ ).

The copy paper 4 transported to the reversing device 100 is transported to different destinations depending on whether the final copy mode is one-sided copying or double-sided copying. During single-sided copying, the copy paper is conveyed in the direction shown by arrow C, and is ejected onto a paper ejection tray 33 outside the machine by a pair of paper ejection rollers 32, and during double-sided copying, the copy paper is transported in the direction shown by arrow C, and when it is double-sided copying, the copy paper is transported in the direction shown by arrow C, and is ejected onto a paper ejection tray 33 outside the machine by a pair of paper ejection rollers 32. With the edge of the copy paper as the tip,
The reversing device 100 is sent out in the direction indicated by _B1 . These will be explained in detail later.

The copy paper leaving the reversing device 100 is sent to the intermediate tray 34 as shown by arrow _B2 and placed on the tray 34.

The above operation is repeated a predetermined number of times, and the intermediate tray 34
When a predetermined number of copy sheets are deposited on the tray 34, the paper feed roller 35 is driven to rotate counterclockwise.
The copy paper placed on top is sent again to the registration roller pair 24 by the separation roller 36, the feed roller 37, and the intermediate roller pair 38 (arrow B ₃ ), and is then moved in the same manner as described above. , photoreceptor 25
The toner image is transferred to the surface of the At this time, since the leading and trailing ends of the copy paper have already been reversed by the reversing device 100, the front and back sides of the copy paper have been reversed from when they first reached the photoreceptor 25, and the toner lines have been transferred first. The toner image is transferred to the opposite side. The copy paper on which a copy image is formed on each side in this manner passes through the fixing device 29 and the reversing device 100, and is then conveyed in the direction of arrow C and discharged onto the paper discharge tray 33.

Next, the configuration and operation of the reversing device 100 will be explained.

The copy paper 4 that has completed the copying process on one side and is sent to the reversing device 100 in the direction of arrow _A4 is guided by the guide plates 39 and 40 as shown by the dashed line in FIG. It is advanced by 3. The first conveyance means 3 has a conveyance roller 1 that rotates clockwise and a pair of conveyance rollers 2 that rotate counterclockwise. are respectively supporting shafts 4
1 and 42, and are fixedly spaced apart from each other in the axial direction. The copy paper 4 is conveyed while being held between both rotating conveyance rollers 1 and 2.

Viewed in the direction of conveyance of the copy paper, the conveyance direction converting device 7 according to the present invention is provided downstream of the first conveyance means 3, and further downstream thereof, the second conveyance means 10 is located. A switching pawl 43 is disposed between the conveyance means 3 and the conveyance direction changing device 7 and rotates between the position indicated by the solid line and the position indicated by the broken line by rotation of the shaft 44.

When the copy paper carried into the reversing device 100 is to be ejected from the machine with a single-sided copy, the switching claw 43 occupies the position shown by the broken line, and the copy paper is moved to the position indicated by the arrow C shown by the broken line in FIG. direction, and the paper is sent to the output tray 33.
is discharged to the top.

When the other side of the copy paper 4 is to be copied, the switching claw 43 is rotated to the position shown by the solid line in FIG. The paper is transported to the transport direction changing device 7 and the second transport means 10 while being guided by the guide plates 39 and 45.

As shown in FIGS. 2 and 3, the conveyance direction converting device 7 includes a plurality of return rollers 6 fixedly supported by a rotating shaft 46 at intervals, and these rollers 6.
It has a plurality of contact/separate rollers 5 provided above positions corresponding to , and a return roller 6 supports the conveyed copy paper from below. The approaching/separating rollers 5 are also fixedly supported by the support shaft 47 at intervals in the axial direction thereof.
The rotating shaft 46 is rotatably supported by two side plates 48 and 49, and is driven by a drive device (not shown) as shown in FIG. It is rotated only in the clockwise direction, that is, in the direction in which the copy paper is conveyed in the opposite direction. Further, the support shaft 47 has both ends connected to the fourth
An arm 50 fixed to a pivot 51 as shown in the figure,
It is rotatably supported by 50a. The pivot 51 is rotatably supported by both side plates 48 and 49 via bearings, and a first tension spring 53 is attached to an actuating plate 52 fixed to one end thereof and a support member 57 fixed to the side plate 48. The actuating plate 52, the pivot 51 and the arms 50, 50a
The rotation habit is given in the counterclockwise direction in the figure. Furthermore, a plunger 56 of a solenoid device 55 is connected to the actuation plate 52 via a second tension spring 54 located on the opposite side of the first tension spring 53, and the solenoid device 55 is connected to the support plate 52 as shown in FIG. 5
It is fixedly supported by the side plate 48 via 8. Normally, the solenoid device 55 is deenergized, and therefore the actuating plate 52, the pivot shaft 51, the arms 50, 50a, and the contact/separation roller 5 are held in the position shown by the solid line in FIG. 2 by the action of the first tension spring 53. The separation roller 5 is spaced apart from the return roller 6.

When the solenoid device 55 is energized, its plunger 56 is pulled to the right in FIG.
50a and the support shaft 47 to the position shown by the two-dot chain line in FIG. 2, and come into pressure contact with the return roller 6.
Further, as will be described later, when the copy paper 4 passes between the approaching/separating roller 5 and the return roller 6, the copy paper 4 passes through the paper passing range shown by E in FIG. The support shaft 47 and the rotation shaft 46 include a first
When the transmission roller 105 and the second transmission roller 106 are fixed and the contact/separation roller 5 contacts the return roller 6 through the copy paper, both transmission rollers 105, 10
6 are in contact with each other, and due to the frictional force, the rotating shaft 4
6 is transmitted to the support shaft 47. That is, the rotation of the return roller 6 is transmitted to the contact/separation roller 5 via the transmission rollers 105, 106, and the roller 5 is rotated as a result. Both transmission rollers 105 and 106 are made of a high-friction material, such as rubber, and are configured to reliably transmit force between them.

On the other hand, as shown in FIGS. 2 and 5, the second conveying means 10 has a plurality of feed rollers 8 fixed to a rotating shaft 60 and a guide plate 61 that can be brought into contact with the rollers 8. An electromagnetic clutch 63 is installed at the end of the 60.
is provided, and a gear 62 is rotatably supported via a bearing. electromagnetic clutch 63
is a core 64 and a coil 6 wound around it.
5, and the core 64 is fixed to the rotating shaft 60 so as to be rotatable together with the coil 6.
5 is arranged non-rotatably, and the core 64 is connected to the coil 65.
It does not rotate integrally with the

When the copy paper 4 shown by the dashed line in FIG. 2 is transported forward by the first transport means 3 and is fed into the transport direction changing device 7 while being guided by the switching pawl 43, the solenoid device 55 is deenergized. Ori,
The contact/separation roller 5 is spaced apart from the return roller 6 as shown by the solid line in FIG. Therefore, although the return roller 6 is constantly rotating in the clockwise direction in FIG. The leading end 14 passes through the conveyance direction changing device 7 and reaches the feed roller 8 in the second conveyance means 10.
and the guide plate 61. At this time, the coil 6 of the electromagnetic clutch 63 shown in FIG.
5 is energized, so that the gear 62, which is rotationally driven by a drive (not shown), is magnetically coupled to the core of the clutch 63, causing the gear 62 to rotate.
The rotation is transmitted to the rotating shaft 60, and the feed roller 8 rotates clockwise in FIG. Therefore, the copy paper 4 held between the feed roller 8 and the guide plate 61 receives a conveyance force from the feed roller 8, and continues to move forward as shown by the dashed line in FIG.

In order for the feed roller 8 to reliably exert a conveying force on the copy paper 4, the frictional force between the peripheral surface of the feed roller 8 and the copy paper 4 is greater than the frictional force between the copy paper 4 and the guide plate 61. The coefficient of friction between the circumferential surface of the feed roller 8 and the surface of the guide plate 61 with respect to the copy paper is set so that. For example, the feed roller 8 is formed of a soft roller such as a soft urethane foam having a high coefficient of friction and excellent wear resistance. Further, the copy paper 4 between the feed roller 8 and the guide plate 61 is
The paper is pressed against the surface of the guide plate 61 by the feed roller 8. At this time, a plurality of beads 66 (FIG. 5) extending in the conveying direction of the copy paper 4 are formed on the guide plate 61, and the beads are separated from each other. The feed roller 8 is positioned between the two to give stiffness to the copy paper 4 being conveyed and to apply a uniform conveyance force to the copy paper.

A first actuator 68 for detecting paper, which is operated by copy paper, is supported by a rotation shaft 69 at or near the position where the first conveying means 3 is provided, and the copy moves forward as shown by the dashed line. The trailing edge 11 of the copy paper 4 (FIG. 2) is detected by the first actuator 68, and after a certain period of time has elapsed since this detection, the trailing edge 11 of the copy paper 4 moves as shown by the two-dot chain line in FIG. When it leaves both conveying rollers 1, 2 and reaches the position indicated by the symbol D, for example, the solenoid device 55 is energized and at the same time the electromagnetic clutch 63 is de-energized.

As the solenoid device 55 is energized, the approaching/separating roller 5
is in pressure contact with the return roller 6 through the copy paper 4 as shown by the two-dot chain line in FIG.
is also rotationally driven. Therefore, the return roller 6 and the approaching/separating roller 5 exert a force on the copy paper 4 to transport it in the opposite direction to the direction in which the copy paper has been advanced. In addition, since the electric weak clutch 63 is disengaged, the connection between the gear 62 and the rotating shaft 60 is released, and the rotating shaft 60 is in a state where it can freely rotate without being transmitted with the driving force from the gear 62. No conveying force is exerted on 4. For this reason, the copy paper 4 is placed with the rear end 11 as the leading edge, as shown by the arrow in FIG.
It begins to be transported in the opposite direction indicated by B ₁ and is sent toward the third transport means 13 while being guided by the switching claw 43 .

In the above-described configuration, the coefficient of friction of the surface of the approaching/separating roller 5 with respect to the copy paper 4 is set to be larger than the coefficient of friction of the surface of the return roller 6 with respect to the copy paper 4. That is, the contact/separation roller 5 and the return roller 6
When the copy paper 4 moves forward with
The surface of the return roller 6 is made of a low-friction material so that the copy paper 4 slides on the surface of the return roller 6, and when the contact/separation roller 5 and the return roller 6 come into contact, the copy paper 4 existing between them is rotated in the opposite direction. To ensure safe transportation,
The surface of the contact/separation roller 5 is made of a high friction material. In this way, of the return roller 6 and the contact/separation roller 5, only the return roller 6 is rotationally driven.
When both rollers 5 and 6 come into contact, the rotation of the rotating shaft 46 is transferred to the support shaft 4 via the transmission rollers 106 and 105.
7, and the contact/separation roller 5 is also actively rotated, so that the copy paper can be reliably conveyed in the opposite direction.
If the copy paper 4 enters during that time, even if its leading edge hits the return roller 6,
This slides on the surface of the roller 6 and can continue moving forward smoothly.

For example, the approaching/separating roller 5 is made of low hardness rubber, the return roller 6 is made of, for example, polyacetal resin, and the surface of the return roller 6 is made of a smooth resin surface or a metal surface.

The third conveyance means 13 includes the aforementioned conveyance roller 2,
It is made up of a plurality of conveyance rollers 71 that are paired with this and are fixed to a shaft 70 and rotate clockwise, and the copy paper 4 is conveyed while being held by these conveyance rollers 2 and 71, and sent out of the reversing device 100 ( (see FIG. 6), and is fed into the intermediate tray 34 while being guided by guide plates 72 and 73. In this way, the copy sheet 4 is switched back by the reversing device 100 and the other side of the sheet can be subjected to the copying process.

By the way, other copy sheets are fed sequentially after the above-mentioned copy paper 4, but in order to increase the copying speed of the copying machine, the gap between the preceding copy paper and the following copy paper should be made as narrow as possible. That is advantageous. Therefore, in this example, before the trailing edge 14 of the preceding copy sheet 4, shown by the two-dot chain line in FIG. To the extent that it reaches
The structure is such that even if the distance between the two copy sheets is narrow, they do not interfere with each other. Although this configuration is not essential to the present invention, a specific example regarding this will be clarified below.

The conveyance direction of the copy paper 4 is changed from the forward direction A ₄ to the opposite direction B ₁ and fed into the third conveyance means 13 , but its leading edge 11 (the rear end before the conveyance direction is changed) touches both conveyance rollers 2 . , caught in 71,
When the conveyance effect starts to be exerted by these, the third
The rotation shaft 7 is arranged at or near the conveyance means 13.
The third actuator 74 supported by the third actuator 74 is actuated by the leading edge 11 of the copy paper 4, thereby again de-energizing the solenoid device 55 and starting energizing the electromagnetic clutch 63. Therefore, the contact/separation roller 5 separates from the return roller 6, and at the same time, the feed roller 8 is rotated clockwise again. Along with this, the feed roller 8 begins to exert a conveying force on the copy paper 4 in the forward direction _A4 , but
The conveyance force exerted on the copy paper 4 by both conveyance rollers 2 and 71 of the third conveyance means 13 (this is assumed to be F ₁ ) is
The conveyance force exerted by the feed roller 8 on the copy paper 4 (this is
(F ₂ ) is set larger than (F ₁ >
F ₂ ), therefore, the copy paper 4 is transported in the direction of arrow _B1 without any trouble even if it receives a force from the feed roller 8, and the feed roller 8 rotates clockwise while slipping on the copy paper 4.

If the contact/separation roller 5 separates from the return roller 6,
Before the preceding copy sheet 4 has yet passed through the feed roller 8, the following copy sheet 1, indicated by a dashed line in FIG.
Even if the copy paper 104 moves forward in the direction of arrow _A4 and its tip 114 enters between the approaching/separating roller 5 and the return roller 6, the progress of the copy paper 104 will not be hindered by these rollers 5 and 6. You can continue moving forward without any problems. Moreover, since the electromagnetic clutch 63 is energized and the feed roller 8 is rotating clockwise in FIG. Also, the copy paper 104 is further subjected to a forward conveyance force by the feed roller 8. That is, since the friction coefficient of the peripheral surface of the feed roller 8 with respect to the copy paper is set to be relatively large, the friction coefficient between the roller 8 and the copy paper 104 is set to be relatively large.
The frictional force acting on both copy sheets 4, 104
Therefore, the following copy paper 104 is reliably advanced by the feed roller 8, and since the copy papers slip against each other, the preceding copy paper 4 moves in the direction of arrow _B1 . transportation is not obstructed.

As described above, it is possible to narrow the interval between copy sheets that are fed one after the other, and the method of determining this interval is more specifically as follows.

First, as shown in FIG. 7, the distance between the contact point t ₁ of the two transport rollers 1 and 2 and the contact point t ₂ of the approaching/separating roller 5 and return roller 6 is a, and both transport rollers 2,
Let c be the distance between the contact point t ₃ of 71 and the above contact point t ₂ . Further, a line segment facing both contact points t ₂ and t ₃ is designated as G, and passes through a point D where the trailing edge 11 of the copy paper is located at the time when the copy paper is changed from the forward direction to the reverse direction.
Consider an arc F centered on the tangent point _t2 , let H be the intersection of the line segment G and the arc F, and let b be the radius of the arc F.

When the rear end 11 of the copy paper 4 reaches position D as shown by the solid line in FIG. 7, the copy paper 4 falls onto the switching claw 43 (see FIG. 2) as shown by the broken line. The rear end 11 reaches H, and then it is sent in the direction of arrow _B1 , and the leading end 11 reaches the conveyor rollers 2, 71.
As described above, the roller 5 is gripped by the roller 6, and at this time, the roller 5 separates from the roller 6, as shown in FIG. If the leading edge 114 of the succeeding copy sheet 104, indicated by a dashed line in FIG. 8, reaches the return roller 6 after the contact/separation roller 5 separates from the return roller 6, its progress will not be hindered. Therefore, if the distance from the trailing edge of the preceding copy sheet to the leading edge of the following copy sheet is l (l in this case is the distance when both copy sheets advance in the same direction), then approximately When the formula holds true, it is possible to transport both copy sheets within the reversing device while preventing transport troubles.

(a-b)+(c-b)=a+c-2・b≦l+a
(1) Rearranging equation (1), c-2b≦l (2) (However, it is assumed that the circumferential speed of each roller is the same, and that there is no slip between each roller and the copy paper.) As shown in FIG. 9, a bearing 80 for the support shaft 47 that supports the approaching/separating roller 5 is supported so as to be movable up and down in a long hole 81 formed in the arm 50 in the vertical direction. The bearing 80 is rotated by the compression spring 83 that is locked to the locking portion 82.
It can also be configured to bias downward. In this case, it is a matter of course that the arm 50a on the other side is configured in the same manner. If you do this,
When the contact/separation roller 5 comes into contact with the return roller 6, both ends of the support shaft 47 are elastically pressed against the return roller 6 by the compression spring 83, so that the support shaft 47 is uniformly pressed over the entire longitudinal direction of the support shaft 47. Each contact/separation roller 5 is
can be brought into pressure contact with the return roller 6.

Also, as in the embodiment described above, the reversing device 1
00 is provided with the second conveyance means 10, instead of using the guide plate 61 as a guide member that is a counterpart member of the feed roller 8, for example, a plurality of claw-shaped guides 161 as shown in FIG. It is also possible to connect them by a shaft 90 and apply a conveying force to the paper passing between the feed roller 8 and these claw-shaped guides 161. Furthermore, a roller can also be used as a counterpart member of the feed roller 8.

Similarly, when the third conveyance means is used, the conveyance force F ₁ exerted on the copy paper by the conveyance rollers 2 and 71 should be larger than the conveyance force F ₂ exerted on the copy paper by the second conveyance means 10. As explained earlier, other
When the approaching/separating roller 5 hits the return roller 6 through the copy paper, the conveyance force exerted on the copy paper by these rollers is F ₃
It is also advantageous to configure the structure so that the relationship F ₃ >F ₂ is satisfied. In this way, even when the drive of the feed roller 8 is cut off slightly after the time when the contact/separation roller 5 contacts the return roller 6 to change the feed of the copy paper in the direction of arrow _B1 , the copying Paper can be reliably conveyed in _one direction of arrow B. Furthermore, if the conveying force F ₂ exerted on the copy paper by the rotationally driven feed roller 8 is sufficiently small, the means for turning on and off the drive of this roller 8 (an electromagnetic clutch in the example shown) can be omitted and the feed roller 8 can be turned on and off. Even if the copy paper is always rotated clockwise, it is possible to transport the copy paper in the direction of arrow _B1 by the approaching/separating roller and the return roller.

Further, the timing of the contact/separation roller 5 approaching and separating from the return roller 6 and the timing of starting or canceling the drive of the feed roller 8 may be appropriately shifted. For example, in the above description, when the rear end 11 of the advancing copy paper 4 comes to the position D, the contact/separation roller 5 is brought into pressure contact with the return roller 6, and at the same time, the drive of the feed roller 8 is released. After releasing the drive of the feed roller 8, when the contact/separation roller 5 is brought into pressure contact with the return roller 6, the copy paper 4 is temporarily stopped, and then the direction indicated by the arrow
B Since the copy paper is fed in _one direction, it is possible to prevent the inconvenience of applying excessive external force to the copy paper, and it is possible to prevent copy paper skew. Further, the timing at which the contacting and separating rollers 5 are separated can be changed as appropriate. In other words, after the copy paper 4 begins to receive the conveyance force from the third conveyance means 13, and when the subsequent copy paper 10
The contact/separation rollers may be separated at an appropriate time before the paper 4 reaches the conveyance direction changing device 7.

Further, as an operating means for bringing the approaching/separating roller toward and away from the return roller at the above-described predetermined timing,
Although solenoid devices, tension springs, arms, actuators, etc. are used, other suitable means may be used; for example, although two actuators 68, 74 were used in the previous embodiment, only one actuator 68 was used. It is also possible to separate the approaching/separating roller from the return roller depending on the time since this detects the trailing edge of the copy paper.

The sheet conveyance direction changing device according to the present invention can be used for purposes other than a copy paper reversing device for double-sided copy paper, such as a device that reverses the copy paper when it is discharged to align the order of the copy paper, or a device that aligns the order of the copy paper, or an original It can be widely applied to devices that reverse the process.

Effects According to the present invention, since the return roller is driven to rotate only in the direction in which the sheet-like conveyed object is conveyed in the opposite direction, an expensive reversible motor is not required to feed the sheet-like conveyed object in the reverse direction. It takes full advantage of the conventional advantages of not having to use it and can reduce costs, and even if the return roller is constantly rotating in the direction of conveying the sheet-like conveyed object in the opposite direction, it will enter in the opposite direction. It is possible to prevent transportation troubles for sheet-like conveyed objects, and when conveying sheet-like conveyed objects in the opposite direction, a contact/separation roller whose surface is made of high friction material is driven, which exerts a large conveying force on the sheet-like conveyed objects. Therefore, the object can be reliably transported in the opposite direction.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing a double-sided copying machine equipped with a conveying direction changing device according to the present invention, FIG. 2 is a sectional view of a reversing device, and FIG. 3 is a sectional view taken along the line - Figure 4 is a view taken in the - line direction of Figure 2, Figure 5 is a sectional view taken along the - line in Figure 2, and Figure 6 is a cross section similar to Figure 2, showing the state in which the following copy paper has been carried in. 7 and 8 are explanatory diagrams that clarify how to determine the distance between the preceding copy paper and the following copy paper, and FIG. 9 is a cross-sectional portion showing a preferred support mode of the support shaft for the contact/separation roller. 10 are perspective views showing other embodiments of the guide member in the second conveying means. 5... Approach/separation roller, 6... Return roller, 7...
Conveyance direction conversion device, 46...rotation shaft, 47...support shaft, 105, 106...transmission roller, H...range.

Claims (1)

[Claims for Utility Model Registration] In a sheet-like conveyance direction converting device that converts the feeding direction of a sheet-like conveyed object to a reverse direction and conveys the forward-conveyed sheet-like object, the sheet-like conveyed object is conveyed in the opposite direction. A return roller that is rotationally driven only in the direction of rotation and supports the sheet-like conveyed object being transported, a rotating shaft that fixedly supports the return roller, and a rotating shaft that is provided above the return roller and that can move toward and away from the return roller. A supported approach/separate roller, a support shaft that fixedly supports the approach/separate roller, and a return roller and a contact/separate roller that are respectively fixed to the rotating shaft and the support shaft outside the range through which the sheet-like conveyed object passes, and the return roller and the approach/separate roller contact each other. When the return roller is moved, the rotation of the return roller is transmitted to the approach/separation roller, and the conveyor rollers are brought into contact with each other so as to cause the roller to rotate in a driven manner. The surface of the return roller is made of a low-friction material so that the sheet-like conveyed object slides on the surface of the return roller when moving forward, and when the approaching/separating roller and the return roller come into contact, the sheet-like conveyed object existing between them is made of a low-friction material. A conveying direction changing device for a sheet-like conveyed object, characterized in that the surface of the contact/separate roller is made of a high-friction material so that the sheet-like conveyed object is conveyed in the opposite direction.