JPH0673011U - Paper feeder - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the action of separating paper. [Structure] On the lower surface of the tip of the upper plate 23, projections 27, 2 are provided.
8 is provided, and the rubber plate 25 has these protrusions 27,
It is pressed by 28 and is bent and deformed along the peripheral surface of the paper feed roller 21.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sheet feeding device that separates and feeds sheets one by one.

[0002]

[Prior art]

 As shown in FIG. 8, a sheet feeding device of this type applied to a facsimile apparatus or the like has a mounting table 1 that is inclined, a sheet feeding roller 2 that is located at the lower end of the table 1, and the sheet feeding roller 2. And a paper separating structure 3 located above the paper roller 2.

The structure 3 has an upper plate 4 and a lower plate 5 whose bases are detachably coupled to each other, and a rubber plate 6 whose base is sandwiched by these plates 4 and 5. It is rockably supported by a shaft 7 which is fitted to the base portion of No. 4. Therefore, assuming that 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 contacts the peripheral surface of the paper feed roller 2.

The upper plate 4 is biased in the clockwise direction by the elastic force of the pressing spring 9, and the lower surface of the tip end thereof extends along the width direction of the upper plate 4 and directly above the contact point P. The protrusion 10 is provided in a positionally arranged manner. Therefore, the contact point P 1 of the rubber plate 6 is pressed against the peripheral surface of the sheet feeding roller 2 by the pressing force of the protrusion 10.

The paper feed roller 2 and the rubber plate 6 are arranged 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 (larger than the friction coefficient between the papers). In addition, each material is selected.

Now, when the paper feed roller 2 is rotated with a plurality of papers 8 (transmission originals in the facsimile apparatus) placed on the mounting table 1, the paper 8 at the bottom reaches the point P. After being fed out, it passes through the point P and is discharged to the right side of the paper feed roller 2. At this time, the movement of the other sheet 8 is suppressed by the leaf springs 5a provided on both sides of the lower plate 5.

By the way, when the sheets 8 are not well separated from each other, the lowermost sheet 8 and the sheet 8 immediately above the lowermost sheet 8 may be fed toward the point P at the same time.

In this case, the upper sheet 8 is restrained from moving due to the frictional force between the upper sheet 8 and the rubber plate 6 when passing the point P, while the lowermost sheet 8 is separated from the sheet feeding roller 2. It is carried to the right side of the roller 2 by the frictional force acting between the rollers.

Therefore, according to this paper feeding device, it is possible to separately feed a plurality of sheets 8 one by one.

[0010]

[Problems to be solved by the device]

 In such a conventional device, since the protrusion 10 exerts a pressing force linearly distributed on the upper surface of the rubber plate 6, the lower surface of the rubber plate 6 comes into line contact with the sheet feeding roller 2 at the point P. Become. This means that the frictional force action area of the rubber plate 6 in the document conveying direction with respect to the paper 8 is small.

Therefore, in the conventional apparatus, a phenomenon (separation failure phenomenon) in which the upper sheet 8 is carried out to the right side of the sheet feeding roller 2 together with the lowermost sheet 8 is likely to occur, and particularly, the sheet feeding speed is increased. If the number of rotations of the paper feed roller 2 is set to be high in order to increase the frequency of occurrence of the above phenomenon.

In view of the above situation, an object of the present invention is to provide a paper feeding device that can obtain a higher paper separating action than a conventional device.

[0013]

[Means for Solving the Problems]

 In the present invention, a paper feed roller, a friction member having a friction coefficient smaller than the friction coefficient of the paper feed roller and larger than the friction coefficient of the paper, and the friction member are pressed and brought into pressure contact with the paper feed roller. In a sheet feeding device that includes a pressing member and causes a sheet to pass through a pressure contact portion of the friction member by rotation of the sheet feeding roller, the pressing member is configured so that the friction member bends and deforms following the peripheral surface of the sheet feeding roller. The shape of the pressing part of is set.

[0014]

[Action]

 Since the friction member is bent and deformed by the pressing force of the pressing member, following the peripheral surface of the paper feed roller, the friction member comes into surface contact with the paper. As a result, a large frictional force action area for the original conveying direction of the friction member is secured, so that the frictional force repeatedly acts on the upper surface of the sheet, and as a result, the sheet movement suppressing action by the friction member is achieved. Will improve.

[0015]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a paper feeding device according to the present invention applied to a facsimile machine. This paper feeding device is provided with a mounting table 20 that is inclined, and is located at the lower end side of the table 20. The sheet feeding roller 21 and the sheet separating structure 22 located above the sheet feeding roller 21.

The sheet separating structure 22 includes an upper plate 23 serving as a pressing member, a lower plate 24 having a base portion removably coupled to the base portion of the upper plate 23, and the base portion sandwiched by these plates 23, 24. And a rubber plate 25 as a friction member, and is swingably supported by a shaft 26 fitted to the base of the upper plate 23.

On the lower surface of the tip portion of the upper plate 23, projections 27, 28, 28 shown in FIG. The protrusion 27 is located in the central portion of the lower surface tip 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 protrusion 27, and are provided along the width direction of the plate 23, respectively. Has 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 due to the weight of the structural body 22. In this state, the protrusion 27 and the protrusion 28 are They are placed at symmetrical positions with respect to the normal line passing through the contact point P between the paper feed roller 21 and the rubber plate 25.

The operation of this embodiment will be described below.

When the upper plate 23 is biased in the clockwise direction by the pressing spring 29 shown in FIG. 1, the pressing force of the projections 27 and 28 acting on the upper surface of the rubber plate 25 causes it to be shown by a chain line in FIG. As described above, the rubber plate 25 flexes and deforms along the peripheral surface of the paper feed roller 21. Therefore, according to this embodiment, the lower surface of the front end of the rubber plate 25 comes into surface contact with the sheet feeding roller 21.

As shown in FIG. 1, assuming that a plurality of sheets 30 (hereinafter referred to as originals) are placed on the table 20, the originals 30 located above the lowermost original 30 are placed. The tip of the spring contacts a leaf spring 24a integrally formed on both sides of the lower plate 24. Therefore, when the originals 30 are sufficiently separated and the movement suppressing action of the leaf spring 24a with respect to the upper originals 30 is sufficient, the rotation of the paper feed roller 21 is prevented. Along with this, only the lowermost original 30 advances to the portion where the rubber plate 25 is pressed against the paper feed roller 21.

The paper feed roller 21 and the rubber plate 25 are arranged so that the friction coefficient between the former and the original document 30 is larger than the friction coefficient between the latter and the original document 30 (larger than the friction coefficient between the original documents). Since the material is selected, the document 30 reaching the pressure 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 positioned immediately above the document 30 are simultaneously moved to the pressure contact portion because the above conditions are not satisfied.

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

On the other hand, the upper original 30 has a frictional force acting on the lower surface thereof with the movement of the lowermost original 30 and a frictional force acting on the upper surface of the rubber plate 25.

At the above-mentioned pressure contact portion where the rubber plate 25 is in surface contact, since the frictional force action area of the rubber plate 25 with respect to the upper original 30 in the original conveying direction is large, if the upper original 30 is at the bottom. When the original 30 is moved with the original 30, the frictional force of the rubber plate 25 is repeatedly applied to the upper surface of the upper end of the original 30. As a result, as shown in FIG. 4, the movement of the original document 30 is stopped by the time the end of the upper original 30 has finished passing through the pressure contact portion.

Thus, according to this embodiment, even when a plurality of originals 30 are simultaneously delivered to the pressure contact portion, only the lowermost original 30 is separated and placed on the right side of the paper feed roller 21. Can be supplied.

It should be noted that the document 30 carried out to the right side of the paper feed roller 21 has its recorded content read by a reading means (not shown).

By the way, when the number of rotations of the paper feed roller 21 is set to be high in order to increase the paper feed speed, the moving force given from the lowermost original 30 side to the upper original 30 is strengthened. According to this embodiment in which the frictional force is repeatedly applied to the upper surface of the upper 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. The paper separating structure 122 in this embodiment has a rubber plate 35 provided with two slits 35a along its longitudinal direction at its tip. I'm using it. Each slit 35a has a length longer than the distance from the tip of the rubber plate 35 to the side protrusion 28 of the upper plate 23, and the tongues 35b, 35c formed by the slits 35a and 35d is located above the one side projection 28, the center projection 27, and the other side projection 28 of the upper plate 23, respectively.

According to this embodiment, since the upper surface of the tip of the tongue piece 35c is pressed by the central protrusion 27 of the upper plate 23, a part of this tongue piece 35c, specifically, the point P in FIG. A portion located closer to the tip end side than the above is flexibly deformed in a manner that follows the peripheral surface shape of the sheet feeding roller 21.

On the other hand, since the bases of the tongues 35b and 35d are pressed by the side projections 28 of the upper plate 23, a part of these tongues, specifically, the rear side of the point P in FIG. The portion located at is flexibly deformed in the same manner as the tongue piece 35c.

Therefore, also in this embodiment, it is possible to obtain a high paper separating action similarly to the above-mentioned embodiment.

FIGS. 6 and 7 show still another embodiment of the present invention. In this embodiment, the sheet separating structure 222 is an upper plate having an arcuate concave surface 43a formed on the lower surface of the front end portion thereof. I am using 43. The arcuate concave surface 43a has a radius of curvature similar to or slightly larger than the radius of curvature of the sheet feeding roller 21, and 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, As shown in FIG. 6, the rubber plate 25 bends and deforms in a manner that follows the shape of the peripheral surface of the paper feed roller 21. Therefore, a high paper separating action can be obtained in this embodiment as well.

Although the above-described embodiment is applied to the facsimile apparatus, it is also possible to apply this embodiment to other devices such as a copying machine that requires paper feeding.

[0037]

[Effect of device]

 According to the present invention, since the friction member flexes and deforms following the peripheral surface of the paper feed roller, it is possible to repeatedly apply the frictional force of the friction member to the upper surface of the leading end portion of the paper. Therefore, even when a plurality of sheets of paper are supplied between the friction member and the paper feed roller, or even when the rotation speed of the paper feed roller is high, the paper can be reliably separated and supplied.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a main part of a paper 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 showing a state where a rubber plate is brought into contact with and pressed against 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 the configuration of a rubber plate in the embodiment of FIG.

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

[Explanation of symbols]

 21 ... Paper Feed Rollers 22, 122, 222 ... Paper Separation Structure 23, 43 ... Upper Plate (Pressing Member) 25, 35 ... Rubber Plate (Friction Member) 27, 28 ... Protrusion 29 ... Pressing Spring 30 ... Paper

Claims (1)

[Scope of utility model registration request] 1. A paper feed roller, a friction member having a friction coefficient smaller than a friction coefficient of the paper feed roller and larger than a friction coefficient of paper, and the friction member being pressed to come into pressure contact with the paper feed roller. And a pressing member that causes the sheet to pass through the pressure contact portion of the friction member by the rotation of the sheet feeding roller. A paper feeding device characterized in that the shape of the pressing portion of the member is set.