JPH09124207A - Paper reversal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the paper feeding interval small and enable the normal/ reverse rotation of a normal and reverse rotation roller to be surly switched by a simple structure. SOLUTION: A paper reversal device is provided with a feeding roller placed in a switchback path, a feeding gear H attached to a drive shaft 12b of the feeding roller, and a first gear train 20 and a second gear train 30 which are linked with the feeding gear H through a drive gear A to which one-way rotational drive force from a driving means is transmitted to drive the feeding roller and transmit the driving force of each opposite direction. The first gear train 20 and the second gear train 30 are provided with a clutch respectively, so that the feeding gear H is driven in the normal or reverse rotation by the one-way rotation of the drive gear A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet reversing device provided in a sheet processing device such as a copying machine or a printer and capable of reversing and conveying a sheet, and more specifically, a conveying roller for reversing the sheet. The present invention relates to a sheet reversing device characterized by a driving force transmission mechanism for driving a sheet.

[0002]

2. Description of the Related Art The above-described sheet reversing device is constructed so that the conveyed sheets are reversed and conveyed toward a discharge tray so that the sheets can be discharged in a page aligned state. Yes, as such a paper reversing device,
A so-called switchback method is known in which the forward direction of the conveyed sheet is converted from the forward direction to the reverse direction.
This switchback system is configured such that a switchback path is provided in the paper conveyance path, the paper is fed into the switchback path, the fed paper is conveyed backward, and is returned to the paper conveyance path again. However, in the switchback path, since the paper is fed in and conveyed in the reverse direction, there is a problem that the sheet conveying speed is slowed down as a whole, and high-speed processing of the sheet is hindered.

In order to solve this problem, JP-A-59-
No. 97957 discloses a sheet reversing device configured to increase the conveying speed when the sheet sent to the switchback path is conveyed in the reverse direction.

In this paper reversing device, a gear having a large number of teeth and a gear having a small number of teeth are attached to the drive shaft of the forward / reverse rotation roller provided in the switchback path. When the paper is fed, the driving force from the drive gear is applied. When the sheet is conveyed in the reverse direction via the two forward rotation gear trains, the reverse rotation of the sheet is switched and transmitted to the gear with the small number of teeth via the single reverse rotation gear. That is, when the forward / reverse rotation roller is driven in the reverse direction, the driving force is transmitted through the gear having a small number of teeth, so that the rotation speed of the forward / reverse rotation roller during reverse rotation is increased, and as a result, the conveyance speed of the sheet is high. Become.

[0005]

However, the forward rotation gear train and the reverse rotation gear are supported by the support plate urged by the urging spring, and the urging force causes the drive gear to move to the forward rotation gear train. Through a reverse gear, and the drive gear meshes with a gear with a small number of teeth by a solenoid that applies a force against the urging force of the urging spring to the support plate. It is like this. That is, the driving force is transmitted to the forward / reverse rotation roller through the forward rotation gear train or the reverse rotation gear provided on the support plate that is swung by the biasing spring and the solenoid. The reverse rotation is switched by swinging the support plate. Therefore, it takes time to switch between the gear having a large number of teeth and the gear having a small number of teeth, and it is impossible to reduce the sheet conveyance interval.

Further, the solenoid and the urging spring for holding the meshing relationship between the gears need to be firmly constructed so that the meshing relationship is not released during the switching drive thereof, and further, the tooth jump during meshing is eliminated, Since it is necessary to devise the shape of the gear so that the gears mesh with each other immediately and accurately,
There are problems that the entire device is complicated and expensive.

It is an object of the present invention to provide a sheet reversing device which can reduce the sheet conveyance interval and can reliably switch the forward / reverse rotation of the forward / reverse roller with a simple structure.

[0008]

In order to solve the above-mentioned problems, a sheet reversing device of the present invention comprises a conveying roller provided on a switchback path, a conveying gear attached to a drive shaft of the conveying roller, A first gear train and a second gear train, which are connected to the transport gear via a drive gear to which the one-way rotational drive from the drive means is transmitted so as to drive the transport roller, and transmit driving forces in opposite directions to each other. And a gear train, and these first gear train and second gear train,
It is characterized in that clutch means are provided so that the transport gear is driven to rotate normally / reversely by one-way rotation of the drive gear.

With the above structure, the transport gear attached to the drive shaft of the transport roller is always connected to the drive gear which is rotationally driven only in one direction via the first gear train and the second gear train. It is in a broken state. In this case, the first gear train and the second gear train are set so as to transmit driving forces in mutually opposite directions to the transport gear, and when the transport gear is driven to rotate normally or reversely, Clutch means are provided so that the rotation of the gear train does not affect the other gear train. In this way, the transport gear is always connected to the drive gear via the first gear train and the second gear train, so that the ON / OFF operation of the clutch means is sufficient for the transport gear. The forward / reverse switching operation is performed immediately.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A sheet reversing device of the present invention reverses a sheet processed by a sheet processing section of a sheet processing device such as a printer through a switchback path and discharges it to a sheet discharge tray. It can be incorporated into the paper processing apparatus, or can be configured as a unit to be mounted between the paper processing unit and the paper discharge tray. The paper reversing device of the present embodiment is configured to be detachably incorporated between a printer, which is a paper processing device, and a sorter capable of collating and discharging paper on which an image is formed by the printer. There is.

First, the overall construction of the sheet reversing device will be briefly described with reference to FIGS. The sheet reversing device 1 is detachably mounted between the printer 70 and the sorter 75, and has a sheet inlet 2 and a sheet outlet 3 corresponding to the outlet 71 of the printer and the inlet 76 of the sorter, respectively. ing. The sheet on which the image is formed by the image forming unit (not shown) of the printer 70 is conveyed to the carry-in path 5 in the sheet reversing device 1 via the discharge roller 72, and the carry-in roller 7 and the carry-in roller 7 arranged in the carry-in path. It is guided to the switchback path 10 via the pinch roller 7a that abuts against this. The switchback path 10 has a transport roller 1 capable of forward and reverse rotation.
2 and a pinch roller 12a that abuts on the sheet, and the paper guided to the switchback path 10 drives the transport roller 12 in the normal rotation (counterclockwise rotation) and in the reverse rotation (clockwise rotation). It is reversed by and is conveyed toward the discharge path 15.

The discharge path 15 is provided with a branching means such as a switching valve for guiding the paper conveyed from the carry-in path 5 to the switchback path 10 and guiding the paper conveyed from the switchback path 10 to the discharge path 15. It is provided. In this embodiment, the branching means is constituted by the elastic mylar 16 attached to the upper wall of the discharge path 15, and the sheet carried by the carrying roller 12 is transferred from the switchback path 10 to the carry-in path 5. It guides to the discharge path 15 side without guiding. A discharge roller 17 and a pinch roller 17a that contacts the discharge roller 17 are arranged in the discharge path 15, and the sheet reversed by the switchback path is discharged into the sorter 75 via the discharge roller 17. In addition, unloading roller pair 1
The sheet may be directly discharged into the sorter 75 without providing the 7, 17a.

A receiving roller 77 is arranged at the suction port 76 of the sorter 75, and the sheet carried in through the suction port 76 is conveyed to the distributor 78 by the reception roller. The distributor 78 includes a driving unit 80 and a discharge roller 81 that is driven by the driving unit 80. The distributor 78 discharges the paper discharged from the receiving row 77 toward the tray 90 arranged substantially parallel to the vertical direction, and also moves up and down. It is attached to a wire 86 which is stretched in the direction and driven by the drive means 85 so that it can be driven in the vertical direction. This distributor 78
Is driven in the vertical direction in synchronism with the sheet conveyance interval, so that the sheets 90 aligned in the vertical direction are collated and ejected.

Next, the driving force transmission system of the above-described sheet reversing device will be described with reference to FIGS. The conveyance roller 12 is fixed to the drive shaft 12b and is fixed to the sheet reversing device 1
Is rotatably supported by the frame 1a, and a transport gear H is attached to the end of the drive shaft 12b.
The transport gear H includes the first gear train 20 and the second gear train 20 so that the drive force in the forward / reverse rotation direction is transmitted from the sorter-side drive source.
Meshes with the gear train 30 of (in mesh with the final gear of each gear train). The number of gears of the gear trains 20 and 30 is not limited, but is set to be different by subtracting an odd number so that the driving force in the forward / reverse rotation direction is transmitted to the transport gear H. Has been done.

The transmission of the driving force to the conveying gear H is performed via a driving gear A which receives the driving force from the driving source of the sorter,
A gear B that meshes with a drive gear A is rotatably supported on the frame 1a when the paper reversing device is mounted between the printer and the sorter. The gear trains 20 and 30 include a gear B.

Of the gear trains, the second gear train 30 is rotatably supported by the frame 1a, has a gear C meshing with the gear B, and a gear D successively meshing with the gear C.
To G. In this case, the carry-out roller 17 described above
Is configured to be driven by the rotation of the gear C, and the gear C is attached to the drive shaft 17b of the carry-out roller 17. Further, the carry-in roller 7 is configured to be driven via a third gear train 40 that is in mesh with the second gear train 30, and this gear train 40
A gear I that meshes with the gear E, and a gear J that meshes with the gear I and is attached to the drive shaft 7b of the carry-in roller 7.
And

As described above, the forward / reverse driving force is transmitted to the transport gear H that drives the transport roller 12 via the first gear train 20 and the second gear train 30. Therefore, each gear train is provided with a clutch means so that the respective driving forces do not interfere with each other. The clutch means provided in each gear train in the present embodiment will be specifically described below.

The first gear train 20 is configured to transmit the rotation in the same direction as that of the drive gear A to the carrier gear H via one gear, which is the gear B and the gear B. It is constituted by a gear B'coaxially arranged in the. The gear B meshes with the drive gear A, and the gear B ′ meshes with the transport gear H. The clutch means provided in the first gear train 20 is composed of an electromagnetic clutch 22, and the drive of the gear B'is turned on / off by inputting a drive signal from a control means (not shown) to this electromagnetic clutch. It is off.

The second gear train 30 is configured to drive the carry-in roller 7 arranged in the carry-in path 5 and the carry-out roller 17 arranged in the discharge path 15, as described above. The clutch means provided in the second gear train so that they are driven via the second gear train 30 is the second gear train.
It is provided in the final gear G portion of the gear train 30 of FIG. Of course, in the case where the carry-in roller 7 and the carry-out roller 17 are not driven by the second gear train, the position at which the clutch means is provided is not limited.

In the present embodiment, a gear G'is arranged in parallel on the shaft on which the gear G is provided, and the clutch means serves as the gear G.
And gear G '. Like the first gear train 20, the clutch means may be constituted by an electromagnetic clutch, but in order to facilitate the constitution and control, it is constituted by a torque limiter 25 which operates by utilizing a frictional force. The torque limiter 25 includes a spring member 25a that applies a pressing force in the thrust direction and a spring member 25a.
The friction member 25c is interposed between the pressing portion 25b pressed by the gear G and between the gears G and G ', and the driving force input to the gear F is transmitted to the gear G'through the gear G. The driving force transmitted and input to the gear G ′ via the transport gear H is slid between the gears G and G ′ so that the driving force is not transmitted to the gear G side. The second
With regard to the clutch means provided in the gear train 30, the specific configuration thereof can be variously modified if such an action is obtained.

As described above, the carry-in roller 7, the carry roller 12, and the carry-out roller 17 shown in FIG.
The drive source of the sorter is driven at a high speed with respect to the drive source of the printer,
The carry-in roller 7 and the carry roller 12 must be driven so as to correspond to the carrying speed of the paper discharged from the printer. Further, when the transport roller 12 rotates in the reverse direction, the carry-out roller 17 must rotate at the same speed as the transport roller 12. Therefore, the number of teeth (gear ratio) and the meshing relationship of the gears B to H of each gear train 20, 30, 40 are preset so that such a drive is performed.

Further, since the transport gear H, which drives the transport roller 12 in the normal / reverse rotation, is always in mesh with the first and second gear trains as described above, the forward rotation is the reverse rotation.
The switching of the driving direction from reverse rotation to forward rotation is performed immediately. Therefore, the sheet conveyance interval can be reduced, but in this case, the gear ratio of the first and second gear trains is set so that the reverse rotation driving speed of the conveyance gear H is higher than the normal rotation driving speed. It is preferable to keep. If the gear ratio is set in this way, the speed at which the paper is conveyed when switched back becomes faster, and the paper conveyance interval can be further reduced.

With the sheet reversing device configured as described above, the operation of reversing the sheet from the printer and conveying it to the sorter will be described based on the time charts shown in FIGS. 1 to 4 and 5. explain. In this embodiment, as shown in FIG. 2, the electromagnetic clutch 22 is an optical sensor 51, which is a detection unit arranged immediately before the transport roller 12.
Is ON / OFF driven based on a signal issued when the passage of a sheet is detected. Further, in FIG. 2, a sensor 52 for detecting the passage of the sheet is arranged immediately before the carry-in roller 7, but this is arranged for convenience so that the sheet conveyance interval can be easily understood, and is essential in the present invention. Is not an element of. However, the signal emitted from this sensor may be used to control ON / OFF of driving of the driving source, for example.

As shown in FIG. 1, the sheet on which the image is formed by the printer is fed to the sheet reversing device 1 via the discharge roller 72.
Is conveyed to the carry-in path 5. The carry-in roller 7 arranged in the carry-in path 5 is driven by a drive gear A (+) that is driven by a drive source of the sorter in a clockwise direction (hereinafter, a clockwise direction is +, and a counterclockwise direction is −). Gear B (−), gear B ′ (−), gear C (+), gear D (−), gear E
It is driven via (+), gear I (-), and gear J (+). In this case, the drive source of the sorter is driven at high speed, but the gear ratio between the gears is set so that the gear J that drives the carry-in roller 7 is driven at the same speed as the discharge roller 72 of the printer. Therefore, the conveyed sheet is not bent or pulled between the discharge roller 72 and the carry-in roller 7. In addition, the transport roller 12 disposed on the switchback path 10 has a gear F that meshes with the gear E (+).
(-), Gear G (+), gear G '(+), transport gear H
Driven via (-). Similarly to the above, the gear ratio between these gears is set so that the transport gear H that drives the transport roller 12 is driven at the same speed as the carry-in roller 7, so that the sheet to be transported is transported by the carry-in roller 7. ,
It is not bent or pulled between the transport rollers 12.

Since the electromagnetic clutch 22 is in the OFF state in the above-described sheet conveying state, the gears B and B'are in the OFF state, and the driving force input to the drive gear B is transmitted to the gear B '. It will not be done. Therefore, no driving force is input to the gear G ′ from the gear B ′ side, so that the torque limiter 25 is turned on without slipping, and as a result, the transport gear H is driven via the second gear train 30. .

The sheet is transferred from the carry-in path 5 to the switchback path 1
When the sheet is conveyed to 0 and the leading edge of the sheet passes the sensor 51, the sensor 51 issues an ON signal. Then, when the sheet is further conveyed, the trailing edge of the sheet passes through the sensor 52, and the signal emitted from the sensor 52 is turned off. Further, the sheet is conveyed, the trailing edge of the sheet passes the sensor 51, and the sensor 51
The electromagnetic clutch 22 is driven by the control means (not shown) to be in the ON state when the signal emitted from the solenoid is OFF.

When the electromagnetic clutch 22 is turned on, the gear B'is in a state in which the driving force from the driving gear A (+) is transmitted, and is driven in the (-) direction. Therefore, the transport gear H meshing with this is (+) through the first gear train 20.
The transport roller 12 is driven in the reverse direction. In this case, the gear B is also rotationally driven integrally with the gear B ′, and the driving force thereof is transmitted to the gear G (rotation in the + direction) via the second gear train 30. On the other hand, the rotation in the (-) direction is transmitted to the gear G'via the transport gear H. This gear G
Rotation of the gear G ′ in the (+) direction and rotation of the gear G ′ in the (−) direction cause the torque limiter 25 to slip, and the gears G,
The transmission of the driving force is interrupted between G '(clutch OFF).
As a result, the sheet is conveyed on the switchback path 10 with the trailing edge of the sheet up to that point as the leading edge of the sheet. The conveyed sheet is guided to the discharge path 15 by the mylar 16 and conveyed in an inverted state.

In this case, the gear C meshing with the gear B is rotationally driven in the same direction as the carrying gear H and has the same speed, and between the gear B'and the carrying gear H and between the gear B and the gear C. Since the gear ratio is set, the switched-back paper is not bent or pulled between the transport roller 12 and the discharge roller 17. When the sensor 51 detects the trailing edge of the sheet, the electromagnetic clutch is turned off,
As a result, the transport gear H is driven in the (-) direction via the second gear train 30 and the torque limiter 25 in the clutch ON state, and the transport roller 12 is again driven in the normal direction.
Since the torque limiter 25 is provided between the gears G and G ′ on the downstream side of the third gear train 40, the carry-in roller 7 is always kept in operation even if the transport roller 12 is reversely driven by the electromagnetic clutch 22. It is in a state of being rotationally driven in the sheet loading direction at the same feed speed as the printer side.

In the time chart shown in FIG. 5, the first
The portion indicated by the symbol a in which the sensor is ON is the time corresponding to the length of the sheet, and the portion indicated by the symbol b in the OFF is the feeding interval between the sheets. Also, the second sensor
The portion indicated by reference sign c, which detects the trailing edge of the sheet conveyed from the carry-in path 5 and switches it back to detect the leading edge of the next sheet, corresponds to the sheet conveyance interval in the switchback path. It's time to do it. Switchback route 10
In (1), the feeding interval b of the printer must be equal to or longer than the switchback time c so that the sheet to be switched back does not interfere with the sheet to be conveyed subsequently.

As described above, the transport gear H that drives the transport roller 12 has the second gear train 30 that transmits the normal rotation driving force and the first gear train 20 that transmits the reverse rotation driving force.
Since there is always a meshing relationship with, and a conventional planetary mechanism is not used, it is possible to immediately switch from normal rotation drive to reverse rotation drive, and as a result, the time c required for switchback is shortened as much as possible. be able to. Therefore, along with this, the feeding interval b of the printer can be shortened, and the paper feeding interval can be shortened. In this case, if the gear ratio of the first gear train 20 and the second gear train 30 is set so that the reverse drive speed of the transport gear H is higher than the normal drive speed, switchback is required. The time c can be further shortened, and the paper conveyance interval can be further shortened.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments and can be variously modified. In the above-described embodiment, the driving force is input from the drive source on the sorter side, but in the case where the paper reversing device is incorporated in the printer, the driving force may be input from the drive source on the printer side. In the above embodiment, the carry-in roller 7 and the discharge roller 17 are configured to be driven via the second gear train 30, but the second gear train is configured to drive only the carry roller 12. Alternatively, the configuration may be such that the carry-in roller or the like is driven via the first gear train 20. Thus, the first gear train 20 and the second gear train 3
The number of gears forming 0 and the gear ratio can be variously modified in addition to the above-described embodiment depending on the sheet conveyance path, the conveyance speed, and the like. Further, in accordance with this, the position of the clutch means provided in each gear train can be variously changed.

[0032]

According to the present invention, the conveying gear that drives the conveying roller in the normal / reverse rotation is always meshed with the forward rotation gear train and the reverse rotation gear train, so that the time required for connecting and disconnecting the gears is eliminated. Therefore, it becomes possible to reduce the sheet conveyance interval. Further, since the gears are always meshed with each other and there is no need to separately provide a biasing member, a swinging member, etc., forward / reverse rotation can be reliably switched and driving force can be transmitted with a simple configuration. Furthermore, since the transmission ratio (gear ratio) of each of the forward and reverse rotations can be easily adjusted, when the paper reversing device is connected to a connecting device such as a printer, speed adjustment can be easily performed between them.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a sheet reversing device of the present invention, showing a state in which the sheet reversing device is detachably incorporated between a printer and a sorter capable of collating and ejecting sheets. FIG.

FIG. 2 is an enlarged view of the sheet reversing device shown in FIG.

3 is a diagram showing a driving force transmission system of the sheet reversing device shown in FIG.

FIG. 4 is a diagram of the driving force transmission system shown in FIG. 3 viewed from a direction orthogonal to the axial direction.

FIG. 5 is a diagram showing the sheet reversing device shown in FIGS.
7 is a time chart illustrating an operation when the paper is conveyed and inverted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Paper reversing device, 5 ... carry-in path, 7 ... carry-in roller, 10
... switchback path, 12 ... transport roller, 15 ... discharge path, 16 ... mylar, 20 ... first gear train, 22 ... electromagnetic clutch, 25 ... torque limiter, 30 ... second gear train,
40 ... Third gear train, 70 ... Printer, 75 ... Sorter.

Claims (3)

[Claims] 1. A conveying roller provided on a switchback path, a conveying gear attached to a drive shaft of the conveying roller, and a unidirectional rotational drive transmitted from a driving means so as to drive the conveying roller. A first gear train and a second gear train, which are connected to the transport gear via a driving gear and which transmit driving forces in opposite directions to each other, and these first gear train and second gear train are provided. A sheet reversing device, wherein the gear train is provided with respective clutch means so that the transport gear is driven to rotate forward / reversely by one-way rotation of the drive gear. 2. The clutch mechanism provided in the first gear train is an electromagnetic clutch that relays the transmission of the driving force from the drive gear to the transport gear by turning on / off, and the clutch mechanism provided in the second gear train. The provided clutch mechanism is a torque limiter arranged between gears provided on the same shaft,
The sheet reversing device according to claim 1, wherein the driving force from the driving gear is transmitted to the conveying gear via the second gear train only when the electromagnetic clutch is turned off. 3. The gear ratio of the first gear train and the second gear train is set so that the reverse drive speed of the transport gear is higher than the normal drive speed. The sheet reversing device according to claim 1 or 2.