JPH04169425A - Paper feeding roller - Google Patents

Abstract

PURPOSE:To increase frictional power with a small pressure power of a roller for separating and feeding a cut paper sheet on a tray by linking a cylindrical elastic outer wall part to a rotational shaft through an elastic member whose elasticity is lower than that of the outer wall part, and which is elastically deformed in such a way that the outer wall part becomes a flat contact surface through the contact pressure between the outer wall part and the cut paper sheet. CONSTITUTION:A feeding roller 12 is composed of an elastic outer wall part 31, which has an uneven surface, and which comes into contact with a cut paper sheet P, and of an elastic holding part 33, which is weaker in elasticity than the outer wall part 31, and which connects the outer wall part 31 to a rotational shaft 32. The holding part 33 is composed of a plate body 33b arranged radially. The outer wall part 31 and the plate body 33b are molded into one plate by a rubber material in common. In this structure, since a space is formed between the holding part 33 and each plate body 33, the elasticity of the holding part is very low compared with the outer wall part 31. The outer wall part 31 is thus deformed into flat surface by the contact with the cut paper sheet P, and its contact area is increased and its frictional power is also increased, and the feeding performance is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a paper feed roller that separates and sends cut sheets stored in a stacked state in a paper tray one by one.

[Prior art] This type of paper feed roller feeds the paper by the frictional force generated between it and the paper by rotation, so the greater the frictional force, the better the paper feeding performance. It will be done. For this reason, unlike the conventional paper feed roller 1, it is made of an elastic member such as rubber, and by pressing the paper feed roller against the cut paper and causing it to elastically deform, the contact area with the cut paper and, as a result, the frictional force can be reduced. It is increasing.

[Problems to be Solved by the Invention] However, since the conventional paper feed roller was formed only from an elastic member such as rubber, there is a limit to its elastic deformation. The frictional force between the paper feed roller and the cut sheet is greater than the frictional force between the cut sheet to be sent and the sheet below it, resulting in double feeding of the cut sheets. Another problem is that if the paper feed roller is used for a long period of time, the surface of the roller will wear out and the frictional force will be insufficient, making it impossible to obtain the original paper feeding performance.

On the other hand, in order to solve this problem, a belt-type paper feed roller has been developed in which a belt made of an elastic material such as rubber is placed between two rotating shafts, and the slip paper is sent out by rotating this belt. It is considered. In this belt-type paper feed roller, it is possible to bring surface contact between the sheet and the roller surface, so it provides extremely good paper feeding performance compared to the conventional paper feed roller mentioned above, but the structure is more complicated. Therefore, there is a problem in that it cannot be applied to a conventionally used device equipped with one drive shaft for a paper feed roller.

Therefore, the present invention (with a relatively weak pressing force, the contact surface between the roller surface and the cut sheet can be extended and the frictional force can be increased,
Moreover, the present invention has been made for the purpose of providing a paper feed roller that operates on one rotating shaft. A paper feed roller that separates and sends out cut sheets one by one.The rotating shaft that receives rotational force from the outside comes into contact with the assembled surface of the cut sheets, and the frictional force generated by rotation separates the sheets. an elastic outer wall portion formed in a cylindrical shape that separates and sends the paper; The present invention is characterized in that it is provided with a holding portion which is elastically deformed under the contact pressure of 1 to make the contact portion of the outer wall portion with the cut paper flat, and has at least a weaker elasticity than the outer wall portion.

[Function] As described above, in the paper feed roller of the present invention, a holding portion having lower elasticity than the outer wall portion is provided between the rotating shaft and the outer wall portion. Therefore, when the outer wall portion is brought into contact with the cut sheet in order to feed the cut sheet, the holding portion is elastically deformed by the contact pressure, and the contact portion between the outer wall portion and the cut sheet becomes flat.

[Embodiment] A printer 1 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Note that FIG. 1 is a sectional view showing the paper conveyance system in the printer 1 of the embodiment, and FIG. 2 is a perspective view showing the external appearance of the printer 1.
FIG. 3 is a sectional view illustrating the feeding state of cut sheets.

As shown in FIG. 2, an auto-cut sheet feeder (hereinafter referred to as an auto-cut sheet feeder) equipped with a pair of paper feed trays 3 for stacking and holding cut sheets before printing is provided at the rear of the upper surface of the printer 1.

5 (simply referred to as AC3F), and a paper discharge stacker 9 having a pair of paper discharge trays 7 at the center of the upper surface from which cut sheets after printing are discharged are removably provided. Further, an operating section 10 for inputting various commands from the outside is provided at the front of the top surface of the printer 1.

Next, as shown in FIG. The paper feed roller 2, which serves as a paper feed roller of the present invention, separates and sends out the held cut sheets P one by one, and the cut sheet P supplied from the paper feed roller 12 is sent into the printer. A pair of large and small feeding rollers 14 and 15 are provided.

The paper feed roller 12 is provided eccentrically with respect to the drive shaft 12a, and is normally arranged at a position away from the cut paper P.The rotation of the drive shaft 12a feeds the cut paper as shown in FIG. Separates the cut sheet P by contacting the surface of the P.
Send.

Note that the drive shaft 12a of the paper feed roller 12 and the feed roller 14,
Power is transmitted from the printer side to the drive shafts 14a and 15a of the drive shafts 14a and 15a of the drive shafts 15a through a well-known gear mechanism provided in the side case 5a of the drive shaft 1iAcSF5. The cut sheet P is separated and sent out from the roller 12, and then the drive shafts 14a and 15
a rotates and the feed rollers 14 and 15 feed the cut sheet P into the printer.

Further, the paper separation claw 3a provided on the paper feed tray 3 is a well-known type that locks the corner of the cut paper P and prevents the cut paper P from being double fed when the paper feed roller 12 sends out the paper. in,
The cut sheets P stacked on the paper feed tray 3 are separated by a biasing plate 3b that urges the cut sheets P from below and a support plate 3C that supports the upper surface of the cut sheets P, regardless of the number of sheets. It is always in contact with the paper separating claw 3a so that the slip can be sent out.

Next, the cut sheet P sent out from the AC8F5 is guided to a platen roller 19 in the printer 1 by a guide plate ]8. Then, the cut sheet P is wound around the platen roller 19 due to the rotation of the platen roller 9 and the action of the guide plate 18 and the feed rollers 2 to 22, and the print head 2
After being printed with 0, the paper is discharged to the paper discharge stacker 9 side by the action of the feed roller 23.

In addition to the pair of paper ejection trays 7 described above, the paper ejection stacker 9 also includes a paper ejection sheet having an uneven surface for ejecting the cut sheet P ejected from the printer side onto the paper ejection tray 7. The sheets P without rollers 25 are neatly stacked on the paper discharge tray 7 by the action of the paper discharge rollers 25.

Next, as is clear from FIG. 1, the paper feed roller 12 as a paper feed roller, which is a main part related to the present invention, has an uneven surface formed on the outer wall whose uneven surface is in direct contact with the cut sheet P. 31 and a rotating shaft 32 fitted to the drive shaft] 2a.
and a holding part 33 that arranges and holds the outer wall part 3 in a cylindrical shape around the rotating shaft 32.

Further, the holding part 33 is composed of a cylindrical shaft part 33a fitted to the rotation shaft 32 and a plurality of plate-like bodies 33b provided radially around the shaft part 33a, and is elastically deformable together with the outer wall part 31. It is integrally molded from rubber material.

In the paper feed roller] 2 configured in this way, since there is a space between each plate-like body 33b of the holding part 33, the elasticity of the holding part 33 itself is significantly weaker than the elasticity of the outer wall part 31. Become. Therefore, when the drive shaft 12a rotates and the outer wall portion 31 comes into contact with the cut sheet P, as shown in FIG. 3, the holding portion 33 is elastically deformed by the contact pressure, and the outer wall portion 3]
The contact portion with the cut sheet P becomes flat.

Therefore, according to the paper feed roller 12 of this embodiment, the holding portion 33
Compared to conventional paper feed rollers, which are simply made of an elastic material such as rubber, the contact area between the roller surface and the paper sheet is reduced with a weaker pressing force.

As a result, the frictional force can be increased, and extremely good paper feeding performance can be obtained. In addition, compared to conventional paper feed rollers, it is possible to increase the contact area with the cut paper with a weaker pressing force, resulting in less wear on the roller surface and improved durability. Since only one roller is required, the structure does not become complicated like a belt-type paper feed roller.

Here, in the above embodiment (the case where the Shiki invention is applied to the paper feed roller 12 that separates and feeds the paper from the paper feed tray 3 equipped with the paper separation claw 3a), the present invention is applied to the paper feed tray 40. As shown in FIG. 4(A), a friction separation roller 44 is provided at a position opposite to the paper feed roller 42 and rotates in the direction opposite to the conveyance direction i of the cut paper P. As shown in FIG. 4(b), a guide plate 46 supported by the drive shaft 42a of the paper feed roller 42 is mounted on the drive shaft 44a of the friction separation roller 44 to prevent the sheet from being sent out by the paper feed roller 42. Reverse feed roller 48 that prevents double feeding of slips P
It can also be applied to the paper feed roller 42 of AC8F50 equipped with. In this AC3F50, when feeding the cut sheet P, the paper feed roller 42 rotates once by a one-turn clutch, etc., and then stops floating above the cut sheet P, and is then dragged by the first sheet of paper and continues to the second sheet. The sheets after the first sheet are about to be double fed, but the guide plate 46 contacts the top surface of the cut sheet P and the reverse feed roller 48 rotates downward to return the double fed sheets. Double feeding of P is reliably prevented.

The paper feed roller 42 shown in FIG. 4 is constructed in the same manner as in the above embodiment, but in the AC8F50, when the paper feed roller 42 rotates and sends out the cut paper P to the printer side, (It is possible to reliably separate the cut sheets below the cut sheet P to be sent out by the friction separation roller 44, and even after the feed roller 42 finishes sending out the cut sheet P, the reverse feed roller Since double feeding of the cut sheets P can be prevented by the action of 48, by using the paper feed roller 42, the types of cut sheets P that can be automatically fed can be expanded compared to the AC3F5 of the above embodiment.

In other words, in the AC3F 50 shown in FIG. 4, not only can the paper feed roller 42 increase the frictional force with the cut paper P to improve the paper feeding performance, but also the friction separation roller 44 and the reverse feed roller 48 can improve the paper feed performance. Since the separation performance of the paper P can also be improved, paper can be fed efficiently regardless of the paper type, from extremely thin cut sheets such as paper sheets to extremely thick cut sheets such as postcards.

Next, in the above embodiment, the holding portion 33 of the (companion paper feed roller) 2
In order to make the holding part 33 less elastic than the outer wall part 31,
Although the shaft portion 33a and a plurality of plate-like bodies 33b provided radially from the shaft portion 33a are used, the outer wall portion 3 may be made of rubber, sponge, or the like having a weaker elasticity than the outer wall portion 3.

[Effects of the Invention] As explained above, in the paper feed roller of the present invention, when the outer wall portion is brought into contact with the cut paper in order to feed the cut paper, the holding portion is elastically deformed by the contact pressure. Since the contact portion between the outer wall portion and the cut sheet is planar, the contact area between the roller surface and the cut sheet, and hence the frictional force, can be increased with a weak pressing force. In addition, compared to conventional paper feed rollers, the area of contact with the cut sheet can be increased with a weaker pressing force, resulting in less wear on the opening and opening surfaces and improved durability. Also, since there is only one rotation axis,
Unlike belt-type paper feed rollers, the structure does not become complicated, and it can be applied as is to devices that are conventionally used and have one rotating shaft for paper feed rollers.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the structure of the paper conveyance system of the printer of the embodiment, FIG. 2 is a perspective view showing the external appearance of the printer, and FIG. 3 is an explanatory diagram illustrating the feeding state of cut sheets. FIG. 4 is an explanatory diagram when the present invention is applied to an AC8F different from that in FIG. 1.

Claims (1)

[Scope of Claims] A paper feed roller that separates and sends out cut sheets stored in a stacked state in a paper tray one by one, comprising a rotating shaft that receives rotational force from the outside, and a surface where the cut sheets are assembled. an elastic outer wall portion formed in a cylindrical shape that is in contact with the rotary shaft and separates and feeds the slip paper by frictional force generated by rotation; and the outer wall portion is arranged and held in a cylindrical shape around the rotation axis. At the same time, when the outer wall comes into contact with the cut paper, the contact pressure causes the outer wall to elastically deform, so that the contact portion of the outer wall with the cut paper becomes flat, and the retainer has elasticity at least weaker than the outer wall. A paper feed roller comprising: and.