JPH0452203Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Summary] The paper conveyance mechanism of the present invention utilizes the fact that the bearing has a degree of freedom in tilting with respect to the axis, and the support shaft of the presser roller that controls paper conveyance is Even if it is tilted, the presser roller itself is structured so that it does not tilt. Therefore, it is possible to always maintain a good contact state between the paper and the press roller, and it is possible to reduce accidents in which the paper travels skewed during conveyance.

[Industrial application field]

The present invention relates to an improvement of a paper conveyance mechanism installed in a printer or the like, and particularly relates to a paper conveyance mechanism that can stably convey narrow sheets of paper.

[Conventional technology]

FIG. 2 is a side sectional view of the main part showing an example of the configuration of a conventional paper transport mechanism, in which a shows a case where the paper width is wide;
b shows the case where the paper width is narrow.

As shown in these figures, the paper conveyance mechanism includes a pair of presser rollers 3 disposed at both ends of a roller shaft 5 via two bearings 4 each, and a drive roller 2.
The structure is equipped with the following.

Then, the paper 1 held between the presser roller 3 and the drive roller 2 is conveyed from the paper surface direction to the paper spine direction (from the front side to the far side) by rotating the drive roller 2 in the direction of arrow B. Ru.

The pressure spring 6 disposed on the housing 9 is a member for urging the roller shaft 5 in the direction of arrow A, and the pressing force of the pressure spring 6 causes the presser roller 3 to move the paper 1 to the drive roller. It will come into pressure contact with 2.

Note that the reason why the roller width W of the presser roller 3 is increased is to avoid a skew phenomenon during paper conveyance.

[Problem that the invention attempts to solve]

However, in the above conventional paper conveyance mechanism, the width of the paper 1 is wide and the left and right presser rollers 3
It is good when the paper 1 is pressed evenly as shown in Figure 2a, but the width of the paper 1 is narrow and the second
As shown in FIG. Only a part of the outer peripheral surface of the roller 3 contacts the paper 1, and naturally the presser roller 3 and the paper 1 are in a line contact state, which is the first cause of the paper 1 being skewed.

Note that the thickness t of paper 1 is approximately 1 mm or more for thick paper.
It is about 1.5mm.

[Means for solving problems]

As shown in FIG. 1, the above-mentioned problem lies in the paper transport mechanism in which the paper is held between a drive roller and a presser roller, and the paper is fed by the rotation of the drive roller and the follower movement of the presser roller. 2, a roller shaft 5 supported by an elastic member 6 and urged in the direction of the drive roller 2, a pair of rolling bearings 4 that pivotally support an inner ring 4a at both ends of the roller shaft 5, and Drive roller 2 by fitting outer ring 4b
A pair of presser rollers 3 are in line contact with each other through the paper 1.
When the paper 1 is fed between one of the pair of presser rollers 3 and the drive roller 2, the inner ring 4a of each of the pair of rolling bearings 4 is The axis of the roller shaft 5 is aligned with the drive roller 2 with an inclination of
The paper is inclined with respect to the axis of the paper, and one presser roller 3 is in line contact with the drive roller 2 through the paper 1, and the other presser roller 3 is in direct line contact with the drive roller 2. This problem is solved by the transport mechanism.

[Effect]

As shown in FIG. 1, in the paper conveyance mechanism of the present invention, when the paper 1 is interposed between one presser roller 3 and the drive roller 2, and is not interposed between the other presser roller longitudinal 3 and the drive roller 2, In this case, the inner ring of each of the pair of rolling bearings 4 (hereinafter referred to as "bearing 4") is inclined with respect to the outer ring, so that the axis of the roller shaft 5 is inclined with respect to the axis of the drive roller 2.

Therefore, although the outer rings of the pair of bearings 4 move independently in the direction of the drive roller 2, they are not inclined with respect to the drive roller 2, so that the paper is held between one presser roller 3 and the drive roller 2. exists, and even if the paper 1 is not interposed between the other presser roller 3 and the drive roller 2, one presser roller 3 is in line contact with the drive roller 2 via the paper 1,
The other pressing roller 3 comes into direct line contact with the driving roller 2.

In this way, the paper conveyance mechanism of the present invention can feed the paper 1 without causing it to skew even if the paper width is narrow.

〔Example〕

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a sectional side view of essential parts of an embodiment of the paper conveyance mechanism of the present invention, and the same parts as in FIG. 2 are given the same reference numerals.

As shown in FIG. 1, the paper conveyance mechanism of the present invention has a configuration in which a pair of presser rollers 3 disposed at both ends of a roller shaft 5 are each tiltably supported by a single bearing 4. It's getting old.

Therefore, even when paper 1 with a narrow paper width is conveyed by only one presser roller 3, the presser roller 3 does not tilt at all (the roller shaft 5 is It is tilted by an angle θ, but the tilt is covered by the bearing 4 which has a degree of freedom in the axial direction as described above), and its entire outer circumferential surface presses the paper 1 evenly, so that the tilt of the paper 1 is reduced. No row phenomenon occurs.

If the thickness t of the paper 1 is particularly large and the normal type bearing 4 cannot cover the axial inclination, it is recommended to use a self-aligning type bearing that can handle large inclination angles. Good.

[Effect of idea]

As explained above, the present invention has a structure in which the paper and the wide presser roller are always in close contact with each other, so abnormal phenomena such as skewing are unlikely to occur even when transporting narrow paper, and the paper transport is significantly stabilized.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the main part showing an embodiment of the paper transport mechanism of the present invention, and Fig. 2 is a diagram showing an example of the configuration of a conventional paper transport mechanism, where a is a case where the paper width is wide, and b is a case where the paper width is wide. FIG. 4 is a side sectional view of a main part showing a narrow case. In the figure, 1 is the paper, 2 is the drive roller, 3 is the presser roller, 4 is the bearing, 5 is the roller shaft, 6 is the pressure spring, 9 is the housing, θ is the inclination of the roller shaft, and t is the thickness of the paper. Each is shown below.

Claims (1)

[Claims for Utility Model Registration] A paper conveyance mechanism that sandwiches a sheet of paper between a drive roller and a presser roller, and feeds the sheet by the rotation of the drive roller and the driven movement of the presser roller, the drive roller 2; A roller shaft 5 supported by an elastic member 6 and urged in the direction of the drive roller 2
A pair of rolling bearings 4 that pivotally support an inner ring 4a at both ends of the roller shaft 5, and a pair of presser rollers 3 that fit into the outer ring 4b of the rolling bearings 4 and make line contact with the drive roller 2 through the paper 1. When feeding the paper 1 while holding it between one of the pair of presser rollers 3,
The axis of the roller shaft 5 is aligned with the drive roller 2 by the inclination of the inner ring 4a of each of the pair of rolling bearings 4.
The paper is inclined with respect to the axis of the paper, and one presser roller 3 is in line contact with the drive roller 2 through the paper 1, and the other presser roller 3 is in direct line contact with the drive roller 2. Conveyance mechanism.