Patent Application
20200172354
The present invention relates to a sheet supporting apparatus for supporting sheets, and an image forming apparatus equipped with the same.
Heretofore, a printer including a printer body, a sheet feed cassette capable of being attached detachably to the printer body, and a drawing apparatus for drawing and attaching the sheet feed cassette into the printer body is proposed (refer to Japanese Patent Application Laid-Open Publication No. 2006-151687). The drawing apparatus draws in a locking pin provided on the sheet feed cassette by urging force of a toggle spring, by which the sheet feed cassette is attached to the printer body. The locking pin is supported pivotably in right and left directions by a pin retaining arm provided on the sheet feed cassette.
However, the locking pin disclosed in Japanese Patent Application Laid-Open Publication No. 2006-151687 is arranged to protrude from a rear side of the sheet feed cassette, and it is not arranged movably in a vertical direction with respect to the sheet feed cassette. Therefore, if the whole body of the sheet feed cassette is drawn out of the printer body and the sheet feed cassette is placed on a worktable, for example, the locking pin may collide against the worktable or an object placed on the worktable. In this state, if load in the vertical direction is applied on the locking pin, the locking pin may be damaged.
According to one aspect of the present invention, a sheet supporting apparatus includes an apparatus body, a sheet supporting unit comprising a sheet supporting portion including a supporting surface on which a sheet is supported, and a first engagement unit attached to the sheet supporting portion, the sheet supporting unit being configured to be attached to and drawn out of the apparatus body, and a second engagement unit provided on the apparatus body and configured to draw in the sheet supporting unit toward an attaching position where the sheet supporting unit is attached to the apparatus body, wherein the first engagement unit comprises a first engagement portion, and a holder that is supported movably in a perpendicular direction perpendicular to the supporting surface and configured to hold the first engagement portion, and the second engagement unit comprises a second engagement portion configured to engage with the first engagement portion, and a drawing-urging portion configured to urge the second engagement portion so that the sheet supporting unit is drawn toward the attaching position in a state where the second engagement portion is engaged with the first engagement portion.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, a first embodiment will be described with reference to the drawings. In the following description, a state in which the image forming apparatus is viewed from a front side, that is, viewpoint of
At first, the first embodiment will be described. A printer 1 serving as an image forming apparatus is a laser beam printer adopting an electrophotographic system. The printer 1 includes, as illustrated in
The printer body 100 includes a main cassette 111 that supports stacked sheets S, an image forming unit 102 that forms an image on a sheet S, a fixing unit 96 that fixes an image on a sheet S, and a sheet discharge roller pair 120. A sheet discharge tray 121 on which the sheet S discharged by the sheet discharge roller pair 120 is placed is provided on an upper portion of the printer body 100.
The image forming unit 102 is an image forming unit adopting a so-called four-drum full color system equipped with a laser scanner 31, four process cartridges 32Y, 32M, 32C and 32K, and an intermediate transfer belt 33. The process cartridges 32Y, 32M, 32C and 32K form toner images of respective colors of yellow (Y), magenta (M), cyan (C) and black (K), and the configurations other than the toner color are the same. Therefore, only the configuration of the process cartridge 32Y will be described, and the description of other the process cartridges 32M, 32C and 32K will be omitted. The process cartridge 32Y includes a photosensitive drum 34, a charge roller 35, and a developing roller 36. Toner cartridges 37Y, 37M, 37C and 37K that store toners of respective colors are attached detachably to the printer body 100 at an upper portion of the image forming unit 102.
An intermediate transfer belt 33 is wound around a drive roller 33a, a secondary transfer counter roller 33b and a tension roller 33c, and it is arranged below the four process cartridges 32Y, 32M, 32C and 32K. The intermediate transfer belt 33 is arranged to be in contact with the photosensitive drums of the respective process cartridges 32Y, 32M, 32C and 32K, and driven to rotate in a counterclockwise direction by the drive roller 33a. Further, four primary transfer roller 38Y, 38M, 38C and 38K that abut against an inner circumferential surface of the intermediate transfer belt 33 at positions opposed to the respective photosensitive drums are provided on an inner side of the intermediate transfer belt 33. Further, the image forming unit 102 includes a secondary transfer roller 39 that abuts against an outer circumferential surface of the intermediate transfer belt 33 at a position opposed to the secondary transfer counter roller 33b.
The sheet feeding apparatus 200 includes two deck-type storage portions 61a and 61b which are arranged on right and left sides. The configurations of the storage portions 61a and 61b and the circumference configurations thereof are approximately the same, so in the following description, an arbitrary one of the two storage portions 61a and 61b on left and right sides is described as a storage portion 61. As illustrated in
The storage portion 61 includes a storage body 60 that serves as a sheet supporting portion that supports sheets S, and a drawing arm unit 3 that serves as a first engagement unit that is attached to a rear wall 64 of the storage body 60. A drawing mechanism 4 for drawing the storage portion 61 toward the attaching position is attached to the casing 200a in a state engaged with the drawing arm unit 3. The casing 200a, the storage portion 61, the drawing arm unit 3 and the drawing mechanism 4 constitute a sheet supporting apparatus 600. The drawing arm unit 3 and the drawing mechanism 4 will be described in detail later. A lift plate 52 on which the sheets S are placed on a supporting surface 52a thereof and capable of being lifted and lowered by a wire is provided on the storage body 60.
Next, an image forming process of the printer body 100 configured as above will be described. In a state where image data transmitted from a personal computer and the like not shown is entered to the laser scanner 31, laser beam corresponding to the image data is irradiated from the laser scanner 31 on the photosensitive drum 34 of the process cartridge 32Y.
In this state, the surface of the photosensitive drum 34 is charged uniformly to a predetermined polarity and potential in advance by the charge roller 35, and electrostatic latent image is formed on the surface by the laser beam irradiated from the laser scanner 31. The electrostatic latent image formed on the photosensitive drum 34 is developed by the developing roller 36, and a yellow (Y) toner image is formed on the photosensitive drum 34.
Similarly, laser beams are irradiated from the laser scanner 31 to respective photosensitive drums of the process cartridges 32M, 32C and 32K, and toner images of magenta (M), cyan (C) and black (K) are formed on the respective photosensitive drums. The toner images of respective colors formed on the respective photosensitive drums are transferred to the intermediate transfer belt 33 by the primary transfer roller 38Y, 38M, 38C and 38K, and conveyed to the secondary transfer roller 39 by the intermediate transfer belt 33 rotated by the drive roller 33a. The image forming processes of respective colors are performed at such a timing that the images are superposed on a primary transfer toner image formed upstream on the intermediate transfer belt 33.
In parallel with the image forming process, the sheet S stacked and supported on the main cassette 111 of the printer body 100 or the storage portion 61 of the sheet feeding apparatus 200 is fed in a sheet feeding direction by a pickup roller 54. Then, the sheet S fed by the pickup roller 54 is separated one by one by a feed roller 55 and a separation roller 56, and the sheet is conveyed toward a registration roller pair 57. A loop is formed on the sheet S being abutted against the registration roller pair 57 in a rotation stopped state, and skewing of the sheet is corrected.
The registration roller pair 57 is driven in synchronization with the image forming timing, and the sheet S is conveyed to the secondary transfer roller 39. A full-color toner image on the intermediate transfer belt 33 is transferred to the sheet S conveyed to the secondary transfer roller 39 by secondary transfer bias applied to the secondary transfer roller 39. Predetermined heat and pressure are applied by the fixing unit 96 to the sheet S to which the toner image is transferred, by which toner is melted to fix the toner image on the sheet. The sheet S having passed through the fixing unit 96 is discharged by the sheet discharge roller pair 120 to the sheet discharge tray 121.
Next, a drawing mechanism 4 serving as a second engagement unit will be described in detail, with reference to
A guide groove 216 is formed on the frame body 210, and a locking pin 203 serving as a first engagement portion of the drawing arm unit 3 is guided along the guide groove 216. The gripping member 217 serving as a second engagement portion includes a concave portion 217a capable of being engaged with the locking pin 203. In a state where the storage portion 61 is drawn out, the gripping member 217 is positioned at a receiving position by the operation of the toggle spring 213, as illustrated in
In a state where the storage portion 61 in a state drawn out of the casing 200a (refer to
If the storage portion 61 is further pushed in from this state, the toggle spring 213 urges the storage portion 61 to be drawn in toward the attaching position through the gripping member 217, the swing arm 211 and the locking pin 203. Then, as illustrated in
Next, the drawing arm unit 3 will be described in detail with reference to
The horizontal arm shaft 205 serving as a shaft extending in a vertical direction VD serving as a perpendicular direction is arranged at the rear wall 64, and it is inserted to a shaft hole 201a provided on the horizontal swing arm 201. The horizontal swing arm 201 serving as a base portion is supported swingably in the horizontal direction around the horizontal arm shaft 205. Thereby, the locking pin 203 described later is also swingable in the horizontal direction, and it plays a role in absorbing relative positional error between the locking pin 203 and the concave portion 217a of the gripping member 217.
A shaft hole 201b that extends in the horizontal direction is formed on the horizontal swing arm 201, and a shaft hole 202a is formed also on the perpendicular swing arm 202. The perpendicular arm shaft 204 is inserted to the shaft holes 201b and 202a, and the perpendicular swing arm 202 is swingable in the vertical direction around the perpendicular arm shaft 204 serving as the swing shaft. The perpendicular arm shaft 204 extends in a direction orthogonal to both of an inserting direction of the sheet and the vertical direction. A pin hole 202b is formed on the leading end portion of the perpendicular swing arm 202 serving as a holder, and the locking pin 203 is fixed to the pin hole 202b.
In the following description, a state in which the printer 1 is mounted on a horizontal supporting surface is referred to in describing the vertical direction and up-down direction, and the perpendicular direction perpendicular to the supporting surface 52a (refer to
The urging spring 206 serving as an urging portion is a torsion coil spring arranged around the perpendicular arm shaft 204, and it urges the perpendicular swing arm 202 downward. The perpendicular swing arm 202 includes an abutment portion 202c, as illustrated in
That is, in a non-loaded state where external force is not applied, the locking pin 203 fixed to the perpendicular swing arm 202 is positioned at a standby position as illustrated in
In the present embodiment, as illustrated in
In this case, a draw-in force in which the drawing mechanism 4 draws in the storage portion 61 may cause elastic deformation of the rear wall 64 on which the drawing arm unit 3 is attached. If the rear wall 64 is elastically deformed, the position of the sheet S in the storage portion 61 may become unstable, and may affect the quality of the image. Therefore, it is preferable to attach the drawing arm unit 3 to a position of the storage portion 61 where stiffness is as high as possible, and in the box-shaped storage body 60 with an upper portion opened, it should be attached to a position closed to a bottom plate 66 of the storage body 60.
Therefore, as illustrated in
By arranging the drawing mechanism 4 and the drawing arm unit 3 as illustrated in
Further, as illustrated in
For example, even if the storage portion 61 is drawn out of the casing 200a (refer to
Furthermore, by the swinging of the perpendicular swing arm 202 in contact with the loaded object 901, as illustrated in
Next, a second embodiment of the present invention will be described. According to the second embodiment, the configuration of the drawing arm unit 3 according to the first embodiment is changed. Therefore, configurations similar to the first embodiment are either not shown in the drawing or denoted with the same reference numbers.
A drawing arm unit 3B serving as a first engagement unit according to the present embodiment includes, as illustrated in
A spring bearing 303a is provided on the locking pin 303, and the urging spring 307 serving as an urging portion is arranged between the spring bearing 303a and a top panel 301c of the horizontal swing arm 301. The locking pin 303 is urged downward by the urging spring 307 in the non-loaded state, as illustrated in
In a state where external force containing an upward component acts on the locking pin 303, the locking pin 303 slides upward with respect to the horizontal swing arm 301, as illustrated in
Next, a third embodiment of the present invention will be described. According to the third embodiment, the configuration of the drawing arm unit 3 according to the first embodiment is changed. Therefore, configurations similar to the first embodiment are either not shown in the drawing or denoted with the same reference numbers.
A drawing arm unit 3C serving as a first engagement unit according to the present embodiment includes, as illustrated in
Side end portions of the concave portion 406 are engaged to the pair of slide grooves 407, and the slider member 403 is capable of moving in the vertical direction along the side end portions of the concave portion 406. The horizontal arm shaft 205 is attached to a bearing 408 provided on the slider member 403. The horizontal swing arm 401 is supported swingably in the horizontal direction around the horizontal arm shaft 205. That is, the horizontal swing arm 401 is supported swingably in the horizontal direction around the horizontal arm shaft 205 with respect to the slider member 403.
A pin hole 401b is formed at a leading end portion of the horizontal swing arm 401, and the locking pin 203 is fixed to the pin hole 40 lb. That is, the horizontal swing arm 401 serving as a retaining member is supported slidably in the vertical direction with respect to the rear wall 64 and fixes the locking pin 203. The urging spring 404 serving as the urging portion is arranged between the slider member 403 and the rear wall 64, and the urging spring 404 urges the slider member 403 downward. As illustrated in
In a state where external force containing an upward component acts on the drawing arm unit 3C, the slider member 403 moves upward in sliding motion with respect to the rear wall 64, as illustrated in
According to the second and third embodiments, as described in
In all the embodiments described above, especially the locking pin among the drawing mechanism is movable in the vertical direction, but the present invention is not limited to this configuration. A member constituting the drawing mechanism other than a locking pin can be provided movably in the vertical direction, as long as the member can receive application of external force. For example, the perpendicular swing arm 202 according to the first embodiment and the horizontal swing arm 401 according to the third embodiment are configured movable in the vertical direction with respect to the storage body 60. Therefore, it is necessary to configure at least a portion of the drawing mechanism movably in the vertical direction.
In all the embodiments described above, a deck-type storage portion was described, but the present invention is not limited thereto. For example, the present invention is applicable to a cassette-type storage portion. Further, in all the embodiments described above, the urging spring 206, 307 or 404 was used to urge the locking pin to the standby position, but the present invention is not limited thereto. It is also possible to omit the urging spring and to adopt a configuration where the locking pin is urged to the standby position by gravity. Further, in the first and third embodiments, the locking pin 203 was fixed to the perpendicular swing arm 202 or the horizontal swing arm 401, but the present invention is not limited thereto. For example, the locking pin 203 can be supported slidably in the vertical direction with respect to the perpendicular swing arm 202 and the horizontal swing arm 401.
Further, in all the embodiments described above, the printer 1 adopting an electrophotographic system was described, but the present invention is not limited thereto. For example, the present invention is applicable to an image forming apparatus adopting an ink-jet system in which image is formed on a sheet by discharging ink through a nozzle.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2018-225288, filed Nov. 30, 2018, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-225288 | Nov 2018 | JP | national |
