JPH05155446A - Paper feeding device - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a sheet feeding device used in a copying machine, a fax machine, a printer or the like, which uses cut sheets, and has a simple and inexpensive structure, and a larger sheet separating effect can be obtained. The purpose is to provide a paper device. A sheet feeding device includes a sheet feeding roller 31 for feeding out stacked sheets, a sheet guide 35 for separating a large number of sheets fed by the sheet feeding roller 31, and a large number of sheets conveyed over the sheet guide 35. It is provided with a double feed preventing mechanism including a feed roller 32 and a reverse roller 64, which separates one sheet and makes it possible to feed one sheet. The paper feed roller 31 and the feed roller 32 are the feed belt 33.
Are connected by. Further, the sheet conveying surface 33a of the feed belt 33 and the sheet traveling surface 35a of the sheet guide 35 are arranged on the same plane or overlap each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device used in copying machines, fax machines, printers and the like which use cut sheets.

In recent years, there has been a demand for a printer that can print a large amount of information at high speed with the increase in the amount of information, or can print on cut paper, tack paper, mail seal paper, etc. of plain paper with the diversification of paper. Has been done. In this printer, it is an important issue to solve the double feed problem, which is directly related to the disappearance of data.

[0003]

2. Description of the Related Art In a conventional paper feeding device of this type of printer, a roller or a belt is used for a feeding portion and is independent of the paper feeding roller. The structure and operation of this paper feeding device will be described below with reference to FIGS.

The sheet feeder shown in FIG. 4 uses rollers in the feed section. In the figure, 1 is a feed roller, 2 is a sheet feed roller, 3 is a sheet feed roller driving belt, and 4 is a sheet guide.

The feed roller 1 is fixed to the feed shaft 5. The feed shaft 5 is supported by a metal fitting 6 fixed to a body frame (not shown) via bearings 7, 7, and is driven by a drive gear 8 supported by the body frame via a gear 9 to rotate. The paper feed roller 2 is fixed to the paper feed shaft 10. The paper feeding shaft 10 is supported by the metal fitting 11 via bearings 12, 12, and the metal fitting 11 is mounted on the feed shaft 5 by bearings 13, 13.
It is swingably supported via. Further, the metal fitting 11 is biased in one swinging direction by a spring (not shown), so that the paper feed roller 2 is brought into pressure contact with a stacked sheet (not shown).

The paper feed roller drive belt 3 has a feed shaft 5
And a pulley 14 fixed to the paper feed shaft 10, respectively, and transmits the rotation of the feed shaft 5 to the paper feed shaft 10. The sheet guide 4 is attached to the body frame side and has an inclined surface 4a of about 40 to 45 °. A pad 15 having a high friction coefficient is attached to the inclined surface 4a, and plays a role of separating a large number of sheets.
Reference numeral 16 denotes a hole provided in the sheet guide 4 at a portion that interferes with the feed roller 1.

When feeding paper, the drive gear 8 is operated to rotate the feed shaft 5 (feed roller 1). As a result, the paper feed shaft 10 (paper feed roller 2) also rotates in the same direction, and the paper feed roller 2 in pressure contact with the paper feeds the paper. The fed-out paper is fed to the inclined surface 4a of the sheet guide 4.
And is fed by the feed roller 1. At this time, a reverse roller (not shown) provided so as to come into pressure contact with the feed roller 1 below prevents double feeding of the sheets.

Further, the sheet feeding device of FIG. 5 uses a belt for the feeding portion, and in the figure, 21 is a feed belt, 2
2 is a paper feed roller. Reference numerals 23 and 100 denote a reverse roller and a sheet omitted in FIG.

The feed belt 21 is a feed roller 2
4 and the driven roller 25, and is driven by the drive gear (not shown) via the feed roller 24 to travel in the direction of the arrow. The paper feed roller 22 is rotatably supported by a metal fitting (not shown) swingably supported by the shaft of the feed roller 24, and is driven by the feed roller 24 via a belt 26 to rotate in the arrow direction.

The paper feed roller 22 is pressed against the paper 100 as in the case of FIG. 4, and the feed roller 2 is driven by the drive gear.
4, driven by the belt 26 and rotated to feed the paper 100. The fed-out sheet is separated by the inclined surface 4 a of the sheet guide 4 and conveyed by the feed belt 21. The reverse roller 23 plays a role of preventing double feeding of sheets.

[0011]

However, the above-mentioned conventional paper feeding mechanism has the following drawbacks. That is, in the case of FIG. 4 in which a roller is used for the feed unit, the rotation space is transmitted from the feed roller unit by a timing belt or the like for rotation of the paper feed roller, and the mounting space becomes large
Moreover, the number of parts increased and it became expensive. In the case of FIG. 5 in which a belt is used for the feed section, an example in which the sheet traveling surface of the sheet guide is configured to be substantially parallel to the sheet conveying surface of the feed belt and having a constant gap g (see FIG. 5) In many cases, when a large number of sheets at a time enter between the feed belt and the reverse roller, they cannot be separated completely. As described above, in the conventional structure, the mounting space is large, and the separation ability for separating the sheets in advance is insufficient.

It is an object of the present invention to provide a sheet feeding device which has a simple structure and is inexpensive, and which can obtain a larger sheet separating effect.

[0013]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 31 is a paper feed roller, 32 is a feed roller, and 33 is a feed belt hung over both rollers. The feed belt 33 is made of rubber having a high friction coefficient. That is, the feed roller 31 and the feed roller 32 are connected by the feed belt 33. Further, 34 is a reverse roller, which constitutes a double feed prevention mechanism together with the feed roller 32, and 35 is a sheet guide, which separates a large number of sheets fed by the sheet feed rollers. Each of the above members constitutes a paper feeding device. The sheet running surface 35a of the sheet guide 35 and the feed belt 3
The sheet transport surface 33a of No. 3 is on the same plane or is overlapped (in this figure, it is overlapped).

As described above, since the paper feed roller 31 and the feed roller 32 are connected by the single feed belt 33, the rotation drive mechanism conventionally required for rotating the paper feed roller becomes unnecessary. Therefore, a paper feeder having a simple structure and a low cost is realized.

Further, the sheet running surface 35 of the sheet guide 35.
a and the sheet conveying surface 33a of the feed belt 33 are face-to-face or overlap each other (for this purpose, the position of the contact portion between the sheet feeding roller 31 and the sheet 100 is set to the feed roller 32 and the reverse roller 34). It suffices if the height is lower than the contact position).
The large number of sheets of paper that have come up from b are blocked by the contact points 36 of the feed belt 33 and the sheet guide 35.
Therefore, only the uppermost sheet that is in contact with the feed belt 33 is conveyed, other sheets are less likely to move forward, and the sheets are separated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a plan view showing the sheet feeding device of this example, and the same members as those of the conventional device (FIG. 4) and FIG. 1 are designated by the same reference numerals. The structure and operation of this paper feeding device are as follows.

The feed roller 32 is fixed to the foot shaft 5. The feed shaft 5 is supported by the metal fitting 6 via bearings 7, 7 and is driven by a drive gear 8 via a gear 9 to rotate. The paper feed roller 31 is fixed to the paper feed shaft 10. The paper feed shaft 10 is supported by a metal fitting 11 via bearings 12, 12, and the metal fitting 11 is mounted on the feed shaft 5 by bearings 1, 1.
It is swingably supported via 3. Paper feed roller 31
Are pressed against the stacked sheets 100.

The feed belt 33 is stretched over the paper feed roller 31 and the feed roller 32 to connect the two rollers, and the feed roller 3 rotates together with the foot shaft 5.
The rotation of 2 is transmitted to the paper feed roller 31 via the feed belt 33. In other words, the rotation drive mechanism that was conventionally required to rotate the paper feed roller is no longer required,
The structure is simplified and the price is reduced.

FIG. 3 is a structural explanatory view of the reverse portion including the reverse roller 34 and the sheet guide 35 (FIG. 3A is a side view and FIG. 3B is a front view).
It is made of rubber having a high friction coefficient similar to that of the feed belt 33, and is attached to the outer circumference of the torque limiter 37. The inner ring of the torque limiter 37 is press fitted into the shaft 38. The shaft 38 has notches 38a formed at both ends.
Is fitted in the groove of the metal fitting 39 and locked in the rotating direction, and is movable only up and down. Reference numeral 40 denotes a leaf spring screwed to the metal fitting 39, which biases the shaft 38 upward to apply a contact pressure of the reverse roller 34 to the feed roller 32.

A sheet guide 35 is attached to the metal fitting 39. The sheet guide 35 is partially provided with an inclined surface 35b having an angle of about 40 to 45 °, and the fed sheet 100 is brought into contact with the inclined surface 35b. Further, a hole 41 (see FIG. 2) is provided in a portion of the sheet guide 35 that interferes with the feed belt 33, and a pad 42 having a high friction coefficient is attached to the inclined surface 35b of the sheet guide 35. , Plays the role of separating a large number of sheets.

A sheet running surface 35a of the sheet guide 35.
And the sheet conveying surface 33a of the feed belt 33 overlap (may be the same surface). For this,
The position of the contact portion between the paper feed roller 31 and the paper 100 may be lower than the contact position between the feed roller 32 and the reverse roller 34. This causes the sheet guide 35 to be fed.
A large number of sheets of paper that have risen up from the inclined surface 35b are blocked by the contact points 36 (see FIG. 1) of the feed belt 33 and the sheet guide 35.

Therefore, only the uppermost sheet that is in contact with the feed belt 33 is conveyed and other sheets are less likely to move forward, and the sheets are separated.

[0024]

As described above, according to the present invention, by connecting the sheet feeding roller and the feed roller with one feed belt, the rotation drive mechanism conventionally required for rotating the sheet feeding roller. Is unnecessary, and the structure can be simplified and the cost can be reduced. Further, since the gap between the sheet guide and the feed belt can be narrowed, it is possible to improve the sorting effect of a large number of sheets.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a plan view showing a sheet feeding device according to an embodiment of the present invention.

3 is a structural explanatory view of the reverse section of FIG. 2, and FIG.
Is a side view and FIG. 3 (B) is a front view.

FIG. 4 is a plan view showing a conventional paper feeding device.

FIG. 5 is a side view showing another conventional sheet feeding device.

[Explanation of symbols]

 31 Paper Feed Roller 32 Feed Roller 33 Feed Belt 33a Paper Conveying Surface 34 Reverse Roller 35 Sheet Guide 35a Paper Traveling Surface 35b Inclined Surface 100 Paper

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location B65H 3/68 9148-3F G03G 15/00 309 7369-2H H04N 1/00 108 C 4226-5C

Claims (2)

[Claims] 1. A paper feed roller (31) for feeding a stack of paper.
A sheet guide (35) for separating a large number of sheets fed by the sheet feed roller (31), and the sheet guide (3
A feed roller (32) that separates a large number of sheets of paper conveyed over 5) and enables single-sheet feeding.
A sheet feeding device having a double feed prevention mechanism including a reverse roller (34), the sheet feeding roller (31) and the feeding roller (32)
And a feed belt (33) which are connected to each other. 2. A sheet conveying surface (33a) of the feed belt (33) and a sheet traveling surface (3) of the sheet guide (35).
The sheet feeding device according to claim 1, wherein the sheet feeding device and the sheet forming device 5a) are flush with each other or overlap each other.