JP2596027Y2 - 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 sheet feeding apparatus for feeding sheets separated one by one.

[0002]

2. Description of the Related Art As shown in FIG. 8, a sheet feeding apparatus of this type applied to a facsimile apparatus or the like includes a mounting table 1 arranged at an angle and a sheet feeding roller 2 positioned at the lower end of the table 1. When,
Sheet separating member 3 located above the sheet feeding roller 2
And

The above-mentioned structure 3 comprises an upper plate 4 and a lower plate 5 whose bases are detachably connected to each other,
And a rubber plate 6 having a base portion sandwiched between the upper plate 4 and a rocker 7 supported by a shaft 7 fitted to the base of the upper plate 4. Therefore, if the paper 8 is not interposed between the paper feed roller 2 and the rubber plate 6, the point P of the rubber plate 6 comes into contact with the peripheral surface of the paper feed roller 2.

The upper plate 4 is urged in a clockwise direction by the elastic force of a pressing spring 9 and has a lower surface at the front end portion along the width direction of the upper plate 4 and directly above the contact point P. The protrusion 10 is provided in a positioned manner. Therefore, the contact point P of the rubber plate 6 is pressed against the peripheral surface of the paper feed roller 2 by the pressing force of the projection 10.

The paper feed roller 2 and the rubber plate 6 are designed so that the friction coefficient between the former and the paper 8 is larger than the friction coefficient between the latter and the paper 8 (greater than the friction coefficient between the papers). In addition, each material and the like are selected.

When the paper feed roller 2 is rotated while a plurality of sheets 8 (transmission originals in a facsimile apparatus) are placed on the mounting table 1, the lowermost sheet 8 is moved to the point P. After being fed out, the paper feed roller 2 passes through the point P.
It is carried out to the right side of. At this time, the other paper 8
The movement of is controlled by the leaf springs 5 a provided on both sides of the lower plate 5.

In the case where the papers 8 are not easily separated from each other, for example, the paper 8 immediately above the lowermost paper 8 may be fed out toward the point P at the same time.

In this case, the movement of the upper sheet 8 is suppressed by the frictional force between the upper sheet 8 and the rubber plate 6 when passing through the point P. The roller 2 is carried out to the right side by the acting frictional force.

Therefore, according to this paper feeder, a plurality of papers 8 can be separated and supplied one by one.

[0010]

In such a conventional apparatus, the projections 10 exert a linearly distributed pressing force on the upper surface of the rubber plate 6, so that the lower surface of the rubber plate 6 is applied to the lower surface of the rubber plate 6.
A point makes line contact with the feed roller 2 at a point. This means that the frictional force acting area of the rubber plate 6 in the document conveying direction with respect to the sheet 8 is small.

For this reason, in the conventional apparatus, the phenomenon that the upper sheet 8 is carried out to the right side of the paper feed roller 2 together with the lowermost sheet 8 is likely to occur (separation failure phenomenon), and in particular, the paper feeding speed is increased. If the rotation speed of the paper feed roller 2 is set to be high in order to increase the frequency of occurrence of the above phenomenon.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeder capable of obtaining a higher sheet separation effect than conventional apparatuses in view of the above-mentioned circumstances.

[0013]

According to the present invention, a paper feed roller, a friction member having a friction coefficient smaller than a friction coefficient of the paper supply roller and larger than a friction coefficient of paper, and pressing the friction member are provided. And a pressing member that presses against the paper feed roller, and feeds the paper to a press-contact portion of the friction member by rotation of the paper feed roller.
A first projection for pressing a center portion in the width direction of the friction member against a paper feed roller is provided at a portion of the pressing member located at a downstream end portion in the sheet transport direction, and the first projection of the pressing member is provided. A second projection is provided at a position located on the upstream side in the paper transport direction with respect to the widthwise side edges of the friction member so as to press the respective friction members against the paper feed roller. The roller is bent and deformed following the peripheral surface of the roller.

[0014]

The friction member is bent and deformed following the peripheral surface of the sheet feeding roller by the pressing force of the projection provided on the pressing member, so that the friction member comes into surface contact with the sheet. As a result, a large frictional force acting area of the friction member in the paper transport direction is secured, so that the frictional force repeatedly acts on the upper surface of the paper. As a result, the sheet movement suppressing action of the friction member is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a paper feeder according to the present invention applied to a facsimile machine. This paper feeder is provided with a mounting table 20 arranged at an angle and a lower end of the table 20. And a sheet separating member 22 positioned above the sheet feeding roller 21.

The sheet separating assembly 22 has an upper plate 23 serving as a pressing member, a lower plate 24 having a base detachably connected to the base of the upper plate 23, and a base sandwiched between these plates 23 and 24. It has a rubber plate 25 serving as a friction member, and is swingably supported by a shaft 26 fitted to the base of the upper plate 23.

The projections (first projections) 27 and projections (second projections) 2 shown in FIG.
8, 28 are protrudingly provided. The protrusions 27 are located at the center of the lower end of the lower surface of the upper plate 23, and the protrusions 28, 28 are located on both side edges closer to the base side of the upper plate 23 than the protrusions 27, and are provided along the width direction of the plate 23, respectively. Have been.

FIG. 3 shows a state in which the lower surface of the rubber plate 25 is in contact with the peripheral surface of the paper feed roller 21 by the weight of the structural member 22. In this state, the protrusions 27 and 28 are supplied. It is placed at a position symmetrical about the normal passing through the contact point P between the paper roller 21 and the rubber plate 25.

The operation of this embodiment will be described below.

The upper plate 2 is pressed by a pressing spring 29 shown in FIG.
3 is urged in the clockwise direction, the pressing force of the projections 27 and 28 acting on the upper surface of the rubber plate 25 causes the rubber plate 25 to move as shown by a chain line in FIG.
Bends and deforms in a manner along the peripheral surface of. Therefore, according to this embodiment, the lower surface of the tip of the rubber plate 25 is
1 is in surface contact. In this case, since the projections 28 located on the base end side of the upper plate 23 are provided only on both side edges of the upper plate 23, the distal end of the rubber plate 25 is unnecessarily attached to the feed roller 21. There is no risk of separation from the peripheral surface. Therefore, the protrusion 27 located at the tip of the upper plate 23 does not need to press the tip of the rubber plate 25 more than necessary against the paper feed roller 21. Performs sufficient functions.

Now, as shown in FIG. 1, if a plurality of sheets 30 (hereinafter referred to as "documents") are placed on the placing table 20, the document 30 located above the lowermost document 30 will be described.
Is a leaf spring 24a integrally formed on both sides of the lower plate 24.
The tip comes into contact with. Therefore, each original 30 is sufficiently separated, and the leaf spring 2
When conditions such as a sufficient action of suppressing the movement of 4a are satisfied, only the lowermost document 30 advances to the position where the rubber plate 25 is pressed against the paper feed roller 21 with the rotation of the paper feed roller 21. .

The paper feed roller 21 and the rubber plate 25 are made of a material such that the friction coefficient between the former and the original 30 is larger than the friction coefficient between the latter and the original 30 (greater than the friction coefficient between the originals). Is selected, the original 30 that has reached the press-contact portion is fed to the right side of the roller 21 by the rotation of the roller 21.

Next, a case will be considered in which, for example, the lowermost document 30 and the document 30 located immediately above the lowermost document 30 are simultaneously moved to the press-contact portion because the above conditions are not satisfied.

In this case, the lowermost original 30 is moved rightward by the frictional force generated by the rotation of the paper feed roller 21.

On the other hand, a frictional force due to the movement of the lowermost document 30 acts on the lower surface of the upper document 30, and a friction force by the rubber plate 25 acts on the upper surface thereof.

In the above-mentioned press-contact portion where the rubber plate 25 is in surface contact, the frictional force acting area of the rubber plate 25 with respect to the upper document 30 in the document conveying direction is large. In the case of moving together with the original 30, the frictional force of the rubber plate 25 repeatedly acts on the upper surface of the leading end of the upper original 30. As a result, as shown in FIG. 4, the movement of the original 30 is stopped before the leading end of the upper original 30 has passed through the press-contact portion.

Thus, according to this embodiment, even when a plurality of originals 30 are simultaneously fed to the press-contact portion, only the lowermost original 30 is separated and supplied to the right side of the paper feed roller 21. be able to. Moreover, in the first stage of paper feeding, the original 30 is held in a wide range in the width direction by the pressing action of the projections 28 provided on both side edges of the upper plate 23, so that the original 30 It is possible to prevent a situation in which the sheet is transported obliquely.

The recorded contents of the original 30 conveyed to the right side of the paper feed roller 21 are read by reading means (not shown).

When the number of rotations of the paper feed roller 21 is set high to increase the paper feed speed, the moving force applied from the lowermost original 30 to the upper original 30 is increased. According to this embodiment in which a frictional force is repeatedly applied to the upper surface of the original 30, the movement of the upper original 30 can be sufficiently suppressed even in such a case.

FIG. 5 shows another embodiment of the present invention. In this embodiment, a paper separating structure 122 is provided with a rubber plate 35 provided with two slits 35a at its leading end along the longitudinal direction. I'm using Each slit 35a is
The tongue pieces 35b, 35c and 35d formed by the slits 35a have a length equal to or greater than the distance from the tip of the rubber plate 35 to the side protrusion 28 of the upper plate 23. Are located above the one side projection 28, the center projection 27, and the other side projection 28, respectively.

According to this embodiment, the upper end of the tongue piece 35c is pressed by the central projection 27 of the upper plate 23, so that a part of the tongue piece 35c, specifically, the point P in FIG. The part located closer to the tip end side is flexed and deformed in a manner following the peripheral surface shape of the paper feed roller 21.

On the other hand, the bases of the tongues 35b and 35d are pressed by the side projections 28 of the upper plate 23, and a part of these tongues, specifically, the rear side from the point P in FIG. Is bent and deformed in the same manner as the tongue piece 35c.

Therefore, also in this embodiment, a high sheet separating action can be obtained as in the above-described embodiment.

FIGS. 6 and 7 show still another embodiment of the present invention.
22 uses an upper plate 43 having an arcuate concave surface 43a formed on the lower surface of the distal end. The arcuate concave surface 43a has a radius of curvature similar to or slightly larger than the radius of curvature of the paper feed roller 21. Therefore, when the upper surface of the rubber plate 25 is pressed against the concave surface 43a by the pressing force of the pressing spring 29, the figure is obtained. As shown in FIG. 6, the rubber plate 25 is
1 is deformed in a manner following the peripheral surface shape. Therefore, also in this embodiment, a high sheet separating effect can be obtained.

Although the above embodiment is applied to a facsimile machine, this embodiment can also be applied to other equipment such as a copying machine which requires paper feeding.

[0037]

According to the present invention, since the friction member is bent and deformed following the peripheral surface of the paper feed roller, the frictional force of the friction member can be repeatedly applied to the upper surface of the leading end of the sheet. Therefore, even when a plurality of sheets are supplied between the friction member and the sheet supply roller, or when the rotation speed of the sheet supply roller is high, the sheets can be reliably separated and supplied.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a main part of a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing shapes and positions of protrusions formed on an upper plate.

FIG. 3 is a conceptual diagram illustrating a state in which a rubber plate is in contact with and pressure contact with a sheet feeding roller.

FIG. 4 is a conceptual diagram showing the operation of the embodiment.

FIG. 5 is a conceptual diagram showing another embodiment of the present invention.

FIG. 6 is a conceptual diagram showing still another embodiment of the present invention.

FIG. 7 is a perspective view showing a configuration of a rubber plate in the embodiment of FIG. 6;

FIG. 8 is a conceptual diagram illustrating a configuration of a main part of a conventional sheet feeding device.

[Explanation of symbols]

 Reference numeral 21: paper feed roller 22, 122, 222 ... paper separating structure 23, 43 ... upper plate (pressing member) 25, 35 ... rubber plate (friction member) 27, 28 ... protrusion 29 ... pressing spring 30 ... paper

Claims (1)

(57) [Scope of request for utility model registration] 1. A paper feed roller, a friction member having a friction coefficient smaller than a friction coefficient of the paper feed roller and having a friction coefficient larger than a friction coefficient of paper, and pressing the friction member to press the friction member against the paper feed roller. And a pressing member for causing the paper to convey and pass through a press-contact portion of the friction member by the rotation of a paper feeding roller. A first protrusion for pressing a central portion of the member in the width direction with the paper feed roller is provided, and a portion of the pressing member located on the upstream side of the first protrusion in the paper transport direction with respect to the width direction of the friction member is provided. Second protrusions are provided for pressing both side edges against the paper feed roller, and the friction member is bent and deformed following the peripheral surface of the paper feed roller by the pressing action of these protrusions. Sheet feeder.