JPH1120981A - Paper transport roller - Google Patents

Abstract

(57) Abstract: In a bearing structure of a paper transport roller including a pair of rollers, one of which is attached to an openable / closable member, the position accuracy of the roller when the openable / closable member is closed is ensured. A common bearing (6) that supports and holds both a lower roller (4) and an upper roller (5) has a lower roller bearing (6a) that receives the shaft of the lower roller (4) and a retaining member from the main body structure (1). Flange 6b for prevention, and U groove 6d in the center
The engagement protrusion 6c for holding the upper roller having the above shape is integrally formed. The shaft 4a of the lower roller 4 is rotatably supported by a lower roller bearing 6a, and the shaft or bearing 7 of the upper roller 5 is held in a U groove 6d of an engagement protrusion 6c for holding the upper roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport roller such as a paper feed roller, a transport roller, a registration roller, and a fixing roller in an image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus of a type in which an upper body is opened and closed by an opening / closing shaft which is divided into an upper body and a lower body, a sheet conveying path is exposed when the upper body is opened. It is generally that. That is, since the upper roller constituting the paper transport roller is attached to the upper body and the lower roller is attached to the lower body, when the upper body is opened, the upper roller is separated from the lower roller, thereby The paper transport path is exposed. In this state, paper jam processing and other maintenance are efficiently performed. After the maintenance is completed, when the upper body is closed, the upper roller abuts on the lower roller so that the paper can be nipped and conveyed to the nip portion between the two. The problem here is the displacement of the upper roller and the lower roller when the upper body is closed. Further, even if the image forming apparatus is not the above-described type, there is a paper transport roller composed of a pair of rollers attached to a member which can be opened and closed, and this case has the same problem. In order to eliminate this displacement, for example, there is a technique described in Japanese Patent Application Laid-Open No. 8-113386. This is to eliminate the deviation by moving the bearing means supported by the support portion within the range of play by the urging means when the position of one roller and the other roller is displaced. .

[0003]

In the above-mentioned prior art, there is play between the bearing of the pair of paper transport rollers and the notch hole supporting the same, and the rotation of the rollers forms the correct tangential relationship by itself. However, for example, in the case where thick paper is sent skewed, the rollers are inclined by the amount of play due to the waist of the paper, causing a problem that skew correction cannot be sufficiently performed. Therefore, it is hard to say that the mechanism for eliminating the displacement between the pair of rollers is appropriate.

An object of the present invention is to eliminate such inconvenience, and in a bearing structure of a paper transport roller composed of a pair of rollers one of which is attached to an openable / closable member, a roller when the openable / closable member is closed. The purpose of the present invention is to provide a sheet transport roller capable of ensuring the positional accuracy of the sheet.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a paper transport roller comprising a pair of rollers for transporting paper, one of which is attached to a member which can be opened and closed with respect to a member holding the other roller. According to the first aspect, the first means is provided in which one of the pair of rollers is integrally provided with an engagement protrusion for positioning by engaging with the shaft of the other roller. The above problem is caused by a pair of rollers that transport a sheet, and one roller is attached to a member that can be opened and closed with respect to a member that holds the other roller. The problem is solved by a second means in which one of the bearings is integrally provided with an engagement protrusion for positioning by engaging with the bearing of the other roller. An object of the present invention is to provide a paper transport roller comprising a pair of rollers for transporting a sheet, one roller being attached to a member which can be opened and closed with respect to a member holding the other roller, wherein a bearing is provided on a first structural member. And a driven roller supported via a bearing on a second structural member that opens and closes with respect to the first structural member, wherein the driven roller has a second structure. In a state where the member is fixed to the first structural member, pressure is applied by a pressing means so that predetermined pressure is applied, and the bearing of the drive roller rotates about an axis with respect to the first structural member. And the bearing of the drive roller is provided with the second
This is solved by a fourth means provided with an engagement projection which engages with the shaft or bearing of the driven roller when the structural member is fixed to the first structural member.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a sheet transport roller attached to a member whose upper roller can be opened and closed. A guide plate (or cover) 2, which is a first structural member that can be opened and closed around a shaft 3, is provided on an upper portion of a main body structure (first structural member) 1 such as a resin frame and a sheet metal side plate. A lower roller 4 is pivotally supported by the structure 1, and an upper roller 5 is pivotally supported by the guide plate 2 so as to face the lower roller 4. FIG. 1 shows the open / closed state of the guide plate 2 by a two-dot chain line and a solid line. When the guide plate 2 is closed, a paper feed roller for feeding the stacked sheets one by one, a conveying roller for conveying the sheet, a registration roller for abutting the leading end of the sheet to forcibly skew the sheet, and a fixing roller The lower roller 4 and the upper roller 5, which constitute a paper transport roller, contact each other, hold the paper at the nip portion thereof, and transport the paper to the downstream side. On the other hand, when processing a paper jam or when a serviceman performs maintenance or the like, the guide plate 2 is rotated counterclockwise in FIG. 1 to open the paper transport path. Although the guide plate 2 is opened around the shaft 3 in this embodiment, the guide plate 2 may be opened and closed by parallel movement using a link or the like. Either the lower roller 4 or the upper roller 5 is a driving roller and the other is a driven roller. Both rollers may be provided with a drive transmission mechanism, for example, a gear, and may be driven on both sides. Denotes a drive roller which is a reference for sheet feeding. Further, in the example of FIG. 1, the rollers 4 and 5 are arranged in the up-down direction, but they may be arranged in the left-right and diagonal directions.

FIG. 2 is a perspective view showing a main part of a common bearing according to an embodiment of the present invention and a main body structure (first structural member) to which the common bearing is attached. A common bearing 6 that supports and holds the lower roller 4 and the upper roller 5 together has a lower roller bearing 6a that receives the shaft of the lower roller 4 and a stopper for preventing the lower roller 4 from coming off from the main body structure 1. Flange 6b
And an engagement protrusion 6c for holding the upper roller having a U-shaped groove 6d at the center is integrally formed. Since the common bearing 6 is formed integrally, a resin is suitable as a material. Further, a material having excellent slidability is preferable. Polyacetals, polyamides, nylons, and their oil-impregnated grades are desirable.
Also, sintering may be used. Further, a combination of different materials may be used. For example, two-color molding of ABS and POM, outsert molding of sheet metal and resin, and the like. The U groove 6d of the engagement protrusion 6c for holding the upper roller is a portion for directly receiving the shaft or bearing of the upper roller 5, and when directly receiving the shaft,
In order to reduce the surface pressure, it is necessary to consider that the thickness is larger than that of the flange portion 6b or the engagement protrusion 6c for holding the upper roller. The open end side of the U groove 6d is a tapered portion 6e that expands upward to facilitate guiding the shaft and bearing of the upper roller 5. The common bearing 6 is attached to the main body structure 1 by fitting the lower roller bearing 6a into the groove 1a of the main body structure 1. The lower roller bearing 6a is flat on both sides, and the flat portion 6a1 is in surface contact with the U-shaped groove 1a, whereby the rotation of the common bearing 6 is restricted. The regulation of rotation is not limited to this. For example, a projection for stopping rotation is provided on the common bearing 6, and a hole corresponding to the projection is provided on the main body structure 1. Alternatively, if the main body structure 1 is a resin frame, the common bearing 6 may be integrally formed. In this case, it is necessary to consider the above-mentioned slidability. When the common bearing 6 is held in the main body structure 1 in this manner, as described above,
The position in the thrust direction is regulated by the flange portion 6b. In this example, the flange portion 6b is integrally formed. However, when the thrust is stopped by attaching an E-ring or the like to the shaft, the flange portion 6b may be omitted.

FIG. 3 is a perspective view showing a first example of a bearing of a driven roller and a pressing mechanism for the bearing. In the present embodiment, the upper roller 5 is a driven roller, and its bearing 7
Is attached to the guide plate 2 which can be opened and closed, and is locked in the U groove 6d of the engaging projection 6c for holding the upper roller shown in FIG. The guide plate 2 has a groove 2 for guiding the bearing 7 up, down, left and right.
a, and the groove 2a is set wider so as to have a play with respect to the corresponding width dimension of the bearing 7. Due to this play, the driven roller (upper roller 5) is guided by the U groove 6d of the common bearing 6, moves to a predetermined position, and is positioned. Bearing 7
Various shapes are possible. As an example, 7a is a receiving portion of a compression spring 8 for pressing a driven roller, 7b
Is a groove guided by the groove 2a to restrict movement in the thrust direction, and 7c is a hole into which the shaft 5a of the upper roller 5 is inserted. The material of the bearing 7 may be the same as that of the common bearing 6.

FIG. 4 is a perspective view showing a second example of the pressing mechanism for the bearing of the driven roller. In this method, a tension spring 9 is hung around a bearing 10, and both ends of the tension spring 9 are hooked into holes 2 b, 2 b provided in the guide plate 2. 10b
Is a groove guided by the groove 2a to regulate the movement in the thrust direction, and 10c is a hole into which the shaft 5a of the upper roller 5 is inserted. The material of the guide plate 2 is made of resin, sheet metal, or a combination thereof, similarly to the main body structure 1.

FIG. 5 is a front view showing a bearing structure in which a common bearing receives a driven shaft. In this example, the common bearing 6 directly receives the shaft 5a of the upper roller 5, which is a driven roller.
Of course, the common bearing 6 also receives the shaft 4a of the lower roller 4 that is the driving roller.

FIG. 6 is a front view showing a bearing structure in which a common bearing receives a driven bearing. In this example, the bearing 7 of the upper roller 5 is received by the common bearing 6. In any case, since the lower roller 4 (drive roller) and the upper roller 5 (driven roller) are held by the common bearing 6, the positional accuracy of the two when the guide plate 2 is closed is secured. . In addition,
The present invention is not limited to the above embodiment, and the present invention is not limited to the position of the bearing 7 in FIG. 5, the direction of the common bearing 6, the direction of the common bearing 6 in FIG. 6, and the direction of the bearing 7. . Further, the driving and the following, the opening and closing, and the fixed side may be switched.

In the above-described embodiment, a pair of rollers 4 and 5 for transporting a sheet is provided, and one of the rollers 4 or 5 is opened and closed with respect to a member holding the other roller 4 or 5. A pair of rollers 4 (or 5) in a paper transport roller attached to a possible member
Since one of the bearings 6 (or 7) is integrally provided with an engagement projection 6c for positioning by engaging with the shaft 5a (or 4a) of the other roller 5 (or 4), One of the bearings 6, 7 or 10 of the pair of rollers 4 (or 5) is
(Or 4) Since the engaging projection 6c for engaging and positioning with the bearing 7 (10) of 5 is provided integrally, the bearings of the rollers 4 and 5 can be integrated without interposing other parts such as side plates and structures. Because it can be positioned with parts, high positioning accuracy is obtained.
Since the rollers (driven and driven) are positioned in parallel, skewing and wrinkling of the sheet can be prevented, and the configuration can be simplified, so that the cost can be reduced. Further, in the above-described embodiment, the roller 4 or 5 includes a pair of rollers 4 or 5 that convey a sheet, and one of the rollers 4 or 5 is a member that can be opened and closed with respect to the member that holds the other roller 4 or 5. A driving roller 4 (or 5) supported by the first structural member 1 via a bearing 6 and a second structural member 2 that opens and closes with respect to the first structural member 1 are mounted on the paper transport rollers. And a driven roller 5 (or 4) supported via a bearing 7 (10). The driven roller (or 4) is in a state where the second structural member 2 is fixed to the first structural member 1. Pressurizing means (8, 9) so as to obtain a predetermined press
The bearing 6 of the drive roller 4 is attached to the first structural member 1 by restricting rotation around the axis by bringing the flat portion 6a1 into surface contact with the U-shaped groove 1a. On the bearing 6 of the roller 4, when the second structural member 2 is fixed to the first structural member 1, an engaging engagement projection 6 c that engages with the shaft 5 a of the driven roller 5 or the bearings 7 and 10 is provided. Since the bearings are provided, the bearings of the rollers 4 and 5 can be positioned by one component without intervening other components such as side plates and structures, so that high positional accuracy can be obtained and the rollers (drive and driven) can be positioned in parallel. Therefore, skewing and wrinkling of the sheet can be prevented, and the configuration can be simplified, so that the cost can be reduced.

[0013]

According to the first, second or third aspect of the present invention, the roller bearing can be positioned by one component without intervening other components such as side plates and structures, so that a high positional accuracy can be obtained. Further, since the rollers (drive and follower) are positioned in parallel, skewing and wrinkling of the sheet can be prevented, and the configuration can be simplified, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a sheet transport roller in which an upper roller is attached to a member that can be opened and closed.

FIG. 2 is a perspective view showing a main part of a common bearing according to the embodiment of the present invention and a main body structure to which the common bearing is attached.

FIG. 3 is a perspective view showing a first example of a bearing of a driven roller and a pressing mechanism for the bearing.

FIG. 4 is a perspective view showing a second example of a bearing of a driven roller and a pressing mechanism for the bearing.

FIG. 5 is a front view showing a bearing structure in which a common bearing receives a driven shaft.

FIG. 6 is a front view showing a bearing structure in which a common bearing receives a driven bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body structure (1st structural member) 2 Guide plate 4 Lower roller 5 Upper roller 6 Common bearing 6a Lower roller bearing part 6b Flange part 6c Engagement protrusion part 6d for holding upper roller 6d U groove 7,10 Follower Roller bearing 8 Compression spring 9 Tension spring

Claims (3)

[Claims] A pair of rollers for conveying a sheet,
A paper transport roller in which one roller is attached to a member that can be opened and closed with respect to the member holding the other roller, and engages with one of the pair of rollers and the shaft of the other roller. A sheet conveying roller, wherein an engaging projection for positioning the sheet is provided integrally. 2. A method comprising a pair of rollers for conveying a sheet,
In a paper transport roller in which one roller is attached to a member that can be opened and closed with respect to a member holding the other roller, one of a pair of rollers is engaged with a bearing of the other roller. A sheet conveying roller, wherein an engaging projection for positioning the sheet is provided integrally. 3. It comprises a pair of rollers for conveying the paper,
A sheet conveying roller in which one roller is attached to a member that can be opened and closed with respect to a member holding the other roller, wherein a driving roller supported by a first structural member via a bearing; A second structural member that opens and closes with respect to the structural member, comprising a driven roller supported via a bearing, wherein the driven roller is in a state where the second structural member is fixed to the first structural member. Pressure is applied by a pressing unit so that a predetermined pressure is obtained. The bearing of the drive roller is attached to the first structural member while restricting rotation around an axis. A sheet transporting roller provided with an engaging projection which engages with a shaft or a bearing of the driven roller when the second structural member is fixed to the first structural member.