JP3287674B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus used for an image forming apparatus such as a copying machine or a laser beam printer.

[0002]

2. Description of the Related Art Conventionally, a sheet feeding apparatus such as a copying machine has a sheet stacking unit on which sheets are stacked, a sheet feeding roller for feeding the sheets on the sheet stacking unit one by one, and a sheet to the sheet feeding roller. 2. Description of the Related Art There is known a sheet feeding apparatus including a pressing member that presses and biases and a pair of width regulating plates that regulate a position in a width direction of stacked sheets.

[0003] In such a sheet feeding apparatus, a sheet stacking means body or is supported on the armor cover, a projection on the circumference of the central axis of rotation of the sheet stacking means is provided, body or exterior cover this protrusion In the thrust direction of the sheet stacking means with respect to the main body or the outer cover.

[0004]

However, in the above conventional example, the sheet stacking means having the width regulating plate for regulating the sheet width direction and the main body or the outer cover supporting the sheet stacking means are not provided. Although the positioning in the thrust direction is performed, the rollers for feeding the sheets one by one are positioned via the main body or the outer cover, so that the parallelism between the feeding rollers and the sheet stacking means cannot be reliably obtained.

[0005] For this reason, the sheet on the sheet stacking means fed one by one by the feeding roller has a drawback that the printing error and the jam occur due to the skew depending on the accuracy of the parts such as the main body frame and the outer cover. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a sheet feeding apparatus and an image forming apparatus which can increase the degree of parallelism between a feeding roller and a sheet stacking means. To provide.

In order to achieve the above object, according to the present invention, a rotating shaft is attached to an apparatus main body so as to be freely opened and closed,
Sheet stacking means for stacking a plurality of sheets, and the apparatus
A feed roller shaft rotatably supported by the main body;
Feeds the sheets loaded on the sheet loading means one by one
A sheet feeding device, comprising:
The sheet stacking means includes a pair of sheets movably in the sheet width direction.
A sheet width regulating member is attached, and the sheet width regulating member
Is fitted to the feed roller shaft of the feed roller and
A guide hole is provided for guiding when the loading means is opened and closed.
By this, the sheet width regulating member is fed by the feeding roller.
Positioning unit for connecting a roller shaft and the sheet stacking means
It is characterized by forming a material.

[0008]

[0009]

[0010]

[0011] The image forming apparatus may further include the sheet feeding device and an image forming unit that forms an image on a sheet fed by the sheet feeding device.

[0012]

According to the present invention having the above-described structure, the sheet loading means has a positioning member connecting the feed roller shaft of the feed roller and the sheet loading means. Like the conventional one positioned at
This prevents the degree of parallelism between the sheet stacking means and the feed roller from being affected by the accuracy of the components of the apparatus main body.

[0013]

DETAILED DESCRIPTION FIG. 1, 2 and 3 show a first exemplary embodiment of the present invention, FIG. 2 is a first best represents the drawing characteristics of the reference example of the present invention, a first aspect of the present invention FIG. 3 is a vertical sectional side view of the sheet feeding device of the reference example , and FIG. 3 is a vertical sectional front view of the sheet feeding device.

In FIG. 1, a front cover 1 as an apparatus main body of a sheet feeding apparatus A is rotatable around a rotation fulcrum shaft 1a on a main body frame 13 of an image forming apparatus B.

In FIG. 1, a front cover 1 of a sheet feeding apparatus A holds a sheet feeding tray 2 as a sheet stacking means on which a plurality of sheets 10 are stacked. Is provided with a pair of sheet width regulating plates 11a and 11b for regulating the width direction of the sheet 10, respectively.

A pinion 1 is provided on the back of the paper feed tray 2.
2 is rotatably supported by the boss 9. Pinion 12
A pair of racks 15 and 16 mesh with each other at positions facing each other. The racks 15 and 16 are slidably supported in the width direction of the paper feed tray 2, and are provided with holes provided in the width direction of the paper feed tray 2 and the width regulating plates 11 a and 11 b.
And are respectively connected. Thus, the width regulating plates 11a and 11b are configured to be able to guide in the width direction of the sheet by moving in the width direction of the sheet in conjunction with each other.

The paper feed tray 2 is supported by a rotation center shaft 2a as a rotation shaft of the front cover 1 of the sheet feeding device A,
Normally, when the paper feed tray 2 is not used, it is fixed and held by a lock mechanism of the front cover 1 of the sheet feeding device A (not shown) as shown in FIG. 2, and when the paper feed tray 2 is used, as shown in FIG. The sheet feed tray 2 is rotated about the rotation center axis 2a until a proper sheet setting state.

At both ends of the paper feed tray 2, one sheet 10 on the paper feed tray 2 is fitted with a paper feed roller shaft 3a as a feed roller shaft of a paper feed roller 3 as a feed roller for feeding. A coupling member (positioning member) 6 having a U-shaped groove 6a as a fitting portion to be fitted is provided. Thrust regulating members 14a and 14b are provided on the sheet feeding roller shaft 3a to abut on the positioning member 6 to determine the position in the thrust direction, and the sheet feeding tray 2 is rotated about the rotation center axis 2a. It rotates in conjunction with it, and as shown in FIG.
When setting a sheet, the U-shaped groove 6a of the positioning member 6 fits the feed roller shaft 3a of the feed roller 3.

At this time, since the rotation center shaft 2a of the sheet feeding tray 2 is fitted to the round hole so as to have a play with respect to the front cover 1 of the sheet feeding apparatus A, the sheet feeding tray 2 is positioned by the positioning member 6. And the paper feed roller shaft 3a of the paper feed roller 3.

On the downstream side of the paper feed tray 2, a pressing member 4 for pressing the sheet 10 against the paper feed roller 3 is supported at a position coaxial with the rotation center shaft 2 a of the paper feed tray 2, and a pressing spring (not shown) There pressing member 4 by pushing up the backside of the pressing member 4 is Ru is biased to the paper feed roller 3.

At this time, the center axis of rotation of the pressing member 4 may be provided on the main body frame 13 of the image forming apparatus B or on the sheet feed tray 2.

On the downstream side of the pressing member 4, a plurality of sheets 1
A separation pad 5 having a rubber material having a high friction coefficient for separating 0 is biased by the feed roller 3 by a pressing spring (not shown) provided on the main body frame 13 pushing up the back surface of the separation pad 5. .

The paper feed roller 3 is bonded or pressed into a substantially central portion of the paper feed roller shaft 3a, and the paper feed roller shaft 3a is held on the main body frame 13 via a bearing. The paper feed roller 3 is connected to an image forming apparatus B (not shown).
The motor rotates only clockwise by receiving a driving force from a driving gear transmitted from the motor.

[0024] The sheet 1 on the downstream side of the paper feed roller 3
A conveyance roller pair 18 including a guide member 17 for guiding the zero and a pinch roller 7 pressed against the conveyance roller 8 is provided.

In the present reference example , the sheet 1
In the case where 0 is set on the paper feed tray 2, the lock mechanism holding the paper feed tray 2 of the front cover 1 of the image forming apparatus B (not shown) is released, and the sheet as shown in FIG. 1 can be set. The paper feed tray 2 is rotated about the rotation center shaft 2a until the state.

At this time, the positioning member 6 also rotates in conjunction with the paper feed tray 2, and is fitted into the U-shaped groove 6 a of the positioning member 6 and the paper feed roller shaft 3 a of the paper feed roller 3.
The thrust direction is regulated by 4a and 14b, so that the parallelism between the paper feed tray 2 and the paper feed roller 3 for feeding a plurality of sheets on the paper feed tray 2 one by one can be ensured.

That is, the sheet 10 set on the paper feed tray 2 can be fed at right angles to the axis of the paper feed roller 3,
The skewing of the sheet 10 can be prevented.

When the sheet 10 is set on the paper feed tray 2, the sheet 10 passes over the pressing member 4 pressed down by a cam provided on the main body frame side of the image forming apparatus B (not shown), and is located just before the separation pad 5. Push the sheet until it hits the surface.

Next, when the paper feed is started, the cam provided on the main body frame (not shown) rotates, and the pressing member 4 absent on the paper feed roller 3 is pushed up by a pressing spring (not shown). So that multiple sheets 1
The pressing member 4 presses the paper feed roller 3 via the “0”. Further, the sheet 10 is fed to the separation pad 5 by the paper feed roller 3 which rotates in a clockwise direction by transmitting a driving force by a driving gear (not shown) of the main body. The sheet 10 is squeezed between the separation pad 5 having a rubber material having a high friction coefficient and the feed roller 3 and fed one by one from the top.
The uppermost sheet sent from between the separation pad 5 and the sheet feed roller 3 is guided by the guide member 17 and is fed to the transport roller pair 18. The sheet fed by the conveying roller pair 18 is fed to an image forming unit 80 in the image forming apparatus B shown in FIG.

As described above, when a plurality of sheets 10 are set on the paper feed tray 2, the positioning of the paper feed tray 2 and the paper feed roller 3 is performed directly by the positioning member 6 of the paper feed tray 2. Therefore, no parts are interposed in the middle, and it is easy to improve accuracy.

That is, the feed roller shaft 3 of the feed roller 3
Since the sheet is fed at right angles to the axis a, the sheet does not skew.

Hereinafter, other reference examples and embodiments of the present invention will be described. The same components as those in the first reference example are denoted by the same reference numerals, and description thereof will be omitted.

Next, a second reference example will be described. The paper feed auxiliary tray 52 is configured to be slid while being guided by the guide surface of the slide guide member 51a, and to be housed in the paper feed tray 51 as sheet stacking means. The sheet feed tray 51 is rotatable about a sheet feed roller shaft 3a of the sheet feed roller 3 that feeds the sheets 10 one by one. Usually, when the sheet 10 is not set, the sheet feed tray 51 is rotated about the center of rotation 3a. , And is fixed by a lock mechanism of the front cover 1 (not shown) along a locus as shown in FIG.

When the sheet 10 is set, the front cover 1 is unlocked as shown in FIG. 4 and the sheet feed tray 51 is rotated to a predetermined position about the sheet feed roller shaft 3a serving as the rotation center.
Pull out the paper feed auxiliary tray 52. At this time, the auxiliary paper feed tray 52 is positioned with respect to the paper feed tray 51.

In the first embodiment , the positioning member 6 having the U-shaped groove 6a is provided in the sheet feeding tray 2 and the sheet feeding roller shaft 3a and the positioning member 6 are rotated by rotating the sheet feeding tray 2. 6, the parallelism with the paper feed roller 3 is obtained, but the same effect can be obtained even when the rotation center of the paper feed tray 51 is directly used as the paper feed roller shaft 3a.

That is, since there are few components in the middle from the paper feed auxiliary tray 52 to the paper feed roller 3 for feeding the sheet 10 one by one, the parallelism with the paper feed roller 3 is increased by accumulating the precision of each component. Since there is nothing that can not be put out,
The sheet 10 is fed smoothly without skewing.

[0037] shows the real施例to the next in Figure 5.

The paper feed tray 2 the sheet width regulation plate 61 as a pair of sheet width regulating member having a sufficient thickness to regulate the width of the sheet 10 on the round as the paper feed roller shaft 3a and the guide holes It is fitted through the long guide hole 61a.

A pinion 12 is fitted to the boss 9 on the back surface of the paper feed tray 2.
5 and 16 are engaged. One rack 16, the paper feed tray 2 through a hole provided in the width direction is connected to the sheet width regulating plate 61, a pair of sheet width regulation plate 61 has a structure linked to the seat width direction Has become.

At this time, the sheet feeding tray 2 and the sheet width regulating plate 6
1. The paper feed tray 2 and the racks 15 and 16 are attached to the paper feed tray 2 with a certain gap.
In 1, the perpendicularity to the axis of the feed roller shaft 3 a is regulated by the feed roller shaft 3 a and the round guide hole 61 a.

As described above, a pair of sheet width regulating plates 6 for regulating the width direction of the plurality of sheets 10 on the sheet feeding tray 2 are provided.
Since the right angle with respect to the axis of one feed roller shaft 3a can be obtained, the sheets fed one by one from above by the feed roller 3 can be fed by the sheet width regulating plate 61 without skew. .

[0042]

As described above, in the present invention,
Since there is provided a positioning member for connecting the feed roller shaft of the feed roller and the sheet stacking means, the sheet stacking means is positioned on the feed roller via the apparatus main body. This prevents the degree of parallelism between the sheet stacking means and the feed roller from being affected by the component accuracy.

As a result, the sheet is smoothly fed without skew, so that printing failure and jam due to skew can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a sheet feeding device according to a first reference example of the present invention when a sheet stacking unit is opened.

FIG. 2 is a schematic configuration diagram of the image forming apparatus according to the reference example and a state where a sheet stacking unit of a sheet feeding apparatus is closed.

FIG. 3 is a vertical sectional front view of the apparatus.

FIG. 4 is a schematic configuration diagram of a sheet feeding device according to a second reference example of the present invention .

5 is a schematic diagram of a sheet feeding apparatus according to actual施例of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front cover (apparatus main body) 2, 51 Paper feed tray (sheet loading means) 2a Rotation center axis (rotation axis) 3 Paper feed roller (feed roller) 3a Paper feed roller axis (feed roller axis) 6 Connecting member (Positioning member) 6a U-shaped groove (fitting portion) 10 Sheet 61 Sheet width regulating plate (sheet width regulating member) 61a Round guide hole (guide hole) 80 Image forming unit

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroki Nomura 6651-1 Shimokagemori, Chichibu City, Saitama Prefecture (56) References JP-A-4-339678 (JP, A) JP-A-62-140944 (JP, A) 55-96843 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 1/04 B65H 3/06 B65H 11/00

Claims (2)

(57) [Claims] 1. A sheet stacking means having a rotating shaft, which is attached to an apparatus main body so as to be openable and closable, and stacks a plurality of sheets, and a feeding roller shaft rotatably supported by the apparatus main body, A feed roller for feeding the sheets stacked on the sheet stacking unit one by one, wherein the sheet stacking unit includes a pair of sheet widths movably in a sheet width direction. A regulating member is attached, and the sheet width regulating member is provided with a guide hole which is fitted to a feed roller shaft of the feed roller and guides the sheet stacking means when opening and closing the sheet stacking means. A sheet feeding device, wherein a member forms a positioning member for connecting a feeding roller shaft of the feeding roller and the sheet stacking means. 2. An image forming apparatus 1 SL and placing the sheet feeding apparatus according to claim, and an image forming unit for forming an image on the fed sheet by the sheet feeding device, characterized in that it has a.