JP2842432B2 - 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 used for a copying machine, a printer, and a facsimile machine, and more particularly to a paper feeder having a skew correction mechanism for sheet paper.

[0002]

2. Description of the Related Art Conventionally, a carrier roller and a pair of registration rollers are arranged at a predetermined distance from each other, and the leading end of the sheet paper conveyed by the carrier roller is positioned at a nip portion (2) of a non-rotating registration roller. 2. Description of the Related Art There is known a paper feeding device in which a skew of a sheet is corrected by abutting against a portion where two rollers are in contact with each other to bend and then fed by a registration roller.

For example, in Japanese Patent Application Laid-Open No. Hei 7-117899, a pressure sensor is provided between a registration roller and a conveyance roller when the leading end of a sheet of paper is brought into contact with a nip portion of a registration roller to correct skew. A configuration is disclosed in which the stiffness of a sheet of paper is detected, and the angle of a regulating plate for setting a curvature for bending the sheet of paper in front of a registration roller is controlled in accordance with the stiffness of the sheet. In this conventional example, an electromagnetic clutch for stopping rotation is connected to the registration roller in order to stop rotation of the registration roller when the leading edge of the sheet paper comes into contact, and to form a curve of the sheet paper. It is controlled by the control unit.

Further, Japanese Utility Model Laid-Open Publication No. 1-111648 discloses a sheet feeding device which is provided with a skew correction assisting mechanism and acts on a bent portion of a sheet paper to correct skew. The skew correction assisting mechanism includes a mechanism for pressing a sheet of paper with an electromagnetic clutch and a mechanism for blowing air, and each is controlled by a microcomputer.

[0005]

However, in any of the conventional examples, the mechanism for correcting the skew of the sheet paper must be operated by an electromagnetic clutch or microcomputer controlled by a sensor or a control unit. A skew correction auxiliary mechanism to be controlled was required, and electrical control was required.
For this reason, the control circuit must be designed, and there is a disadvantage that the cost is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to configure a skew correction mechanism using only mechanical parts without using electric parts such as a sensor and an electromagnetic clutch, and to detect skew of a sheet of paper to correct skew. Accordingly, it is an object of the present invention to provide a sheet feeding device which has a simplified structure and low power consumption.

[0007]

A sheet feeder according to the present invention comprises a registration roller (1 in FIG. 1) in which the leading end of a sheet conveyed by a conveying body (8, 9 in FIG. 1) is arranged in the conveying direction. The sheet has a function of correcting the skew of the sheet by abutting against the conveying surface of the sheet, and is rotated by a curved portion of the sheet which occurs when the sheet is abutted against the conveying surface of the registration roller. Rotating member (4 in FIG. 1)
A rotation drive source (3 in FIG. 1) serving as a generation source of a force for rotating the registration roller, and a rotation drive source (4 in FIG. 1) provided on a rotation member (4 in FIG. 1). (3), and a sheet of paper conveyed by the registration roller rotating via the rotation transmission mechanism (6 in FIG. 1) for transmitting the rotation from the rotation drive source to the registration roller. And a state maintaining mechanism (7 in FIG. 1) for maintaining a state in which the rotational force transmitting mechanism is coupled to the rotational drive source during the contact. When the trailing edge of the sheet paper passes through the state maintaining mechanism and stops contacting, the state maintaining mechanism (7 in FIG. 1) releases the state in which the rotational force transmitting mechanism is coupled to the rotational drive source, and stops the rotation of the registration roller. Stop.

With this configuration, the mechanism from the skew correction to the discharge of the sheet from the registration roller is all mechanically configured, and the control of the sensor, the electromagnetic clutch, and the rotation drive source is unnecessary.

The rotational force transmitting mechanism is provided with a mechanical delay mechanism (17 in FIG. 2) for delaying the time for transmitting the rotational force to the registration roller when it is coupled to the rotation drive source, so that the registration roller can transfer the sheet paper. Immediately after the conveyance, the rotation member is rotated to prevent the rotational force transmission mechanism from separating from the rotational drive source.

Specifically, the rotary drive source has a drive gear (3 in FIG. 1) for transmitting the rotational force, and the registration roller has a driven gear (1a in FIG. 1) to which the rotational force is applied. Specifically, the rotational force transmission mechanism includes first and second idle gears (15 and 16 in FIG. 2) that mesh with the driven gear and the drive gear by the rotation of the rotation member, and the first and second idle gears. 2 is an idle gear assembly having a mechanical delay mechanism (17 in FIG. 2) coupled between the idle gears.

[0011] The mechanical delay mechanism is, for example, a spring that connects the first and second idle gears. Even after the idle gear assembly meshes with the driven gear and drive gear,
The rotation start time of the registration roller is delayed by the time for which the spring is bent, and as a result, the sheet paper is excessively bent.
After the spring is bent, the registration roller rotates and the sheet paper is conveyed. In this case, the pivoting member does not move until it is conveyed by a distance corresponding to the length of the curved portion of the sheet paper formed within the deflection time of the spring, and the idle gear assembly remains connected to the driven gear and the driving gear. The length of the curved portion of the sheet paper formed within the bending time of the spring is the distance between the nip portion of the registration roller 1 and the state maintaining mechanism (L in FIG. 1).
That is all.

More specifically, the state maintaining mechanism has a rotating lever having a first contact portion that contacts the sheet paper and a second contact portion that contacts the rotating member. The rotation lever presses the rotation member while rotating the rotation member toward the rotation drive source while contacting the sheet paper, thereby maintaining the state in which the rotation force transmission mechanism is coupled to the rotation drive source and reducing the rotation force. Notify the registration rollers. With this configuration, the number of parts can be reduced.

[0013]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the sheet feeding device of the present invention. In the figure, conveying bodies 8 and 9 composed of a pair of rollers convey the sheet paper 2 in a conveying direction A along a guide plate 10. The pair of registration rollers 1 are arranged in the paper feeding direction A.

A guide plate 11 is disposed between the conveying members 8 and 9 and the registration roller 1 so as to face the guide plate 10. The guide plate 11 is curved upward with respect to the guide plate 10, and a through hole 11a is formed in the curved portion.
The curved portion 4a of the lever 4 that is a rotating mechanism is inserted into the through hole 11a. When the sheet paper 2 comes into contact with the nip of the registration roller 1 and stops, the curved portion of the guide plate 11
This is provided to bend the sheet paper inside the guide plate 11.

The bending portion 4a of the lever 4, which is a rotating mechanism,
It is located upstream of the fulcrum 5 supporting the lever 4 in the paper feeding direction, and is curved toward the sheet paper. Lever 4
It is held rotatably about the fulcrum 5 and is pulled counterclockwise by a spring 12 provided downstream of the fulcrum 5 in the paper feeding direction. As a result, in a state before the sheet paper 2 hits the nip portion of the registration roller 1 and a curved shape is formed, the lever 4 stops substantially horizontally while maintaining the state shown in the figure in combination with the locking by the lever 7 described later. I have.

On the downstream side of the fulcrum 5 of the lever 4, an idle gear assembly 6 that can freely rotate with respect to the lever 4.
Is attached. The idle gear assembly 6
As shown in FIGS. 3 and 4, the first idle gear 15
Idle gear 16 having a hollow cylindrical portion 16a
And a spring 17 connecting between them. The first idle gear 15 and the second idle gear 16 can rotate independently of each other, and rotate integrally by a spring 17.

FIG. 2 is a partial top view of FIG. 1 showing the structure around the idle gear assembly 6. 1 and 2, a driven gear 1a is fixed to a rotation shaft of a roller above the registration roller 1. The driven gear 1a can be engaged with the first idle gear 15 of the idle gear assembly 6, and the drive gear 3 connected to a motor (not shown) can be connected to the second idle gear 16. Therefore,
The idle gear assembly 6 is a torque transmitting mechanism that transmits the torque of the drive gear 3.

As shown in FIG. 2, the lever 4 is bifurcated in the vicinity of the idle gear assembly 6, and the hollow cylindrical portion 16a of the second idle gear 16 is divided by a gear holding shaft 14b formed at an intermediate portion. It is rotatably supported. The lever 4 does not directly contact the drive gear 3 or the driven gear 1a.

In the state shown in FIG. 1, the driven gear 1a is separated from the first idle gear 15 of the idle gear assembly 6 at a predetermined interval, and the drive gear 3 is separated from the second idle gear 16 at a predetermined interval.

Therefore, in the state shown in FIG. 1 (the state before the sheet paper 2 hits the nip portion of the registration roller 1 to form a curve), the rotational force of the driving gear 3
It does not reach a. However, when the sheet 4 is curved, the lever 4 is lifted up by the curve, and when the lever 4 is turned around the fulcrum 5 in the direction B (clockwise) in the figure, the idle gear assembly 6 is driven by the drive gear 3 and the driven gear 1a. And the rotational force of the drive gear 3 is transmitted to the driven gear 1 a via the idle gear assembly 6, and
Rotates.

In the idle gear assembly 6, the spring 17 is a mechanical delay mechanism that delays transmission of the rotational force of the drive gear 3 to the driven gear 1a. That is, even if the first and second idle gears 15 and 16 are engaged with the driven gear 1 a and the driving gear 3, the rotation of the driving gear 3 does not cause the driven gear 1 a to rotate immediately. The rotation of the spring 17 causes the spring 17 to bend. The force stored in the spring 17 overcomes the frictional force of the registration roller 1 and then rotates.

Therefore, even after the idle gear assembly 6 meshes with the driven gear 1a and the driving gear 3, the rotation start time of the registration roller 1 is delayed by the time for which the spring 17 bends. Guide plate 11
It is formed extra inside. After the spring 17 is bent, the registration roller 1 rotates, and the sheet paper is conveyed. In this case, the lever 4 does not move until it is conveyed by a distance corresponding to the length of the curved portion of the sheet paper 2 formed within the bending time of the spring 17, and the idle gear assembly 6 is connected to the driven gear 1a and the driving gear 3. Remains. As will be described later, the distance is not less than the distance L between the nip portion of the registration roller 1 and the lever 7 in FIG.

A curved portion 7a of the lever 7, which can swing about a fulcrum 14, is disposed downstream of the registration roller 1 for detecting sheet paper. The bending portion 7a is bent toward the sheet paper. The lever 7 is pulled clockwise by the spring 13, and comes into contact with a stopper 15 located on the opposite side of the fulcrum 14 from the spring 13 and is stationary. At this time, the lower curved portion 7 a of the lever 7 is inserted into the notch 20 a of the guide plate 20. Further, one end of the lever 7 on the side opposite to the curved portion 7a abuts on the upper part of the fulcrum 5 of the lever 4 at a downstream position in the sheet feeding direction. Therefore, the lever 4 is stopped by the lever 7.

If the leading end of the sheet 2 conveyed from the registration roller 1 pushes up the curved portion 7a, the lever 7
Rotates counterclockwise about the fulcrum 14, and moves lever 4 to B
Apply a force to rotate in the direction. At this time, lever 7
Maintains the state in which the idle gear assembly 6 is coupled to the driving gear 3 and the driven gear 1a, so that the lever 7 is a state maintaining mechanism.

Next, the operation of the embodiment of the present invention will be described.

When the sheet paper 2 is conveyed by the conveyance bodies 8 and 9, the leading end of the sheet paper 2 contacts the nip portion of the registration roller 1. At this time, the driven gear 1 of the registration roller 1
a does not rotate because it is not coupled to the drive gear 3 via the idle gear assembly 6. When the sheet 2 is further conveyed in this state, the leading end of the sheet 2 is corrected so as to be parallel to the registration roller 1, the skew is corrected, and the sheet 2 is curved inside the guide plate 11.

When the curving proceeds further, the sheet paper 2 pushes up the curving portion 4a of the lever 4, and the lever 4 rotates in the direction B about the fulcrum 5. As a result, the idle gear assembly 6 connects the drive gear 3 and the driven gear 1a. Even if the idle gear assembly 6 meshes with the driven gear 1a and the driving gear 3, the rotational force of the driving gear 3 is not immediately transmitted to the driven gear 1a, and the rotation start time of the registration roller 1 is delayed by the time during which the spring 17 is bent. . As a result, the spring 17
During the time when the sheet is bent, the curvature of the sheet paper 2 is additionally formed inside the guide plate 11.

After the bending time of the spring 17, the registration roller 1
Rotates, and the sheet paper 2 is conveyed. At this time, the spring 1
The lever 4 does not move until the sheet is conveyed by a distance corresponding to the length of the curved portion of the sheet paper 2 formed within the bending time of 7, and the idle gear assembly 6 remains connected to the driven gear 1a and the driving gear 3. . As shown in FIG.
The distance L between the nip portion and the lever 7 is equal to or less than the curved length of the sheet paper 2 formed during the bending time of the spring 17. Gear assembly 6 remains coupled to driven gear 1a and drive gear 3.

As described above, while the sheet paper 2 is transporting the distance L between the registration roller 1 and the curved portion 7a of the lever 7,
The curvature of the sheet paper 2 in the guide plate 11 is gradually released, and the force with which the idle gear assembly 6 meshes with the drive gear 3 and the driven gear 1a becomes weaker, but the idle gear assembly 6 is moved from the drive gear 3 and the driven gear 1a. I won't go away.

When the sheet paper 2 advances the distance L and pushes up the curved portion 7a, the lever 7 pushes the lever 4 toward the driven gear 1a, because the force of pushing up the curved portion 4a of the lever 4 is lost. The power to work works. As a result, while the sheet 2 passes under the lever 7, the registration roller 1 continues to rotate.

When the rear end of the sheet 2 passes through the curved portion 7a, the lever 7 rotates clockwise by the tension of the spring 13. As a result, the lever 4 also rotates counterclockwise due to the tension of the spring 12, and when the lever 7 comes into contact with the stopper 15, each lever comes to a standstill in the state of FIG.

As described above, according to the embodiment of the present invention, there is no electric mechanism other than the motor for rotating the drive gear 3 in the mechanism from the correction of the skew of the sheet paper to the end of the conveyance. Since 3 always keeps rotating, all the correction and conveyance are performed mechanically without requiring a control circuit. Therefore, the design is easy and low power consumption can be realized.

The present invention is not limited to the embodiment described above. For example, registration roller 1
Is a pair of rollers, but one side has a guide plate on one side.
One roller may be used. Further, a member that replaces a lever or a gear, such as a rotating member, a rotating force transmitting member, or a state maintaining mechanism, may be used.

[0035]

As described above, according to the present invention,
In the mechanism from skew correction of sheet paper to the end of conveyance,
There is no electric mechanism other than the motor that rotates the rotary drive source,
In addition, the rotary drive source only needs to keep rotating at all times, and correction and transport are all performed mechanically without the need for a control circuit. Therefore, the design is easy and low power consumption can be realized.

[0036]

[Brief description of the drawings]

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

FIG. 2 is a top view showing a mechanism around an idle gear assembly of the sheet feeding device of FIG. 1;

FIG. 3 is an exploded view of the idle gear assembly.

FIG. 4 is a sectional view of the idle gear assembly of FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 registration gear 2 sheet paper 3 drive gear 4 lever 5 fulcrum 6 idle gear assembly 7 lever 8, 9 carrier 10 guide plate 11 guide plate 12 spring 13 spring 14 fulcrum 15 stopper 20 guide plate

Claims (5)

(57) [Claims] 1. A sheet feeding device having a function of correcting skew of a sheet paper by abutting a leading end of the sheet paper conveyed by a conveyance body on a conveyance surface of a registration roller arranged in a conveyance direction. A rotating member that is rotated by a curved portion of the sheet paper that is generated when the sheet paper abuts against a conveyance surface of the registration roller; a rotation driving source that is a source of a force for rotating the registration roller; A rotation force transmission mechanism provided on the rotation member, coupled to the rotation drive source by rotation of the rotation member, and transmitting a rotation force from the rotation drive source to the registration roller; A state of maintaining the state in which the rotational force transmitting mechanism is coupled to the rotational drive source during the contact with the sheet paper conveyed by the registration roller rotating via When the rear end of the sheet of paper passes through the state maintaining mechanism and stops contacting, the state maintaining mechanism releases the state in which the rotational force transmitting mechanism is coupled to the rotational drive source, and releases the registration roller. A sheet feeder, wherein the rotation of the sheet is stopped. 2. The apparatus according to claim 1, wherein said torque transmitting mechanism includes a mechanical delay mechanism for delaying a time for transmitting said torque to said registration roller when coupled to said rotary drive source. Paper feeder. 3. The rotation driving source includes a driving gear for transmitting a rotating force, the registration roller includes a driven gear to which a rotating force is applied, and the rotating force transmitting mechanism includes a rotating member configured to rotate the rotating member. An idle gear assembly having first and second idle gears meshing with the driven gear and the drive gear, and the mechanical delay mechanism coupled between the first and second idle gears. The sheet feeding device according to claim 2, wherein: 4. The apparatus according to claim 1, wherein the mechanical delay mechanism includes the first and second mechanical delay mechanisms.
4. The paper feeding device according to claim 3, wherein the feeding device is a spring that couples the idle gear. 5. The state maintaining mechanism includes a rotating lever having a first contact portion that contacts the sheet paper and a second contact portion that contacts the rotating member, wherein the lever includes the rotating lever. By pressing the rotating member toward the rotation drive source while contacting the paper while rotating the rotation member, the rotation force transmission mechanism is maintained in a state of being coupled to the rotation drive source, and the rotation force is applied to the registration roller. The sheet feeding device according to claim 1, wherein the information is transmitted.