JPH0671961B2 - Sheet member transport mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet member transport mechanism, and more particularly, to a sheet member transport mechanism suitable for a branch reversal unit of a double-sided copying machine.

<Prior Art> In recent years, with the diversification of copying, a so-called double-sided copying apparatus capable of performing copying on both sides of a sheet member has been proposed and put into practical use. In such a double-sided copying machine, a sheet member is conveyed through a sheet member conveying path, and copying is performed on one side of the sheet member during the conveyance. And
In the case of single-sided copying, the sheet member is ejected outside the housing as it is, while in the case of double-sided copying, the sheet member is conveyed to the reversing section and then passed through the sheet member return conveying path and the sheet member conveying path. Is conveyed to the upstream side of the sheet, and while being conveyed again through the sheet member conveying path, the other surface is copied, and then discharged to the outside of the housing.

Since the double-sided copying machine needs to convey the sheet member as described above, the branch reversing unit is provided at the downstream end of the sheet member conveying path, and the branch reversing unit is rotated in a predetermined direction. A sheet member transport mechanism including a first transport roller, a second transport roller disposed above the first transport roller, and a third transport roller disposed below the first transport roller is provided. Has been. In a double-sided copying machine equipped with such a sheet member transport mechanism, in the case of single-sided copying, the sheet member is transported to the outside of the housing by the action of the first transport roller and the second transport roller, and double-sided copy is performed. In this case, the sheet member is conveyed to the reversing section by the action of the first conveying roller and the second conveying roller, and then from the rear edge portion by the action of the first conveying roller and the third conveying roller. The sheet is conveyed toward the sheet member return conveyance path.

In the sheet member conveying mechanism as described above, the sheet member whose one side is copied at the time of double-sided copying is conveyed from the rear edge portion toward the sheet member return conveying path through the first conveying roller and the third conveying roller. Therefore, conventionally, the guide plate arranged in relation to the first transport roller, the second transport roller and the third transport roller has a specific shape, and the sheet member is made into a sheet. When the sheet member is conveyed toward the member return conveying path, the sheet member is surely guided between the first conveying roller and the third conveying roller, or the swing guide plate is provided downstream of the second conveying roller. Is provided, and when the sheet member is conveyed toward the sheet member return conveying path, the swing guide plate is positioned at the operation position to reliably guide the sheet member between the first conveying roller and the third conveying roller. It is way.

However, when the above-mentioned guide plate has a specific shape, it is difficult to set the shape because the shape is determined by the waist of the sheet member to be copied, and when the sheet member is curved. This sheet member may be guided between the first transport roller and the second transport roller.
Further, when the rocking guide plate is provided, the rocking guide plate and an actuating mechanism for rocking the rocking guide plate are required, which complicates the configuration and control.

Further, in the above-described sheet member conveying mechanism, in order to convey the sheet member as required, three types of rollers arranged at intervals in the vertical direction and three support shafts for supporting the rollers are provided. Therefore, there is a problem in that the structure is complicated, a relatively large space is required, and the size of the entire apparatus is increased.

<Object of the Invention> The present invention has been made in view of the above facts, and an object of the present invention is to provide a sheet member conveyed in a first direction by a first conveying roller and a second conveying roller, It is possible to reliably convey from the rear edge portion through the lower side of the first conveying roller in the second direction different from the first direction, and to make the entire apparatus compact in size. It is to provide a sheet member transport mechanism.

<Summary of the Invention> According to the present invention, a first support shaft that is rotationally driven in a predetermined direction, a second support shaft that is arranged at a predetermined distance from the first support shaft, and The sheet member is conveyed in the first direction in cooperation with the plurality of first conveying rollers mounted on the first supporting shaft and the first conveying rollers mounted on the second supporting shaft. A sheet member that is provided with a plurality of second conveying rollers and is conveyed in the first direction by the action of the first conveying roller and the second conveying roller; And a sheet member transport mechanism capable of transporting from a trailing edge of the second transport roller through a lower side of the first transport roller in a second direction different from the first direction after passing through a nip portion of the second transport roller, A third conveyor roller mounted on the first support shaft, and a side surface of the first conveyor roller. A plurality of detaching rollers mounted on the first supporting shaft, having a diameter larger than that of the first conveying roller, and having a plurality of protrusions at intervals on the peripheral surface; and the first supporting shaft. Of the sheet member, which is disposed below the first transport roller in cooperation with the third transport roller and has passed through the nip portion of the first transport roller and the second transport roller from the rear edge thereof. A sheet guide for transporting a sheet member, comprising: a return guide portion for allowing the sheet to be conveyed through the lower side in the second direction, and a guide plate having a clearance portion for allowing the peripheral edge of the separation roller to be fitted. A mechanism is provided.

<Preferred Specific Example of the Invention> A specific example of the sheet member transport mechanism configured according to the present invention will be described below with reference to the accompanying drawings. still,
In the specific example, the sheet member transport mechanism is applied to the branch reversal unit of the double-sided copying apparatus, but the present invention is not limited to this and can be applied to various other apparatuses.

Referring to FIG. 1 showing a branch reversal unit of a double-sided copying machine equipped with a sheet member transport mechanism constructed according to the present invention, a sheet member transport mechanism 2 shown in the figure is a pair arranged vertically at intervals. The first support shaft 4 and the second support shaft 6 are provided. Then, the first conveying roller 8 is mounted on the first supporting shaft 4 arranged on the lower side, and the second conveying roller 10 is mounted on the second supporting shaft 6 arranged on the upper side. ing. Referring to FIG. 2 together with FIG. 1, in the specific example, the first
A plurality of conveying rollers 8 are arranged at intervals in the axial direction of the first supporting shaft 4, and a second conveying roller 10 corresponds to the first roller 8 and is arranged on the second supporting shaft 6. A plurality of them are arranged at intervals in the axial direction. As described later, the first transport roller 8 and the second transport roller 10 mainly serve to transport the sheet member from right to left in FIG.

The lower first support shaft 4 further includes a third transport roller 12
Is installed. In the specific example, this third transport roller
Numerals 12 are arranged alternately with the first transport rollers 8 at intervals in the axial direction of the first support shaft 4. A guide plate 14 is attached to the lower side of the third transport rollers 12 in relation to the third transport rollers 12. The guide plate 14 has a return guide portion 16 extending toward a sheet member return conveyance path (not shown).
have. The third transport roller 12 and the guide plate 14
As will be described later, has the function of mainly conveying the sheet member from the upper left side to the lower right side in FIG.

Regarding the first transport roller 8, the second transport roller 10 and the third transport roller 12 described above, in the specific example, the hardness of the second transport roller 10 is higher than the hardness of the first transport roller 8, The hardness of the third conveyance roller 12 is the first conveyance roller 8
Is smaller than the hardness of. As the first conveying roller 8, for example, one formed of a rubber material can be used, and its hardness is particularly Hs (JIS A) 50 to 70.
A material formed of a rubber material which is a value (measured by a spring hardness test (A type) in "JIS K 6301 vulcanized rubber physical test method") is suitable. Also, the second
As the conveying roller 10 of, for example, one formed of a synthetic resin material can be used, and its hardness is particularly H _R R110.
It is preferable to use a synthetic resin material having a thickness of 1 to 130 (value measured by scale R in “JIS K 7202 plastic Rockwell hardness test method”). Further, the third conveying roller 12 may be made of a foam material such as urethane foam, resin foam, or rubber, and has a hardness of 15 to 25.
A material formed of a urethane foam material having a Kg (a value measured by a hardness test in "JIS K 6401 hard urethane foam for cushion") is suitable. Further, in the specific example, as shown in FIGS. 1 and 2, the outer diameter of the first transport roller 8 is somewhat smaller than the outer diameter of the third transport roller 12, which is related to this. And the peripheral surface of the first conveying roller 8 facing the return guide portion 16 defines substantially the same parallel to the upper surface of the return guide portion 16, and the portion of the third conveying roller 12 facing the return guide portion 16 Is this return guide
It is pressed against the upper surface of 16 and is somewhat elastically deformed.

Regarding the guide plate 14, as shown in FIGS. 1 to 3, a rectangular opening 18 is formed in the return guide portion 16 in correspondence with the first conveying roller 8 and the separating roller described later. . The opening 18 prevents the peripheral surface of the first conveying roller 8 from coming into contact with the upper surface of the return guide portion 16 of the guide plate 14, and when the first conveying roller 8 is formed of a rubber material, While preventing deterioration due to contact, it forms an escape portion into which a peripheral edge portion of a separation roller described later fits.

In the illustrated example, the first support shaft 4 is configured to be rotationally driven in the direction indicated by the arrow 20 by the action of a drive source (not shown), and accordingly, the first transport roller. 8
The third transport roller 12 is rotated in the direction indicated by the arrow 20 by the rotation of the first support shaft 4, and the second transport roller 10 is rotated by the rotation of the first transport roller 8. Is rotated in the direction indicated by arrow 22.

In the illustrated sheet member conveying structure, a detaching roller is attached to the first support shaft 4. In the illustrated embodiment, the separating roller is integrally formed on each side of the first conveying roller 8 and is provided with a plurality of protrusions 24 at intervals on its peripheral surface. The diameter is larger than the outer diameter of the first transport roller 8. As described above, since the outer diameter of the detaching roller is larger than the outer diameter of the first conveying roller 8, on the return guide portion 16 side,
As shown in FIG. 2, the peripheral portion is fitted into the opening 18 which constitutes the escape portion. The distances l ₁ and l ₂ between the peripheral edge of the detaching roller to be fitted and both edges of the opening 18 are
It is desirable to make it relatively large. Note that, in the specific example, the detaching roller is shown as being integrally formed on the side portion of the first conveying roller 8, but the separating roller is configured separately from the first conveying roller 8 and one side of the first conveying roller 8 is formed. Or first on both sides
It may be mounted on the support shaft 4.

Referring again to FIG. 1, the sheet member transport mechanism 2 described above.
A pair of guide plates 26 and 28 are disposed on the upstream side of the. The guide plates 26 and 28 define the downstream end portion of the sheet member conveyance path.

Further, downstream of the sheet member transport mechanism 2, a transport direction switching means 29 for switching the transport direction of the sheet member is provided. The illustrated conveyance direction switching means 29 has a lower guide member 30 and an upper guide member 32, and the lower guide member 30 and the upper guide member 32 are integrally swingably mounted about a shaft member 34 in the vertical direction. There is. The lower guide member 30 and the upper guide member 32 are positioned at the reversal position shown by the solid line in FIG. 1 when the sheet member is conveyed to the sheet member return conveying path in the case of double-sided copying, and in the case of single-sided copying or double-sided copying. When the sheet member is discharged to the outside of the housing (not shown), it is positioned at the discharge position shown by the chain double-dashed line in FIG.
Downstream of the lower guide member 30 and the upper guide member 32 in the reversal position, a pair of guide plates 35 and 36 forming a reversal portion are further provided.
Is provided. Although not shown in the drawing, the sheet member conveyed to the reversing unit is directed from the rear edge thereof to the first conveying roller 8 and the third conveying roller 12 and the return guide unit 16 of the guide plate 14. A reversing transporting means for transporting as a whole is provided.

Next, mainly referring to FIG. 1, the operation and effect of the above-described sheet member transport mechanism 2 will be described.

The sheet member conveyed through the sheet member conveying path (a copy is made on one surface while being conveyed through the sheet member conveying path) is guided by the guide plate 26 as shown by an arrow 38.
And 28 to be conveyed between the first conveying roller 8 and the third conveying roller 12 of the sheet member conveying mechanism 2 and the second conveying roller 10. In the sheet member transport mechanism 2, the first transport roller 8 and the third transport roller 12 have arrows.
The second conveying roller 10 is rotated in the direction indicated by 20 and the arrow 22
When the sheet member is conveyed between the first conveying roller 8 and the third conveying roller 12 and the second conveying roller 10, the sheet member is rotated in the direction indicated by Nipped between the carrying roller 8 and the second carrying roller 10,
It is transported toward the downstream side mainly by the action of the first transport roller 8 and the second transport roller 10. During such conveyance, since the outer diameters of the third conveying roller 12 and the separating roller are somewhat larger than the outer diameter of the first conveying roller 8, as can be easily understood from FIG. The third conveying roller 12 acts on the lower surface of the sheet member in the state of being nipped by the first conveying roller 8 and the second conveying roller 10, and this causes the sheet member to move in the conveying direction. On the other hand, the sheet member tends to be curved in a vertical direction, that is, in the left-right direction in FIG. 2 in a somewhat wavy manner. Thus, the so-called stiffness of the sheet member is enhanced, and the sheet member is reliably conveyed.

In the case of double-sided copying, when the sheet member is conveyed to the sheet member return conveying path, the lower guide member 30 and the upper guide member 32 are positioned at the inversion position shown by the solid line in FIG. The sheet member transported by the action of the transport roller 8 and the second transport roller 10 has an upper guide member 30 and a lower guide member 32 in the first direction indicated by an arrow 40.
It is conveyed between the guide plates 35 and 36 which constitute the reversing section. When the sheet member is conveyed and its rear edge passes through the nip portions of the first conveying roller 8 and the second conveying roller 10, the protrusions provided on the first conveying roller 8
24 acts on the rear edge of the sheet member, and the projection 24 forcibly disengages the rear edge from the first transport roller 8 downward. That is, the moving speed of the protrusion 24 is somewhat higher than the peripheral speed of the first conveying roller 8 (in other words, the conveying speed of the sheet member). Therefore, when the trailing edge of the sheet member passes through the nip portion, A specific projection of the plurality of projections 24 comes into contact with the trailing edge of the sheet member and forcibly moves it downward in the direction indicated by the arrow 20, and thus the trailing edge portion of the sheet member is forced downward from the nip portion. Will be moved.

After a lapse of a predetermined time after the trailing edge of the sheet member passes through the nip portions of the first transport roller 8 and the second transport roller 10,
Next, the reversing conveyance means (not shown) arranged in the reversing section is operated. As a result, the sheet member conveyed between the guide plates 35 and 36 is moved downward from the trailing edge in the second direction indicated by the arrow 42 in the direction opposite to the arrow 40 to the lower guide member located at the reverse position.
It is conveyed between the first conveying roller 8 and the third conveying roller 12 and the return guide portion 16 of the guide plate 14 through the space between the upper guide member 32 and 30. At this time, when the trailing edge of the sheet member has passed the nip portion of the first transport roller 8 and the second transport roller 10 forward, it is forcibly moved downward by the action of the protrusion 24 of the separation roller. Since it is urged, this sheet member is moved along the upper surface of the lower guide member 30,
The sheet is reliably conveyed between the conveying roller 8 and the third conveying roller 12 and the return guide portion 16 of the guide plate 14. When the sheet member is conveyed between the first conveying roller 8 and the second conveying roller 10 and the return guide portion 16 of the guide plate 14 as described above, the third member is rotated in the direction indicated by the arrow 20. Since the conveying roller 12 of the first conveying roller 12 is pressed against the upper surface of the return guiding portion 16, the sheet member is moved mainly by the action of the third conveying roller 12 while being guided by the returning guiding portion 16, and the first conveying roller 8 Then, the sheet is conveyed through the lower side of the third roller 12 in the second direction indicated by the arrow 42 toward the sheet member return conveying path (not shown). During the conveyance by the third conveying roller 12, a part of the third conveying roller 12 is pressed by the return guide portion 16 and is elastically deformed, so that the sheet member is mainly the third conveying roller 12 and The return guide portion 16 of the guide plate 14 ensures reliable conveyance.

During such conveyance, the protrusion 24 forming the peripheral portion of the separation roller is fitted into the opening 18, and therefore the third
The sheet member that moves between the conveying roller 12 and the return guide portion 16 is curved in a wavy shape in the direction perpendicular to the conveying direction by the protrusion 24, so that the so-called stiffness is enhanced and the sheet member is more reliably conveyed. .

On the other hand, in the case of single-sided copying or drawing copying, when the sheet member is discharged to the outside of the housing (not shown), the lower guide member 30 and the shape guide member 32 are positioned at the discharge position shown by the chain double-dashed line in FIG. Therefore, as described above, the first transport roller 8 and the second transport roller are mainly used.
The sheet member conveyed by the action of 10 is conveyed to the downstream side toward the outside of the housing while being guided by the upper surface of the lower guide member 30 at the discharge position in the direction indicated by the two-dot chain line arrow 44. Even during such conveyance, when the trailing edge of the sheet member passes through the nip portions of the first conveying roller 8 and the second conveying roller 10, the protrusion 24 of the first conveying roller 8 is trailing edge as described above. The trailing edge of the sheet member is forcibly separated from the first conveying roller 8 downward, and the sheet member is conveyed in the direction indicated by the arrow 44 as required.

<Effects of the Invention> The present invention is configured as described above, and the first support shaft has a plurality of protrusions that have a diameter larger than the diameter of the first conveying roller and are spaced from each other on the peripheral surface. Since the detaching roller is attached, when the sheet member passes through the nip portion of the first conveying roller and the second conveying roller during the conveyance of the sheet member in the first direction, the protrusion of the detaching roller causes Since it acts on the edge portion and forcibly moves the trailing edge portion downward, when the sheet member is subsequently moved from the trailing edge portion to the third guide roller and the return guide portion of the guide plate, the sheet member is surely moved. I can guide you.

Further, since the diameter of the separating roller is configured to be larger than the diameter of the first conveying roller, the first roller is conveyed during the first direction.
By cooperating with the second conveyance roller and the second conveyance roller, the sheet member is curved in a wave shape in a direction perpendicular to the conveyance direction, and so-called stiffness is enhanced, so that the sheet member is more reliably conveyed, In order to enhance the so-called stiffness, the sheet member is curved in a wave shape in a direction perpendicular to the conveying direction by the cooperation of the third conveying roller and the return guide portion and the escape portion of the guide plate during the conveying in the direction. Therefore, the sheet member can be conveyed more reliably.

Further, according to the present invention, the first carrying roller and the third carrying roller are mounted on the first supporting shaft, and the second carrying roller mounted on the first carrying roller and the first supporting shaft. To move the sheet member in the first direction, and to cooperate with the third conveying roller and the guide plate to move the sheet member in the second direction. Can be achieved by having two support shafts, so that the structure is relatively simple, the entire device can be configured compactly, and the cost is low. A sheet member transport mechanism can be obtained.

[Brief description of drawings]

FIG. 1 is a simplified cross-sectional view schematically showing a branch reversal unit of a double-sided copying machine provided with a sheet member conveying mechanism constructed according to the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a view as seen from the line III-III in FIG. 2 ... Sheet member transport mechanism 4 and 6 ... Support shaft 8 ... First transport roller 10 ... Second transport roller 12 ... Third transport roller 14 ... Guide plate 24 ... Projection (forced disengagement) means)

Claims (1)

[Claims] 1. A first support shaft rotatably driven in a predetermined direction, a second support shaft arranged at a predetermined distance from the first support shaft, and a first support shaft. A plurality of mounted first transport rollers and a plurality of second transports mounted on the second support shaft to transport the sheet member in the first direction in cooperation with the first transport rollers. A sheet member transported in the first direction by the action of the first transport roller and the second transport roller, the trailing edge of the first transport roller and the second transport roller. In the sheet member transport mechanism capable of transporting from the trailing edge portion through the lower side of the first transport roller in the second direction different from the first direction after passing through the nip portion of the first support shaft, The mounted third transport roller and the first support shaft mounted on the side of the first transport roller. A plurality of separating rollers having a diameter larger than the diameter of the first conveying roller and having a plurality of protrusions at intervals on the peripheral surface; and a plurality of separating rollers arranged below the first supporting shaft. The sheet member that has passed through the nip portion of the first transport roller and the second transport roller in cooperation with the third transport roller is passed from the trailing edge to the lower side of the first transport roller in the second direction. A sheet member conveying mechanism, comprising: a return guide portion for conveying the sheet; and a guide plate having a clearance portion that allows the peripheral edge of the separation roller to be fitted.