JPH0986749A - Feed roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a spur from damaging a friction body, and further to improve the operation efficiency of assembling a friction body at the time of manufacture in a system where a sheet material is sent by a roller having a friction body on the outer peripheral surface and a spur. SOLUTION: A groove 14d is formed on a roller main body 14a in such a manner as to make a turn on the outer peripheral surface thereof. The roller main body is covered with a friction body 20 formed by a heat contraction type tube, and the tube is made closely adhere to the roller main body by contraction to form a groove 20a on the surface of the friction body 20. The spur 16 is disposed in such a manner that the contact end provided tooth-like on the periphery thereof is opposite to the groove 20a of the friction body 20. Thus, if a sheet material does not exist between the friction body 20 and the spur 16, the contact end of the spur is kept from coming contact with the friction body 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed roller, for example, a feed roller for ejecting a printed sheet in an inkjet printer or the like.

[0002]

2. Description of the Related Art Like ink jet printers,
Printers are known in which liquid ink is ejected onto paper to print. In such a printer, when ink is ejected on a normal paper, it may take time to dry the ink on the paper. For this reason, non-dry ink adheres to the discharge roller for discharging the printed paper, and when the adhered roller portion touches the paper again due to its rotation, the ink adheres to the paper and the printed paper There was a problem of soiling.

As a solution to this problem, a discharge roller using a roller on the side in contact with the printing surface of the paper as a spur has been proposed (Japanese Utility Model Laid-Open No. 55-179851). This product contacts the printing surface of the paper at the contact end provided in the shape of a tooth around the spur, sandwiches the paper with the roller that contacts the back side of the paper, and rotates the spur. I was sending paper. Since the tip of the contact end of the spur only touches the printed surface on which the ink is attached, it is possible to discharge the paper without soiling the printed surface. Conversely, the rollers rotate to feed the paper,
It has also been proposed that the spur side serves as a paper pressing member to prevent the paper from floating so that the paper is not contaminated with ink (JP-A-59-188467).

[0004]

However, in the former conventional example, the contact end of the spur pierces the roller when the paper is not present between the roller and the spur. Therefore, the rubber as a friction body provided on the surface of the roller is damaged. When such a state is repeated, the rubber portion is gradually destroyed and large unevenness is generated on the surface of the roller, and the paper is caught in the unevenness, which hinders the paper feeding operation. There is a risk that the scraps of the paper may get caught in the gears of the printer and the driving of the printer may be hindered.

For this reason, in the latter conventional example, the spur is placed away from the roller so that the contact end does not touch the roller, and the spur is only used to prevent the sheet lifted from the roller from being lifted more than necessary. Was using. However, this makes it impossible to bring the paper into contact with the rotating roller with a sufficient pressure, so that sufficient frictional force is not generated between the paper and the rotating roller, and there is a fear that the paper cannot be smoothly fed.

In order to prevent the spurs from damaging the rubber of the roller, it is conceivable to dispose the rubber on the opposite sides of the spurs and to provide the rubber on both sides thereof. However, for example, in the case where the rubber is provided on the roller by covering the roller with a tube-shaped rubber, two rollers are provided for each spur.
Two rubber tubes must be covered, which causes a problem in work efficiency. Further, if the portions where the spurs face each other are wide open and the rubber tubes are covered on both sides thereof, it is not possible to apply sufficient pressure to the sheets from the spurs due to the bending of the sheets. Therefore, the two rubber tubes have to be arranged at precise positions with a fairly narrow interval, which further causes a problem in work efficiency.

The present invention provides a feed roller that does not damage the friction body such as rubber even if it is used in combination with spurs, and does not deteriorate the workability of assembling the friction body during manufacturing. It is intended.

[0008]

Means for Solving the Problems and Effects of the Invention
The described invention has a roller body and a friction body provided on an outer peripheral surface thereof, and a spur provided opposite to the friction body and the friction body sandwich a sheet body to be fed, A feed roller for feeding a sheet body in accordance with rotation of a roller body, wherein the roller body is placed at a position on the surface of the friction body, where contact ends provided in a tooth shape around the spur face each other.
By providing the groove formed around, the contact end of the spur is prevented from coming into contact with the friction body when the sheet body is not present between the spur and the friction body. It is a characteristic feed roller.

According to a second aspect of the present invention, a groove is formed on the roller body so as to go around the outer peripheral surface of the roller body, and the roller body is inserted into a tubular friction member up to the position of the groove. The feed roller according to claim 1, wherein a groove on the surface of the friction body is formed by shrinking and closely contacting the tubular friction body.

According to a third aspect of the present invention, since the tubular friction body is a heat-shrinkable tube, the tubular friction body is heated so as to be contracted from above the groove of the roller body. The feed roller according to claim 2, wherein the feed roller is brought into close contact with the feed roller.

According to a fourth aspect of the present invention, since the tubular friction member is a rubber tube, the contraction force of the friction member itself causes the friction member to contract from above the groove of the roller body so as to be in close contact. The feed roller according to claim 2, which is characterized in that.

A fifth aspect of the present invention is the feed roller according to any one of the first to fourth aspects, which is used for discharging a printed sheet in an ink jet type printer. Here, in the feed roller according to claim 1, one of the surfaces of the friction body provided on the outer peripheral surface of the roller body is rotated around the roller body at a position where the tooth-shaped contact ends around the spur face each other. The formed groove is provided.

Thus, when there is a sheet body such as a sheet due to the presence of the groove on the friction body, the sheet body bridges over the groove to receive the pressure from the spur, and the sheet on both sides of the groove is received. Since a sufficient frictional force is generated between the roller body and the friction body, the rotation of the roller body does not hinder the feeding.
If there is no sheet body, the contact end of the spur enters the groove and does not directly contact the friction body. Therefore, the friction body is not damaged, and there is no hindrance in the feeding or driving of the mechanism such as the printer.

The groove on the friction body is formed, for example, as follows. That is, a groove is formed on the roller body around the outer peripheral surface of the roller body, and the roller body is inserted into the tubular friction body up to the position of the groove, and the tubular friction body is contracted. Make them adhere closely. As a result, the friction body tends to follow the shape of the surface of the roller body when contracted, so that a groove corresponding to the groove of the roller body is formed on the surface of the friction body.

It is easy to form a groove on the outer peripheral surface of the roller body so as to make one round of the outer peripheral surface so as to be accurately aligned with the position of the spur. Therefore, by simply shrinking the tube-shaped friction body inserted to the groove position of the roller body and bringing it into close contact with the roller body, it is extremely easy to form a groove accurately aligned with the spur position on the surface of the friction body. Therefore, high-precision positioning work is not required, and work efficiency does not decrease.

The shrinkage and adhesion of the tubular friction body can be achieved by heating the tubular friction body by using a heat-shrinkable tube as the tubular friction body, for example.
It is extremely easy to shrink the roller body from above the groove and bring it into close contact. Also, if a rubber tube is used as the tubular friction body, the contraction force of the friction body itself causes
It is extremely easy to shrink the roller body from above the groove and bring it into close contact.

These rollers are particularly useful as rollers for ejecting printed paper in an ink jet type printer.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of an ink jet printer 2 to which a feed roller of the present invention is applied. Here, the sheet (not shown) fed from the sheet feeding cassette 4 by the sheet feeding roller 6 collides with the pressing roller holder 8a at its tip, and then the pressing roller 8 and the sheet feeding roller 10 are moved by the roller holder 8a. Was guided between
It is sent out in front of the ink jet head 12. Here, ink is recorded on the surface of the paper by ejecting ink from the ink ejecting head 12 for each line. After that, it is nipped between the discharge roller 14 as a feed roller and the spur 16,
By being pulled out by the rotation of the discharge roller 14,
The paper is discharged to the paper discharge tray 18.

The relationship between the discharge roller 14 and the spur 16 is shown in FIG.
The enlarged perspective view of FIG. The discharge roller 14 is the roller body 1
A gear 14b is provided at one end of 4a, and a plurality of large-diameter portions 14c are provided at the central portion. This large diameter portion 14c
A friction body 20 made of a soft resin is covered on the top in a close contact state. The discharge roller 14 is rotatably supported inside the frame 22 of the inkjet printer 2, and the gear 14
By transmitting the rotational force from the stepping motor 24 to b, the sheet sandwiched between the stepping motor 16 and the spur 16 is rotated in the direction of discharging the sheet.

A spur 16 is arranged facing the friction body 20. The spur 16 is supported inside the frame 22 by a support plate 26 having a substantially L-shaped cross section so that its rotation axis is parallel to the rotation axis of the discharge roller 14. The spur 16 includes a hub portion 16a and a plurality of sharpened protrusion portions 16b protruding from the periphery thereof. Of the protrusions 16b, the contact end 1 of the tip of the protrusion 16b facing the discharge roller 14 side.
6d is inserted in a groove 20a formed at the center of the friction body 20 by making one round around the roller body 14a.

As shown in FIG. 3A, the roller body 14
A groove 14d is formed at the center of the large-diameter portion 14c of a so as to go around the outer peripheral surface of the roller body 14a once. The large-diameter portion 14c is covered with a friction body 20 made of a tubular heat-shrinkable resin whose cross section is shown in FIG. The shape becomes a close contact. As a result, FIG.
As shown in (c), the groove 20a of the friction body 20 is formed along the groove 14d of the large diameter portion 14c.

The spur 16 is rotatably supported by a coil spring 28 as a shaft means inserted through a shaft hole 16c provided in the center of the hub portion 16a. Coil spring 28
Is the support arm 3 formed at the front end of the support plate 26.
It is supported by the support plate 26 by 0 and 32. The support arm 30 has an axial groove 30a opened upward in FIG. 3 (c).
And the other support arm 32 has an axial groove 32a opened downward. Axial groove 30 of two support arms 30
At a, on both sides of each spur 16, of the coil springs 28, the one closer to the spur 16 is supported from below, and the shaft groove 32a of the other support arm 32 supports the farther one from above. It As a result, the coil spring 28 is supported without falling off from the support plate 26.

FIG. 4A shows the positional relationship of the spur 16 with respect to the discharge roller 14 when the paper is not fed. Since there is no paper between the spur 16 and the discharge roller 14, the protrusion 16b of the spur 16 is located up to the middle of the groove 20a of the friction body 20. However, the groove 20
Since it does not reach the bottom of a, the contact end 16d of the protrusion 16b does not contact the friction body 20. Therefore, in this state, even if the stepping motor 24 rotates and the discharge roller 14 rotates in conjunction with it, the protrusion 16b does not damage the friction body 20.

As shown in FIG. 4B, when the paper 40 printed by the ink jetting by the ink jet head 12 is sent, the paper 40 ejects the coil spring 28 supporting the spur 16 from the discharge roller 14. The spur 16 is pushed up by bending it to the side opposite to the discharge roller 14 and the spur 16
And so as to bridge the groove 20a. Therefore, the restoring force of the coil spring 28 causes the spur 16 to press the sheet 40 toward the friction body 20 at the contact end 16d of the protrusion 16b, as indicated by the arrow P in the figure. Due to this pressing pressure, a sufficient frictional force is generated between the paper 40 and the friction bodies 20 on both sides of the groove 20a, and the paper 40 is smoothly discharged to the paper discharge tray 18 as the roller body 14a rotates. Go away.

In the ink jet type printer 2, when the groove 40a is present on the friction member 20, the sheet 40 as the sheet member is located between the spur 16 and the discharge roller 14 as shown in FIG. ), The paper 40 is bridged on the groove 20a, and a sufficient frictional force is generated between the paper 40 and the friction body 20 under the pressure from the spur 16, so that the paper feeding operation by the rotation of the roller body 14a is performed. It will not cause any problems.

When the paper 40 is not present, the contact end 16d of the protrusion 16b of the spur 16 enters the groove 20a,
There is no direct contact with the friction body 20. Therefore,
The friction body 20 is not damaged, and the discharge roller 14 does not hinder the sheet feeding operation or the driving of the inkjet printer 2.

Further, since the friction body 20 is made of a tube-shaped heat-shrinkable resin, the friction body 20 is covered with the large diameter portion 14c of the roller body 14a and then heated only. The shape follows and adheres. Therefore, it is extremely easy to set the groove 20 at an accurate position on the friction body 20.
a can be formed, accurate positioning work is not required, and work efficiency does not decrease.

As described above, the positioning of the friction body 20 does not require accuracy, and if the position of the groove 14d on the roller body 14a is accurately formed, the groove 20 on the friction body 20 is formed.
The positioning of a is done accurately. The roller body 14a is
For example, by integrally molding plastic, it is easy to form the groove 14d, which makes one round of the outer peripheral surface, at the outer peripheral surface of the spur 16 so as to be accurately aligned with the spur 16.

[Others] In the above-described embodiment, a tube of heat-shrinkable resin is used in order to facilitate the formation of the groove 20a on the friction body 20, but in addition to this,
A rubber tube may be used as the tubular friction body 20. If a rubber tube is used, this friction body 20
If the large-diameter portion 14c of the discharge roller 14 is covered with the large-diameter portion, the large-diameter portion 1c is caused by the contracting force of the friction body 20 itself when it is restored.
4c, the groove 14d is contracted to form a groove along the groove 14d, and the same effect as that of the above-described embodiment can be obtained.

In addition, without forming a groove such as the groove 14d in the roller body 14a, a groove equivalent to the groove 20a is previously formed on the surface of a tube made of heat-shrinkable resin or rubber for friction. The roller body 1 on which the body 20 is to be formed
It may be contracted at the portion 4a to be in close contact.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory diagram of an inkjet printer to which a feed roller of the present invention is applied.

FIG. 2 is an enlarged perspective view showing a relationship between a discharge roller and a spur.

FIG. 3 is an explanatory diagram showing a configuration and an assembled state of a discharge roller.

FIG. 4 is an explanatory diagram of a positional relationship between a spur and a discharge roller.

[Explanation of symbols]

2 ... Inkjet printer 12 ... Ink jet head 14 ... Ejection roller 14a ... Roller body 14b ...
Gear 14c ... Large diameter part 14d ... Groove 16 ... Spur 16
a ... Hub portion 16b ... Projection portion 16c ... Shaft hole 16d ... Contact end
20 ... Friction body 20a ... Groove 26 ... Support plate 28 ... Coil spring 30, 32 ... Support arm 30a, 32a ... Shaft groove
40 ... Paper

Claims (5)

[Claims] 1. A roller main body and a friction body provided on an outer peripheral surface thereof, and a spur provided opposite to the friction body and the friction body sandwich a sheet body to be fed, A feed roller that feeds a sheet body as the roller body rotates, wherein the roller body is rotated once around the surface of the friction body at a position where tooth-shaped contact ends around the spur face each other. By providing the formed groove, the contact end of the spur is prevented from coming into contact with the friction body when the sheet body is not present between the spur and the friction body. Feed roller. 2. A groove is formed on the roller body so as to go around the outer peripheral surface of the roller body, and the roller body is inserted into a tubular friction member up to the position of the groove. The feed roller according to claim 1, wherein a groove on the surface of the friction body is formed by contracting and closely contacting. 3. The tube-shaped friction body is a heat-shrinkable tube, and by heating the tube-shaped friction body, the friction body is contracted from above the groove of the roller body to be brought into close contact therewith. The feed roller according to claim 2. 4. The tube-shaped friction body is made of a rubber tube, and the contraction force of the friction body itself causes the friction body to contract from above the groove of the roller body to be brought into close contact. Feed roller. 5. The feed roller according to claim 1, wherein the feed roller is used for ejecting printed paper in an inkjet printer.