JP3178743B2 - Paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder which is applied to a copying machine, a facsimile machine, a printer, etc., and which automatically feeds a cut sheet.

[0002]

2. Description of the Related Art In a conventional paper feeding apparatus, the paper feeding is turned on / off.
The off operation and the resist operation are usually controlled using an electromagnetic clutch.

FIG. 13 is a front view showing an example of a conventional paper feeding apparatus, and FIG. 14 is a plan view of the apparatus shown in FIG. 13, where 1 is a registration roller pair consisting of a rubber roller 1a and a pressure roller 1b, and 2 is a separation roller. Rollers 3, a feed roller with a one-way clutch in contact with the separation roller 2, a pickup roller 4 capable of coming into contact with and separating from the uppermost one of the stacked sheets of paper P;
Reference numeral 5 denotes a spring that pulls the pickup roller 4 in the direction opposite to the direction of the stacking surface of the paper P, 6 denotes a stopper that regulates the rising position of the pickup roller 4, 7 denotes a stepping motor, and 8 denotes an output shaft 7a of the stepping motor 7. It was output gear, 9, the drive gear having an electromagnetic clutch 11b provided in the resist roller shaft 1c of the rubber roller 1a
And 10a, an electromagnetic clutch provided to the feed roller shaft 3a
A timing belt for transmitting a driving force from the output gear 8 to a driving gear 10b having a driving gear 11a, and a registration roller shaft 1 for turning on / off the transmission of the driving force.
c and an electromagnetic clutch provided on the feed roller shaft 3a, 12 is a bracket on which the feed roller 3 and the pickup roller 4 are installed, 13 is provided on the bracket 12,
A connecting gear meshing with the feed roller gear 14 and the pickup gear 15, a torque limiter 16 connecting the bracket 12 and the feed roller shaft 3a, and a register sensor 17 are provided.

FIG. 13 shows the operation from the feed roller 3 sending out the paper P to registering the paper. The timing belt 9 is rotated in the direction of the arrow by the rotation of the stepping motor 7 in FIG. When the electromagnetic clutch 11a is turned on, a rotational driving force is transmitted to the feed roller shaft 3a, and the feed roller shaft 3a rotates.

At the same time, the bracket 12 connected to the feed roller shaft 3a via the torque limiter 16 rotates in the direction in which the feed roller shaft 3a rotates until the pickup roller 4 comes into contact with the surface of the sheet P. Since the torque limiter 16 becomes idle at the same time when the pickup roller 4 comes into contact with the surface of the sheet P, the pickup roller 4 comes into contact with the surface of the sheet P by applying a pressure corresponding to the idling torque of the torque limiter 16.

When the feed roller shaft 3a rotates,
The feed roller 3 has an integrated one-way clutch, and rotates in this case because it is set in the locking direction. Further, the feed roller 3 is connected to the pickup roller 4 by a connecting gear from the feed roller gear 14.
The pickup roller 4 is rotated to give a rotational driving force via the pickup gear 13 and the pickup gear 15.

Accordingly, the pickup roller 4 rotates while applying a constant pressure to the surface of the sheet P, and sends out the sheet P. In addition, since the feed roller 3 is also rotating, the paper P is sent out to the registration roller pair 1.

At this time, the fed sheet P
The electromagnetic clutch 11b of the roller shaft 1c is in the off state,
Since the driving force is not transmitted to the registration roller shaft 1c and the registration roller pair 1 is not rotating, it is sent to the nip of the registration roller pair 1 and detected by the registration sensor 17. Then, the paper P collides with the registration roller pair 1 and is bent.
As shown in FIG. 13, the feed roller shaft 3a is stopped in the time until the loop L is formed, and the electromagnetic clutch 11a of the feed roller shaft 3a is turned off to stop paper feeding.

In this state, the leading end of the sheet P is brought into contact with the nip of the pair of registration rollers 1 by the bending force of the loop L so that the leading ends are aligned (register operation). Then, at the timing when the image on the photosensitive member (not shown) and the leading end of the sheet P are brought together, the electromagnetic clutch 11b of the registration roller shaft 1c is turned on, and the registration roller pair 1 rotates as shown in FIG. I do.

The feed roller shaft 3a is provided with an electromagnetic clutch 11a.
Is off, and is in a state where it can idle. Accordingly, the bracket 12 is lifted by the tensile force of the spring 5, and the pickup roller 4 separates from the surface of the sheet P,
Is released.

[0011]

In the above-described conventional paper feeding apparatus, the electromagnetic clutch 11a is used for the on / off operation of paper feeding, and the electromagnetic clutch 11b is used for performing the registration operation. Therefore, a sheet feeding device having one sheet feeding port requires two electromagnetic clutches, and if one sheet feeding port is added, one electromagnetic clutch is added.

However, since the electromagnetic clutch is expensive, there is a problem that an increase in the number of used electromagnetic clutches causes an increase in cost.

An object of the present invention is to provide a sheet feeding device capable of feeding sheets by reducing the number of electromagnetic clutches used.

[0014]

In order to achieve the above object, a first means of the present invention comprises a feed roller for separating and conveying a sheet, a registration roller for receiving the sheet and adjusting the feed of the leading end of the sheet, met paper feeding apparatus that includes a reversible motor for driving the feed roller and the resist roller
Te, the transmission means for transmitting the rotational driving force of the motor is provided to each support shaft of the feed roller and the registration rollers, provided a one-way clutch for locking rotating at different rotational directions, the at forward rotation of the motor Les
With the dystro roller idling, the feed roller is
Rotate the paper in the paper transport direction, and
Rotate the registration rollers in the paper transport direction and
The feed roller is idling .

The second means includes a pickup roller for feeding the sheet in contact with the upper surface of the stacked sheets, a feed roller for separating and conveying the sheet, and a registration roller for receiving the sheet and adjusting the feed of the leading end of the sheet. , a sheet feeding apparatus having a a reversible motor <br/> over motor for driving the pickup roller and the feed roller and the registration rollers, the rotational driving force of said motor to said pick-up roller and the feed roller A one-way clutch is provided in a transmission means that transmits the torque via a torque limiter and is provided on the support shaft of the registration roller and transmits the rotational driving force of the motor.
Sometimes the registration roller is idle and the pick
Rotate the up roller and feed roller in the paper transport direction.
And use the registration roller when the motor rotates in the reverse direction.
While rotating in the paper transport direction,
The feed roller is idling .

The third means includes a two-stage paper feed port having a pick-up roller for feeding the paper in contact with the upper surface of the stacked paper sheets and a feed roller for separating and conveying the paper, and a paper feed port from these paper feed ports. In a paper feeder provided with a registration roller that receives a sheet and adjusts the feed of the leading end of the sheet, and a motor that drives a pickup roller, a feed roller, and a registration roller, the start and end of conveyance to a paper feed port near the registration roller are described. An electromagnetic clutch for performing the operation is provided, and the sheet feeding configuration between the registration roller and the sheet feeding port far from the registration roller is configured as the sheet feeding device of the above-described first means or second means. .

[0017]

According to the first means, a one-way clutch is provided for each transmission means for transmitting the rotational driving force of the motor to the feed roller and the registration roller, and these one-way clutches are rotationally locked in different rotation directions. By doing so, the paper can be sent out and the registration operation can be performed.

According to the second means, the rotational driving force of the motor is transmitted to the pickup roller and the feed roller via the torque limiter, and further transmitted to the registration roller via the one-way clutch. , First
The number of one-way clutches to be installed is reduced as compared with the means of (1).

Further, according to the third means, the paper feed port provided with the pickup roller and the feed roller has two stages, and even when the driving motor is commonly used, the paper feed port closer to the registration roller is used. Only by installing an electromagnetic clutch, and by adopting the above-described first and second means of the paper feeding configuration in the configuration of the registration roller and the paper feeding port far from the registration roller, 2
Paper can be fed with a small number of electromagnetic clutches even in a paper feed port of a stage.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. Members corresponding to those described with reference to FIGS. 13 to 15 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 1 is a front view of a first embodiment of the present invention, and FIG.
FIG. 3 is a plan view of the first embodiment of FIG. 1. In the first embodiment, the rubber roller 1a of the pair of registration rollers 1 is installed below the pressing roller 1b, and the timing from the output gear 8 of the stepping motor 7 is adjusted. One-way clutches are provided on drive gears 10a and 10b, which are transmission means provided on the registration roller shaft 1c of the rubber roller 1a, which receives rotational driving force by the belt 9, and on the feed roller shaft 3a, respectively, as shown in FIG. The electromagnetic clutches 11a and 11b have been removed.

FIG. 1 shows the operation until the feed roller 3 feeds out the paper P and performs registration. When the stepping motor 7 shown in FIG. 2 rotates, the field roller shaft 3a is driven by a drive having a one-way clutch. Since the lock state is set by the gear 10b, it rotates, and FIG.
The sheet is sent out to the pair of registration rollers 1 in the same manner as described with reference to FIG.

Then, the feed of the paper P is detected by a registration sensor 17 provided near the registration roller pair 1, and
When the sheet P forms the loop L, the rotation of the stepping motor 7 is stopped.

During the above operation, since the driving gear 10a having the one-way clutch is set to run idle in the rotating direction in this case, the registration roller shaft 1c
Is not transmitted, the registration roller pair 1 remains stopped, and the registration operation is performed.

Next, the stepping motor 7 is rotated in a direction opposite to that in FIG. Therefore, since the timing belt 9 rotates in the direction of the arrow shown in FIG. 3, the one-way clutch in the drive gear 10a of the registration roller shaft 1c is locked, and the rotation driving force is applied from the registration roller shaft 1c to the registration roller pair 1. The paper P is conveyed.

On the other hand, the drive gear 10b of the feed roller shaft 3a
In this case, since the one-way clutch rotates in the direction in which the one-way clutch idles in this case, the rotation driving force is not transmitted to the feed roller shaft 3a, so that the feed roller shaft 3a can idle. Then, the pickup roller 4 separates from the surface of the sheet P, and the pressure on the sheet P is released.

FIG. 4 is a perspective view of a feed roller portion according to a second embodiment of the present invention, and FIG. 5 is an exploded perspective view of a main portion of the second embodiment. Although a one-way clutch is provided on the gear 10b,
In the second embodiment, the drive gear 10b is not provided with a one-way clutch, is directly fixed to the feed roller shaft 3a, and is provided with a torque limiter that generates a rotational load torque in both forward and reverse rotations on the feed roller shaft 3a. This is different from the first embodiment.

4 and 5, the torque limiter 20
A cylindrical receiver 21 fixed to the bracket 12, forward and reverse winding torque limiter springs 22, 23, and a torque limiter hub 24 installed between the two torque limiter springs 22, 23; And a stopper hub 26 fixed to the feed roller shaft 3a with screws 25.

The forward winding torque limiter spring 22 is joined to a part of the bearing 21 and the torque limiter hub 24,
A reverse winding torque limiter spring 23 is joined to a part of the torque limiter hub 24 and a part of the stopper hub 26, and the feed roller shaft 3a is inserted into each central hole.

The paper feeding operation using the torque limiter 20 will be described. That is, the process is the same as that of the first embodiment until the feed roller 3 sends out the sheet and performs registration.
Thereafter, as shown in FIG. 3, when the feed roller 3 rotates in the same direction as the timing belt 9, the feed roller 3 rotates in the direction in which the feed roller shaft 3a idles due to the integrated one-way clutch. Is not transmitted.

The bracket 12 is provided on the feed roller shaft 3.
Since the torque limiter 20 receives the driving force for rotating a, and acts even when the torque limiter 20 rotates in the reverse direction, the torque limiter 20 rotates and rises, and the bracket 12 comes into an idling state when the bracket 12 comes into contact with the stopper 6.

Therefore, the pickup roller 4 stops without rotating because the feed roller 3 is not rotating, and moves away from the sheet P because the bracket 12 is raised. Since the pickup roller 4 moves up and down as described above, the pickup roller return spring 5 used in the first embodiment is unnecessary in the second embodiment.

As the torque limiter 20 ', those having the constructions shown in the exploded perspective view of FIG. 6 and the assembled perspective view of FIG. 7 can be employed. 6 and 7, reference numeral 30 denotes a bracket 12
, A fixed disk, 32 is a rotating disk, 33 is a pedestal, 34 is a pressure spring, 35 is a washer, 36 is an E-shaped ring as a locking member, and 37 is a feed roller shaft. This is a locking pin provided so as to project to the side of 3a.

The fixed disk 31 and the rotating disk 32
Is arranged between the receiving body 30 and the receiving base 33, and in a state where the feed roller shaft 3a is inserted into each central hole, the locking pin 37 of the feed roller shaft 3a enters the cutout groove 33a of the receiving base 33, At the protruding end of the roller shaft 3a, a pressurizing spring 34 is provided in a compressed state between the receiving table 33 and a washer 35 fixed to the feed roller shaft 3a by an E-shaped ring 36. In both forward and reverse rotations, a rotational load torque is generated.

FIG. 8 is a structural view of a third embodiment of the present invention. In the third embodiment, the upper and lower paper feed ports are used, and the distance between the registration roller pair 1 and the feed roller 3 is shorter. first sheet feeding port and (upper), also if the distance is the longer the second sheet feeding port (bottom), the rotation stopping operation of the feed b <br/> over La 3 in the first sheet feeding port, i.e. The start and end of feeding of the paper P are performed by the on / off operation of the electromagnetic clutch 11a described with reference to FIGS.
At the second paper feed port, the configuration of the first embodiment or the second embodiment described above is adopted (the configuration of the first embodiment is adopted in the third embodiment). Try to quit.

In FIG. 8, reference numeral 40 denotes a stepping motor 41.
Driven by the output gear 41a of the
And a timing belt 42 provided between the drive gear 10a of the first feed port 3 and the drive gear 10b of the feed roller 3 'of the second paper feed port. A timing belt bridged with the connecting gear 43, 44 is a guide plate, 45a is a first sheet feeding cassette, and 45b is a second sheet feeding cassette.

FIG. 9 is a view for explaining the feed roller conveyance of the first paper feed port. When the stepping motor 41 rotates in the direction of the arrow and the electromagnetic clutch 11a is turned on, the pickup roller 4 is turned on.
Is pressed and rotated with respect to the sheet P, and the sheet P is sent out. The feed roller 3 also rotates to separate and transport the paper P. When the paper P reaches the registration roller pair 1, the registration sensor 17 is turned on, and at the timing when the paper P enters the registration roller pair 1, the rotation of the stepping motor 41 is stopped, and the electromagnetic clutch 11a is turned off.

At this time, since the driving gear 10a is rotating in the locking direction, even if the paper enters the registration roller pair 1,
Since the registration roller pair 1 is rotating, registration is not performed. In the second paper feed port, the stepping motor 41
Does not transport the paper P because the drive gear 10b is rotated in the idling direction of the one-way clutch.

Then, as shown in FIG. 10, when the stepping motor 41 is rotated again in the same direction as the state shown in FIG.
The sheet P is transported by the registration roller pair 1. At this time, since the electromagnetic clutch 11a is off, the second sheet is not fed.

FIG. 11 is an explanatory view of the feed roller conveyance of the second paper feed port, in which the stepping motor 41 is rotated in a direction opposite to that of FIGS. Then, since the driving gear 10b rotates in the locking direction, the pickup roller 4 performs a pressurizing rotation on the sheet P, and sends the sheet P to the feed roller 3 '. Since the feed roller 3 'is also rotating, the paper P is separated and conveyed. The paper P turns on the registration sensor 17 while being conveyed, and enters the registration roller pair 1.

The registration roller pair 1 does not rotate because the drive gear 10a is rotating in the idling direction. Therefore, the sheet P forms a loop L and stops the stepping motor 41 at that timing. At this time, the feed roller 3 of the first paper feed port is in the off state because the electromagnetic clutch 11a is in the off state.
Do not transport paper.

As shown in FIG. 12, when the stepping motor 41 is rotated in the direction opposite to that of FIG. 11 (the same direction as in FIGS. 9 and 10), the driving gear 10a rotates in the locking direction. The pair 1 rotates to convey the paper P.
Further, since the drive gear 10b of the feed roller 3 'of the second paper feed port rotates in the direction in which the one-way clutch idles, the feed roller 3' of the second paper feed port does not rotate, and the pickup roller 4 also stops rotating. Since the pressurization of the sheet P is released, the second sheet is not sent out.

[0043]

As described above, according to the first means of the present invention, the conveyance of the sheet can be started by using the one-way clutch without using the electromagnetic clutch, so that the cost can be reduced, and the second means can be achieved. According to the first means, one of the one-way clutches, which needs to be installed at two places by the first means, can be used as a torque limiter, thereby further reducing the cost. In the case of paper, it is possible to reduce the number of electromagnetic clutches to be used, such as reducing the need to install an electromagnetic clutch at three places to one, and reducing costs. Equipment can be provided.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of a sheet feeding device of the present invention.

FIG. 2 is a plan view of the first embodiment of FIG.

FIG. 3 is an explanatory diagram of an operation state of the first embodiment.

FIG. 4 is a perspective view of a feed roller portion according to a second embodiment of the present invention.

FIG. 5 is an exploded perspective view of a main part of the second embodiment.

FIG. 6 is an exploded perspective view of another example of the torque limiter.

FIG. 7 is a perspective view of the torque limiter of FIG. 6 in an assembled state.

FIG. 8 is a configuration diagram of a third embodiment of the present invention.

FIG. 9 is an explanatory diagram of feed roller conveyance of a first paper feed port of the third embodiment.

FIG. 10 is an explanatory view of a pair of registration rollers of a first paper feed port of the third embodiment and conveyance.

FIG. 11 is an explanatory diagram of feed roller conveyance of a second paper feed port of the third embodiment.

FIG. 12 is an explanatory diagram of a pair of registration rollers of a second paper feed port of the third embodiment and conveyance.

FIG. 13 is a front view showing an example of a conventional sheet feeding device.

FIG. 14 is a plan view of the device of FIG.

FIG. 15 is an explanatory diagram of an operation state of the device of FIG.

[Explanation of symbols]

1 ... registration roller pair, 1c ... registration roller shaft,
2. Separation roller, 3, 3 '... Feed roller, 3a ...
Feed roller shaft, 4 Pickup rollers, 7 Stepping motor, 8 Output gear, 9 Timing belt, 10a, 10b Drive gear (transmission means), 11a, 11b ...
Electromagnetic clutch, 20, 20 '... torque limiter.

Claims (3)

(57) [Claims] 1. A feed roller for separating and transporting a sheet, a registration roller for receiving a sheet and adjusting a feed of a leading end of the sheet, and a forward / reverse drive for driving the feed roller and the registration roller
A paper feeding device provided with a rolling motor capable, the transmission means for transmitting the rotational driving force of the motor is provided to each support shaft of the feed roller and the registration rollers, the lock rotate at different rotational directions a one-way clutch to be provided, the register at the time of the normal rotation of the motor
Idle the roller and feed the roller
Rotate in the transport direction, and when the motor rotates in the reverse direction,
While rotating the distroller in the paper transport direction,
A sheet feeding device characterized by rotating an idler roller . 2. A pickup roller that feeds a sheet in contact with an upper surface of a stacked sheet, a feed roller for separating and conveying the sheet, a registration roller that receives the sheet and adjusts a leading end of the sheet, and a pickup roller and a feed roller. a sheet feeding apparatus comprising a reversible motor for driving the roller and the resist roller, the rotational driving force of said motor transmitted via the torque limiter against the pickup roller and the feed roller, the resist roller A one-way clutch is provided in the transmission means provided on the support shaft for transmitting the rotational driving force of the motor, and the registration roller idles when the motor rotates forward.
And use the pickup roller and feed roller.
Rotate in the paper transport direction, and when the motor rotates in the reverse direction,
While rotating the registration roller in the paper transport direction,
A sheet feeding device characterized by spinning a pickup roller and a feed roller . 3. A two-stage paper feed port having a pick-up roller for feeding paper in contact with the upper surface of stacked paper and a feed roller for feeding and separating the paper, and receiving paper from these paper feed ports. An electromagnetic clutch for starting and ending conveyance to a paper feed port close to the registration roller in a paper supply device including a registration roller for adjusting a feed of a leading end, and a motor for driving a pickup roller, a feed roller, and a registration roller. 3. The sheet feeding device according to claim 1, further comprising a sheet feeding unit configured to feed the registration roller and a sheet feeding port far from the registration roller.