JP2001039549A - Feed roller and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a robber roller from partially wearing due to conveyance of sheets. SOLUTION: A conveyer roller 10 has a collar 12 and a robber roller 14 covering the outer periphery of the collar 12. The rubber roller 14 is formed on its outer peripheral part with several protrusions 14a which are projected at equal intervals along the outer periphery thereof and which are extended axially, and is also formed in its inner peripheral part with recesses 14b which are extended axially, and the collar 12 has, at its outer peripheral part, protrusions 12a engaged in the recesses 14b formed in the inner peripheral part of the robber roller 14. Further, the protrusions 14a formed on the outer peripheral part of the rubber roller 14 and the recesses 14b formed in the inner peripheral part thereof have such a relationship as to have a predetermined phase difference therebetween along the peripheral direction in order to prevent the protrusions 14a from twisting in the direction orthogonal to the sheet conveying direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed roller used in a sheet feeder of OA equipment such as a copying machine, various printers, and a facsimile.

[0002]

2. Description of the Related Art Conventionally, in the OA apparatus described above, a separation / conveyance mechanism is provided for separating a large number of sheets stacked on a cassette or the like one by one and conveying them into the apparatus body. As this kind of separation transport mechanism,
For example, as shown in FIGS.
1 and feed roller 70 or separation pad 92 and feed roller 7
When a sheet 93 made of paper or the like is passed between 0 and 0, a friction separation method is known in which the sheets are separated one by one using friction.

Conventionally, as the feed roller 70, FIG.
As shown in FIGS. 1 and 12, in order to increase the coefficient of friction with the sheet and improve the sheet conveying force, a plurality of grooves 72 are formed on the peripheral surface of the roller along a direction substantially orthogonal to the sheet conveying direction.
a, grooved roller 7 having an elastic body formed with 73a
2,73 were used.

Each of the grooved rollers 72 and 73 has a cylindrical hole formed therein, and a cylindrical collar 71 fitted into the hole has a cross section substantially similar to that of the hole of the grooved rollers 72 and 73. When the grooves 71 and 72 are fitted into the collar 71 respectively, the grooves 72 and 73 are resiliently moved by the elastic force.
One was to be supported.

[0005]

The grooved roller 7 extends along a direction substantially perpendicular to the sheet conveying direction.
Feed rollers 70 in which a plurality of rollers 2 and 73 are arranged at predetermined intervals.
Depending on the way of fitting, as shown in FIG. 13, the phase of the rotation of the grooved roller 72 and the grooved roller 73 with respect to the collar 71 is shifted, so that the height of the contact surface with the sheet is maximum. Causes a difference in the dimension Y.

Further, as shown in FIG. 14, even in the case of the feed roller 70 in which one grooved roller 74 is arranged in a direction substantially perpendicular to the sheet conveying direction, the groove 74a is formed more in comparison with the non-groove roller. The formation makes it easier for the grooved roller 74 to be fitted into the collar 71 in a state of being twisted in a direction substantially perpendicular to the sheet conveyance direction, and to form a groove in the direction substantially perpendicular to the sheet conveyance direction. There is a possibility that a difference occurs in the height of the contact surface between the roller 74 and the sheet.

[0007] When the feed roller 70 rotates, a difference in the height of the contact surface with the sheet occurs alternately in a direction substantially orthogonal to the sheet conveyance direction, and the difference in height occurs substantially in the sheet conveyance direction. In the direction orthogonal to the above, the separation roller 91
There is a problem in that skew feeding and uneven wear occur due to a difference in contact force between the roller and the separation pad 92, and further uneven wear shortens the life of the roller and impairs the conveying force.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a feeding roller capable of preventing uneven wear caused by sheet conveyance and enduring long-term use. It is in.

[0009]

In order to achieve the above object, according to the present invention, a collar member arranged coaxially with a drive shaft and an elastic member covering an outer peripheral side of the collar member are provided. In the feeding roller having, the elastic member,
On the outer peripheral portion, a number of elastic projections formed to project at substantially equal intervals along the circumferential direction and extending substantially parallel to the axial direction,
A concave portion or a protruding portion formed on the inner peripheral portion and extending substantially parallel to the axial direction, and the collar member has an outer peripheral portion,
The elastic member has a protruding portion or a concave portion which engages with the concave portion or the protruding portion formed on the inner peripheral portion of the elastic member.

According to a second aspect of the present invention, the elastic member includes:
It is characterized in that a plurality of the collar members are arranged at predetermined intervals along an axial direction at a portion where the protruding portion or the recessed portion is formed on the outer peripheral side of the collar member.

According to a third aspect of the present invention, the concave portion formed on the inner peripheral portion of the elastic member is disposed at an intermediate position along the circumferential direction of the adjacent elastic projecting portion. I do.

According to a fourth aspect of the present invention, the concave portion formed on the inner peripheral portion of the elastic member is arranged at substantially the same position as the elastic projecting portion along the circumferential direction. I do.

According to a fifth aspect of the present invention, the collar member is made of a synthetic resin.

The invention according to claim 6 is the first to fifth aspects.
A feeding roller according to any one of the above, a separating unit facing the feeding roller and separating sheets one by one between the feeding roller, and an image forming unit forming an image on the separated sheet. It is characterized by having.

[0015]

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

[First Embodiment] FIGS. 1 to 3 show the configuration of a feed roller 10 according to the present invention.

The feed roller 10 is a collar (color member) arranged coaxially with a drive shaft of a paper feeder (not shown).
The collar 12 has a cylindrical rubber roller (elastic member) 14 that covers the outer peripheral side of the collar 12. The collar 12 has a hole 13 to be inserted into the drive shaft.

The rubber roller 14 is made of a friction material such as rubber, and its outer peripheral portion 14A is formed with protruding portions 14a protruding at substantially equal intervals along the circumferential direction. It is formed substantially parallel along the axial direction. In addition, a concave portion 14b extending substantially parallel to the axial direction is formed on the inner peripheral portion 14B of the rubber roller 14.

The collar 12 is made of resin, and its outer peripheral portion is provided with protruding portions 12 at substantially equal intervals along the circumferential direction.
a is formed so as to protrude, and this protruding portion 12 a is engaged with a concave portion 14 b formed on the inner peripheral portion of the rubber roller 14.

The projecting portion 14a formed on the outer peripheral portion of the rubber roller 14 and the concave portion 14b formed on the inner peripheral portion of the rubber roller 14 have a predetermined phase difference along the circumferential direction. Therefore, when the protrusion 12a of the collar 12 is engaged with the recess 14b, the protrusion 14a of the rubber roller 14 and the protrusion 12a of the collar 12 It is arranged so as to have a predetermined phase difference along the direction. The protruding portion 12a is provided partially or along the entire length in the axial direction.

In this embodiment, a concave portion 14b is formed on the inner peripheral portion 14B of the rubber roller 14, and a projecting portion 12a is formed on the outer peripheral portion of the collar 12 so as to be fitted into the concave portion 14b. Has been described.
For example, a protruding portion may be formed on the inner peripheral portion 14B of the rubber roller 14, and a concave portion fitted into the protruding portion may be formed on the outer peripheral portion of the collar 12. Further, in this embodiment, the number of the protrusions 12a of the collar 12 is
Are smaller than the protruding portions 14a formed on the outer peripheral portion, but may be the same.

Further, the concave portion 14b of the rubber roller 14 and the protruding portion 12a of the collar 12 are arranged below the groove 14c between the adjacent protruding portions 14a on the outer peripheral portion of the rubber roller 14. The influence on the outer peripheral portion of the rubber roller 14 due to the presence or absence and the dimensional error of the concave portion 14b and the protruding portion 12a does not occur on the outer peripheral portion 14A of the rubber roller 14 other than the groove 14c. There is no difference in the contact force with the separation pad, and there is no uneven wear on the protrusion 14a of the rubber roller 14.

FIG. 4 shows an axial direction of the collar 12,
This shows a state in which two rubber rollers 14 are fitted at a predetermined interval, and a rib 16 for positioning the rubber rollers 14 in the axial direction is formed on the collar 12.

According to this arrangement, the circumferential positions of the rubber rollers 14, 14 are positioned with respect to the collar 12, so that the protrusions 14a, 14a of the two rubber rollers 14, 14 are connected to each other. The phase in the circumferential direction does not shift, and the height of the contact surface with the sheet coincides in the direction substantially orthogonal to the sheet conveying direction.

As a sheet separating member used in combination with the above-described feeding roller 10, any of a separating roller and a separating pad may be used.

When the feeding roller 10 is rotated to convey the sheet, the collar 12 and the rubber roller 14,
The rotation of the rubber roller 14 is stopped by the concave portion 14b of the inner peripheral portion of the rubber roller 14 and the protruding portion 12a of the collar 12. When fitted, the rubber roller 14
It is not necessary to bring the collar 12 into close contact with the elastic force, and a clearance fit may be used.

[Second Embodiment] FIGS. 5 and 6 show the structure of a feed roller 10 'according to another embodiment of the present invention.

The feed roller 10 'includes a collar (color member) 12' arranged coaxially with a drive shaft of a sheet feeding device (not shown), and a cylindrical rubber roller (covering the outer periphery of the collar 12 '). (Elastic member) 14 ', and the collar 1
A hole 13 'for insertion into the drive shaft is formed in 2'.

The outer peripheral portion 14A 'of the rubber roller 14' has projecting portions 14a 'protruding at substantially equal intervals along the circumferential direction, and the projecting portions 14a' extend along the axial direction. They are formed substantially in parallel. In addition, a concave portion 14b 'having a mountain-shaped cross section is formed on the inner peripheral portion 14B' of the rubber roller 14 'so as to extend substantially in parallel in the axial direction.

Projections 12a 'are formed on the outer periphery of the collar 12' at substantially equal intervals along the circumferential direction, and the projections 12a 'are formed on the inner periphery of the rubber roller 14'. It is adapted to be engaged with a concave portion 14b 'formed in the portion.

The protruding portion 14a 'formed on the outer peripheral portion of the rubber roller 14' and the concave portion 14b 'formed on the inner peripheral portion of the rubber roller 14' have the same pitch along the circumferential direction. And are arranged so as to have the same phase difference.
When the protrusion 12a 'of the rubber roller 1 is engaged,
4 ′ projection 14a ′ and collar 12 ′ projection 12a ′
Are arranged so as to have the same phase along the circumferential direction. The protruding portion 12a 'is provided partially or along the entire length in the axial direction.

FIG. 8 shows a rubber roller 1 attached to the collar 12 '.
The collar 12 ′ has a rib 1 ′ for positioning the rubber roller 14 ′.
6 'is formed.

According to the present embodiment, the rubber roller 14 '
Since the position in the rotation direction of the rubber roller 14 'is finely positioned with respect to the collar 12', the projection 14a 'formed on the outer peripheral portion of the rubber roller 14' is not twisted and attached.
Since the height of the contact surface with the sheet coincides with the direction substantially orthogonal to the conveying direction of the sheet, there is no difference in the contact force between the separation roller and the separation pad, and no oblique feeding or uneven wear occurs.

A protruding portion 14a 'formed on the outer peripheral portion of the rubber roller 14' and a concave portion 14a formed on the inner peripheral portion of the rubber roller 14 '.
b ′ are formed at substantially the same pitch, so that the thickness of the rubber also changes at the same pitch, and the hardness of any part of the outer peripheral surface of the rubber roller 14 ′ becomes substantially the same. There is no difference in the contact force between them.

In each of the above descriptions, as a sheet separating member used in combination with the feeding roller 10 ', any of a separating roller and a separating pad may be used.

When the feeding roller 10 'is rotated to convey the sheet, the collar 12' and the rubber roller 1 'are rotated.
The detent is prevented by the concave portion 14b 'of the inner peripheral portion of the rubber roller 14' and the protruding portion 12a 'of the collar 12'. When the rubber roller 14 'is fitted on the collar 12', the elastic force of the rubber roller 14 'does not need to make close contact with the collar 12'.

Next, referring to FIG.
(10 '), a copy provided with a sheet feeding device 50 having a separation roller 57 as a separating unit for separating sheets one by one between the sheets, and an image forming unit 202 for forming an image on the separated sheet. The device 200 will be described. The sheet feeding device 50 is incorporated in a side deck 204, and the side deck 204
No. 0 is installed on the side of the main body so as to face the conveyance path 203 on the upstream side in the sheet conveyance direction from the image forming means 202.

The side deck 204 separates and feeds a plurality of sheets on the lifter plate 205 one by one from a sheet stacking portion 207 provided with a lifter plate 205 for stacking sheets at the bottom so as to be able to move up and down. Sheet feeding device 50
And the sheet stacking unit 207 and the sheet feeding device 5
0, and a guide rail 209 that slides on the side deck 204 when the side deck 204 is installed in the copying machine 200.

The image forming means 202 includes a drum-shaped electrophotographic photosensitive member 215, a charger 216 for primary charging the electrophotographic photosensitive member 215 around the drum-shaped photosensitive member 215, and an electrostatic latent image formed by irradiating a laser beam. The developing unit 217 includes a developing unit 217 that forms a toner image by attaching toner to the electrophotographic photosensitive member 215, and a transfer unit 218 that transfers the toner image on the electrophotographic photosensitive member 215 to a sheet.

In the copying machine 200 having the above-described configuration, an image of a document (not shown) placed on the platen 219 is read by the optical reading unit 219, and the electrophotographic photosensitive member 2 is read.
15 is formed on the sheet feeding device 50 as an electrostatic latent image.
Is transferred to the sheet sent from. The image formed on the sheet is fixed by the fixing unit 220, and the sheet on which the image is fixed is discharged to the tray 221.

Further, the present invention is not limited to each of the above-described embodiments, but includes the collars 12 and 1.
As for the number of grooves and the cross-sectional shape of the 2 ′ and rubber rollers 14 and 14 ′, various types can be used.
Various modifications are possible.

[0042]

As described above, according to the present invention,
By engaging the protrusions or recesses of the collar member with the recesses or protrusions of the inner periphery of the elastic member, the elastic member is positioned in the circumferential direction with respect to the collar member. Even if a plurality of elastic members are arranged along the direction, the phase of the elastic member in the circumferential direction with respect to the collar member does not shift, and the elastic protrusion of the elastic member is substantially perpendicular to the sheet conveying direction. Therefore, there is no difference in the contact force between the separation roller and the separation pad, and the skew of the sheet and uneven wear of the elastic member can be prevented. Therefore, it is possible to provide a feeding roller that can withstand long-term use.

Further, according to the present invention, the protrusion or the concave portion of the collar member is engaged with the concave portion or the protrusion of the inner peripheral portion of the elastic member, so that the elastic member and the collar member are prevented from rotating in the circumferential direction. Is performed at the concave and convex portions, so that there is no need to tightly fit the elastic member to the collar member by the elastic force of the elastic member as in the conventional case, and thus the assembling work can be easily performed.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a feeding roller.

FIG. 2 is a side sectional view of a rubber roller.

FIG. 3 is a side sectional view of a collar.

FIG. 4 is a front view of a feeding roller according to the present invention.

FIG. 5 is a side sectional view of a feeding roller according to another embodiment.

FIG. 6 is a side sectional view of a rubber roller according to another embodiment.

FIG. 7 is a side sectional view of a collar according to another embodiment.

FIG. 8 is a front view of a feeding roller according to another embodiment.

FIG. 9 is a front sectional view of a copying machine provided with a feeding roller.

FIG. 10A is a schematic diagram of a main part of a feeding device using a separation roller, and FIG. 10B is a schematic diagram of a main portion of a feeding device using a separation pad.

FIG. 11 is a side sectional view of a conventional feeding roller.

FIG. 12 is a front view of a conventional feeding roller.

FIG. 13 is a partially enlarged view of FIG. 10;

FIG. 14 is a front view of a conventional feed roller in which a groove is twisted in a direction substantially orthogonal to a sheet conveying direction.

[Explanation of symbols]

 10, 10 'feeding roller 12, 12' collar 12a projecting portion 13, 13 'hole 14, 14' rubber roller 14a convex portion 14b concave portion 14c groove 14A outer peripheral portion 14B inner peripheral portion 200 copying machine (image forming apparatus) 202 Image Forming Means

Claims (6)

[Claims] 1. A feed roller having a collar member arranged coaxially with a drive shaft and an elastic member covering an outer peripheral side of the collar member, wherein the elastic member is provided on an outer peripheral portion in a circumferential direction. A number of elastic projections formed at substantially equal intervals along the axis and extending substantially in parallel in the axial direction, and concave portions or protrusions formed in the inner peripheral portion and extending substantially in parallel in the axial direction, The collar member has, on an outer peripheral portion, a protrusion or a concave portion that engages with the concave portion or the protrusion formed on an inner peripheral portion of the elastic member. Feed roller. 2. A plurality of the elastic members are provided at predetermined intervals along an axial direction at a portion on the outer peripheral side of the collar member where the protruding portion or the concave portion is formed. The feed roller according to claim 1. 3. The elastic member according to claim 1, wherein the concave portion formed on an inner peripheral portion of the elastic member is arranged at an intermediate position along a circumferential direction of the adjacent elastic projecting portion. Feed roller as described. 4. The elastic member according to claim 1, wherein the concave portion formed on the inner peripheral portion of the elastic member is arranged at substantially the same position as the elastic projecting portion along a circumferential direction. Feed roller as described. 5. The feed roller according to claim 1, wherein the collar member is made of a synthetic resin. 6. A feeding roller according to claim 1, a separating means for facing the feeding roller and separating sheets one by one between the feeding roller, and An image forming apparatus, comprising: an image forming unit that forms an image.