JP2007254138A - Sheet feeding device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeding device and an image forming device capable of stably feeding sheets and easily replacing a roller. <P>SOLUTION: A roller shaft holding member 52 is mounted to a first shaft 35 and a second shaft 39 at both ends of a sheet carrier roller 28 and a sheet feed roller 26, and the roller shaft holding member 52 is axially fitted to a fitting part provided at least at one of the first shaft 35 and second shaft 39, to hold the first shaft 35 and the second shaft 39. The roller shaft holding member 52 is releasable from fitting to the fitting part and detachable from at least one of the first shaft 35 and second shaft 39 after fitting to the fitting part is released. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus and an image forming apparatus, and more particularly to a configuration for exchanging a sheet feeding roller and the like.

  2. Description of the Related Art Conventionally, image forming apparatuses such as printers, copiers, and fax machines are provided with a sheet feeding device that separates and feeds sheets one by one from a sheet stacking unit on which a plurality of sheets are stacked. In such a sheet feeding apparatus, a retard separation mechanism is often used in recent years as a mechanism for separating sheets one by one.

  Here, as shown in FIG. 18, such a retard separation mechanism rotates in a direction in which the sheet S is returned by a certain range of torque by a feed roller 128 that rotates in the direction in which the sheet S is fed and a torque limiter 132. And a retard roller 129.

  When the sheet S stacked and set on the cassette or the like is sent out by the pickup roller 126, the sheet enters a nip portion between the feed roller 128 and the retard roller 129 (hereinafter referred to as a separation nip portion) as shown in FIG. To do.

  Here, when only the uppermost sheet S <b> 1 is fed from the pickup roller 126, the feed roller 128 rotates in the feeding direction indicated by the arrow A. The retard roller 129 is driven by the rotation of the feed roller 128 to rotate in the feeding direction indicated by the arrow C to feed the sheet. When two or more sheets enter the separation nip portion, the retard roller 129 rotates in the direction opposite to the arrow C by the action of the torque limiter 132, and the sheets other than the uppermost sheet S1 are pushed back. Thereby, only the uppermost sheet S1 can be fed.

  By the way, in the image forming apparatus provided with such a conventional sheet feeding apparatus, when the image forming apparatus has a slow printing speed and a product life shorter than that of each roller such as a pickup roller, the roller is used. There is no need to replace it. However, when the printing speed is fast and the product life is longer than the life of each roller, the roller deteriorates due to wear or the like, causing a reduction in feeding performance.

  For example, the sheet separation and feeding operation described above operates correctly due to friction between the rollers 126, 128, and 129 and the sheet and proper friction between the rollers. However, when the wear of the rollers 126, 128, and 129 progresses, the pickup roller 126 cannot feed the sheet S to the separation nip portion. Further, the driven rotation of the retard roller 129 with respect to the feed roller 128 is not normally performed, and in this case, the sheet feeding performance is deteriorated.

  Accordingly, in order to maintain a predetermined sheet separating and feeding performance in the sheet feeding device, it is necessary to replace the roller before the normal operation of the roller cannot be maintained due to the wear of the roller. Therefore, there is a conventional configuration in which the rollers 126, 128, and 129 can be replaced by a user or a service person (see, for example, Patent Document 1).

JP 7-24594 A

  Here, in the conventional sheet feeding apparatus and image forming apparatus in which the rollers can be replaced in this way, for example, when replacing the feed roller, first, the paper feed round shaft to which the feed roller is attached is removed from the apparatus main body. I am doing so. Thereafter, the feed roller is removed from the paper feed round shaft.

  However, both ends of this paper feed round shaft are rotatably supported by support portions such as the side wall of the printer body. Therefore, when replacing the roller, not only the trouble of pulling out the feed roller from the paper feed round shaft but also the paper feed It takes time to remove the round shaft from the main body. For this reason, the user and the service man have required a great deal of labor and labor.

  Therefore, in order to improve such roller exchangeability, the pickup roller, the feed roller, and the retard roller may be supported by a support shaft to which only one is fixed. In such a configuration, when replacing the roller, the roller to be replaced is slid to the opened side of the support shaft and removed from the support shaft, and then replaced with a new roller. Therefore, it becomes possible to easily perform the maintenance of the roller.

  However, when the roller is supported by a support shaft that is fixed only on one side in this way, a paper feed failure may occur due to insufficient rigidity of the support shaft. For example, in the retard separation mechanism described above, it is necessary to apply a predetermined pressure to each roller by a spring or the like in order to obtain appropriate friction between the roller and the sheet and between the rollers. May bend. If the support shaft is bent in this manner, a predetermined feeding pressure may not be obtained, and in this case, a paper feeding failure occurs.

  Accordingly, the present invention has been made in view of such a current situation, and is capable of stably feeding a sheet and easily replacing a roller and an image forming apparatus. Is intended to provide.

  The present invention is a sheet feeding apparatus comprising a sheet feeding roller for feeding a sheet, and a sheet feeding roller for separating and feeding the sheets fed by the sheet feeding roller one by one, The sheet conveying roller is detachably attached in the axial direction and one end is held by the apparatus main body, the sheet feeding roller is detachably attached in the axial direction, and one end is attached to the apparatus main body. A second shaft that is held, and attached to the first shaft and the second shaft on both ends of the sheet conveying roller and the sheet feeding roller, and at least one of the first shaft and the second shaft A roller shaft holding member that is fitted in the provided fitting portion in the axial direction and holds the first shaft and the second shaft, and the roller shaft holding member is fitted to the fitting portion. Releasable And after the engagement between the engaging portion is released, and is characterized in that it has removable from at least one of the first axis and the second axis.

  As in the present invention, the roller shaft holding member is attached to the first shaft and the second shaft to which the sheet conveying roller and the sheet feeding roller are detachably attached in the axial direction. And holding the second shaft. Thereby, it can prevent that a 1st axis | shaft and a 2nd axis | shaft bend, and can feed a sheet | seat stably. Further, the roller shaft holding member can be released from the fitting portion and can be removed from at least one of the first shaft and the second shaft after the fitting portion is released. Thus, the roller can be easily replaced.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a laser beam printer which is an example of an image forming apparatus provided with a sheet feeding apparatus according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a laser beam printer, and 1A denotes a laser beam printer main body (hereinafter referred to as a printer main body). The laser beam printer 1 includes an image forming unit 1B, cassette feeding devices 5 and 6 as an example of a sheet feeding device that feeds the sheet S to the image forming unit 1B, and a transfer that transfers a toner image to the sheet S. 1C. Further, the image forming apparatus includes a fixing unit 13 that fixes the toner image transferred by the transfer unit 1C to the sheet S, and a manual sheet feeding device 4 that is an example of a sheet feeding device provided on a side surface of the printer main body 1A. .

  Here, the image forming unit 1B exposes the surface of the photosensitive drum 31 by exposing the surface of the photosensitive drum 31, the process cartridge 30 including the photosensitive drum 31, the charging roller 32, the developing sleeve 33, a toner container (not shown), and the like. And a laser scanner 2 for forming an electrostatic latent image. The laser scanner 2 includes a laser light emitting unit (not shown), a rotating polygon mirror 21, a folding mirror 22, and the like.

  Further, the cassette feeding devices 5 and 6 include sheet feeding trays 5a and 6a for stacking sheets S, a feeding roller 26 for feeding sheets S on the sheet feeding tray one by one, and a retard separation type sheet described later. Separators 8 and 9 are provided. Further, the manual sheet feeder 4 includes a manual tray 4a, a feeding roller 26 that feeds the sheets S on the manual tray one by one, and a retard separation type sheet separation unit 7 to be described later.

  The transfer unit 1 </ b> C forms a transfer nip by pressing against the photoconductive drum 31 and the photoconductive drum 31. When the sheet S passes through the transfer nip, the toner image on the photoconductive drum 31 is transferred to the sheet S. The transfer roller 11 is configured.

  Next, an image forming operation in the laser beam printer 1 configured as described above will be described.

  When the image forming operation is started, the photosensitive drum 31 first rotates in the direction of the arrow, and is uniformly charged to a predetermined polarity and a predetermined potential by the charging roller 32. Then, laser light L is emitted from the laser light emitting unit of the laser scanner 2 to the photosensitive drum 31 whose surface has been charged based on image information, and this laser light L passes through the polygon mirror 21 and the folding mirror 22. Irradiated. As a result, an electrostatic latent image is formed on the photosensitive drum 31.

  Next, the electrostatic latent image is developed as a toner image when toner that has been appropriately charged with the rotation of the developing sleeve 33 is supplied onto the photosensitive drum 31 and attached to the electrostatic latent image. Visualized.

  On the other hand, in parallel with such a toner image forming operation, the sheets S stacked and stored in the sheet feeding trays 5a and 6a are fed by the feeding roller 26 and then separated by the sheet separating units 8 and 9 to be registered. It is conveyed to the roller 10. Alternatively, after the sheets S stacked and stored on the manual feed tray are sent out by the feeding roller 26, they are separated by the sheet separating unit 7 and conveyed to the registration rollers 10.

  The sheet S thus transported to the registration rollers 10 is transported to the transfer unit 1C at the timing of the latent image formed on the photosensitive drum 31 after the skew is corrected by the registration rollers 10. Is done. Thereafter, the toner image formed on the photosensitive drum by the transfer unit 1 </ b> C is transferred to a predetermined position on the sheet S by the transfer roller 11.

  Next, the sheet S on which the toner image has been transferred in this manner is conveyed to a fixing unit 13 having a driving roller 14 and a fixing roller 15 having a built-in heater via a conveying belt 12. The toner image is heated and pressurized and fixed on the sheet surface.

  The laser beam printer 1 has a duplex printing mode for performing duplex printing on the sheet S and a simplex printing mode. In the single-sided print mode, the sheet S after the fixing process is discharged onto the discharge tray 18 outside the apparatus by the inner discharge roller pair 16 and the outer discharge roller 17.

  In the double-sided printing mode, the paper is temporarily stored on the intermediate tray 24 via the refeed path 20 and the double-sided conveyance path 23 by the internal discharge roller pair 16 or the switchback roller pair 19. Thereafter, the sheet S stored on the intermediate tray 24 is conveyed again to the registration roller 10 for image formation by the refeed device 25, and thereafter discharged outside the apparatus through the same process as the single-sided printing.

  Next, the sheet separating unit 7 provided in the manual sheet feeder 4 will be described. Needless to say, the sheet separating units 8 and 9 provided in the other cassette feeding devices 5 and 6 may have the same configuration.

  A sheet separating unit 7 provided in the manual sheet feeding device 4 separates the sheets S fed by a pickup roller 26 which is a sheet feeding roller one by one and feeds them into the printer main body. As shown in FIG. 2, the sheet separating unit 7 feeds the sheet with a predetermined pressure against the feed roller 28, which is a sheet conveying roller that rotates in the sheet conveying direction, and returns the sheet. It is comprised with the retard roller 29 which is a rotary body which rotates to (3).

  The pickup roller 26, the feed roller 28, and the retard roller 29 are transmitted with rotational drive from a drive source (not shown) installed in the printer main body via a power transmission mechanism shown in FIG. That is, one end of the rotational power of the drive source can freely rotate to the manual feed frame 55 shown in FIG. 4 via the input gear 33, idler gears 49 and 50, and the roller gear 40 provided on the feed roller shaft 35 of the feed roller 28. Is transmitted to a feed roller shaft 35 supported by the shaft.

  Further, the rotational power transmitted to the feed roller shaft 35 is 1: 1 to the pickup roller shaft 39 rotatably held by the feed roller shaft 35 through idler gears 36 and 37 and a gear 38 that drives the pickup roller 26. 1 is transmitted.

  The rotational power is transmitted from the roller shaft 35 to the relay shaft 43 via the roller gear 40, the idler gear 41 and the relay shaft drive gear 42. Further, the rotational power from the roller shaft 35 is transmitted from the relay shaft 43 to the retard roller 29 via a torque limiter 32 and a coupling 44 that transmit only a torque within a certain range by a friction member or the like.

  Here, on the downstream side of the drive train of the input gear 33, a two-step missing gear 46 composed of internal teeth 46a and external teeth 46b is arranged. It should be noted that a spring (not shown) is incorporated between the inner teeth 46a and the outer teeth 46b of the two-step missing gear 46 so as to give opposite rotations. Further, a cam 47 formed integrally with the external teeth 46b is provided at one end of the external teeth 46b. The flapper 45 of the solenoid 34 is locked to the cam 47 when paper is not passed. As a result, when the solenoid 34 is not passing paper, the drive of the input gear 33 is not transmitted to the two-step missing gear 46.

  On the other hand, when the paper is passed, a voltage is applied to the solenoid 34, and the flapper 45 is sucked in the direction D by the suction force generated in the coil, so that the flapper 45 is unlocked from the cam 47. When the locking of the flapper 45 is released in this way, the cam 47 and the external teeth 46b of the two-step missing gear 46 formed integrally therewith rotate in the direction E by the rotation of the input gear 33. .

  When the outer teeth 46b rotate in the E direction in this way, an abutment rib (not shown) provided between the inner teeth 46a and the outer teeth 46b brings the inner teeth 46a and the outer teeth 46b into contact with each other, thereby The two-step missing gear 46 is integrally rotated in the direction E by a predetermined rotation amount. Since the internal teeth 46 a of the two-step missing gear 46 are connected to the drive shaft 48, the rotational power of the input gear 33 is supplied to the feed roller shaft 35 via the drive shaft 48, idler gears 49 and 50 and the roller gear 40. Is transmitted to.

  Further, when the driving force is transmitted in this manner, the feed roller 28 rotates in the sheet conveying direction (the direction of arrow A in FIG. 2). Further, the pickup roller 26 also rotates in the direction of conveying the sheet (in the direction of arrow F in FIG. 2) via idler gears 36 and 37 and a pickup roller driving gear 38 that drives the pickup roller 26.

  The rotation of the roller shaft 35 is transmitted to the relay shaft 43 via the roller gear 40, the idler gear 41 and the relay shaft drive gear 42, and the retard roller 29 returns the sheet S in synchronization with the rotation of the feed roller 28 (FIG. 2). In the direction of arrow B).

  Here, since the rotational power is transmitted to the retard roller 29 via the torque limiter 32, when the torque greater than the set value is applied, the retard roller 29 is idled, and the sheet S is conveyed by being driven by the feed roller 28. It rotates in the direction (opposite direction of arrow B in FIG. 2). As a result, when only one sheet fed by the pickup roller 26 enters the separation nip portion of the sheet separation unit 7, the retard roller 29 enters an idle state and is driven by the feed roller 28 to convey the sheet downstream. To do.

  On the other hand, when a plurality of sheets fed by the pick-up roller 26 enter the separation nip portion, the retard roller 29 rotates in the direction to return the sheet S by the action of the torque limiter 32, whereby the sheets other than the uppermost sheet are retarded. Returned by roller 29. As a result, only the uppermost sheet is separated by the feed roller 28 and conveyed downstream.

  Incidentally, as shown in FIG. 4, the pickup roller 26 and the feed roller 28 are covered in a state where both ends are held by a roller holder 52 which is a roller shaft holding member that also serves as a reinforcement member for the pickup roller 26 and the feed roller 28. It has been broken.

  In FIG. 4, 39A is a connecting arm that is a connecting member that is rotatably attached to a feed roller shaft 35 that is a first shaft and to which a pickup roller shaft 39 that is a second shaft is attached. That is, the pickup roller shaft 39 is attached to the paper feed frame 55 that constitutes the manual feeding device body via the connecting arm 39 </ b> A and the feed roller shaft 35.

  The connecting arm 39A is configured to rotate in the vertical direction as the pickup roller shaft 39 rotates. When the sheet is fed, the pickup roller shaft 39 is rotated to rotate the connecting arm 39A downward, so that the pickup roller 26 comes into contact with the sheet S.

  Further, as shown in FIGS. 5 and 6, the pickup roller 26 is attached to a pickup roller collar 53 formed integrally with the pickup roller driving gear 38. The pickup roller collar 53 is fitted to the pickup roller shaft 39 so as to rotate integrally with the pickup roller shaft 39.

  The pickup roller shaft 39 is made of resin, and a tip 39 of the pickup roller shaft 39 is provided with a bearing portion 39b through which the feed roller shaft 35 is inserted, as shown in FIGS. An arm portion 39a is projected. The pickup roller shaft 39 is supported by the feed roller shaft 35 by inserting the feed roller shaft 35 through the bearing portion 39b.

  Further, the pickup roller shaft 39 is held at the free end side by roller holders 52 attached to the pickup roller shaft 39 at both ends of the pickup roller 26. The pickup roller shaft 39 is reinforced by the roller holder 52 holding the free end side of the pickup roller shaft 39 whose one end is fixed to the connecting arm 39A. As a result, when the sheet is fed, the pickup roller shaft 39 is not bent, and the sheet can be fed stably.

  On the other hand, the feed roller 28 is attached to a feed roller collar 54, and the feed roller collar 54 is fitted to the feed roller shaft 35 so as to rotate integrally with the feed roller shaft 35.

  Here, the free end of the feed roller shaft 35 is manually fed through a bearing 51 which is a bearing member that is elastically and detachably attached to the manual feed frame 55 by a claw portion 51a shown in FIG. It is attached to the paper feed frame 55.

  The feed roller shaft 35 has a roller holder 52 on both ends of the feed roller 28 via a bearing portion 39b which is a fitting portion integrally formed with the bearing 51 at one end and the pickup roller shaft 39 at the other end. It is attached. By attaching the roller holder 52 to the feed roller shaft 35 in this way, both the feed roller shaft 35 and the pickup roller shaft 39 can be connected by the roller holder 52. As a result, when the sheet is fed, the feed roller shaft 35 and the pickup roller shaft 39 are not bent, and the sheets can be stably fed separately.

  The roller holder 52 serves to prevent the feed roller collar 54 and the pickup roller collar 53 from coming off in the direction of the arrow shown in FIG. 6. The roller holder 52 is prevented from coming off by a bearing 51.

  FIG. 7 schematically shows these supported states, and it can be seen from FIG. 7 that many components are attached to the manual feed frame 55 via the roller holder 52.

  Next, replacement of the pickup roller 26 and the feed roller 28 will be described.

  When the pickup roller 26 or the feed roller 28 is replaced due to roller wear or the like, first, the claw portion 51 a of the bearing 51 shown in FIG. 8 is bent and the bearing 51 is removed from the manual feed frame 55. Then, the bearing 51 is moved in the direction of the arrow G in FIG. 8 and removed from the feed roller shaft 35 so as to release the retaining of the bearing 51 with respect to the feed roller shaft 35.

  As a result, the tip of the feed roller shaft 35 is opened as shown in FIG. 11, and the roller holder 52 can move in the arrow H direction, which is the axial direction. Thereafter, when the roller holder 52 is moved in the direction of arrow H, the fitting between the roller holder 52 and the bearing portion 39b integrated with the pickup roller shaft 39 is released.

  As shown in FIGS. 9 and 10, the roller holder 52 is formed with insertion holes 52a and 52b through which the feed roller shaft 35 is inserted, and the insertion holes 52a and 52b are formed as openings. Notches 52a1 and 52b1 are provided. Further, the width of the notch 52a1 indicated by N in FIG. 10 is larger than the diameter O of the feed roller shaft 35. The notch 52b1 has the same configuration.

  For this reason, the roller holder 52 can be rotated about the pickup roller shaft 39 as a rotation shaft when the fitting with the bearing portion 39b is released. Thus, when the fitting with the bearing portion 39b is released, the roller holder 52 is then rotated 180 ° in the direction of arrow I shown in FIG. 11 with the pickup roller shaft 39 as the rotation fulcrum.

  When the roller holder 52 is rotated in this way, the roller holder 52 moves to the position shown in FIG. 12 and comes off from the feed roller shaft 35, whereby the roller holder 52 and the pickup roller 26 can move in the direction of arrow J. It becomes.

  Thereafter, when the roller holder 52 and the pickup roller 26 are moved in the direction of arrow J, the roller holder 52 and the pickup roller 26 are detached from the pickup roller shaft 39 as shown in FIG. As a result, the pickup roller 26 can be removed in the arrow K direction.

  Further, by moving the feed roller 28 in the direction of the arrow L, the feed roller 28 is detached from the feed roller shaft 35 as shown in FIG. 14, thereby enabling the feed roller 28 to be removed in the direction of the arrow M.

  After removing the feed roller 28 and the pickup roller 26 in this way, the new pickup roller 26 and the feed roller 28 are attached to the feed roller shaft 35 and the pickup roller shaft 39. Thereafter, assembly is performed in the reverse order of the above procedure.

  As described above, the roller holder 52 is attached to the feed roller shaft 35 and the pickup roller shaft 39, and the feed roller shaft 35 and the feed roller shaft 35 are held by the roller holder 52, so that the two shafts 35 and 39 are bent. Can be prevented. Thereby, the sheet S can be fed stably.

  Further, the roller holder 52 can be removed from the feed roller shaft 35 after the fitting with the bearing 39b can be released and after the fitting with the bearing 39b is released, so that the roller can be easily exchanged. It can be carried out.

  In the above description, in order to release the roller holder 52, the roller holder 52 is rotated 180 ° in the direction of the arrow I in FIG. 11, but this rotation amount can be changed as appropriate. In this embodiment, the feed roller 28 is removed after the pickup roller 26 is removed. However, the feed roller 28 may be removed first from the state shown in FIG.

  Next, a second embodiment of the present invention will be described.

  FIG. 15 is a perspective view of the sheet feeding apparatus according to the present embodiment. In FIG. 15, the same reference numerals as those in FIG. 11 denote the same or corresponding parts.

  15, 52A is a roller holder that covers the pickup roller 26 and the feed roller 28. The roller holder 52A is inserted through which the feed roller shaft 35 is inserted as shown in FIGS. 16 (b) and 16 (c). Holes 52a and 52b are formed on both side surfaces. An insertion hole 52c through which the pickup roller shaft 39 is inserted is formed on one side surface.

  Further, the three insertion holes 52a, 52b, and 52c are provided with notches 52a1, 52b1, and 52c1, respectively. Here, the width N of the notch 52a1 of the insertion hole 52a is larger than the diameter O of the feed roller shaft 35, and the width T of the notch 52b1 of the insertion hole 52b is larger than the diameter U of the feed roller shaft 35. Further, the width V of the notch 52 c 1 of the insertion hole 52 c is larger than the diameter W of the pickup roller shaft 39.

  Then, by making the widths N, U, V of the notches 52a1, 52b1, 52c1 provided in the insertion holes 52a, 52b, 52c in this way larger than the diameters of the shafts 35, 39, the roller holder 52A is moved upward. It can be removed.

  Next, replacement of the pickup roller 26 and the feed roller 28 in the manual sheet feeder 4 having the roller holder 52A having such a configuration will be described.

  When the pickup roller 26 or the feed roller 28 is replaced due to roller wear or the like, first, the pawl 51a of the bearing 51 shown in FIG. To do. Next, the bearing 51 is moved in the direction of arrow G in FIG.

  As a result, the tip of the feed roller shaft 35 is opened as shown in FIG. 15, and the roller holder 52 can move in the direction of arrow H. Thereafter, when the roller holder 52 is moved in the arrow H direction, the roller holder 52A and the pickup roller shaft 39 and the bearing portion 39b integrated with each other are disengaged.

  Thereby, roller holder 52A can be removed in the direction of arrow P shown in FIG. When the roller holder 52A is removed in this way, the feed roller 28 can be removed in the direction of arrow Q in FIG. 17, and the pickup roller 26 can be removed in the direction of arrow R.

  After removing the feed roller 28 and the pickup roller 26 in this way, the new pickup roller 26 and the feed roller 28 are attached to the feed roller shaft 35 and the pickup roller shaft 39. Thereafter, assembly is performed in the reverse order of the above procedure.

  As described above, in the present embodiment, the roller holder 52A can be released from the bearing 39b, and after the engagement with the bearing 39b is released, the feed roller shaft 35 and the pickup roller shaft 39 are It can be removed from both. Thereby, replacement | exchange of a roller can be performed easily.

  In the description so far, the example using the retard separation mechanism as the sheet separation mechanism has been described, but the present invention is not limited to this. For example, a stop roller separation mechanism that performs sheet separation using only the frictional force of the nip portion between the retard roller 29 and the feed roller 28 without rotating the retard roller 29 may be used. When this stop roller separation mechanism is used, the sheet can be separated at low cost because there is no part for retard driving.

  In the above description, the bearing 51 is fixed to the manual feed frame 55 by the snap-fitting claw 51a. However, it may be fixed by screwing or the like instead of the snap-fitting claw 51a. .

  Further, in the above description, when the roller holders 52 and 52A are removed, the widths of the notches 52a1, 52b1 and 52c1 provided in the insertion holes 52a, 52b and 52c so that the shafts 35 and 39 can pass therethrough. Is larger than the diameter of the shafts 35 and 39. However, the present invention is not limited to this. Even when the roller holders 52 and 52A are attached to the shafts 35 and 39 by snap fitting, the shafts 35 and 39 may pass when the roller holders 52 and 52A are removed. it can.

  In the above description, the case where the roller holders 52 and 52A are moved in the axial direction to release the fitting between the pickup roller shaft 39 and the integral bearing portion 39b has been described. You may make it move to.

  Furthermore, in the above description, the case where the roller holders 52 and 52A are fitted to the pickup roller shaft 39 has been described. However, the roller holders 52 and 52A are attached to the feed roller shaft 35 or both the feed roller shaft and the pickup roller shaft 39. May be fitted.

  In addition, the case where the sheet feeding apparatus has been provided in a copying machine that is an example of an image forming apparatus has been described as an example. However, the sheet feeding apparatus separates and feeds originals one by one, It can also be suitably used for an image reading apparatus such as a scanner for reading document description information.

1 is a diagram illustrating a schematic configuration of a laser beam printer which is an example of an image forming apparatus including a sheet feeding device according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a sheet separating unit provided in a manual feeding device that is an example of the sheet feeding device. The figure explaining the drive mechanism of the said manual feed apparatus. The perspective view of the said manual feeding apparatus. The perspective view which shows the support state of the pick-up roller and feed roller of the said manual feed apparatus. Sectional drawing which shows the support state of the said pick-up roller and a feed roller. The conceptual diagram which shows typically the support state of the said pick-up roller and a feed roller. The 1st figure which shows the replacement | exchange procedure of the said pick-up roller and a feed roller. The perspective view of the roller holding member provided in the said manual feeding apparatus. The figure explaining the structure of the said roller holding member. The 2nd figure which shows the replacement | exchange procedure of the said pick-up roller and a feed roller. The 3rd figure which shows the replacement | exchange procedure of the said pick-up roller and a feed roller. FIG. 4 is a fourth diagram showing a procedure for exchanging the pickup roller and the feed roller. FIG. 10 is a fifth diagram showing a procedure for exchanging the pickup roller and the feed roller. The perspective view of the sheet feeding apparatus which concerns on the 2nd Embodiment of this invention. FIG. 4 is a diagram illustrating a configuration of a roller holding member provided in a manual feeding device that is an example of the sheet feeding device. The figure which shows the replacement | exchange procedure of the pick-up roller and feed roller of the said manual feeding apparatus. The figure explaining the structure of the retard separation mechanism provided in the conventional sheet feeding apparatus. The figure explaining sheet | seat separation operation | movement by the said retard separation mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser beam printer 1A Printer main body 1B Image formation part 4 Manual feed apparatus 7 Sheet separation part 26 Pickup roller 28 Feed roller 29 Retard roller 35 Feed roller shaft 39 Pickup roller shaft 39A Connection arm 39b Bearing part 51 Bearing 52 Roller holder 52A Roller Holder 52a, 52b, 52c Insertion hole 52a1, 52b1, 52c1 Notch 55 Paper feed frame S Sheet

Claims (9)

In a sheet feeding apparatus comprising a sheet feeding roller for feeding a sheet, and a sheet conveying roller for separating and conveying the sheets fed by the sheet feeding roller one by one,
A first shaft on which the sheet conveying roller is detachably attached in the axial direction and one end is held by the apparatus main body;
A second shaft on which the sheet feeding roller is detachably attached in the axial direction and one end is held by the apparatus body;
Axial direction of fitting portions attached to the first shaft and the second shaft at both ends of the sheet conveying roller and the sheet feeding roller and provided on at least one of the first shaft and the second shaft A roller shaft holding member that fits into and holds the first shaft and the second shaft,
The roller shaft holding member is releasable from at least one of the first shaft and the second shaft after being disengaged from the fitting portion and after being disengaged from the fitting portion. A sheet feeding device characterized by that.   The sheet according to claim 1, wherein the roller shaft holding member or the fitting portion is movable in the axial direction so as to release the axial fitting with the fitting portion of the roller shaft holding member. Feeding device. A bearing member that is detachably attached to the apparatus main body and holds the other end of the first shaft;
The sheet feeding device according to claim 2, wherein the axial movement of the roller shaft holding member is regulated by the bearing member. The roller shaft holding member is provided with an insertion hole through which the first shaft and the second shaft are inserted,
4. The opening portion through which the first shaft and the second shaft that are inserted when the roller shaft holding member is removed is formed in the insertion hole. 5. The sheet feeding apparatus described in 1.   The sheet feeding device according to claim 4, wherein the insertion hole is fitted to the fitting portion.   The sheet feeding apparatus according to claim 1, wherein the roller shaft holding member is attached to the first shaft and the second shaft by snap fitting.   The sheet feeding apparatus according to claim 1, wherein the sheet feeding roller and the sheet conveying roller are covered by the roller shaft support member. A connecting member provided rotatably on the first shaft and having the second shaft attached to the rotating end;
The sheet feeding device according to any one of claims 1 to 7, wherein the second shaft is held by the device main body via the connecting member and the first shaft. An image forming apparatus comprising: an image forming unit; and the sheet feeding device according to claim 1 for feeding a sheet to the image forming unit.

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