JP2017128425A - Sheet feeding device, image forming apparatus, and sheet storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device capable of avoiding a sheet jam or the like due to damage to sheets by enabling an excessive loading state to be recognized at the time point where the sheets are loaded to improve usability, an image forming apparatus, and a sheet storage device.SOLUTION: A sheet feeding device includes a sheet cassette 105, and a feeding roller capable of feeding sheets loaded on a sheet loading tray 114 in the sheet cassette 105 while abutting on the uppermost sheet. Further, the sheet feeding device includes an excessive loading prevention member 10 for defining a maximum loading capacity of the sheets loaded on the sheet loading tray 114 by positioning a sheet pressing section at a maximum loading position corresponding to the maximum loading capacity, and a locking member 11. The locking member 11 locks the excessive loading prevention member 10 by a locking section with the sheet pressing section positioned at the maximum loading position at a pullout position of the sheet cassette 105, and releases the locking by the locking section of the excessive loading prevention member 10 at a mounting position.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet feeding apparatus provided with a sheet storage unit that can be attached to and pulled out from an apparatus main body, an electrophotographic image forming apparatus including the sheet feeding apparatus, and a sheet storage apparatus.

  In an image forming apparatus such as an electrophotographic system, in order to enable a large amount of printing, a paper cassette (sheet storage means, sheet storage device) capable of storing a large amount of sheet bundles for transferring images is provided in the apparatus main body. It has been known. A sheet feeding cassette used in such an image forming apparatus usually has a side end regulating member and a rear end regulating member for regulating the position of the sheet in the sheet feeding cassette, and lifts the sheet toward the feeding roller. A sheet stacking table to be uploaded is arranged. Since the sheet height that can be stacked on the sheet stacking table is defined as a predetermined height, the side edge regulating member and the trailing edge regulating member include a stamp, a label, or the like indicating the sheet stacking restriction height. A display is provided.

  If the sheets are stored exceeding the stacking limit height, the following problems are concerned. The first point is that when the load weight exceeds the specified value due to the overloading of sheets, a loss of lift-up pressure is generated by the sheet stacking urging spring that lifts up the sheet stacking table. Poor feeding due to insufficient contact pressure may occur. The second point is that when a sheet feeding cassette is inserted into the apparatus main body in a state where sheets are overloaded, when an overloaded sheet bundle collides with a feeding roller, a feeding roller or a feeding roller holding member In addition, there is a possibility that surrounding parts such as a drive shaft performing drive transmission may be damaged. Therefore, it is necessary to reliably prevent the sheet cassette from being stored in the apparatus main body in an overloaded state.

  However, even if an attempt is made to prevent overloading by providing a full load height indication such as a stamp or label on the side end regulating member or the rear end regulating member, the user (operator) overloads the sheet without noticing the display. There was enough potential. In response to such a problem, when a user inserts a sheet cassette with overloaded sheets into the main body of the apparatus, the sheet exceeding the limit height is pushed out of the sheet cassette to prevent overloading. A technique including an overload prevention lever is known (see Patent Document 1).

JP-A-2005-225643

  In the technique disclosed in Patent Document 1, an overload prevention lever that pushes out an overloaded sheet when a paper feed cassette is inserted into the apparatus main body is provided as a means for preventing sheet overload on the paper feed cassette. It is arranged at the entrance when the cassette is inserted. According to this, there is a possibility that the sheet may be damaged due to the collision with the overload prevention lever, and a crease or the like may be formed, and if the damaged sheet is set in the sheet feeding cassette at the next sheet replenishment timing. , There is a concern of feeding failure such as jam (paper jam).

  Further, according to the technique described in Patent Document 1, the user can recognize that the sheets are overloaded when the sheet feeding cassette is mounted on the apparatus main body, not at the time when the sheets are stacked. There was also an unfavorable problem in usability.

  Therefore, the present invention is a sheet feeding device that allows a user to recognize an overloaded state at the time of stacking sheets, improves usability, and avoids a paper jam or poor feeding due to damage to the sheet, An object is to provide an image forming apparatus and a sheet storage device.

  In the sheet feeding apparatus, the present invention is arranged in the apparatus main body, a sheet storage unit having a sheet stacking unit that can be attached to and withdrawn from the apparatus main body, and that is capable of moving up and down to stack sheets. A sheet feeding means capable of feeding in contact with the uppermost sheet of the sheets stacked on the sheet stacking means of the sheet storing means mounted on the apparatus main body, and disposed on the sheet storing means. An overload preventing means for defining the maximum stacking amount by positioning a defining portion at a maximum stacking position corresponding to the maximum stacking amount of sheets stacked on the stacking means, and a latching portion capable of locking the overload preventing means And the overload prevention means is locked by the locking portion in a state in which the regulation portion is positioned at the maximum loading position when the sheet storage means is pulled out from the apparatus main body. And, in the sheet containing means is mounted to the apparatus main body mounting position, characterized in that and a locking means for releasing the locking by the locking portion with respect to the overload prevention unit.

  The present invention includes a sheet stacking unit that can be mounted on and pulled out from the apparatus main body, and that can move up and down to stack sheets. In a sheet storage apparatus that stores sheets, the maximum number of sheets stacked on the sheet stacking unit is provided. An overload preventing means for defining the maximum load amount by positioning the defining portion at the maximum loading position corresponding to the load amount, and a locking portion for locking the overload preventing means, and is pulled out from the apparatus main body. In the pulled-out position, the overload prevention means is locked by the locking portion in a state in which the defining portion is located at the maximum loading position, and the overload prevention means with respect to the overload prevention means is mounted at the attachment position attached to the apparatus main body. And locking means for releasing the lock by the locking portion.

  According to the present invention, it is possible to improve the usability by enabling the user to recognize the overloading state at the time of stacking sheets, and to avoid a paper jam or feeding failure caused by damage to the sheet. Can be realized.

1 is a schematic cross-sectional view illustrating a laser beam printer as an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. FIG. 3 is a perspective view illustrating the entire sheet feeding cassette according to the first embodiment. 1A and 1B show a fixing structure of a regulation member of a paper feed cassette according to a first embodiment, wherein FIG. 1A is a cross-sectional view showing a fixed state, and FIG. (A) is a perspective view showing the rear end regulating member in the paper feed cassette according to the first embodiment as viewed from the downstream side in the sheet feeding direction, and (b) is a rear end regulating member (a). The perspective view which shows in the state seen from the other side. (A) is a side sectional view showing a state in which sheets are stacked to the full load position on the paper feed cassette according to the first embodiment, and (b) is a full view of the sheet stacking base in the paper feed cassette of (a). Side surface sectional drawing which shows the state lifted up. (A) is a rear view showing the rear end regulating member of the paper feed cassette according to the first embodiment as viewed from the upstream side in the sheet feeding direction, and (b) is a diagram of the paper feed cassette of (a). The rear view which shows the state accommodated in the apparatus main body. (A) is a rear view which shows the rear-end regulation member at the time of the paper feed cassette concerning the 2nd Embodiment of this invention being pulled out. (B) is side surface sectional drawing which shows the rear-end control member of (a). (C) is a rear view showing a rear end regulating member when the paper feed cassette according to the second embodiment is mounted. (D) is a side sectional view showing the rear end regulating member of (c). (A) is a rear view showing a side end regulating member when the paper feed cassette according to the third embodiment of the present invention is pulled out, and (b) is a side end regulation when the paper feed cassette is mounted. The rear view which shows a member.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. First, an image forming apparatus 100 including a sheet feeding device 120 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing the image forming apparatus 100 according to this embodiment as viewed from the front. In the present embodiment, for example, a laser beam printer is used as the image forming apparatus 100.

[Image forming apparatus]
As shown in FIG. 1, the image forming apparatus 100 includes an image forming apparatus main body (hereinafter, referred to as apparatus main body) 100a. The apparatus main body 100a is provided with an image forming unit 118 for forming an image by an electrophotographic method, and a sheet storage unit and a sheet feeding cassette 105 as a sheet storage apparatus are provided so as to be able to be mounted and pulled out from the apparatus main body 100a. Yes. The image forming unit 118 includes a photosensitive drum 101 that forms a toner image, a transfer roller 102 that transfers the toner image formed on the photosensitive drum 101 to the sheet S, and the like.

  When image formation is started in the image forming unit 118, first, the laser scanner 103 emits light corresponding to the image signal to the photosensitive drum 101, and a latent image is formed on the photosensitive drum 101. Subsequently, the latent image is developed with the toner stored in the toner cartridge 104, so that a toner image (visible image) is formed on the photosensitive drum 101.

  When the sheet S is fed from the sheet feeding cassette 105 by the feeding roller 113 in parallel with such a toner image forming operation, the sheet S passes through the conveying roller 115 and the separation roller 116 and the registration roller pair 107. It is conveyed to. Then, this sheet S is synchronized with the image formed on the photosensitive drum 101 toward the transfer portion T composed of the photosensitive drum 101 and the transfer roller 102 via the registration roller pair 107. Be transported. The feeding roller 113 is disposed in the apparatus main body 100a, and is capable of feeding in contact with the uppermost sheet of the sheet S stored in a sheet feeding cassette (sheet storing means, sheet storing apparatus) 105. Configure.

  Then, in the transfer portion T, the toner image is transferred to the sheet S by applying a bias to the transfer roller 102. Further, the sheet S to which the toner image has been transferred is conveyed to the fixing unit 108, where the toner image is fixed by being heated and pressed in the fixing unit 108, and then the upper part of the main body of the apparatus via the discharge roller pair 109. Is discharged to the discharge unit 110. The image forming unit 118 and the fixing unit 108 constitute an image forming unit that forms an image on the sheet S fed by the sheet feeding device 120.

[Paper cassette]
Next, details of the paper feed cassette (sheet storage means, sheet storage device) 105 according to the present embodiment will be described with reference to FIGS. 2, 3A, and 3B. FIG. 2 is a perspective view showing the paper feed cassette 105 according to this embodiment. 3A and 3B show a fixing structure of the regulating member of the paper feed cassette 105 according to the present embodiment, FIG. 3A is a sectional view showing a fixed state, and FIG. 3B shows a state where the fixing is released. It is sectional drawing.

  As shown in FIG. 2, the sheet cassette 105 includes a sheet stacking table 114, a pair of slidable side end regulating members 111a and 111b for regulating the side end positions of various size sheets, and an upstream in the sheet feeding direction. And a rear end regulating member 112 that regulates the end position (rear end position). The sheet feeding cassette 105 is slidably held by a rail portion (not shown) on the apparatus main body 100a side so that rails 105a (only one side is shown) provided on both sides of the cassette main body are attached to the apparatus main body 100a. It is supported so that it can be mounted and pulled out.

  The sheet stacking table 114 can be moved up and down with respect to the sheet feeding cassette 105 and constitutes a sheet stacking unit on which sheets are stacked. The trailing edge regulating member 112 is movably disposed in the sheet feeding cassette 105 and constitutes an edge regulating means for regulating the edge position of the sheets stacked on the sheet stacking table 114, which will be described later. The same applies to the second embodiment.

  The side end regulating members 111a and 111b have racks 1a and 1b, respectively, and these racks 1a and 1b mesh with a common pinion 2 that is rotatably disposed between the racks 1a and 1b. Accordingly, when any one of the side end regulating members 111a and 111b (the side end regulating member 111a in this embodiment) is moved in the width direction, the side end regulating member 111a is operated by the action of the pinion 2 and the racks 1a and 1b. , 111b move in the opposite direction to each other in conjunction with each other.

  The side end regulating members 111a and 111b are fixed at positions corresponding to various sheet sizes, as shown in FIG. 3A, the tooth portion 3a of the width direction fixed rack 3 provided on the bottom surface of the sheet feeding cassette, and the side end. This is performed by meshing with the tooth portion 4a of the width direction fixing member 4 provided on the regulating member 111a. When the upper portion of the fixing release lever 5 is held between the rear end portion 111c of the side end regulating member 111a with the finger held between the width direction fixing member 4 and the lever release fulcrum 6 (see FIG. 3) (See (b)). Therefore, as shown in FIG. 3B, the lower convex portion 5 a of the fixing release lever 5 pushes up the upper engaged portion 4 b of the width direction fixing member 4 in the arrow G direction. Thereby, the width direction fixing member 4 which has engaged the tooth part 4a with the tooth part 3a of the width direction fixing rack 3 will be in a lift state, and the side end regulating member 111a will be in a movable state. In addition, the code | symbol 4c has shown the recessed part.

  As shown in FIG. 2, the trailing edge regulating member 112 is in the sheet feeding direction (arrow D direction) along a trailing edge regulating guide groove (not shown) provided in the arrow W direction on the bottom surface of the sheet feeding cassette 105. It is configured to be movable. Further, the rear end regulating member 112 is fixed similarly to the case of the side end regulating member 111 a, the tooth portion 7 a of the front / rear direction fixing rack 7 provided in the paper feed cassette 105, and the rear end provided in the rear end regulating member 112. This is performed by meshing with the tooth portion 8a (see FIG. 4B) of the regulation rack member 8. The sheet stacking table (sheet stacking means) 114 is supported so as to be rotatable around the rotation fulcrums 9a and 9b, and a lift arm (not shown) is given a driving force from a lift motor (not shown). Is lifted up. That is, when the sheet cassette 105 is inserted into the apparatus main body 100 a after the user has stacked the sheets S on the sheet stacking table 114, the bundle of sheets S is pushed up to a position where the sheet S comes into contact with the feeding roller 113.

  Since the sheet height that can be stacked on the sheet stacking table 114 is set to a predetermined height, the sheet side edge regulating members 111a and 111b and the trailing edge regulating member 112 are engraved indicating the sheet stacking limit height. And a label (refer to the full load indicator 40 in FIG. 5A). In the overload preventing member 10 according to the present embodiment, the sheet pressing portion 10b at the drawing position of the sheet feeding cassette 105 corresponds to the position of the full load marking portion 40.

[Configuration of rear end regulating member]
Next, a detailed configuration of the rear end regulating member will be described with reference to FIGS. 4 (a) and 4 (b) to FIGS. 6 (a) and 6 (b). 4A is a perspective view illustrating the trailing edge regulating member 112 in the sheet feeding cassette 105 according to the present embodiment as viewed from the downstream side in the sheet feeding direction, and FIG. 4B is a diagram illustrating FIG. FIG. 5A is a perspective view showing the rear end regulating member 112 as viewed from the opposite side to FIG.

  As shown in FIGS. 4A and 4B, the trailing end regulating member 112 includes a sheet position regulating surface 112a standing up and down, and a front side (downstream in the sheet feeding direction) from the lower portion of the sheet position regulating surface 112a. ) Projecting portion 112b. A holding portion 51 extends from one side of the protruding portion 112 b so as to protrude to one side of the paper feed cassette 105. The holding portion 51 supports a long slide portion 11d of the lock member 11 so as to be slidable in the horizontal direction (one side). The holding part 51 supports the slide part 11d of the lock member 11 so as to be slidable by a plurality (six in this embodiment) of support convex parts 51a. The lock member 11 has an abutment portion 11b at one end of the slide portion 11d and an upright portion 11a provided with a locking portion 11c at the other end.

  The sheet position regulating surface 112a of the trailing edge regulating member 112 is provided with an overload preventing member 10 that is slidably held in the height direction (vertical direction). The overload prevention member 10 has a long hole portion 10a formed in the longitudinal direction, and has a locked portion 10c locked by a locking portion 11c below the long hole portion 10a. The overloading prevention member 10 is slidably fitted into the upper and lower two-stage protrusions 112c protruding from between the side part 112d and the side part 112e of the rear end regulating member 112, The parts 112d and 112e are supported so as to be slidable in the vertical direction.

  On the back surface portion of the sheet position regulating surface 112a, an upright portion 11a is supported below the overload prevention member 10 so as to be movable in the directions of arrows H and I. The other end of the compression spring 12 with one end abutting against the upright portion 11a is in contact with the accommodating portion 112f having a shape protruding from the lower portion of the side portion 112e toward the rear end regulating rack member 8. Further, a rear end regulating rack member 8 having a tooth portion 8a in the lower portion is supported on the back surface portion of the seat position regulating surface 112a so as to be slidable in the vertical direction. When the upper part of the fixing release lever 16 is held between the rear surface part 17 of the rear end regulating member 112 and a finger is held, the fixing release lever 16 rotates about the lever rotation fulcrum 16b and the lower convex part 16a. Pushes up the rear end regulating rack member 8. As a result, the rear end regulating rack member 8 that has engaged the tooth portion 8a with the tooth portion 7a of the front-rear direction fixed rack 7 is in a lift state, and the rear end regulating member 112 is in a movable state.

  An overload prevention member 10 as an overload prevention means is disposed in the paper feed cassette 105 and has a sheet pressing portion (regulating portion) 10b at the maximum stacking position corresponding to the maximum stacking amount of sheets stacked on the sheet stacking table 114. Position and define the maximum load capacity. The overloading prevention member 10 is supported by the rear end regulating member 112 so as to be movable in the vertical direction, and constitutes a vertical movement overloading prevention member provided with a sheet pressing part (regulating part) 10b on the upper part.

  Further, the lock member 11 as the lock means has a locking portion 11 c that can lock the overload preventing member 10 below the overload preventing member 10. When the sheet feeding cassette 105 is pulled out from the apparatus main body 100a, the lock member 11 holds the overload preventing member 10 with the locking portion 11c in a state where the sheet pressing portion (regulating portion) 10b is positioned at the maximum stacking position. Lock it. Then, the lock member 11 releases the lock by the locking portion 11c with respect to the overloading prevention member 10 at the attachment position where the paper feed cassette 105 is attached to the apparatus main body 100a.

  That is, when the paper feed cassette 105 is mounted in the apparatus main body, the lock member 11 is attached to the main body frame (contacted part) 14 (see FIG. 6) provided in the apparatus main body, and the locking portion 11c. The abutting portion 11b connected to the abutting portion moves in one direction (arrow H direction). Thereby, the lock | rock of the latching | locking part 11c with respect to the overloading prevention member 10 is cancelled | released. Further, when the paper feed cassette 105 is pulled out from the apparatus main body 100a, the lock member 11 moves in the other direction (arrow I direction) by separating the contact portion 11b from the main body frame 14, and the locking portion 11c. Thus, the lock member 11 is locked. As described above, in this embodiment, the overload prevention member (overload prevention means) 10 and the lock member (lock means) 11 are arranged on the rear end restriction member 112 as the end portion restriction means. The same applies to the second embodiment described later.

  Next, a relationship between the rotating sheet stacking table 114 and the overload preventing member 10 will be described with reference to FIGS. FIG. 5 is a cross-sectional view showing a state viewed from the side of the rear end regulating member 112. FIG. 5A shows a full-load marking unit in which the sheet feeding cassette 105 is pulled out from the apparatus main body 100a for replenishing the sheet S. A state in which the sheets S are stacked up to the full load position indicated by 40 is shown. FIG. 5B shows a state in which the sheet stacking table 114 has been lifted up from the state of FIG.

  In the mounting position where the paper feed cassette 105 is mounted on the apparatus main body 100a, the overloading prevention member 10 has a vertically extending long hole portion 10a formed by a protrusion 112c on the rear end regulating member 112 side in the vertical direction. Supported to move. The overload prevention member 10 is locked with the sheet pressing portion 10b protruding to the sheet side from the sheet position regulating surface 112a of the trailing edge regulating member 112 when the sheet feeding cassette 105 is in the drawing position. The height of sheet stacking is defined (FIG. 5A).

  When the paper feed cassette 105 is inserted into the apparatus main body 100a from the drawing position and positioned at the mounting position, the lock member 11 slides to disengage the locked portion 10c from the locking portion 11c, and the overload prevention member 10 Release the lock on. When the sheet stacking table 114 is lifted up from this state and the sheet bundle is raised, the trailing end of the sheet bundle is inclined with respect to the sheet position regulating surface 112a by the rotation of the sheet stacking table 114. However, since the overload preventing member 10 is movable in the vertical direction, the sheet pressing portion 10b does not press the rear end portion of the sheet bundle. Therefore, the sheet S fed out by the rotation of the feeding roller 113 during feeding does not receive a load at the rear end (upstream end).

  Next, with reference to FIGS. 6A and 6B, a state when the paper feeding cassette 105 is pulled out to the drawing position and a state when it is inserted into the mounting position will be described. 6 is a rear view showing the rear end regulating member 112 as viewed from the rear side (left side in FIG. 5). FIG. 6A shows the sheet feeding of the rear end regulating member 112 in the sheet feeding cassette 105. FIG. Shown from the upstream side of the direction. FIG. 6B shows a state where the paper feed cassette 105 of FIG. 6A is stored in the apparatus main body.

  The overload prevention member 10 in FIG. 6A is positioned at the lowest point due to its own weight within the slide region, and is provided by the locking portion 11c of the lock member 11 urged in the direction of the arrow X1 by the compression spring 12. The locked portion 10c is locked. The compression spring 12 is provided to be contracted between the upright portion 11 a of the lock member 11 and the accommodating portion 112 f of the rear end regulating member 112. In this state, the sheet pressing portion 10b of the overload preventing member 10 that is restricted from sliding in the vertical direction by the lock member 11 is fixed at the maximum sheet stacking height.

  In the present embodiment, the overload prevention member 10 is positioned at the lowest point under its own weight. However, the present invention is not limited to this, and the overload prevention member 10 is overloaded by interposing a spring (not shown) having a relatively weak spring force. It is good also as a structure which urges | biases the prevention member 10 toward the lowest point. In that case, it becomes possible to perform the operation | movement which the latching | locking part 11c of the locking member 11 returns from the state of FIG.6 (b), and latches the to-be-latched part 10c more smoothly.

  Here, in a state in which the paper feed cassette 105 is properly inserted into the mounting position in the apparatus main body, as shown in FIGS. 5B and 6B, the lock member 11 has a main body frame in the apparatus main body. When the abutting portion 11b comes into contact with 14, it is moved in the direction of the arrow X2 by the reaction force. Thereby, the overload prevention member 10 becomes movable in the arrow Z direction (FIG. 6B) when the lock by the lock member 11 is released. For this reason, even when the sheet S is lifted up by the sheet stacking table 114 and moved to a position where it comes into contact with the feeding roller 113, the sheet S is a sheet pressing portion (regulating portion) 10 b of the overload preventing member 10. And the sheet stacking table 114.

  According to the present embodiment described above, since the overload preventing member 10 that can prevent sheets from being stacked to a height higher than the stacking limit height is provided in the rear end regulating member 112, the sheet feeding cassette 105 can be In this state, the overload preventing member 10 is fixed at the full sheet position. When the sheet cassette 105 is inserted into the apparatus main body, it can be moved by releasing the lock so as not to affect the sheet feeding and conveyance. As described above, even when the sheet stacking table 114 is lifted up and the feeding operation is performed, it is possible to reliably prevent overloading without affecting the sheet feeding. For this reason, it is possible to make the user surely recognize the sheet stacking limit height and prevent overloading when sheets are set in the sheet feeding cassette 105.

  In addition, since the sheet stacking limit height can be surely recognized when performing the sheet stacking operation, an overload prevention lever that pushes overloaded sheets when the sheet feeding cassette 105 is inserted into the apparatus main body 100a. It is not necessary to provide (not shown) in the apparatus main body. In such a configuration, it is possible to reliably prevent inconveniences such as paper jams and poor feeding due to damage to the excessively stacked excess sheets. In addition, a structure that can reliably prevent overloading can be realized by a simple configuration in which the overload prevention member 10 is supported by the rear end regulating member 112 so as to be movable in the vertical direction by the protrusion 112c.

  Note that the side end regulating members 111a and 111b adopt a central reference based on the central portion of the transport sheet in the present embodiment, and thus are configured to move relative to each other. However, when the one-side reference based on one side of the transport sheet is employed, only one of the side end regulating members 111a and 111b needs to move. Accordingly, it is sufficient that at least one of the side end regulating members 111a and 111b is configured to be movable in the width direction orthogonal to the sheet feeding direction, and these points also apply to the second and third embodiments described later. It is the same.

<Second Embodiment>
Next, a sheet feeding device 120 according to a second embodiment of the present invention and an image forming apparatus 100 including the same will be described with reference to FIGS. FIG. 7A is a rear view showing the rear end regulating member 112 when the paper feed cassette 105 according to the present embodiment is pulled out. FIG.7 (b) is side surface sectional drawing which shows the state which cut | disconnected Fig.7 (a) by the AA line and looked at the arrow direction. FIG. 7C is a rear view showing the rear end regulating member 112 when the paper feed cassette 105 is mounted. FIG.7 (d) is side surface sectional drawing which shows the state which cut | disconnected FIG.7 (c) by the AA line and looked at the arrow direction. Note that in the second embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and descriptions of components having the same configuration and function are omitted. In the present embodiment, the main components other than the rear end regulating member 112 of the paper feed cassette 105 are the same as those in the first embodiment, and thus description thereof is omitted here.

  The overload prevention member (rotation overload prevention member) 20 as the overload prevention means according to the present embodiment is rotatably supported on the upper portion of the rear end regulating member 112 with the rotation shaft 20a as a fulcrum. . The overload prevention member 20 has a sheet pressing portion (regulating portion) 20b that protrudes beyond the sheet position regulating surface 112a of the trailing edge regulating member 112 that is an edge regulating means. In the overload prevention member 20, the upper sheet pressing portion 20b is retracted from the sheet position regulating surface 112a and the position in FIGS. 7A and 7B where the sheet position regulating surface 112a protrudes downstream in the feeding direction. It is supported to rotate between the positions of FIGS. 7C and 7D. An opening 112g for projecting the sheet pressing portion 20b is formed on the upper portion of the sheet position regulating surface 112a.

  The locking member 21 as the locking means according to the present embodiment includes a contact portion 21b at one end of the slide portion 21d, and an upright portion 21a having a locking portion 21c at the other end. A locking portion 21c is formed on the upright portion 21a. The holding portion 51 supports the slide portion 21d of the lock member 21 so as to be slidable in the horizontal direction (one side). The holding | maintenance part 51 is supporting the slide part 21d of the lock member 21 so that a slide is possible by the some support convex part 51a.

  The lock member 21 moves in one direction (the direction of the arrow X1) when pulled out from the mounting position to the pull-out position, and engages the back surface 20c of the overload prevention member 20 at the position shown in FIGS. 7 (a) and 7 (b). Locked by the stopper 21c. Accordingly, the overload prevention member 20 defines the maximum stacking amount by positioning the sheet pressing portion 20b at the maximum stacking position corresponding to the maximum stacking amount of the sheets stacked on the sheet stacking table 114. Further, the lock member 21 moves in the other direction (the direction of the arrow X2) when the paper feed cassette 105 is inserted into the mounting position, and the overload prevention member 20 is moved as shown in FIGS. 7 (c) and 7 (d). The locking portion 11c is separated from the back surface 20c to release the lock.

  In the above-described embodiment, when the paper feed cassette 105 is pulled out from the apparatus main body 100a, the contact between the lock member 21 and the main body frame 14 is released, and the lock member 21 is urged by the compression spring 12. 7 Move in the direction of arrow X1 as shown in (a) and (b). Thereby, in the drawing position, the lock member 21 locks the back surface 20c of the overloading prevention member 20 by the engaging portion 21c. For this reason, the sheet pressing portion 20b protruding from the sheet position regulating surface 112a can prevent the sheet stack (S) from being overloaded beyond the maximum stacking height (stacking regulation height). .

  When the paper feeding cassette 105 is inserted into the apparatus main body, the lock member 21 is abutted against the main body frame 14 in the apparatus main body as shown in FIGS. It is slid in the direction of arrow X2 by force. When the lock member 21 slides, the locking portion 21c that restricts the rotation of the overload prevention member 20 retracts from the back surface 20c of the overload prevention member 20, so that the overload prevention member 20 is unlocked. Here, as the locking member 21 slides, the inner side of the rear end regulating member 112 is arranged so that the overload prevention member 20 can smoothly rotate from the position of FIG. 7B to the position of FIG. A slope portion 21g is formed in the upper portion of the.

  In this state, when the sheet S on the sheet stacking table 114 is lifted up (see FIG. 5B), the overload preventing member 20 is rotated by the contact pressure from the sheet bundle (S). Move to the retreat position shown in (c), (d). In this way, the overload prevention member 20 functions only when the sheet is replenished and retracts to a position where it does not come into contact with the sheet S during feeding, so that the feeding operation is not impaired.

  According to the present embodiment described above, the same effect as that of the first embodiment can be obtained. In addition, since the overload prevention means can be realized with a simple configuration in which the overload prevention member 20 is supported on the rear end regulating member 112 by the rotation shaft 20a, the configuration is simpler than that of the first embodiment. The effect that it is possible is also acquired.

<Third Embodiment>
Next, a sheet feeding apparatus 120 according to a third embodiment of the present invention and an image forming apparatus 100 including the same will be described with reference to FIGS. 8 (a) and 8 (b). FIG. 8A is a rear view showing the side end regulating member 111a when the paper feed cassette 105 according to the present embodiment is pulled out, and FIG. 8B is a view when the paper feed cassette 105 is mounted. It is a rear view which shows this side edge regulating member 111a. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and descriptions of components having the same configuration and function are omitted. Also in the present embodiment, the main components other than the side end regulating member 111a of the paper feed cassette 105 are the same as those in the first embodiment, and thus the description thereof is omitted here.

  As shown in FIGS. 8A and 8B, the side end regulating member 111a has a long groove portion 111e formed in the vertical direction in the vicinity of one side. In the long groove portion 111e, an overload prevention member 30 as an overload prevention means is accommodated so as to be slidable in the vertical direction (the direction of the arrow Z). At the position corresponding to the long groove portion 111e in the side end regulating member 111a, a two-step projecting portion 111d is provided. The overload prevention member 30 has a long hole portion 30a extending in the longitudinal direction thereof, and a protrusion 111d is slidably engaged with the long hole portion 30a so as to be slidable in the vertical direction. It is supported. The overload preventing member 30 according to the present embodiment is positioned at the maximum stacking position corresponding to the maximum stacking amount of sheets stacked on the sheet stacking table 114 by positioning the sheet pressing portion (regulating portion) 30b provided at the upper portion to the maximum. It is possible to define the loading capacity.

  As shown in FIGS. 8A and 8B, a lock member 31 as a lock unit is rotatably supported by a rotation shaft 31a below the long groove portion 111e in the side end regulating member 111a. . The lock member 31 is always urged in the lock direction (counterclockwise direction in FIG. 8A) by a torsion spring (not shown). The lock member 31 has a hook-shaped locking portion 31c that can lock the locked portion 30c of the overload prevention member 30 formed at the upper portion, and an opening 111f provided at the lower portion of the side end regulating member 111a. A protruding contact portion 31b is formed in the lower portion.

  The locking member (locking means) 31 in the present embodiment locks the overload prevention member 30 when the paper feeding cassette 105 (FIG. 2) is pulled out from the loading position to the drawing position, and is inserted into the loading position of the paper feeding cassette 105. Sometimes the overload prevention member 10 is unlocked. That is, when the paper feed cassette 105 is pulled out from the apparatus main body 100a (FIG. 1), the lock member 31 separates the contact portion 31b from the bottom plate frame (contacted portion) 15 to move in the other direction (counterclockwise). Direction). As a result, the overload prevention member 30 that has been slid to the lowest point shown in FIG. 8A is engaged with the engaged portion 30c by the engagement portion 31c of the lock member 31, and the sheet on the sheet stacking table is Is restricted to a state in which the stacking restriction height is defined by the sheet pressing portion (defining portion) 30b. As shown in FIG. 8A, in the state where the sheet feeding cassette 105 (FIG. 2) is in the pull-out position, the overload preventing member 30 has the sheet pressing portion 30b on the sheet position regulating surface (see FIG. 8 (a) is in a locked state in a state protruding from the sheet side.

  On the other hand, when the paper feed cassette 105 is mounted in the apparatus main body, the contact portion 31b connected to the locking portion 31c is applied to the bottom plate frame (contacted portion) 15 provided in the apparatus main body. By contacting, the lock member 31 rotates in one direction (clockwise direction). Thereby, the lock | rock of the latching | locking part 31c with respect to the overloading prevention member 30 is cancelled | released. That is, as shown in FIG. 8B, when the contact portion 31b of the lock member 31 contacts the bottom plate frame 15 constituting the bottom surface of the main body frame 14 (see FIGS. 6 and 7), the lock member 31 is The overload prevention member 30 is rotated to a position where the locking is released. As a result, the overload prevention member 30 can slide in the direction of the arrow Z in a state where the sheet cassette 105 is stored in the apparatus main body, and the sheet stacking table 114 (see FIG. 5) can be lifted up. Even if it is performed, the feeding operation is not affected.

  Further, when this configuration is provided on both of the side end regulating members 111a and 111b, the sheets stacked up to the vicinity of the full load are skewed by the feeding operation, and the rear end of the sheet gets over the upper surface of the side end regulating member. It is also possible to prevent a large skew of the sheet that occurs due to the ineffective width regulation.

  In the present embodiment, the side end regulating member 111a is configured as the end portion regulating means, but the opposite side end regulating member 111b may be configured as the end portion regulating means, and both the side end regulating members 111a and 111b are provided. It is also possible to provide an overload preventing member 30 as an end regulating means.

  According to the present embodiment described above, the same effect as that of the first embodiment can be obtained. In addition, since the locking means can be realized by a simple configuration in which the locking member 31 is supported on the side end regulating member 111a by the rotation shaft 31a, the number of parts can be reduced as compared with the first embodiment, and the configuration can be further improved. The effect that it becomes simple is also acquired.

  In the first to third embodiments described above, the electrophotographic image forming apparatus has been described, but instead, for example, an image is formed on a sheet by ejecting ink liquid from a nozzle. It can also be used in an inkjet image forming apparatus.

10: Overload prevention member (overload prevention means, vertical motion overload prevention member)
10b, 20b, 30b ... sheet pressing part (regulating part)
11, 21, 31 ... Lock member (locking means)
11b, 21b, 31b ... contact portions 11c, 21c, 31c ... locking portion 14 ... main body frame (contacted portion)
15 ... bottom plate frame (contacted part)
20 ... Overload prevention member (overload prevention means, rotation overload prevention member)
30 ... Overload prevention member (overload prevention means, vertical motion overload prevention member)
DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus 100a ... Apparatus main body 105 ... Paper feed cassette (Sheet storage means, sheet storage apparatus)
108, 118... Fixing section, image forming section (image forming means)
111a, 111b ... side end regulating member (end portion regulating means)
112 ... Rear end regulating member (end portion regulating means)
113: Feeding roller (sheet feeding means)
114 ... Sheet stacking table (sheet stacking means)
120 ... Sheet feeding device S ... Sheet

Claims (14)

The device body;
A sheet storage means that has a sheet stacking means that can be mounted on and pulled out from the apparatus main body, and that can be moved up and down, on which sheets are stacked;
A sheet feeding means arranged in the apparatus main body and capable of feeding in contact with the uppermost sheet of the sheets stacked on the sheet stacking means of the sheet storage means mounted on the apparatus main body;
An overload prevention unit that is disposed in the sheet storage unit and defines the maximum stacking amount by positioning a defining unit at a maximum stacking position corresponding to the maximum stacking amount of sheets stacked on the sheet stacking unit;
A locking portion capable of locking the overload prevention means, and the sheet storage means is in the pulled-out position where the sheet storage means is pulled out from the apparatus main body, and the overload prevention is performed with the defining portion positioned at the maximum stacking position. Locking means for locking the means by the locking portion, and releasing the lock by the locking portion with respect to the overload prevention means at the mounting position where the sheet storage means is mounted on the apparatus main body.
A sheet feeding apparatus characterized by that. An end regulation means that is movably disposed in the sheet storage means and regulates the end position of the sheets stacked on the sheet stacking means;
The overload prevention means and the lock means are disposed in the end regulating means,
The sheet feeding apparatus according to claim 1. The overload prevention means is a vertical overload prevention member that is supported by the end restricting means so as to be movable in the vertical direction, and has the defining portion on the top.
The sheet feeding apparatus according to claim 2, wherein the sheet feeding apparatus is a sheet feeding apparatus. The overload prevention means is a rotation overload prevention member that is rotatably supported by the end regulating means and has the defining portion provided on the upper part.
The sheet feeding apparatus according to claim 2, wherein the sheet feeding apparatus is a sheet feeding apparatus. The locking means is
When the sheet storage means is mounted in the apparatus main body, a contact portion connected to the locking portion is brought into contact with a contacted portion provided in the apparatus main body in one direction. And the lock by the locking portion with respect to the overload prevention means is released, and when the sheet storage means is pulled out from the apparatus main body, the contact portion is separated from the contacted portion. A locking member that moves in the other direction and locks the overload prevention means by the locking portion.
The sheet feeding device according to any one of claims 2 to 4, wherein the sheet feeding device is provided. The end regulating means is a rear end regulating member that regulates the upstream end position in the sheet feeding direction of the sheets stacked on the sheet stacking means.
The sheet feeding apparatus according to claim 2, wherein the sheet feeding apparatus is a sheet feeding apparatus. The end portion restricting means is a pair of side end restricting members that can move at least one of the side end positions in the width direction perpendicular to the sheet feeding direction of the sheets stacked on the sheet stacking means. is there,
The sheet feeding apparatus according to claim 2, wherein the sheet feeding apparatus is a sheet feeding apparatus. A sheet feeding device according to any one of claims 1 to 7,
Image forming means for forming an image on the sheet fed by the sheet feeding device,
An image forming apparatus. In a sheet storage apparatus that has a sheet stacking means that can be mounted on and pulled out from the apparatus main body and that can be moved up and down to stack sheets, and stores sheets.
Overload preventing means for defining the maximum stacking capacity by positioning a defining portion at a maximum stacking position corresponding to the maximum stacking capacity of the sheets stacked on the sheet stacking means;
A locking portion capable of locking the overload preventing means, and the locking portion is locked in a state where the defining portion is located at the maximum loading position at a drawing position pulled out from the apparatus main body; Locking means for locking by the portion, and releasing the lock by the locking portion with respect to the overload prevention means at the mounting position mounted on the apparatus main body,
A sheet storage device. An end portion restricting means for restricting an end position of a sheet placed on the sheet stacking means, which is movably disposed;
The overload prevention means and the lock means are disposed in the end regulating means,
The sheet storage device according to claim 9. The overload prevention means is a vertical overload prevention member that is supported by the end restricting means so as to be movable in the vertical direction, and has the defining portion on the top.
The sheet storage device according to claim 10. The overload prevention means is a rotation overload prevention member that is rotatably supported by the end regulating means and has the defining portion provided on the upper part.
The sheet storage device according to claim 10. The end regulating means is a rear end regulating member that regulates the upstream end position in the sheet feeding direction of the sheets stacked on the sheet stacking means.
The sheet storage device according to claim 10, wherein the sheet storage device is provided. The end portion restricting means is a pair of side end restricting members that can move at least one of the side end positions in the width direction perpendicular to the sheet feeding direction of the sheets stacked on the sheet stacking means. is there,
The sheet storage device according to claim 10, wherein the sheet storage device is provided.

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