JP2017124909A - Shee feeding device and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding device and an image formation apparatus which can draw out sheet storage means sufficiently to the drawn position while avoiding the increase in the installation area and prevent inconvenience such as coming-ahead of a toggle member of a toggle arm and the like during drawing of the sheet storage means.SOLUTION: A sheet feeding device includes a guide rail 23 having a curved guide part 23c that is curved; and drawing mechanisms 50a, 50b which are arranged in a sheet feeding cassette 105 and draw in the sheet feeding cassette guided along the guide rail 23 and inserted over a prescribed position toward an attachment position. The drawing mechanism includes: a toggle arm 20 having an upper surface roller 22 that starts to be introduced to the curved guide part when crossing the prescribed position; and a toggle spring 25 which biases the toggle arm so that the upper surface roller may be introduced to the curved guide part at the prescribed position and draws in the sheet feeding cassette to the attachment position by bringing the upper surface roller introduced to the curved guide part into contact with an inner surface of the curved guide part.SELECTED DRAWING: Figure 5

Description

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

  2. Description of the Related Art Conventionally, in a sheet feeding apparatus used in an image forming apparatus such as a copying machine or a printer, a sheet feeding cassette (sheet storing means) for storing stacked sheets is attached to an image forming apparatus main body (apparatus main body). In general, it is provided so that it can be pulled out. In general, the paper feed cassette is configured to be able to store a large amount of sheet bundles in order to enable a large amount of printing. The sheets stored in the cassette body of the paper feed cassette are fed one by one toward the image forming unit by a sheet feeding unit having a pickup roller and the like.

  In the above sheet feeding device, when there are no sheets stored in the paper cassette or when changing to another sheet of a different size or type, the paper cassette is pulled out from the main body to store a new sheet. After that, the paper feed cassette is inserted into the apparatus main body again. In such a sheet feeding device, it is desirable that the sheet storage space of the sheet feeding cassette can be pulled out sufficiently before the exterior cover surface of the apparatus main body in consideration of workability of replenishing the sheet to the sheet feeding cassette. For this purpose, it is necessary to hold the paper feed cassette so that it does not fall off when the paper feed cassette is sufficiently pulled out of the apparatus main body. A cassette holding means is provided to hold the paper feed cassette. As another means, there is also known a configuration in which a guide rail that can be extended and contracted with respect to the apparatus main body is provided, and the guide rail extends from the apparatus main body to hold the paper feed cassette sufficiently drawn out from the apparatus main body. (See Patent Document 1).

  Many of these paper feed cassettes are equipped with an auto-close mechanism in the apparatus main body in order to improve usability when the sheets are stacked and then inserted into the apparatus main body. There are various methods for the auto-close mechanism, but a typical example is a method for pulling in a paper feed cassette using a toggle mechanism (see Patent Document 2).

JP 2012-126575 A JP 2006-151687 A

  However, when a drop prevention arm that protrudes from the back surface of the paper feed cassette is provided or when an auto-close mechanism is installed, a large space is required on the back surface side of the paper feed cassette. Therefore, the depth dimension of the apparatus main body is increased, which may be an obstacle to downsizing the installation area of the product. In particular, the product rear side is often used as a layout space for electrical components and drive system components, and it is not easy to compress the product depth dimension. As described in Patent Document 1, even in a system using a rail that can be expanded and contracted with respect to an apparatus main body having another configuration, it is necessary to provide two types of rails, an extendable rail and a fixed rail, on the side surface of the paper feed cassette. . For this reason, an extra space in the apparatus width direction is required, which is not suitable for downsizing in the product width direction.

  In the technique of Patent Document 2, when an impact is applied to the apparatus main body when the paper feed cassette is pulled out from the apparatus main body, there is a possibility that the following occurs. That is, there is a concern that the toggle arm waiting on the apparatus main body side for pulling in the paper feed cassette may accidentally turn to the pull-in end position even though the paper feed cassette is not stored. As a means for solving this, there is a method of returning the toggle arm to a standby position with a tool such as a driver as a return method when the toggle arm (toggle member) is advanced, but there is a problem that it is not preferable in terms of usability. is there.

  The present invention is capable of sufficiently pulling out the sheet storage means to the pull-out position while avoiding an increase in the installation area, and does not cause inconvenience such as a toggle member being advanced during the pull-out of the sheet storage means. It is an object to provide a feeding device and an image forming apparatus.

  The present invention relates to a sheet feeding apparatus, an apparatus main body, sheet storage means that can be attached to and withdrawn from the apparatus main body and that stores sheets, and is disposed in the apparatus main body, and the sheet storage means is disposed in the apparatus A rail having a bending guide portion that guides to a mounting position in the body and a drawing position pulled out from the apparatus main body and curves in a direction perpendicular to the mounting direction to the mounting position in the vicinity of the mounting position. And a pull-in means that is arranged in the sheet storage means and that is guided along the rail means and that is inserted into the apparatus main body beyond a predetermined position, and draws the sheet storage means toward the mounting position. The pull-in means includes an introduction member that is rotatably supported by the sheet storage means and starts to be introduced into the curved guide portion when the predetermined position is exceeded. The toggle member is biased so that the introduction member and the introduction member can be introduced into the bending guide portion at the predetermined position, and the introduction member introduced into the bending guide portion is applied to the inner surface of the bending guide portion. And an urging member that pulls the sheet storage means into the mounting position by being brought into contact with each other.

  According to the present invention, it is possible to sufficiently pull out the sheet storage means to the pull-out position while avoiding an increase in the installation area of the apparatus main body, and inconveniences such as the toggle member moving forward while the sheet storage means is being pulled out. It is possible to realize a configuration that does not occur.

1 is a schematic cross-sectional view illustrating an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. FIG. 3A is a perspective view showing a paper feed cassette according to the first embodiment, and FIG. 2B is a plan view showing the paper feed cassette of FIG. 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. FIG. 3 is a perspective view illustrating a lifting mechanism for a sheet stacking table in the sheet feeding cassette according to the first embodiment. It is sectional drawing which shows the drop-off prevention mechanism of the paper feed cassette which concerns on 1st Embodiment, (a) is a state in which a big turning force does not act on a drop-off prevention arm along with a state where three axes are aligned in a straight line. Show. (B) shows a state in which the paper feed cassette is mounted in the apparatus main body. It is a perspective view shown about the paper feed cassette and its drop-off prevention mechanism concerning a 2nd embodiment of the present invention, and (a) shows the state where the drop-off prevention arm protruded. (B) shows a state in which the drop-off prevention arm is folded. The top view shown about the paper feed cassette and its drop-off prevention mechanism which concern on 2nd Embodiment.

[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.

  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 100b for forming an image by an electrophotographic method, and a sheet feeding cassette 105 as a sheet storage unit is disposed so as to be attached to and withdrawn from the apparatus main body 100a. Further, the image forming unit 100b 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 100 b, first, light corresponding to the image signal is irradiated onto the photosensitive drum 101 by the laser scanner 103, 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 111 in parallel with the toner image forming operation, the sheet S is transported to the registration roller pair 107 via the transport roller pair 112. The 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.

  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 then 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 discharge roller pair 109 causes the apparatus to It is discharged to a discharge unit 110 provided at the upper part of the main body. The image forming unit 100b and the fixing unit 108 constitute an image forming unit that forms an image on the sheet S sent out by the sheet feeding device 120.

  Next, details of the paper feed cassette (sheet storage means) 105 according to the present embodiment will be described with reference to FIGS. 2 (a), 2 (b) and FIG. 2A is a perspective view showing the paper feed cassette 105 according to the present embodiment, and FIG. 2B is a plan view showing the paper feed cassette 105 of FIG. 2A. 3A and 3B are diagrams showing a fixing structure of the regulating member of the paper feed cassette 105. FIG. 3A is a cross-sectional view showing a fixed state, and FIG. 3B is a cross-sectional view showing a fixed state.

  As shown in FIGS. 2A and 2B, the sheet feeding cassette 105 includes a sheet stacking table 1 on which sheets S are stacked, and a pair of slide-movable units that regulate the side end positions of sheets S of various sizes. The width direction regulating members 2 and 3 and the rear end regulating member 4 for regulating the rear end position of the sheet S are provided. The width direction regulating members 2 and 3 have rack portions 2a and 3a, respectively, and these rack portions 2a and 3a mesh with one pinion 5 disposed between each other in a state of facing each other. Accordingly, when any one of the width direction regulating members 2 and 3 is moved in the width direction, the other of the width direction regulating members 2 and 3 is interlocked by the action of the pinion 5 and the rack portions 2a and 3a. It moves in the direction opposite to the width direction regulating member.

  The width direction regulating members 2 and 3 are fixed at positions corresponding to various sheet sizes, as shown in FIG. 3A, the tooth portions 6a of the width direction fixing rack 6 provided on the bottom surface of the paper feed cassette 105, This is done by meshing with the tooth portion 7a of the width direction fixed rack 7 provided on the width direction regulating member 3. The width-direction fixed rack 7 rotates around the lever rotation fulcrum 49 when the upper part of the fixing release lever 8 is held between the rear surface portion 3a of the width-direction regulating member 3 with a finger. Therefore, as shown in FIG. 3B, the lower convex portion 8 a of the fixing release lever 8 pushes up the upper engaged portion 7 b of the width direction fixing rack 7. Thereby, the width direction fixed rack 7 which meshed the tooth part 7a with the tooth part 6a of the width direction fixed rack 6 will be in a lift state, the tooth part 7a is released from the tooth part 6a, and the width direction control member 3 is movable. It becomes a state. In addition, the code | symbol 7c has shown the recessed part.

  As shown in FIGS. 2A and 2B, the trailing edge regulating member 4 extends in the sheet feeding direction along the trailing edge regulating guide groove 11 provided in the arrow W direction on the bottom surface of the sheet feeding cassette 105. It is configured to be movable. Also, the rear end regulating member 4 is fixed in the same manner as the width direction regulating member 2, the rear end regulating fixed rack 9 provided in the paper feed cassette 105, and the rear end regulating fixed rack provided in the rear end regulating member 4 ( (Not shown). The sheet stacking table 1 is supported so as to be rotatable about the rotation fulcrums 10a and 10b, and the lift arm 12 is lifted up by applying a driving force from a lift motor 13 (FIG. 4).

  Next, with reference to FIGS. 2A, 2B and 4, the lifting mechanism of the sheet stacking table 1 in the sheet feeding cassette (in the sheet storage means) will be described. FIG. 4 is a perspective view showing an elevating mechanism of the sheet stacking table 1 in the sheet feeding cassette 105.

  As shown in FIG. 4, on the apparatus main body 100a side, a lift motor 13 as a power source having a worm gear 14 fixed to a rotating shaft, and a large-diameter tooth portion 15c meshed with the worm gear 14 supported by the rotating shaft 15a. A transmission gear 15 is arranged. Further, on the apparatus main body 100a side, a transmission gear 16 supported by the rotary shaft 16a and meshed with the small-diameter tooth portion 15b and a small-diameter tooth portion (non-set) of the transmission gear 16 supported by the rotary shaft 17a. And a transmission gear 17 that meshes with the large-diameter tooth portion 17b. The rotary shafts 15a, 16a, and 17a are supported in parallel with each other on the apparatus main body 100a side. Accordingly, the transmission gear 15 is configured to be able to transmit the rotational drive to the drive gear 18 while decelerating via the transmission gear 16 and the transmission gear 17.

  As shown in FIGS. 2A and 2B, a positioning projection 29, a drive gear 18 and a sector gear 19 are provided on one side of the side surface 105d of the sheet feeding cassette 105 into the cassette housing space of the apparatus main body 100a. Has been placed. As shown in FIG. 4, a sector gear 19 having a fan-shaped tooth portion 19a on the upper side of the lift arm 12 rotatably supported by the paper feed cassette 105 about the rotation shaft 12a is provided outside the insertion side surface 105d. It is being fixed to the one end part which protruded. A drive gear 18 is supported on the insertion side surface 105d of the paper feed cassette 105 via a rotation shaft 18a parallel to the rotation shaft 12a. The drive gear 18 meshes with the teeth 19 a of the sector gear 19.

  When the paper feed cassette 105 having the above configuration is mounted in the apparatus main body 100a, the drive gear 18 on the paper feed cassette 105 side meshes with the small-diameter tooth portion 17c of the transmission gear 17 on the apparatus main body 100a side. Therefore, the rotation when the lift motor 13 is driven is transmitted from the small-diameter tooth portion 17 c of the transmission gear 17 to the drive gear 18 via the transmission gears 15 and 16. And it is transmitted to the lift arm 12 via the sector gear 19, and the lift arm 12 is rotated in the direction of arrow A about the rotation shaft 12a. As a result, the sheet stacking table 1 positioned at the upper part of the lift arm 12 is pushed up and lifted up with the pivotal fulcrums 10a and 10b with respect to the sheet feeding cassette 105 as fulcrums.

  Next, with reference to FIGS. 2A and 2B and FIGS. 5A and 5B, a mechanism of the paper feed cassette 105 using a toggle arm (drop-off prevention arm) 20 as a toggle member will be described. To do. FIG. 5 is a cross-sectional view showing a mechanism for preventing the sheet cassette 105 from dropping off according to this embodiment. FIG. 5A shows a state where the three axes are aligned in a straight line and a large rotational force does not act on the toggle arm 20, and FIG. 5B shows the paper feed cassette 105 mounted in the apparatus main body. Indicates the state that has been performed. FIG. 5A shows a state in which the paper feed cassette 105 is pulled out of the apparatus main body for stacking sheets.

  As shown in FIGS. 2 (a), 2 (b) and FIGS. 5 (a), 5 (b), the guide rail 23 as the rail means provided inside the apparatus main body 100a includes an upper guide surface 23a and a lower guide surface. 23b in a state of facing in parallel. A bottom roller 28 that rolls in contact with the lower guide surface 23 b of the guide rail 23 is provided at the bottom front portion of the paper feed cassette 105.

  The guide rail (rail means) 23 guides the paper feeding cassette 105 to a mounting position (see FIG. 5B) in the apparatus main body and a drawing position (see FIG. 5A) pulled out from the apparatus main body 100a. . The guide rail 23 is provided with a curved guide portion 23c that curves in a direction (vertical direction in FIG. 5 in this embodiment) perpendicular to the mounting direction (the direction of arrow B) to the mounting position in the vicinity of the mounting position. Have.

  In addition, the sheet feeding device 120 is disposed in the sheet feeding cassette 105, and is pulled in to draw the sheet feeding cassette 105, which is guided along the guide rail 23 and inserted beyond the predetermined position into the apparatus main body, toward the mounting position. Retraction mechanisms 50a and 50b are provided as means. Each of the retracting mechanisms 50a and 50b has a toggle arm (toggle member) 20 and a toggle spring 25 as an urging member. The toggle arm 20 is rotatably supported by the paper feed cassette 105 and has an upper surface roller (introducing member) 22 that starts to be introduced into the curved guide portion 23c when exceeding a predetermined position. The toggle spring 25 biases the toggle arm (drop-off preventing arm) 20 so that the upper surface roller 22 can be introduced into the curved guide portion 23c at the predetermined position. The toggle spring 25 functions to pull the paper feed cassette 105 into the mounting position by bringing the upper surface roller 22 introduced into the curved guide portion 23c into contact with the inner surface of the curved guide portion 23c. The toggle arm 20 is rotatably supported by the paper feed cassette 105 so as to face the vertical direction perpendicular to the mounting direction (arrow B direction) (FIG. 5B).

  In this embodiment, the toggle arm 20 is shown on the outer surface (side surface portion) 105e and the side surface portion 105c at both ends in the width direction of the insertion side surface 105d of the paper feeding cassette 105 as shown in FIG. It is rotatably supported at a horizontal position and a vertical position shown in FIG. The toggle arm 20 is supported at the distal end portion in the insertion direction of the outer surface 105e and the side surface portion 105c, the center portion is supported by the rotation shaft 24, and the upper surface roller (introducing member) is disposed above the distal end portion (first arm portion) 20a. ) 22 is rotatably supported by the shaft 22a, and the rear end portion (second arm portion) 20b extends rearward.

  A locking pin 27 is attached to the front end side of the rotary arm 24 in the toggle arm 20, and a locking pin 26 is attached to the rear end side of the rotary shaft 24 in each of the recess 105b and the side surface portion 105c. ing. In the horizontal state shown in FIG. 5 (a), the three points of the locking pin 26 and the locking pin 27 with which both ends of the toggle spring 25 made of a tension coil spring are locked and the rotation shaft 24 are close to a straight line. Lined up in a state. Therefore, a large turning force does not act on the toggle arm 20 supported by the rotating shaft 24.

  The toggle arm 20 is supported at the downstream end portion in the mounting direction in the paper feeding cassette 105 by a pivot shaft 24 at its intermediate portion, and the tip portion extending from the shaft support portion (24) to the downstream side in the mounting direction. The upper surface roller 22 is supported by the (first arm) 20a. The toggle spring (biasing member) 25 includes a locking pin (first locking portion) 27 located at the distal end portion 20a and a locking pin (second locking position) located upstream of the shaft support portion (24) in the mounting direction. (Locking portion) 26.

  As shown in FIG. 2B, the paper feed cassette 105 has a recess 105b that is recessed inward from the outermost outer surface 105e at the downstream end in the mounting direction (arrow B direction). The pull-in mechanisms 50a and 50b are respectively arranged at both ends of the paper feed cassette 105 in the horizontal direction (left and right direction in FIG. 2B). The toggle arm 20 in at least one of the pulling mechanisms 50a and 50b at both ends (50a in the present embodiment) is disposed in the recess 105b.

  In the horizontal state shown in FIG. 5A, a bottom roller 21 supported at the upstream end of the lower guide surface 23b and a top roller 22 attached to the tip (downstream end) of the toggle arm 20 are respectively guided. The rail 23 rolls in contact with the lower guide surface 23b and the upper guide surface 23a. Thereby, the paper feed cassette 105 can be stably held in the apparatus main body 100a.

  The toggle arm 20 is held by the paper feed cassette 105 so as to be rotatable around the rotation shaft 24, and the rotation in the counterclockwise direction in FIG. As described above, the toggle spring 25 is stretched between the toggle arm 20 and the paper feed cassette 105. Since the upper surface roller 22 needs to support the weight of the sheet feeding cassette 105 loaded with sheets S in a full load, the upper surface roller 22 is installed at a position where the arm length of the toggle arm 20 is sufficiently taken. In the horizontal state shown in FIG. 5A, the rearward extending portion of the rear end portion 20b is engaged when the upper surface roller 22 tries to rotate counterclockwise by the reaction force from the upper guide surface 23a. The upper surface roller 22 is held against the reaction force by contacting the stop pin 26 from below.

  As described above, the toggle arm 20 has the upper surface roller 22, the rotating shaft 24, the locking pin 27, and the locking pin 26 substantially straight when the upper surface roller 22 is on the drawing position side where the curved guide portion 23 c is not reached. Line up on the line. Then, the rear end portion (second arm portion) 20b extending upstream in the mounting direction of the toggle arm 20 is regulated by a locking pin (second locking portion) 26, whereby the inner surface of the guide rail 23 is obtained. The upper surface roller 22 that is in contact with the upper surface 22 is carried and the load of the sheet feeding cassette 105 at the drawing position is supported.

  As shown in FIG. 5B, when the upper surface roller 22 reaches the curved guide portion 23c of the upper guide surface 23a of the guide rail 23 when the paper feed cassette 105 is inserted into the apparatus main body 100a, the upper surface roller 22 is curved. It moves toward the upper part of the apparatus while being guided by the guide 23c. The curved guide portion 23c is formed to rise while curving upward from the rear end portion of the upper guide surface 23a, which is a straight portion of the guide rail 23.

  That is, as the upper surface roller 22 moves forward in the insertion direction along the upper guide surface 23a, the toggle arm 20 starts to rotate. When the toggle arm 20 is moved to a rotation position of a predetermined angle or more, the toggle arm 20 constitutes a toggle mechanism. Therefore, the urging force of the toggle spring 25 starts rotation about the rotation shaft 24 by itself. With this force, the paper feed cassette 105 is automatically pulled into the apparatus main body 100a. The pulling-in of the sheet cassette 105 ends when the positioning protrusion 29 comes into contact with a positioning portion (not shown) on the apparatus main body 100a side. As described above, when the toggle arm 25 is at the mounting position where the upper surface roller 22 is introduced into the curved guide portion 23c, the toggle arm 25 moves the sheet cassette 105 with the toggle turning power when the toggle spring 25 exceeds the thought point (neutral point). It functions to be pulled into the mounting position.

  In the present embodiment, the toggle mechanism including the toggle arm 20 is disposed as the pull-in mechanisms 50 a and 50 b having the same configuration on both the left and right sides of the paper feed cassette 105. The paper feed cassette 105 has a recess 105b that is recessed inward from the outermost outer surface 105e at the downstream end in the mounting direction. The toggle arm 20 in at least one (for example, 50a) of the pull-in mechanisms 50a and 50b at both ends is disposed in the recess 105b. For this reason, the recess 105b is formed by effectively utilizing the unused space in the function of the paper feed cassette 105 on the outer surface 105e side, thereby effectively arranging the pull-in mechanism 50a and reducing the size in the product width direction. Can be made possible.

  According to the present embodiment, it is possible to fully pull out the paper feed cassette 105 from the apparatus main body 100a to the sheet stacking position without increasing the installation area of the apparatus main body 100a. A toggle arm 20 that prevents the paper cassette 105 from falling off when the paper cassette 105 is fully pulled out to the sheet stacking position is held. When the paper cassette 105 is stored, the paper cassette is an empty space in the conventional technology. It is possible to evacuate to the space that was. Accordingly, the installation area of the apparatus main body 100a can be reduced without sacrificing the ease of sheet replenishment.

  Further, in the toggle type auto-close mechanism, the pull-in mechanisms 50a and 50b are provided on the paper feed cassette 105 side, so that the pull-in failure of the paper feed cassette 105 caused by the forward movement of the toggle arm 20 while the paper feed cassette 105 is being pulled out. It becomes possible to prevent. Therefore, it is possible to greatly improve the usability of the return work.

  In the present embodiment, the toggle arm 20 is rotatably supported by the paper feed cassette 105 so as to face the vertical direction perpendicular to the mounting direction. And since the bending guide part 23c is curved so that it may follow an up-down direction, it becomes possible to reduce the installation space in the apparatus main body 100a, and to contribute to apparatus compactization.

  Further, when the toggle arm 20 is in the mounting position where the upper surface roller 22 is introduced into the curved guide portion 23c, the mounting position of the paper feeding cassette 105 with the toggle turning power when the toggle spring 25 exceeds the thought point (neutral point). Configured to be drawn into. For this reason, when the upper surface roller 22 is introduced into the curved guide portion 23c, a sufficient pulling force for pulling the sheet feeding cassette 105 into the apparatus main body 100a can be obtained.

[Second Embodiment]
Next, a paper feed cassette (sheet storage means) 106 according to the second embodiment of the present invention will be described. In the present embodiment, the mechanisms such as the width direction regulating members 2 and 3, the trailing edge regulating member 4, and the sheet stacking table 1 that regulate the position of the sheet installed in the paper feed cassette 106 are the same as those in the first embodiment. Therefore, the description is omitted here. FIG. 6 is a perspective view showing the paper feed cassette 106 and its drop-off prevention mechanism according to the present embodiment. FIG. 6A shows a state in which the paper feed cassette 106 is pulled out of the apparatus main body 100a for stacking sheets. FIG. 6B shows a state where the toggle arm (drop-off prevention arm) 20 stands up along the vertical direction, and the toggle arm (drop-off prevention arm) 40 is folded to the back side of the sheet feeding cassette. FIG. 7 is a plan view showing a drop-off prevention mechanism for the paper feed cassette 106 according to this embodiment.

  6A and 6B, of the pair of toggle arms 20 and 40 installed on the downstream end surface 106d of the paper feed cassette 106, the toggle arm on the side surface portion 106b side in the vicinity of the rear end regulating member 4 is used. 40 is supported so as to be rotatable in a horizontal plane with respect to the paper feed cassette 106. The toggle arm 40 is supported so as to be rotatable from the protruding position shown in FIG. 6A to the tilted position shown in FIG. 6B. Reference numeral 34 denotes a rail portion provided on the side surface portion 106 c of the paper feed cassette 106.

  Since the toggle arms 20 and 40 are located at a position protruding in the rear direction of the paper feed cassette 106, the paper feed cassette 106 is prevented from falling off and held. When the paper feed cassette 106 is stored in the apparatus main body 100a, the upper surface roller 30 moves to the mounting position while being guided by the guide rail 33 shown in FIG. As a result, as shown in FIG. 6B, the toggle arm 40 is folded to the back side (downstream end face 106d side) of the paper feed cassette 106. At this time, the retracting mechanism 51b including the toggle arm 20 disposed on the side surface portion 106c side is in the same state as the retracting mechanism 50b in the first embodiment.

  In the present embodiment, the toggle arm 20 on the retracting mechanism 51b side configures a toggle mechanism by a toggle spring 25 made of a tension spring, as in the first embodiment. However, the toggle arm 40 on the pulling mechanism 51a side is rotatably supported by the paper feed cassette 106 so as to face the horizontal direction (left and right direction in FIG. 6) orthogonal to the mounting direction.

  That is, as shown in FIGS. 6A and 6B, the toggle arm 40 is pivotally supported at the downstream end in the mounting direction of the paper feed cassette 106 by the rotation shaft 44. An upper surface roller (introducing member) 30 is supported on the upper surface of the first arm portion 40a extending from the shaft support portion (44) to the downstream side in the mounting direction. In the toggle arm 40, the upper surface roller 22 is disposed sideways in the same manner as the upper surface roller 22 on the retracting mechanism 50a side in the first embodiment, and at the same time, the upper surface roller 30 rotates around the vertical axis. It is supported so that it can move. In addition, a toggle spring (biasing member) 55 includes a locking pin (first locking portion) 45 positioned on the first arm portion 40a and a locking pin (upstream in the mounting direction) from the shaft support portion (44). (Second locking portion) 46.

  As described above, the drawing mechanisms (withdrawing means) 51 a and 51 b are arranged at both ends in the horizontal direction of the sheet feeding cassette 106. The toggle arm 40 in at least one of the drawing mechanisms 51a and 51b (51a in the present embodiment) is supported so as to be folded with respect to the downstream end face 106d in the mounting direction of the paper feed cassette 106.

  In this embodiment, as shown in FIG. 7, the curved guide portion 33c provided in the vicinity of the mounting position on the guide rail 33 is curved so as to be along the horizontal direction. Therefore, when the toggle arm 40 starts to be rotated by the guide rail 33 and is bent by the curved guide portion 33c, the paper feed cassette 106 is automatically pulled to the insertion position. At the same time, on the retracting mechanism 51b side, the toggle arm 20 moves along the same guide rail 23 (not shown in FIGS. 6 and 7) as in the first embodiment, and as in the case of the first embodiment. Function.

  Further, as shown in FIGS. 6A and 6B, the sheet cassette 106 has a back surface (downstream end surface 106 d) that is in contact with a size detection switch 31 that is a triple switch that automatically detects the sheet size. A detection lever 32 is provided. The size detection lever 32 moves in conjunction with the sliding operation of the rear end regulating member 4 and detects the sheet size by changing the number of pushes of the triple switch according to the set position of the rear end regulating member 4. In the present embodiment, the toggle arm 40 is arranged in an empty space above the size detection mechanism, thereby effectively using the space and contributing to downsizing of the apparatus main body 100a.

  According to the above embodiment, it is possible to obtain the same effect as that of the first embodiment. That is, it is possible to sufficiently pull out the paper feed cassette 106 from the apparatus main body 100a to the drawing position without increasing the installation area of the apparatus main body 100a. Further, in the toggle mechanism type auto-close mechanism, there is no inconvenience that the toggle arms 20 and 40 move forward while the paper feed cassette 106 is pulled out. Therefore, it is possible to greatly improve the usability of the return work.

  In the present embodiment, the toggle arm 40 is rotatably supported by the paper feed cassette 106 so as to face the horizontal direction orthogonal to the mounting direction. And since the curved guide part 33c is curved so that it may follow along a horizontal direction, it becomes possible to reduce the installation space in the apparatus main body 100a, and to contribute to apparatus compactization.

  In the present embodiment, the electrophotographic image forming apparatus 100 has been described. Instead, for example, an ink jet image forming apparatus that forms an image on a sheet by ejecting ink liquid from a nozzle. It can also be used.

  20 ... Toggle arm (toggle member) / 20a ... Tip (first arm) / 20b ... Rear end (second arm) / 22 ... Top roller (introducing member) / 23 ... Guide rail (rail means) / 23c ... Bending guide part / 24 ... Rotating shaft (axial support part) / 25 ... Toggle spring (biasing member) / 26 ... Locking pin (second locking part) / 27 ... Locking pin (first locking part) ) / 30 ... Upper surface roller (introducing member) / 33c ... Curved guide part / 40 ... Toggle arm (toggle member) / 40a ... First arm part / 44 ... Shaft support part / 45 ... Locking pin (first locking part) ) / 46... Locking pin (second locking portion) / 50a, 50b... Pulling mechanism (pulling means) / 51a, 51b... Pulling mechanism (pulling means) / 55... Toggle spring (biasing member) / 100. Device / 100a... Device main body / 100b, 108... Image forming unit, fixing unit ( Image forming means) / 105, 106 ... sheet cassette (sheet containing means) / 105b ... recess / 105e ... outer surface / 106d ... downstream end surface / 120 ... sheet feeder / B ... mounting direction / S ... Sheet

Claims (10)

The device body;
Sheet storage means that can be attached to and pulled out from the apparatus main body and in which a sheet is stored;
Arranged in the apparatus main body, guiding the sheet storage means to a mounting position in the apparatus main body and a drawing position pulled out from the apparatus main body, and perpendicular to the mounting direction to the mounting position in the vicinity of the mounting position Rail means having a curved guide portion that curves so as to follow the direction of
A pull-in means that is disposed in the sheet storage means and is guided along the rail means and is inserted into the apparatus main body beyond a predetermined position, and draws the sheet storage means toward the mounting position;
The pull-in means is
A toggle member that is rotatably supported by the sheet storage means and has an introduction member that starts to be introduced into the curved guide portion when the predetermined position is exceeded;
The toggle member is biased so that the introduction member can be introduced into the bending guide portion at the predetermined position, and the introduction member introduced into the bending guide portion is brought into contact with the inner surface of the bending guide portion. And a biasing member that pulls the sheet storage means into the mounting position.
A sheet feeding apparatus characterized by that. The toggle member is rotatably supported by the sheet storage means so as to face the vertical direction perpendicular to the mounting direction,
The bending guide portion is bent along the vertical direction;
The sheet feeding apparatus according to claim 1. The toggle member is pivotally supported at an intermediate portion at the downstream end portion in the mounting direction of the sheet storage means, and the introduction member is attached to a first arm portion extending from the pivot support portion to the downstream side in the mounting direction. Supported,
The urging member is stretched between a first locking portion positioned on the first arm portion and a second locking portion positioned on the upstream side in the mounting direction from the shaft support portion.
The sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus is a sheet feeding apparatus. When the introduction member is in the attachment position where the introduction member is introduced into the bending guide portion, the sheet storage means is pulled into the attachment position by a toggle turning force when the biasing member exceeds a thought point. ,
The sheet feeding apparatus according to claim 3. The toggle member is
The introduction member, the shaft support portion, the first locking portion, and the second locking portion are arranged in a substantially straight line on the drawing position side where the introduction member does not reach the curved guide portion; and The second arm portion extending upstream of the mounting direction of the toggle member is regulated by the second locking portion, so that the introduction member contacting the inner surface of the rail means is supported and the Supporting the load of the sheet storage means in the pulled-out position;
The sheet feeding apparatus according to claim 3, wherein the sheet feeding apparatus is a sheet feeding apparatus. The sheet storage means has a recessed portion recessed inward from the outermost outer surface at the downstream end in the mounting direction,
The pull-in means are respectively disposed at both ends in the horizontal direction of the sheet storage means, and the toggle member in at least one of the pull-in means at the both ends is disposed in the recess.
The sheet feeding apparatus according to claim 1, wherein the sheet feeding apparatus is a sheet feeding apparatus. The toggle member is rotatably supported by the sheet storage means so as to face a horizontal direction perpendicular to the mounting direction;
The bending guide portion is bent along the horizontal direction;
The sheet feeding apparatus according to claim 1. The toggle member is pivotally supported at the upstream end at the downstream end in the mounting direction of the sheet storage means, and the introduction member is attached to a first arm portion extending from the shaft support portion to the downstream side in the mounting direction. Is supported,
The urging member is stretched between a first locking portion positioned on the first arm portion and a second locking portion positioned on the upstream side in the mounting direction from the shaft support portion.
The sheet feeding apparatus according to claim 7, wherein the sheet feeding apparatus is a sheet feeding apparatus. The pull-in means is disposed at both ends in the horizontal direction of the sheet storage means, and the toggle member in at least one of the pull-in means at both ends is on the downstream end surface of the sheet storage means in the mounting direction. Supported to be folded against,
The sheet feeding apparatus according to claim 7, wherein the sheet feeding apparatus is a sheet feeding apparatus. A sheet feeding device according to any one of claims 1 to 9,
Image forming means for forming an image on the sheet fed by the sheet feeding device,
An image forming apparatus.

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