CONVEYING APPARATUS AND IMAGE FORMING APPARATUS

Abstract

A conveying apparatus for conveying a flexible sheet along a sheet-convey path including a curved portion. The conveying apparatus includes an outer guide which defines an outer portion of the curved portion of the sheet-convey path. The outer guide includes at least one curved plate having a first curved guide surface which contacts and guides the flexible sheet; and a guide base including at least one holding portion which holds the at least one curved plate. The at least one curved plate is formed of a synthetic resin assuring that the first curved guide surface thereof has a first frictional resistance lower than a second frictional resistance of a surface of the guide base.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and optional objects, features, and advantages of the present invention will be better understood by reading the following detailed description of the preferred embodiments of the invention when considered in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view showing an external construction of a multi-function device (MFD) 1 to which the present invention is applied;

FIG. 2 is a cross-sectional view showing an internal construction of the MFD 1;

FIG. 3 is an enlarged, cross-sectional view showing a relevant portion of a printer portion 2 of the MFD 1;

FIG. 4 is a plan view showing the relevant portion of the printer portion 2;

FIG. 5 is a perspective view showing a construction of an outer guide 18;

FIG. 6 is an exploded, perspective view of the outer guide 18;

FIG. 7 is a perspective view showing a first guide surface of a guide cover 102 of the outer guide 18;

FIG. 8 is a perspective view showing a rear surface of the guide cover 102;

FIG. 9 is a side elevation view of the guide cover 102;

FIG. 10 is a perspective view of a guide plate 104 of the outer guide 18; and

FIG. 11 is a rear elevation view of a guide base 101 of the outer guide 18, as viewed along an arrow 160 in FIG. 5.

Claims

1. A conveying apparatus for conveying a flexible sheet along a sheet-convey path including a curved portion, the conveying apparatus comprising: an outer guide which defines an outer portion of the curved portion of the sheet-convey path,wherein the outer guide includes:at least one curved plate having a first curved guide surface which contacts and guides the flexible sheet; anda guide base including at least one holding portion which holds said at least one curved plate, andwherein said at least one curved plate is formed of a synthetic resin assuring that the first curved guide surface thereof has a first frictional resistance lower than a second frictional resistance of a surface of the guide base.

2. The conveying apparatus according to claim 1, further comprising an inner guide which defines an inner portion of the curved portion of the sheet-convey path and which cooperates with the outer guide to define the curved portion.

3. The conveying apparatus according to claim 1, further comprising a moving device which moves the flexible sheet along the sheet-convey path.

4. The conveying apparatus according to claim 1, wherein the outer guide includes a plurality of said curved plates which are arranged in a widthwise direction of the sheet-convey path and which have respective said first curved guide surfaces that cooperate with each other to guide the flexible sheet, wherein the guide base includes a plurality of said holding portions each of which holds a corresponding one of the curved plates, and wherein each of the curved plates is formed of the synthetic resin assuring that the first curved guide surface thereof has the first frictional resistance lower than the second frictional resistance of the surface of the guide base.

5. The conveying apparatus according to claim 4, wherein the respective first curved guide surfaces of the curved plates cooperate with each other to define a substantially entire width of the curved portion of the sheet-convey path, and thereby guide the flexible sheet with respect to an entire width thereof.

6. The conveying apparatus according to claim 4, wherein the curved plates comprise a middle plate which is provided in a widthwise middle portion of the curved portion of the sheet-convey path, and at least two side plates which are provided on either side of the middle plate, respectively.

7. The conveying apparatus according to claim 6, wherein the curved plates comprise at least two groups of said side plates which are provided on either side of the middle plate, respectively, and each group of which comprise at least two said side plates.

8. The conveying apparatus according to claim 6, wherein the outer guide further includes at least one guide roller which includes a roller body and a shaft, and which is supported by the middle plate such that a portion of the roller body projects inward from the first curved guide surface of the middle plate and the roller body is rotatable about an axis of the shaft.

9. The conveying apparatus according to claim 1, wherein said at least one holding portion of the guide base has one of (a) a plurality of engageable recesses and (b) a plurality of engageable projections which are engageable with the engageable recesses, respectively, and said at least one curved plate has an other of (a) the engageable recesses and (b) the engageable projections, and wherein the engageable projections and the engageable recesses are engaged with each other so that said at least one holding portion of the guide base holds said at least one curved plate.

10. The conveying apparatus according to claim 9, wherein the engageable recesses and the engageable projections are engaged with each other to attach said at least one curved plate to the guide base such that said at least one curved plate is positioned relative to the guide base with respect to a widthwise direction of the sheet-convey path and a direction perpendicular to a tangential plane of the first curved guide surface.

11. The conveying apparatus according to claim 9, wherein said at least one holding portion of the guide base has at least one first abutment surface which abuts on a rear surface of said at least one curved plate that is opposite to the first curved guide surface thereof, so as to cause the engageable projections and the engageable recesses to be firmly engaged with each other and thereby position said at least one curved plate relative to the guide base with respect to an outward direction of the curved portion that is perpendicular to a tangential plane of the first curved guide surface thereof.

12. The conveying apparatus according to claim 9, wherein said at least one holding portion of the guide base has at least one second abutment surface which abuts on at least one side surface of said at least one curved plate, so as to cause the engageable projections and the engageable recesses to be firmly engaged with each other and thereby position said at least one curved plate relative to the guide base with respect to a widthwise direction of the sheet-convey path.

13. The conveying apparatus according to claim 10, wherein the engageable recesses and the engageable projections are engaged with each other to attach said at least one curved plate to the guide base in a state in which said at least one curved plate is elastically deformed and, owing to an elastically restoring force of said at least one curved plate, said at least one curved plate is positioned relative to the guide base with respect to the widthwise direction of the sheet-convey path and the direction perpendicular to the tangential plane of the first curved guide surface.

14. The conveying apparatus according to claim 1, further comprising a pair of conveying rollers which are provided on a downstream side of the outer guide with respect to the sheet-convey path, and which cooperate with each other to provide a nipping portion which nips the flexible sheet and thereby conveys the flexible sheet, wherein the guide base has, in a downstream-side end portion thereof with respect to the sheet-convey path, at least one second guide surface which guides the flexible sheet to the nipping portion of the conveying rollers.

15. The conveying apparatus according to claim 14, wherein said at least one curved plate has at least one guide fin which projects downstream from a downstream-side end thereof with respect to the sheet-convey path, and which extends to a position in a vicinity of an upstream-side end of said at least one second guide surface of the guide base.

16. The conveying apparatus according to claim 1, wherein said at least one curved plate has a plurality of guide fibs which extend along the sheet-convey path and have respective top surfaces that cooperate with each other to define the first curved guide surface.

17. The conveying apparatus according to claim 1, wherein the sheet-convey path is provided between a sheet-supply portion and a sheet-discharge portion, and includes, as the curved portion thereof, a U-turn portion through which the flexible sheet is reversed.

18. The conveying apparatus according to claim 1, wherein the synthetic resin is selected from the group consisting of (a) a polyacetal and (b) a fluororesin.

19. The conveying apparatus according to claim 1, wherein the guide base is formed of a material selected from the group consisting of (a) acrylonitrile butadiene styrene and (b) polystyrene.

20. An image forming apparatus, comprising: the conveying apparatus according to claim 1; andan image forming portion which is provided in the sheet-convey path and which forms an image on the flexible sheet conveyed along the sheet-convey path by the conveying apparatus.