JP2004352380A - Paper carrying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively restrict jam by securely preventing one-side-only closure of a carrying guide member. <P>SOLUTION: This paper carrying device is provided with carrying rollers 23 disposed to protrude from one carrying surface 301 into a carrying passage 7 as paper is carried along a carrying passage 7 formed between a pair of carrying surfaces 301 and 311, and a carrying guide member 31 forming the other carrying surface 311, and journalled to a device main body 30 at one end edge. The paper carrying device is also provided with carrying rollers 24 resiliently in contact with the carrying rollers 23 to follow them to rotate, a case cover 32 supported on the device main body 30 to be capable of opening and closing, lock mechanisms 36 to lock the carrying guide member 31 to the device main body 30 in a case where prescribed pressure is added, and a pressure link member 33 protruded on the carrying guide member 31 and the case cover 32 to add pressure roughly equally to the lock mechanisms 36 in accordance with closing action of the case cover 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paper transport device that transports paper such as a document and transfer paper in a copying machine, a printer, a scanner device, a facsimile device, and the like.
[0002]
[Prior art]
In this type of paper transport device, a transport path is formed between a pair of transport surfaces facing each other, and is elastically contacted with the transport roller by a transport roller that is driven to rotate and a pressing spring while partially protruding into the transport path. In general, a conveyance force is applied across a sheet by a conveyance roller that is driven to rotate, and the sheet is conveyed along a conveyance path (for example, see Patent Document 1).
[0003]
Japanese Patent Application Laid-Open No. H11-163,086 discloses a paper transport apparatus as a paper feed unit that supplies and transports paper to and from an image forming apparatus main body. This paper transport device can be stacked in multiple stages according to the type of paper size and the like. The paper transport device transports the paper transported from the lower paper transport device or the paper picked up from the paper feed cassette to the upper paper transport device. The sheet is transported to the apparatus or the image forming apparatus main body.
[0004]
Specifically, a transport roller is provided on one transport surface side of the transport path, and a transport roller is provided on a transport guide plate that forms the other transport surface. , And a conveying force is applied to the sheet.
[0005]
The transport guide plate provided with the transport rollers is pivotally supported by the apparatus main body with the lower edge as a rotation axis, and rotates the transport guide plate in a direction to separate the respective transport surfaces to expose the transport path. It is configured as follows.
[0006]
An outer cover that covers the outside of the transport guide plate is provided outside the transport guide plate, and the outer cover is also pivotally supported on the apparatus main body with the lower end edge as a rotation axis. The outer cover and the transport guide plate are connected via link members provided at both ends in the width direction (the width direction orthogonal to the transport direction). It is configured to be opened and closed.
[0007]
Further, the outer cover is provided with a lock mechanism for locking the outer cover to the apparatus main body at both ends in the width direction, and the transport guide plate is also formed through the link member by forming a transport path by locking the outer cover. It is made to be locked by.
[0008]
Then, when a jam (paper jam) occurs in the paper conveying apparatus, the outer cover is opened to thereby open the conveying guide plate to expose the conveying path, so that the jam can be cleared through the exposed portion. It has been made. Then, when the outer cover is closed after the jam processing is completed, the transport guide plate is also interlocked through the link member to be closed, and the outer cover is further pressed while the transport rollers provided on the transport guide plate are pressed against the transport rollers. And locked by locking members provided at both ends in the width direction of the outer cover.
[0009]
[Patent Document 1]
JP-A-13-233495
[0010]
[Problems to be solved by the invention]
However, in such a conventional paper conveyance device, depending on the handling of the user, when closing the outer cover and the conveyance guide plate, one of the lock members provided at both ends in the width direction of the outer cover. However, there is a problem that what is called a one-sided closing occurs in which only the lock member is locked.
[0011]
That is, the outer cover cannot be formed thick due to cost, operability, etc., and is formed with high rigidity because many reinforcement ribs are protruded on the inner surface side to cause sink marks and deteriorate the appearance. Difficult and easy to bend. Therefore, when the user holds the outer cover in one of the width directions and performs the closing operation of the outer cover, the outer cover is pressed when the outer cover is further pushed in with the transport rollers pressed against the transport rollers. In some cases, only the locking member held by the user is bent and locked, and the other locking member is not locked.
[0012]
When this one-sided closing occurs, the nip pressure between the conveyance roller and the conveyance roller differs along the width direction perpendicular to the conveyance direction, causing slant conveyance of the paper, or unexpectedly during the conveyance operation due to incomplete locking. In addition, there is a possibility that the conveyance guide plate is opened together with the outer cover, and a jam occurs.
[0013]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a paper transporting device that reliably prevents one-side closing of a transport guide member and effectively suppresses a jam, regardless of handling by a user. With the goal.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problems, a paper transport apparatus according to the present invention includes a transport unit that protrudes from each transport surface into a transport path along a transport path formed between a pair of transport surfaces facing each other. In the paper transporting device that transports the paper by the rollers and the transport rollers, one transport surface is formed, and a transport guide member having one end edge pivotally supported by the device main body so as to be able to open and close with respect to the other transport surface. An outer cover that is provided on the apparatus main body in a state of covering the transport guide member, and is supported at one end by an openable / closable shaft with respect to the apparatus main body; and an apparatus corresponding to both widthwise ends of the transport guide member. A lock member that is provided at a predetermined position of the main body and locks the transport guide member at the closed position to the closed position; and a lock member between the exterior cover and the transport guide member and having a small number of the exterior cover and the transport guide member. And projecting to one and is characterized in that it comprises a pressing member which presses the conveying guide member is displaced the conveying guide member in the closed position when said outer cover is moved to the closed position.
[0015]
According to the present invention, the transfer guide member is protruded from at least one of the outer cover and the outer cover is moved to the closed position to press the transfer guide member to close the transfer guide member to the closed position. Is provided, the closing operation force of the outer cover is transmitted to the transport guide member via the pressing portion by moving the outer cover to the closed position, and the transport guide member is securely closed. Can be shifted into position. In addition, when the transport guide member is at the closed position, the pressing force of the pressing member substantially uniformly acts on each of the lock members provided at both end portions, so that both lock members can be securely locked together. Therefore, for example, even when the user holds one end of the outer cover and closes the outer cover, the pressing force of the pressing member is applied to the appropriate position of the conveying guide member via the pressing portion, thereby causing the one piece of the conveying guide member to be closed. Closing can be reliably prevented, and thereby jams due to one-sided closing can be effectively suppressed. In addition, since the lock member locks the transport guide member at the closed position to the closed position, the transport guide member can be reliably closed.
[0016]
Further, in the present invention, the pressing member may be provided at a plurality of locations on at least one of the transport guide member and the exterior cover, but any one of the transport guide member and the exterior cover may be provided. It is preferably provided at one location on one side (claim 2).
[0017]
According to this structure, the manufacturing cost can be reduced, and since the pressing member is provided only at one position, the projecting position of the pressing member can be easily set, and stably and accurately regardless of the holding position of the user. The pressing force can be applied to both lock members substantially uniformly.
[0018]
For example, when the transport roller is provided near a substantially central portion in the width direction of the transport guide member, it is preferable that the pressing member is provided near a position on the transport guide member opposite to the transport roller. (Claim 3).
[0019]
That is, the transport roller is generally in elastic contact with the transport roller, and when the transport guide member is closed, a reaction force from the transport roller tends to act near the position of the transport guide member opposite to the transport roller. Therefore, with this configuration, the pressing force of the pressing member can be reliably and substantially uniformly applied to both the lock members provided at both ends in the width direction of the transport guide member.
[0020]
Further, in the present invention, both ends of the pressing member in the longitudinal direction are pivotally supported by the transport guide member and the exterior cover, respectively, and are configured as link members for interlocking opening and closing operations of the exterior cover and the transport guide member. (Claim 4).
[0021]
With this configuration, the transport guide member can be closed by simply performing the closing operation of the outer cover, and the opening and closing operability is improved, and the outer cover is also closed via the pressing member as the link member. It is possible to lock at the position, there is no need to provide a lock mechanism for the exterior cover, and it is possible to suppress the manufacturing cost.
[0022]
Further, in the present invention, it is preferable that the transport guide member is formed of a synthetic resin material and is provided with a plurality of reinforcing ribs along the width direction of the transport guide member.
[0023]
According to this structure, the transfer guide member can be integrally formed of a synthetic resin, so that the manufacturing cost can be reduced. Moreover, since a plurality of reinforcing ribs are provided along the width direction of the transport guide member, the rigidity of the transport guide member can be improved, thereby stably and reliably locking the pressing force of the pressing portion. Can be transmitted to the mechanism.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an overall schematic diagram showing an embodiment in which a sheet conveying device according to the present invention is applied to a sheet feeding unit mounted below a copying machine as an image forming apparatus. In the present embodiment, a case in which this paper transport apparatus is applied to a copying machine will be described. However, the present invention is also applicable to a printer apparatus, a facsimile apparatus, a scanner apparatus, and a multifunction peripheral having these functions. .
[0025]
The image forming apparatus 1 includes an image forming apparatus main body 2 and a plurality of sheet feeding units 3, 4, 5, and 6 stacked on a plurality of stages below the image forming apparatus main body 2. The paper accommodated in each paper feed unit 3, 4, 5, 6 can be supplied to and conveyed to the image forming apparatus main body 2 through a communication hole 74 provided in the image forming apparatus 2.
[0026]
The image forming apparatus main body 2 supplies an image read by the image reading section 40 disposed above the image forming apparatus main body 2 and the image read by the image reading section 40 from the paper feed units 3, 4, 5, and 6. An image forming unit 50 formed on the formed sheet P, a fixing unit 60 for fixing an image formed on the sheet P by the image forming unit 50, and an image formed by the fixing unit 60 via a discharge roller pair 71. And a paper discharge section 72 for discharging the paper P on which the fixing has been performed, and paper transport paths 75 and 76 for transporting the paper P from the communication hole 74 to the paper discharge section 72 are formed.
[0027]
The image reading section 40 is composed of an optical system member or the like, and irradiates a document placed on the contact glass 41 with light from an exposure lamp, and the reflected light is transmitted through a reflecting mirror to a photoelectric conversion device such as a CCD line sensor. The image information of the document is read by being guided to the conversion unit.
[0028]
The image forming unit 50 is disposed below the image reading unit 40, forms a predetermined toner image on the sheet P by an electrophotographic process, and has a photoconductive rotatably supported. The photosensitive drum 51 includes a charging unit 52, an exposure unit 53, a developing unit 54, a transfer unit 55, a cleaning unit 56, and a charge removing unit (not shown) along the rotation direction around the photosensitive drum 51.
[0029]
The fixing unit 60 is disposed downstream of the image forming unit 50 in the sheet conveying direction, and heats the sheet P on which the toner image has been transferred in the image forming unit 50 by sandwiching the sheet P between a pair of fixing rollers 61 including heating rollers. Is to fix the toner image on the paper P. Further, the cleaning unit 56 is for cleaning the toner remaining on the surface of the photoconductor drum 51 after the transfer, and the charge removing unit is for removing the residual charge on the surface of the photoconductor drum 51.
[0030]
More specifically, the photoconductor drum 51 rotating in the direction of the arrow in the drawing is uniformly charged by the charging unit 52, and the exposure unit 53 (such as a laser operation unit) based on the image information read by the image reading unit 40. ), An electrostatic latent image is formed on the photosensitive drum 51 by the laser beam, and a developer (toner) is attached to the electrostatic latent image by the developing unit 54 to form a toner image.
[0031]
The paper P is transported from the paper supply unit 3 to the image forming unit 50 via the communication hole 74, the pair of registration rollers 73, and the paper transport path 75 toward the photosensitive drum 51 on which the toner image has been formed as described above. In the image forming unit 50, the toner image on the surface of the photosensitive drum 51 is transferred to the sheet P by the transfer unit 55 including a transfer roller. Then, the paper P on which the toner image has been transferred is separated from the photosensitive drum 51, and is conveyed to the fixing unit 60 where the toner image is fixed. The sheet P that has passed through the fixing unit 60 is sent to a sheet conveyance path 76 and is discharged to a sheet discharge unit 72 via a discharge roller pair 71.
[0032]
After the transfer by the transfer unit 55, the photosensitive drum 51 is removed by the cleaning unit 56 and the charge removing unit to remove the residual toner and the residual charge, and is charged again by the charging unit 52 as necessary.
[0033]
On the other hand, the paper feed units 3, 4, 5, and 6 can be stacked in a plurality of levels as described above, and the image forming apparatus main body 2 is stacked on the uppermost paper feed unit 3, and the image forming apparatus main body is stacked. 2 to supply the paper P. In each of the paper feed units 3, 4, 5, and 6, these papers P are stored, for example, for each vertical and horizontal orientation.
[0034]
Specifically, as shown in FIG. 2, the sheet feeding units 3, 4, 5, and 6 have a plurality of positioning pins 100 projecting therefrom. By stacking the paper units 3, 4, 5 or the image forming apparatus main body 2, the upper connector 101a can be inserted and connected to the lower connector 101b of the upper sheet feeding unit (image forming apparatus main body 2). The image forming apparatus main body 2 and each of the paper feed units 3, 4, 5, and 6 can be electrically connected via the upper and lower connectors 101a and 101b.
[0035]
Since the configurations of these paper feed units 3, 4, 5, and 6 are the same, the second-stage paper feed unit from the top will be described here with reference to FIGS.
[0036]
The paper feeding unit 4 includes a device main body 30 having a concave portion 300 provided at a substantially central portion in a lateral direction (left side in FIGS. 1 and 2) in a width direction orthogonal to the conveying direction, and is disposed in the concave portion 300. A transport guide member 31, and an exterior cover 32 disposed in the recess 300 so as to cover the outside of the transport guide member 31 (the left side in FIGS. 1 and 2). A first paper transport path 7 that transports the paper P supplied from the lower paper feed units 5 and 6 is formed between the inner bottom surface 301 and the facing surface 311 of the transport guide member 31. The first paper transport path 7 transports the paper P sent from the lower paper feed units 5 and 6 to the uppermost paper feed unit 3, and introduces paper from the lower paper feed units 5 and 6. From the lower paper introduction hole 13 to the upper paper supply hole 14 for leading the paper to the upper paper supply unit 3.
[0037]
The apparatus main body 30 includes a paper feed cassette 10, a feed roller 20, a paper feed roller 21, a separating roller 22, a paper feed guide 26, and a transport roller 23.
[0038]
The paper feed cassette 10 has a paper stacking tray 11 for stacking and stacking the papers P, and stores the papers P to be image-transferred on the paper stacking tray 11, and stores the papers P in the apparatus main body 30 in a drawable manner. Have been. The forward feed roller 20, the paper feed roller 21, and the separating roller 22 are disposed on the leading end side of the sheet stacking tray 11, and are the uppermost sheet P among the plurality of sheets P stacked on the sheet stacking tray 11. Are sequentially fed one by one at a predetermined timing. The paper feed guide 26 is disposed downstream of the paper feed roller 21 and the separating roller 22, and the paper feed guide 26 forms a second paper transport path 8 extending from the paper stack tray 11. The second paper transport path 8 joins the first paper transport path 7 on the downstream side of the paper feed guide section 26.
[0039]
The transport roller 23 is disposed downstream of the confluence of the first and second paper transport paths 7 and 8 and is driven to rotate by driving means (not shown). Specifically, the transport roller 23 is formed of a pair of front and rear elongate cylindrical rollers that rotate integrally with the rotation shaft 230, and a part of the peripheral surface thereof extends from the inner bottom surface 301 of the concave portion 300 in the apparatus main body 30 to the first surface. In a state protruding from the paper transport path 7, it is disposed substantially at the center in the width direction of the apparatus main body 30 so as to correspond to paper of various sizes.
[0040]
On the other hand, the transport guide member 31 is a synthetic resin molded product that can be formed at low cost and light weight, and is configured as a substantially rectangular plate-shaped body corresponding to the inner bottom surface 301 in the concave portion 300 of the apparatus main body 30. It has a rib 312, reinforcing ribs 313, 314, and a transport roller 24. As shown in FIGS. 2 to 4, the transport guide member 31 has a bearing portion formed at a lower portion on both ends in a width direction (hereinafter, simply referred to as a “width direction”) orthogonal to the paper transport direction. Is rotatably supported with respect to the apparatus main body 30 by being fitted into the rotation shaft 310 provided in the apparatus. Then, by rotating the transport guide member 31 in a direction to separate it from the inner bottom surface 301 of the apparatus main body 30, the first paper transport path 7 is exposed and the jam clearance can be easily performed.
[0041]
A plurality of reinforcing conveyance ribs 312 are arranged side by side in the sheet conveyance direction on the opposing surface 311 of the conveyance guide member 31 to improve the rigidity of the conveyance guide member 31 and reduce the friction acting on the sheet P to reduce the sheet friction. P can be smoothly transported. On the other hand, the reinforcing ribs 313 and 314 are formed on the surface (the surface on the side of the exterior cover 32) opposite to the facing surface 311 of the transport guide member 31 in the form of a cross along the paper transport direction and a direction orthogonal thereto. The rigidity of the transport guide member 31 is improved.
[0042]
The transport roller 24 is disposed downstream of the confluence of the first and second paper transport paths 7 and 8 and at a position facing the transport roller 23 in the transport guide member 31. It is made to be driven and rotated by being hit. Then, between the transport rollers 24 and the transport rollers 23, the paper P transported from the lower paper feed units 5 and 6 or the paper P supplied from the paper feed cassette 10 is sandwiched to apply a transport force, The sheet is sent to the upper sheet feeding unit 3 (the image forming apparatus main body 2 in the upper sheet feeding unit 3).
[0043]
Specifically, the transport roller 24 is configured by a pair of front and rear cylindrical rollers that rotate relative to the support shaft 240. The support shaft 240 is movably attached to and separated from the transport roller 23 by a support portion 241 provided upright in the transport guide member 31, whereby the transport roller 24 moves relative to the transport roller 23. It can be moved in the direction of contact and separation. Further, the support shaft 240 is urged in a direction in which the transport roller 24 approaches the transport roller 23 by a pressing elastic member 34 such as a spring having one end attached to the transport guide member 31 in a position regulating state. The transport roller 24 is in elastic contact with the transport roller 23 by the elastic member 34.
[0044]
The exterior cover 32 is a substantially rectangular synthetic resin molded product formed corresponding to the transport guide member 31, and the concave portion 300 of the device main body 30 is substantially flush with the exterior surface of the device main body 30. It is arranged in. In addition, a plurality of reinforcing ribs are protrudingly provided on the inner surface of the outer cover 32 within a range that does not cause trouble such as sink marks.
[0045]
As shown in FIGS. 2 to 4, the outer cover 32 is attached to the rotating shaft 320 provided on the apparatus main body 30 by bearings formed at lower portions at both ends in the width direction. It can be rotated in a state where it can be opened and closed. A finger hook 321 is formed from the viewpoint of improving the operability of the opening and closing operation.
[0046]
On the other hand, the paper feed unit 4 includes a lock mechanism 36 that locks the transport guide member 31 in the closed posture state, that is, in a state where the first paper transport path 7 is formed, at both ends in the width direction of the first paper transport path 7. It is provided in each part. Each locking mechanism 36 includes a locking piece 37 provided on the apparatus main body 30 and a locked part 38 provided on the transport guide member 31, and when a predetermined pressing force acts on the locking mechanism 36. The locking piece 37 is elastically deformed outward in the width direction of the first paper transport path 7, and the locking projection 372 provided at the leading end thereof is locked in the locked part 38, and the transport guide member 31 is provided. Is locked in the closed posture state.
[0047]
Specifically, the locking piece 37 is provided on the side wall surface of the concave portion 300 of the apparatus main body facing in the width direction (front-rear direction), and the separating portion 370 slightly protruding from the side wall surface near the side opening of the concave portion 300. An extension 371 extending from the distal end of the separating portion 370 to the deep bottom surface 301 side of the concave portion 300; and a locking projection 372 projecting inward in a triangular shape near the distal end of the extension 371. The locking pieces 37 can be elastically deformed outward by an amount separated by the separation portion 370. On the other hand, the locked portions 38 are respectively provided on both end surfaces in the width direction of the transport guide member 31 so as to correspond to the locking pieces 37, and are opened on the back side of the transport guide member 31 (the side opposite to the facing surface 311). It is configured as a cut-out recess.
[0048]
As the transport guide member 31 provided with the locked portion 38 is turned from the open position exposing the first sheet conveying path 7 to the closed position, first, the locking projection of the locking piece 37 is projected. The portion 372 contacts the opposing surface 311 of the transport guide member 31. When the transport guide member 31 is further rotated, a predetermined pressing force is applied to the lock mechanism 36, and the locking piece 37 is elastically deformed outward, crosses the facing surface 311 and engages with the locked portion 38. The stop projection 372 is locked so that the transport guide member 31 can be locked in the closed posture state.
[0049]
The lock mechanism 36 is not limited to the lock mechanism of the present embodiment, and may be another known lock mechanism, for example, a lock mechanism of a magnet type using a magnet or a catcher type of elastically holding a bulging portion. A lock mechanism or the like may be employed.
[0050]
Further, the paper feed unit 4 has a longitudinal linking end that is pivotally supported by the transport guide member 31 and the exterior cover 32, respectively, and presses the opening and closing operations of the transport guide member 31 and the exterior cover 32 in conjunction with each other. 33 are provided.
[0051]
Specifically, as shown in FIG. 2, the pressing link member 33 is formed in an elongated rod shape, and one end in the longitudinal direction is formed at the center of one reinforcing rib 313 formed along the transport direction of the transport guide member 31. The support pin 330 is pivotally supported near the upper part, while the other end in the longitudinal direction is supported by the support pin 331 near the center above one reinforcing rib formed on the inner surface side of the outer cover 32 along the transport direction. It is rotatably supported and interlocks the opening and closing operation of the exterior cover 32 and the transport guide member 31.
[0052]
The pressing link member 33 is for linking the transport guide member 31 with the opening / closing operation of the exterior cover 32 as described above, and for pressing the transport guide member 31 when the exterior cover 32 is closed. In the present invention, the number of the pressing link members 33 (pressing portions) and the conveying direction are adjusted so that the pressing force accompanying the closing operation is applied substantially equally to the lock mechanisms 36 provided at both ends in the width direction of the conveying guide member 31. The arrangement position in the width direction that is orthogonal is set. In other words, in order to apply the pressing force to the lock mechanism 36 approximately equally, both ends in the width direction of the conveyance guide member 31 are supported in consideration of the reaction force generated by the conveyance roller 24 elastically contacting the conveyance roller 23. In this case, it may be set so that substantially equal forces act on both ends.
[0053]
In the present embodiment, as shown in FIG. 3, one pressing link member 33 is located substantially at the center of the transport guide member 31 in the width direction, and the transport roller 24 and its support shaft are arranged in the width direction of the transport guide member 31. It is arranged near the position opposite to 240, especially near the position opposite to the pressing elastic member 34.
[0054]
Next, a process performed when a jam (paper jam) occurs in the paper feeding unit 4, particularly in the first paper transport path 7, will be described.
[0055]
When a paper jam occurs in the paper feeding unit 4, a message to that effect is displayed on a display unit (not shown) of the image forming apparatus main body 2, and the user performs the paper jam processing.
[0056]
First, a finger or the like is inserted into the finger hook portion 321 of the exterior cover 32 and pulled toward the front side (the left side in FIG. 2) as shown by a two-dot chain line in FIG. The transport guide member 31 pivots about the rotation shaft 310 via the pressing link member 33 and shifts from the closed posture to the open posture. At this time, the locking piece 37 of the lock mechanism 36 elastically deforms outward with the rotation of the transport guide member 31, and the locked state between the locking projection 372 and the locked portion 38 is released. The locked state of the transport guide member 31 is also released.
[0057]
Then, when the transport guide member 31 shifts to the open position, the first paper transport path 7 is exposed, and in this state, jam processing such as removing jammed paper can be performed.
[0058]
After the jam processing is completed, a part of the outer cover 32 is supported and rotated about the rotation shaft 320 toward the apparatus main body 30, so that the transport guide member 31 is pressed by the pressing link member 33, and the transport guide The member 31 also rotates toward the apparatus main body 30.
[0059]
When the outer cover 32 is rotated together with the transport guide member 31 toward the apparatus main body 30, the peripheral surface of the transport roller 24 of the transport guide member 31 comes into contact with the peripheral surface of the transport roller 23 of the apparatus main body 30. When the exterior cover 32 is further pushed into the apparatus main body 30 and rotated from this state, the pressing elastic member 34 for urging the support shaft 240 of the transport roller 24 is elastically deformed, and the support shaft 240 moves inside the support portion 241. The transport guide member 31 also rotates while moving.
[0060]
Then, during the turning operation of the transport guide member 31, the locking projection 372 of the locking piece 37 of the lock mechanism 36 comes into contact with the facing surface 311 of the transport guide member 31, and from this state, the transport guide member 31 is moved. When the pressing force is applied by further rotating, the locking piece 37 is elastically deformed outward in the width direction perpendicular to the transport direction, and the locking projection 372 of the locking piece 37 is locked by the transport guide member 31. When the locking projection 37 moves over the peripheral edge of the portion 38 and the locking projection 372 reaches the locked portion 38, the locking piece 37 elastically recovers, and the locking projection 372 is locked by the locked portion 38, The transport guide member 31 is locked to the apparatus main body 30 in a state where the first paper transport path 7 is formed.
[0061]
In the sheet feeding unit 4, no matter which position of the exterior cover 32 is supported and the closing operation is performed, a constant position is always pressed through the pressing link member 33 in the transport guide member 31 and the closing operation is performed. The distribution state of the force in the transport guide member 31 becomes constant. In addition, since the transport guide member 31 is provided with the reinforcing ribs 312, 313, and 314 and is formed with relatively high rigidity, it is hardly bent. Therefore, the pressing force of the pressing link member 33 acts on the lock mechanisms 36 provided at both ends orthogonal to the transport direction substantially uniformly, and the lock mechanisms 36 can be reliably locked. Thereby, the one-side closing of the transport guide member 31 can be reliably prevented, and the occurrence of a jam due to the one-side closing can be effectively suppressed.
[0062]
Moreover, the lock mechanism 36 does not lock the exterior cover and the apparatus main body and indirectly locks the transport guide member via a link member as in the conventional apparatus. Since the transport guide member 31 is locked, the transport guide member 31 can be reliably closed.
[0063]
Although the paper feed unit as the paper transport device according to the present embodiment has been described above, the paper transport device according to the present invention is not limited to the above-described embodiment, and various types may be used without departing from the gist of the present invention. Can be changed. For example, the following changes are possible.
[0064]
{Circle around (1)} In the above-described embodiment, the pressing link member 33 is employed as the pressing portion, and the opening / closing operation of the transport guide member 31 and the exterior cover 32 is interlocked. It may be configured as a protruding portion protruding from any one of the covers 32. In the case where the protruding portion is employed as the pressing portion, it is necessary to separately provide a lock mechanism for locking the outer cover 32 to the apparatus main body 30. In this case, the transport guide member 31 is closed and then the outer cover 32 is closed. For example, even when the transport guide member 31 is partially closed, the pressing portion is pressed when the outer cover 32 is closed. Presses the transport guide member 31 to securely lock the two lock mechanisms, so that the transport guide member 31 can be reliably prevented from being partially closed.
[0065]
However, by adopting the pressing link member 33 as the pressing portion as in the present embodiment, the transport guide member 31 can be opened and closed only by opening and closing the outer cover 32, and not only the operability is improved, but also Since the outer cover can also be locked in the closed position by the pressing link member 33, there is no need to provide a lock mechanism for the outer cover, which is advantageous in that manufacturing costs can be reduced.
[0066]
{Circle around (2)} In the above embodiment, the transport guide member 31 and the outer cover 32 are rotatable while pivotally supporting the lower edges thereof. One of them may be pivotally supported.
[0067]
Further, the positions at which the transport guide member 31 and the exterior cover 32 are pivotally supported can be determined between the two members. For example, in the above embodiment, the pivotal support position of the exterior cover 32 may be the one end edge in the width direction orthogonal to the transport direction. However, in this case, a pressing link member cannot be used as the pressing portion, and a separate lock mechanism needs to be provided for the exterior cover.
[0068]
{Circle around (3)} In the above-described embodiment, a description has been given of the case where the pressing portion is provided only at a substantially central portion in the width direction of the transport guide member. However, the mounting position of the pressing portion is not particularly limited. However, the manufacturing cost can be reduced by providing the pressing portion only at one position, and the projecting position of the pressing portion can be easily set to apply the pressing force to the two lock mechanisms 36 almost equally. Is advantageous.
[0069]
{Circle around (4)} In the above embodiment, two transport rollers 23 and two transport rollers 24 are provided, but the numbers are not particularly limited.
[0070]
{Circle around (5)} In the above-described embodiment, the description has been given of the case where only one pressing elastic member 34 for determining the elastic contact force of the conveying roller 24 with respect to the conveying roller 23 is provided. Instead, it is appropriately set in consideration of the nip pressure and the like.
[0071]
【The invention's effect】
As described above, according to the paper transport apparatus of the present invention, by closing the outer cover, both lock mechanisms provided at both ends in the width direction orthogonal to the transport direction are securely locked, and the transport guide member One-sided closing can be reliably prevented, thereby making it possible to effectively suppress inconveniences caused by one-sided closing, for example, oblique conveyance and occurrence of jam.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an embodiment of an image forming apparatus including a sheet conveying device according to the present invention.
FIG. 2 is a longitudinal sectional view showing a sheet feeding unit as a proton transport device according to the present invention.
FIG. 3 is an explanatory cross-sectional view showing the sheet feeding unit.
FIG. 4 is a partial perspective view showing the sheet feeding unit with a conveyance guide member and an outer cover opened.
[Explanation of symbols]
1 Image forming apparatus
2 Image forming apparatus main body
3,4,5,6 Paper feed unit (paper transport device)
7 First paper transport path
23 Transport rollers
24 transport rollers
30 Main unit
31 Transport guide member
32 Exterior cover
33 Press link member
34 Pressing elastic member
36 Lock mechanism
37 Locking piece
38 Locked part
300 recess
301 Back bottom (transfer surface)
311 Opposite surface (transport surface)
312 Reinforcement transport rib
313,314 Reinforcing rib
P paper

Claims (5)

Along a transport path formed between a pair of opposed transport surfaces, a transport roller and a transport roller arranged to protrude into the transport path from each transport surface, in a paper transport device that transports the paper,
A transport guide member that forms one transport surface and is openable and closable with respect to the other transport surface, one end of which is pivotally supported by the apparatus body;
An exterior cover that is provided on the apparatus main body in a state of covering the transport guide member, and is axially supported at one edge so as to be openable and closable with respect to the apparatus main body,
A lock member that is provided at a predetermined position of the apparatus main body corresponding to both widthwise ends of the transport guide member and locks the transport guide member at the closed position to the closed position,
The transport guide member is provided between the exterior cover and the transport guide member and protrudes from at least one of the exterior cover and the transport guide member, and presses the transport guide member when the exterior cover moves to the closed position. And a pressing member that shifts the sheet to a closed position. The sheet conveying device according to claim 1, wherein the pressing member is provided at one position. The transport roller is provided near a substantially central portion in the width direction of the transport guide member, while the pressing member is provided near a position on the transport guide member opposite to the transport roller. 3. The paper transport device according to 2. The pressing member is characterized in that both ends in the longitudinal direction are pivotally supported by the transport guide member and the exterior cover, respectively, and are configured as link members for interlocking the opening and closing operations of the exterior cover and the transport guide member. The sheet transport device according to any one of claims 1 to 3, wherein 5. The transport guide member according to claim 1, wherein the transport guide member is formed of a synthetic resin material, and a plurality of reinforcing ribs are provided along a width direction of the transport guide member. Paper transport device according to the item.

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