JPH06321368A - Paper feeding roller device - Google Patents

Abstract

PURPOSE:To give sufficient transfer forces to a sheet even when the frictional materials of rollers are worn, and also prevent the sheet from being wrinkled. CONSTITUTION:Two rollers 1 and 2 of the same size on the outer periphery of which frictional materials 1a and 2a such as rubber, etc., are installed are provided, and arranged in trancated chevron-configuration so that the directions of their respective transfer forces F1 and F2 against a sheet P are diverged at an equal angle theta in both right and left sides from a specified paper feeding direction A. Then an equal rotating force is given to drive shafts 1b and 2b of two rollers 1 and 2 by connecting gears 3 and 4 positioned at different angle, a connecting shaft 5, a drive belt 6, and a main drive shaft 7. Because the two rollers 1 and 2 are provided in this structure, a contact area of the rollers with the sheet P is large and, even when the frictional materials 1a and 2a are worn, sufficient transfer forces against the sheet P can be maintained. Also the sheet P does not cause any wrinkles because it is fed with its both ends pulled aslant toward its both ends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is provided in an image forming apparatus such as a copying machine or a laser beam printer, and presses a rotating roller against a stacked sheet,
The present invention relates to a sheet feeding roller device that feeds sheets one by one.

[0002]

2. Description of the Related Art A conventional paper feeding roller device of this type is shown in FIG.
As shown in the schematic perspective view of FIG.
A roller 11 having a mounted thereon is provided, and the roller 1
It is configured to rotate the roller 11 by applying a rotational force from a drive source (not shown) to the first drive shaft 11b.
Then, when the rotating roller 11 is brought into pressure contact with the sheets P stacked at a predetermined position, the friction material 11a of the roller 11 is brought into contact.
The conveyance force is applied to the sheet P by the friction between the sheet P and the sheet P, and the uppermost sheet P is fed in a predetermined feeding direction (arrow A).

That is, in the conventional paper feeding roller device, the roller 11 is arranged so that the direction of the conveying force by the roller 11 coincides with the paper feeding direction.

[0004]

In the conventional paper feed roller device as described above, when the friction material 11a of the roller 11 is worn, it is not possible to give a sufficient conveying force to the sheet P, so that the sheet is fed. It sometimes caused paper defects. In order to prevent this, the length of the roller 11 is increased, or a plurality of rollers 11 are provided on the same drive shaft 11b to increase the contact area with the sheet P, thereby increasing the conveying force for the sheet P. However, in that case, due to uneven rotation of the roller 11 or the like, the sheet P
There is a problem that wrinkles occur.

The present invention has been made to solve these problems, and can provide a sufficient conveying force to a sheet even when the friction material is worn, and does not cause wrinkles in the sheet. An object is to provide a paper feed roller device.

[0006]

The paper feed roller device according to the present invention comprises two rollers (1, 2) of the same size having friction materials attached to the outer periphery thereof, and each roller is
Transport force (F ₁ , F ₂ ) for sheet (P)
Direction is the same angle (θ) to the left and right from the specified paper feed direction (A)
Drive means (3,4,5,6,7) that are arranged in a V-shape so as to spread and are applied with equal rotational force to the drive shafts (1b, 2b) of the two rollers. It is characterized by that.

[0007]

In the above structure, when the two rollers (1, 2) are rotated and brought into pressure contact with the sheet (P), the sheet is equidistant from the predetermined sheet feeding direction (A) to the left and right at an equal angle (θ). Two conveying forces (F ₁ , F ₂ ) in the spreading direction are given. Moreover, since the two rollers have the same size and the rotational force applied to each drive shaft (1b, 2b) is also equal, the two conveying forces are equal. Therefore, the sheet is fed in a predetermined sheet feeding direction by being pulled obliquely in both end directions by the two rotating rollers.

The reference numerals in parentheses are for the purpose of contrasting with the drawings, and do not limit the structure of the present invention.

[0009]

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

FIG. 1 is a schematic plan view showing the structure of a paper feeding roller device according to the present invention, and FIG. 2 is a schematic perspective view thereof.

As shown in the figure, this paper feed roller device is equipped with two rollers 1 and 2 of the same size having friction materials 1a and 2a such as rubber attached to the outer periphery thereof.
Are arranged in a V-shape so that the respective conveying forces F ₁ and F ₂ with respect to the sheet P spread from the predetermined sheet feeding direction A to the left and right at an equal angle θ.

The two rollers 1 and 2 have independent drive shafts 1b and 2b, and the respective drive shafts 1b and 2b.
b and 2b are connected to the connecting shaft 5 via different-direction connecting gears 3 and 4, respectively. The connecting shaft 5 is connected to a main drive shaft 7 from a drive source (not shown) via a drive belt 6. The different direction connection gears 3, 4, the connection shaft 5, the drive belt 6, and the main drive shaft 7 are provided as a drive means for applying an equal rotational force to the drive shafts 1b, 2b of the two rollers 1, 2. It is a thing.

In the above structure, when the two rollers 1 and 2 are rotated and brought into pressure contact with the sheet P, the sheet P is spread in two directions from the predetermined sheet feeding direction A to the left and right at an equal angle θ. Conveyance forces F ₁ and F ₂ are given. Moreover, since the two rollers 1 and 2 have the same size and the rotational forces applied to the drive shafts 1b and 2b are also equal, the two conveying forces F ₁ and F ₂ are equal. Therefore, the sheet P is fed in the predetermined sheet feeding direction A by being pulled obliquely in both end directions by the two rotating rollers 1 and 2.

Since the paper feed roller device having the above-described structure is provided with the two rollers 1 and 2, the contact area with the sheet P is large, and even when the friction materials 1a and 2a are worn, the sheet P has a sufficient amount. The carrying force can be secured. Moreover, since the sheet P is fed by being pulled obliquely toward both ends thereof, the sheet P is not wrinkled.

By the way, the sheet P formed by the rollers 1 and 2
If the pressure contact force of the rollers 1 and 2 to the sheet P is constant, the conveying force is proportional to the contact area between the friction materials 1a and 2a and the sheet P. The contact area between the friction materials 1a and 2a and the sheet P is, as shown in the explanatory view of FIG.
a, in a state before the 2a is worn, the circumferential width in contact with the sheet P w _1, of the axial length as t _1, w ₁ × t
Becomes ₁ . However, when the friction materials 1a and 2a are worn and the diameter is reduced, the width in the circumferential direction in contact with the sheet P is reduced. Therefore, if the axial length is constant, the contact area is reduced and the carrying force is also reduced. .

[0016] Therefore frictional member 1a, 2a of each roller 2 in this embodiment is such that the length in the axial direction is shortened as the outside diameter, are labeled with inclined end faces 1a _1, 2a ₁ . According to this, even when the friction materials 1a and 2a are worn out to have a smaller diameter and the circumferential width in contact with the sheet P is reduced to w ₂ , the axial length is extended to t ₂ , so that the contact is reduced. The reduction of the area is suppressed, and the reduction of the carrying force is also suppressed. Therefore, even when the friction materials 1a and 2a are worn, a sufficient conveying force can be always applied to the sheet.

[0017]

As described above, according to the paper feed roller device of the present invention, it is possible to apply a sufficient conveying force to the sheet even if the friction material is worn, and thus prevent the paper feed failure. be able to. In addition, the sheet can be fed without causing wrinkles.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a paper feed roller device according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a paper feed roller device according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating changes in the contact area between the friction material of the roller and the sheet in the example of the present invention.

FIG. 4 is a schematic perspective view of a sheet feeding roller device in a conventional example.

[Explanation of symbols]

1, 2 rollers 1a, 2a friction materials 1a ₁ , 2a ₁ end faces 1b, 2b drive shafts 3,4 different direction connecting gears (driving means) 5 connecting shafts (same) 6 drive belts (same) 7 main drive shafts (same) P sheet

Claims (2)

[Claims] 1. A sheet feeder for feeding a sheet by providing a roller having a friction material on its outer periphery, applying a rotational force to a drive shaft of the roller to rotate the roller, and bringing the rotating roller into pressure contact with the sheet. The paper roller device is equipped with two rollers of the same size with friction material attached to the outer circumference, and each roller is configured so that the direction of each conveying force with respect to the sheet spreads at an equal angle from the predetermined paper feeding direction to the left and right. A sheet feeding roller device, wherein the sheet feeding roller device is arranged in a V-shape and is provided with a driving unit that applies equal rotational force to the driving shafts of the two rollers. 2. The paper feed according to claim 1, wherein the friction materials of the two rollers are inclined at their end faces so that the length in the drive axis direction becomes shorter toward the outside of the diameter. Roller device.