JP2565984B2 - Paper feed mechanism - Google Patents

Description

The present invention relates to a paper feed mechanism that feeds cut paper in a predetermined direction.

[Prior Art] As a sheet feeding mechanism for feeding cut sheets one by one in a predetermined direction, a copying machine, a printer and the like are widely used.

As shown in FIG. 5, such a conventional paper feeding mechanism generally comprises a paper feeding roller 10, a cassette 40, and a friction applying means 50.

That is, the paper feed roller 10 includes a rotating shaft 11 rotated by a motor (not shown) and a high friction coefficient surface 13 provided on the peripheral surface thereof.
It is formed from and. The high friction coefficient surface 13 is formed by fitting the rotating shaft 11 with rubber or the like, and has a constant radius in the entire circumferential direction with respect to the shaft core.

The cassette 40 is composed of a box-shaped case 41 made of synthetic resin or the like and a stacking plate 42 that biases the uppermost sheet toward the paper feed roller 10 with a leaf spring 43, and can be attached to and detached from the main body of a copying machine or the like.

Further, the friction applying means 50 applies a frictional force between the uppermost sheet / paper feeding roller 10 inserted between the paper feeding roller 10 and the arm 52 rotatably supported by the support shaft 51. It comprises a friction plate 53 fixed to the tip of the arm 52 and an urging means 54 for urging the friction plate 53 against the peripheral surface (high friction coefficient surface 13) of the paper feed roller 10 with a constant pressure.

For the friction plate 53, a cork material or the like is often used to ensure the sorting of the uppermost sheet and the second sheet. The friction coefficient of the friction plate 53 is naturally smaller than the friction coefficient of the peripheral surface of the paper feed roller 10.

Further, an upper guide 56 and a lower guide 57 for stabilizing the feeding are provided on the downstream side, and an upper guide 46 and a lower guide 47 for insertion are also provided on the upstream side when feeding the manual feed sheet. Has been.

The paper feed roller 10 is moved from the standby state shown in FIG.
The diameter is selected so that one sheet of paper can be fed before it rotates and returns to the standby state. Further, a control mechanism is provided so as to make one rotation and stop.

Therefore, when the paper feed roller 10 is rotated once, the uppermost paper loaded in the cassette 40 is fed to the paper feed roller 10 and the friction plate.
It passes between 53 and both sides by frictional force 56,57
The paper is fed in a predetermined direction while being guided by.

On the other hand, when one cassette sheet is manually fed between the guides 46 and 47 and the sheet feeding roller 10 is rotated once, only the manual sheet can be fed in a predetermined direction.

[Problems to be Solved by the Invention] However, the above-described conventional paper feed mechanism has the following problems.

Once a jam occurs due to the mechanism side or the sheet side, the present sheet is separated from the high friction coefficient surface 13 of the sheet feeding roller 10 and the friction plate 53 having a large friction coefficient urged by the urging means (spring) 54. Because it is sandwiched between the cassette case 41
Even if the paper feed roller 10 is rotated in the direction of separating it or is pulled out from the main body, it takes a lot of time and trouble to remove the jam. Similarly, it is difficult to pull out the jammed paper from the downstream side.

In the case of manual feeding, since the uppermost sheet in the case 41 is already caught between the sheet feeding roller 10 and the friction plate 53, not only the manually fed sheet but also the uppermost sheet may be fed. is there. Further, there is a possibility that the feeding position may be misaligned no matter how carefully the manual feeding work is performed.

Here, an object of the present invention is to enable quick jam removal, prevent the double feed of the manual feed sheet, and reliably feed it, and eliminate the occurrence of a feed position shift during the manual feed operation. It is an object of the present invention to provide a paper feed mechanism capable of performing the above.

[Means for Solving Problems] The present invention solves the conventional problems in which the surface of the paper feed roller is formed to have a low coefficient of friction that is insufficient or incapable of feeding the paper in the standby state. To do.

That is, the invention according to the first aspect (hereinafter, referred to as the first invention) includes, between the paper feed roller in the standby state and the friction plate pressed against the peripheral surface of the paper feed roller by the urging means,
Insert one end of the top paper loaded in the cassette case and rotate the paper feed roller once to feed the top paper in the specified direction. Also, manually feed the paper from above the top paper and rotate the paper feed roller once. In the paper feed mechanism capable of feeding the manual feed paper in a predetermined direction, most of the peripheral surface of the paper feed roller has a high friction coefficient surface and a part of the peripheral surface has a low friction coefficient surface. The radius of the surface is formed to be smaller than the radius of the high friction coefficient surface, and the low friction coefficient surface is provided at a position in contact with the friction plate in the standby state,
To achieve the above objectives.

Further, the invention described in the second item (hereinafter referred to as the second invention).
Is a storage space in the axial direction with the one member of the paper feed roller whose cross-sectional shape is D-shaped and whose linear portion is a joining plane, and the corresponding joining plane formed by the D-shaped lateral cross-section and its linear portion. And the other member having both end plates that form the abutting surface are brought into contact with both joint planes and are detachably fixed from the axial direction, and the high friction coefficient surface is provided on one of the peripheral surface of the one member and the peripheral surface of the other member. And the low friction coefficient surface is provided on the other side to achieve the above object.

Further, the invention according to the third aspect (hereinafter, referred to as the third invention) forms a concave portion between the high friction coefficient surface and the low friction coefficient surface to facilitate introduction of the leading edge of the manual paper, Achieve the purpose.

[Operation] In the first invention having such a configuration, the paper feed roller is stopped in the standby state. In this case, since the position of the peripheral surface of the paper feed roller in contact with the friction plate is formed to have a low friction coefficient surface, the jammed paper can be easily pulled out from both the upstream side and the downstream side.

Also, since the low-friction coefficient surface has a small diameter, inserting the manually fed paper and rotating the paper feed roller causes the top paper in the cassette to slip with the low-friction coefficient surface, but It is drawn in by the friction coefficient surface and is above the top sheet on the friction plate. Therefore, the high-friction coefficient surface feeds in the predetermined direction, and the uppermost sheet remains in its original position.

In the second invention, in addition to the first invention, the paper feed roller is integrally formed with one member having a high (low) friction coefficient surface and the other member having a low (high) friction coefficient surface in a removable manner. Therefore, it is possible to easily change the length and coefficient of each friction coefficient surface and to perform high precision machining with materials having different properties, and as a result, it is possible to guarantee high precision feeding.

Furthermore, in the third invention, in addition to the first or second invention,
Since a concave portion is provided between the two friction coefficient surfaces so that the front end of the manual feed paper can be easily inserted, reliable and accurate manual feed can be performed as the paper feed roller rotates.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

The same components as those of the conventional feeding mechanism shown in FIG. 5 (particularly, the cassette 40 and the friction imparting means 50) are designated by the same reference numerals, and their description will be simplified or omitted.

First Embodiment The first embodiment is shown in FIG. 1 and constitutes the first invention.

The paper feed roller 10 includes a rotating shaft 11 and a friction coefficient surface,
In FIG. 1 showing the standby state, the friction coefficient surface is the high friction coefficient surface 13 that occupies most of the periphery and the surplus and friction plate 53.
And a low friction coefficient surface 15 provided at a position in contact with.

The high friction coefficient surface 13 is formed from a rubber band plate fitted and fixed to the rotary shaft 11 by bonding, and the perimeter thereof is long enough to feed both the paper stored in the cassette 40 and manual paper. Has been selected.

On the other hand, the low friction coefficient surface 15 is formed of a material that is difficult to feed due to slippage with the inserted sheet even when the friction plate 53 is pressed against the urging force of the urging means 54. There is. That is, the friction coefficient of the low friction coefficient surface 15 is
It is said to be smaller than the friction coefficient of. The perimeter is selected such that the leading edge of the manual paper can contact the surface of the low friction coefficient surface 15 in the standby state.
In this embodiment, it is made of a stainless steel plate and fixed to the rotary shaft 11 by adhesion. Since it does not have a feeding function, it may be fixed with a screw or the like.

In addition, the axial length of the low friction coefficient surface 15 is
Similar to the length of 13, the length of the large diameter portion of the rotating shaft 11 is the same. Although it may be provided discontinuously in the axial direction, it is more effective to provide it along the entire length in the axial direction so as to leave no impression or slip on the paper.

In the first embodiment having such a structure, in the case of cassette feeding, when the feeding roller 10 is rotated, the uppermost sheet in the cassette 40 and the surface of the feeding roller 10 slide with the low friction coefficient surface 15. To do. After the high friction coefficient surface 13 that has moved and the uppermost sheet are joined, only the uppermost sheet is guided by both guides 56 and 57 by the action of the biasing means 54, the friction plate 53, etc. ) Sent to.

As is clear from this action, in the case of manual paper feeding, the manual paper comes into contact with the high friction coefficient surface 13 first,
When the paper is inserted between the paper feed roller 10 and the friction plate 53, the manual paper comes above the uppermost paper stored in the cassette 40 in which the manual paper has already been inserted. Therefore, the paper feed roller 10
As the paper is rotated, only the manual paper can be reliably fed in the predetermined direction.

By the way, whether it is paper stored in the cassette 40 or manual paper,
The paper feed roller 10 stops in a standby state after rotating once. Even if a jam occurs, the surface of the paper feed roller 10 that contacts the jammed paper has a low friction coefficient surface 15. Therefore, the jammed paper can be easily pulled out from the upstream side or the downstream side without breaking.

Therefore, in the first embodiment constituting the first invention, both cassette paper and manual paper feed can be reliably and highly accurately fed.

In addition, the paper feed roller 10 is in a standby state, that is, a surface with a low friction coefficient.
Since 15 stops at the position where it contacts the friction plate 53, jam clearance can be performed easily and quickly.

Second Embodiment The second embodiment is shown in FIG. 2 and constitutes the second invention.

The second embodiment has a surface with a low friction coefficient as compared with the first embodiment.
The peripheral surface radius of 15 is smaller than that of the high friction coefficient surface 13. Both peripheral surfaces are concentric with the axis of the rotating shaft 11.

The purpose is to further ensure the feeding of the manual feed sheet.

That is, in the case of the first embodiment, even if the front end of the manual paper is inserted so as to contact the surface of the paper feed roller 10, insufficient contact or non-contact may occur due to various reasons such as mechanical position fluctuations and insertion method. Can be considered.

In this case, even if the paper feed roller 10 is rotated, both friction coefficient surfaces 1
Since the peripheral surfaces of 3 and 15 are concentric and have the same radius, even if the high friction coefficient surface 13 moves, if it is not in contact with the low friction coefficient surface 15, it is naturally high. It occurs that the friction coefficient surface 13 and the manual paper cannot contact each other. Therefore, the low friction coefficient surface 15 is formed to have a small diameter.

In this embodiment, the paper feed roller 10 is formed of one member 21 and the other member 31 shown in FIG. 3 to facilitate processing, peripheral length change, friction coefficient change, cost reduction and expansion of applicability. . This structure constitutes the third invention. Here, the two members 21 and 31 integrally form the rotary shaft 11.

In FIG. 3, the one member 21 has a D-shaped cross section and a straight portion thereof is a joining plane 22. Further, a D-shaped hole 25 and a screw hole 26 for fitting a shaft, which are connected to the motor, are provided on the upper end surface 24. The same applies to the lower end surface 27 (however, not shown).

On the other hand, the other member 31 has a D-shaped cross section and its straight line portion forms the corresponding joint plane 32. Further, in order to form the storage space 37 on the front side of the corresponding joint plane 32, the upper end plate is formed.
33 and the lower end plate 38 are integrally provided. The upper end plate 33 is provided with a shaft fitting hole 35 and a screw hole 34, and the lower end plate 38 is provided with a hole 39 and a screw hole 34.

In this embodiment, the radius of the peripheral surface 23 of the one member 21 and the radius of the peripheral surface 36 of the other member 31 are the same, the thick rubber high friction coefficient surface 13 is provided on the peripheral surface 23, and the peripheral surface 36 is A low friction coefficient surface 15 made of a stainless thin plate is provided. The peripheral surfaces 23 and 36 may have different radii, and the high friction coefficient surface 13 may be provided on the larger radius. However, the radius may be changed depending on the thickness of the material forming the friction coefficient surfaces 13 and 15. Each surface 2
Installation to 3,36 can be glued respectively.

Therefore, the one member 21 is inserted into the storage space 37 such that the joint plane 22 of the member 21 contacts the corresponding joint surface 32, and the holes 26, 3
If 4 is screwed from the axial direction, the large-diameter high friction coefficient surface 13
It is possible to form the paper feed roller 10 having a small friction coefficient surface 15 having a small diameter.

With such a structure, as shown by the two-dot chain line in FIG.
There is also an advantage that even a soft rubber material can be easily formed into a corrugated shape that can increase the catching force.

Further, a recess 18 as shown in FIG. 4 is provided between the high friction coefficient surface 13 and the low friction coefficient surface 15. This concave portion 18 facilitates the introduction of the leading edge of the manual paper and has a high friction coefficient surface 13
In this embodiment, a gap 17 is provided between the low friction coefficient surface 15 and chamfering. The recess 18 constitutes the fourth invention.

Thus, according to this embodiment, as in the first embodiment, reliable paper feeding and quick and easy jam processing can be performed.

In particular, since the radius of the low friction coefficient surface 15 is formed to be smaller than the radius of the high friction coefficient surface 13, it is possible to reliably insert the manual feed sheet and ensure accurate feeding.

Further, the paper feed roller 10 is formed by a detachable one member 21 and the other member 31, one of which is provided with a high friction coefficient surface 13 and the other of which is provided with a low friction coefficient surface 15. Therefore, the radius ratio, circumference ratio, and increase / decrease of the friction coefficient of the friction coefficient surfaces 13 and 15 can be changed / adjusted, and the cost is wide and the adaptability is wide.

Furthermore, since the concave portion 18 is provided between the friction coefficient surfaces 13 and 15, it is possible to reliably insert and feed the manual paper.

[Advantages of the Invention] According to the first aspect of the invention, since the position of the peripheral surface of the paper feed roller in contact with the friction plate has a low friction coefficient surface, the jammed paper can be easily pulled out. Further, since the radius of the low friction coefficient surface is made smaller than the radius of the high friction coefficient surface, it is possible to prevent double feeding of the manual feed sheet and reliably feed it, and it is possible to eliminate the feeding position deviation in the manual feed operation.

According to the second aspect of the invention, the same action and effect as in the case of the first aspect of the invention can be achieved, and the radius ratio of the low and high friction coefficient surfaces, the circumferential length ratio, and the increase / decrease of the friction coefficient can be changed / adjusted to further improve the It can guarantee accurate feeding.

In the third invention, the same action and effect as in the case of the first or second invention are exhibited, and since the concave portion is provided between the friction coefficient surfaces, the insertion and feeding of the manual paper can be performed more reliably. .

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a first embodiment of a paper feeding mechanism according to the present invention, FIGS. 2 to 4 are a second embodiment, FIG. 2 is a sectional view of the essential part, and FIG. The figure shows an exploded perspective view of the paper feed roller, No. 4.
FIG. 5 is an enlarged front view of a part of the paper feed roller, and FIG. 5 is a sectional view of a conventional paper feed mechanism. 10 ... Paper feed roller, 13 ... High friction coefficient surface, 15 ... Low friction coefficient surface, 18 ... Recess, 21 ... One member, 22 ... Joining plane, 23 ... Peripheral surface, 31 ... Other Member, 32 ... Corresponding joining plane, 33 ... Upper end plate, 36 ... Peripheral surface, 37 ... Storage space, 38 ...
… Lower end plate, 40 …… Cassette, 41 …… Case, 50 …… Friction imparting means, 53 …… Friction plate, 54 …… Spring as biasing means.

Claims (3)

(57) [Claims] 1. One end of the uppermost sheet placed in a cassette case is inserted between a sheet feeding roller in a standby state and a friction plate pressed against the peripheral surface of the sheet feeding roller by a biasing means. A feed roller that can rotate the paper roller once to feed the uppermost sheet in a predetermined direction, and manually feed the sheet from above the uppermost sheet and rotate the sheet feeding roller once to feed the manual sheet in a predetermined direction. In the paper mechanism, most of the peripheral surface of the paper feed roller has a high friction coefficient surface and a part thereof has a low friction coefficient surface, and the radius of the low friction coefficient surface is smaller than the radius of the high friction coefficient surface. And a low friction coefficient surface is provided at a position in contact with the friction plate in the standby state. 2. The one side member of the paper feed roller having a D-shaped cross section and a straight portion of which is a joining plane, and a corresponding joining plane formed by the D-shaped cross section and the straight portion and the axial direction. The other member having both end plates that form a storage space is brought into contact with the joining planes and is detachably fixed in the axial direction, and the height is provided on one of the peripheral surface of the one member and the peripheral surface of the other member. 2. The paper feed mechanism according to claim 1, wherein the paper feed mechanism is provided with a friction coefficient surface and a low friction coefficient surface on the other side. 3. The paper feed mechanism according to claim 1, wherein a recess is formed between the high friction coefficient surface and the low friction coefficient surface to facilitate the introduction of the leading edge of the manual paper. .