JPH0626498Y2 - Paper transport device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sheet conveying device, and more specifically,
The present invention relates to a sheet conveying device including at least a pair of conveying rollers that sandwich a sheet and guide the sheet to a predetermined portion.

<Prior Art> Conventionally, in an image forming apparatus such as an electrostatic copying machine, a printer, or a facsimile, a sheet conveying device that sandwiches a sheet between a pair of conveying rollers and guides the sheet to a predetermined portion. This paper transporting device is provided with a support shaft of one transporting roller, which is located on both sides of the transporting roller sandwiching the transporting roller, to the other transporting roller side by an elastic member having a pair of opposing leg portions. There is provided one that employs a biasing structure (see, for example, Japanese Utility Model Laid-Open No. 57-192544).

In the case of the sheet transporting device adopting such a structure, one transport roller can be brought into close contact with the other transport roller facing each other regardless of the processing error and the assembly error of the transport roller. The paper can be reliably sandwiched between the transport rollers.

<Problems to be Solved by the Invention> By the way, in the above-described sheet conveying apparatus, the leg portions of the elastic member are fitted in the support shaft of the conveying roller so as to be movable in the axial direction. On the other hand, it is difficult for the elastic member to form a constant open leg interval on the tip side of its leg portion due to springback or the like during molding. Therefore, there is a problem in that the interval between the legs is too narrow and the transport roller is strongly sandwiched between the legs, which impedes smooth rotation thereof. Further, there is a problem that the spread leg interval is too wide, the transport roller falls off, or the spread leg interval of the elastic member is further expanded by the biasing force of the elastic member itself, and the biasing force to the support shaft is not constant. . Further, since the conveying roller is supported by the elastic member itself, when an excessive external force is applied to the elastic member by touching the conveying roller during jam processing or the like, the elastic member is deformed and its mounting state is changed. There is a problem in that the paper fluctuates and the conveyance of the paper becomes unstable.

The present invention has been made in view of the above problems, and the transport roller can always be smoothly rotated and a uniform biasing force can be applied to the transport roller regardless of the dimensional variation of the elastic member. It is an object to provide a sheet conveying device.

<Means for Solving the Problems> As a sheet conveying device of the present invention for achieving the above object, a support shaft urged by an elastic member is movable in an urging direction of the elastic member by a supporting member having rigidity. A groove having a predetermined width is formed at both side positions of the support shaft sandwiching the transport roller, and an elastic member is engaged with the groove.

<Operation> According to the paper transporting device having the above configuration, since the supporting shaft is supported by the supporting member having rigidity, the mounting state of the transporting roller varies even when an excessive external force acts on the transporting roller. There is no danger of Further, since the elastic member is engaged with the groove of the support shaft, even if the interval of the engaging portion (leg portion) with the support shaft of the elastic member varies, the interval can be corrected to a constant interval. . Therefore, the support shaft of the carrying roller can be constantly biased in a constant state, and there is no possibility that the carrying roller is sandwiched by the elastic member to limit the rotation or the carrying roller falls off.

<Example> Hereinafter, detailed description will be given with reference to the accompanying drawings illustrating an example.

FIG. 3 is a schematic view showing the internal structure of the paper transporting device of the present invention applied to a copying machine. An optical section (2) for document scanning exposure is provided above the inside of the copying machine main body (1). , A copy processing unit (3) below which forms a copy image on a sheet of paper (P)
Is provided, and a paper transport device (4) is provided from the lower side of the copy processing unit (3) to the front end side (right side in the same figure), and in the middle of the front end side of the paper transport device (4), Paper (P)
Fixing means for fixing the toner image formed on the surface (5)
Is provided.

The optical section (2) includes a light emitter (21), a reflector (22), and a lens (2
It is composed of 3) and the like, and the document conveyed on the contact glass (11) can be scanned and exposed by the document conveying means (7).

Further, as the copy processing section (3), a charging charger is provided around the photosensitive drum (31) which rotates in the direction indicated by an arrow X in the figure.
(32), developing device (33), transfer charger (34), separation charger (35), and cleaner (36) are arranged in this order, and the photoconductor drum is uniformly charged by the charging charger (32). After the original image is formed on (31) to form an electrostatic latent image, the developing device (33) visualizes the toner image, and the transfer charger (34) transfers the toner image onto the paper (P). However, the residual toner can be collected by the cleaner (36).

Further, the paper transporting device (4) has a paper feed roller (41), a first paper guide member (42), and a registration roller (43) from the inner side of the paper insertion portion (12) to the paper ejection side. , A second paper guide member (44) curved as a U shape as a pre-transfer guide,
It has a conveyance roller (45), a third paper guide member (46), a discharge roller (47), and the like in this order, and drives the paper feed roller (41) to insert a paper feed cassette (A) or a paper insert. Division (12)
The paper (P) supplied from the above is guided to the copy processing section (4) to transfer the toner image, and the fixing means (5) heats and fixes the toner image, and then discharges it onto the pedestal (13). can do. At the front end of the paper feed cassette (A), paper feed rollers (A1) (A2) for taking out and feeding the paper (P) contained in the paper feed cassette (A) one by one. Is provided.

The fixing means (5) includes a heating roller (51) and a pressure belt (52) as a pressure member, which are arranged in a state of being opposed to each other. Pressure belt (5
By (2), the paper (P) on which the toner image is transferred can be held and conveyed to the paper discharge side. The heating roller (51) is always driven to rotate while being heated to a predetermined temperature by a heating means such as a heater provided inside.

In addition, the pressure belt (52) is wound around a pair of drums (53) that are separated from each other by a predetermined distance, and is heated by a heating roller.
Pressed against (51).

In the copying machine having the above configuration, the paper feed roller (41) of the paper transport device (4), the first paper guide member (42), the upper roller (43a) of the registration roller (43), and the second paper guide member. (44)
Inner guide member (44a), lower roller of the transport roller (45)
(45a), third paper guide member (46), and discharge roller
(47), transfer charger (34), separation charger (3
5) and the fixing means (5) are unitized, and the unit (U) is provided slidably in the horizontal direction so that the unit (U) can be pulled out to the right side in FIG. Therefore, by pulling out the unit (U), it is possible to widely open the conveyance path of the paper (P),
As a result, it is possible to facilitate jam processing over the entire area of the path.

Furthermore, when pulling out the unit (U), the second
The inside of the paper guide member (44) of the guide member raising / lowering means is arranged so that the id member (44a) does not come into contact with the photoconductor drum (31).
It is automatically moved downward by (B).

More specifically with reference to FIGS. 4 to 6, the inner guide member (44a) is rotatably attached to the side plate (U1) of the unit (U) about a fulcrum (Q1). The frame (48) is held in a state in which the downward rotation is allowed, and the frame (48) is lifted to a predetermined upper position by a swing lever (49). Swing lever (49) above
Is rotatably supported on the side plate (14) of the main body (1) of the copying machine about a fulcrum (Q2) (see FIG. 5), and its tip end is provided with a roller (49a), The frame (48) is brought into contact with the engaging portion (48b) protruding from the end of the frame (48). The engaging part (48b)
Is formed on an inclined surface with the turning front end side (the left end side in FIG. 3) extending obliquely upward, and the height of the left end is such that the frame (48) is turned downward. The height of the rocking lever (49) is set higher than that near the top of the roller (49a) (see FIG. 6). Further, the swing lever (49) is always urged to rotate counterclockwise by a coil spring (49c) attached to the side plate (14) of the copying machine body (1) at one end, and the side plate is Unnecessary counterclockwise rotation in the free state is restricted by the stopper (49d) projecting from (14). The upper part of the frame (48) is connected to the photosensitive drum (3
It is in contact with the flange (31a) of 1), and this
It is positioned with respect to the photoconductor drum (31).

Therefore, by pulling out the unit (U) from the main body (1) of the copying machine, the engaging portion (48b) of the frame (48) is moved to the swing lever (49).
While following the rollers (49a), that is, the frame (48)
While gradually rotating counterclockwise, the paper conveyance path by the second guide member (44) can be opened (sixth).
See figure). However, when the frame (48) is rotated, the engagement portion (4
By properly selecting the inclination angle of 8b), the upper portion of the inner guide member (44a) is prevented from colliding with the photosensitive drum (31). The frame (48) is a unit
The stopper (48c) protruding from the side plate (U1) of (U) restricts unnecessary downward rotation in the free state.

Also, when the unit (U) once pulled out is inserted again,
Insert the engaging part (48b) of the frame (48) into the roller of the swing lever (49).
The frame (48) can be rotated clockwise along (49a), and finally the inner guide member (44a) can be lifted and returned to the original position.

On the other hand, the transport roller (45) of the paper transport device (4) is
As shown in the figure, a plurality of pairs are provided along the axial direction of the photoconductor drum (31), and the lower rollers (45a) thereof are rotatably attached to the frame (48), respectively. A two-legged leaf spring (45c) as an elastic member is urged so as to be in close contact with the upper roller (45b).

Referring to FIG. 1 in more detail, the lower roller (4
5a) is rotatably fitted to the support shaft (45d),
The support shaft (45d) is supported on both sides by a rigid double-legged support member (45e) fixed to the frame (48). Further, both ends of the support shaft (45d) are made to project from the support member (45e) by a predetermined length, and the groove (4
5f) has been formed. This groove (45f) is formed to be slightly wider than the plate thickness of the leaf spring (45c).
It is formed over the entire circumference of (45d). The interval L between the grooves (45f) is set to be equal to the interval on the root side of the leg (C1) of the leaf spring (45c).

Further, the leaf spring (45c) is in a state of straddling the support member (45e), and at the center of the base portion (C2) thereof, the support member (45e).
It is screwed to the base (E2) of the. However, leaf spring (45c)
A predetermined gap is provided between the both sides of the base (C2) of the base plate (C2) sandwiching the screwed portion and the base (E2) of the support member in order to secure the biasing force to the support shaft (45d). ing. Further, a tongue piece (C3) is formed on the long side edge portion of the base portion (C2) of the leaf spring (45c), and the tongue piece (C3) is formed on the long side edge portion of the support member (45e). Part is engaged. This is because when the leaf spring (45c) is screwed to the support member (45e), the leaf spring (45c) is prevented from rotating and the screwing is efficiently performed. However, the detent tongue (C3)
It may be formed on the 5e) side.

Then, at the lower end of the leg portion (C1) of the leaf spring (45c), a U groove (C3)
Is formed, and the U-groove (C3) part is the groove (45f) of the support shaft (45d).
Engaged with the section. The support shaft (45d) is a support member.
It is introduced into the bearing portion (E4) of the support shaft (45d) through the notch groove (E3) formed in the leg portion (E1) of (45e).

As described above, in the paper transporting device (4), the leg portion (C1) of the leaf spring (45c) that urges the lower roller (45a) of the transporting roller (45) is connected to the groove of the support shaft (45d) ( 45f) is engaged,
Even if the open leg spacing on the tip side of the leg (C1) varies during the manufacture of the leaf spring (45c), correct it even if the lower roller (4
5a) can be biased, and the support shaft (45d) and leaf spring
It is possible to prevent relative movement of (45c) in the axial direction. Therefore, the lower roller (45a) can always be urged with a constant pressure, and the lower roller (45a) is fixed by the leaf spring (45c).
There is no risk that the rotation will be restricted due to being caught in and that the support shaft (45d) will be pulled out. Moreover, in the above-mentioned embodiment, since the lower roller (45a) is supported by the supporting member (45e) having rigidity, even if an excessive external force acts on the lower roller (45a) during jam processing, There is no fear that the mounting state will change.

It should be noted that the present invention can be applied and implemented in an image forming apparatus other than a copying machine such as a facsimile and a printer.

<Effects of the Invention> As described above, according to the paper conveying apparatus of the present invention, the conveying roller urged by the elastic member is supported by the supporting member having rigidity, so that the conveying roller is used for the jam treatment or the like. Even when an excessive external force is applied, there is no fear that the mounting state of the transport roller will change, and the sheet can be stably transported. Further, even if the leg opening of the leg portion of the elastic member for urging the conveying roller varies, the conveying roller can be urged in a corrected state. There is a practicable unique effect that the elastic member can prevent the transport roller from rotating and the transport roller can be prevented from dropping off.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing a mounting state of a transport roller, FIG. 2 is a perspective view of a main part of a sheet transport device, FIG. 3 is a schematic view showing an internal structure of a copying machine, and FIG. FIG. 5 is a schematic view of a main part showing the member elevating means, FIG. 5 is a schematic view seen from the same side, and FIG. 6 is a schematic view showing a state where the inner guide member is moved downward, (4). (45) …… Conveying roller, (45c) …… Leaf spring as elastic member, (45d) …… Spindle, (45e) …… Supporting member, (45f) …… Groove (P) …… Paper.

Claims (1)

[Scope of utility model registration request] 1. A support shaft comprising at least a pair of conveying rollers for sandwiching a sheet and guiding the sheet to a predetermined portion, and supporting one of the conveying rollers in close contact with the other conveying roller facing the conveying roller. In a sheet conveying device in which both side positions sandwiching the conveying roller are urged by elastic members, a support shaft urged by the elastic members is movable in an urging direction of the elastic members by a supporting member having rigidity. A sheet conveying device, characterized in that a groove having a predetermined width is formed at both sides of the supporting shaft sandwiching the conveying roller, and an elastic member is engaged with the groove.