JP4082411B2 - Paper feeder - Google Patents

Description

  The present invention relates to a technology of a paper feeding device, and more particularly, to a paper feeding device having a structure that regulates rotation / stop of a pickup roller by operating a locking member with a solenoid.

  In general, a paper feeder such as a facsimile machine, a copier, and a multi-function machine having a plurality of functions including them is formed on the lower side of the machine body, and the paper is stacked on a paper feed cassette that can be taken out in the front-rear direction of the machine body. Stored. In this paper feeding apparatus, a pickup roller having both ends attached to and supported by a casing is disposed on one side of the apparatus main body for feeding out the paper. The pickup roller repeatedly rotates and stops, and the uppermost layer among the stored papers. It is configured to be fed out one by one from the top.

  For example, as described in Patent Document 1, in a conventional paper feeding device, a pickup roller is fixed to a drive shaft supported on both ends of a casing, and the rotation of the pickup roller is restricted to the side of the pickup roller. A locking member is configured (see Patent Document 1). The locking member includes a gear as a rotating body that interlocks with the drive shaft of the pickup roller, and a lever that locks the gear and stops the rotation of the drive shaft. This lever is operated by a solenoid and is displaced in a direction in which the lever is engaged with or released from the gear, thereby restricting the rotation of the pickup roller.

  An elastic member such as a torsion spring or a coil spring is disposed in the vicinity of the lever constituting the locking member, and is always urged by the elastic member in the direction in which the lever abuts the gear. The lever that is attracted and displaced by is returned to a position that restricts the rotation of the pickup roller. In such a configuration, the force that attracts the lever by the solenoid and the elastic force by the elastic member are adjusted to balance each other, and when the solenoid is in an OFF state (excitation state), the lever is moved by the elastic member. It is biased to contact the gear, the solenoid is turned on (excited), and the locking member is attracted and displaced against the biasing force of the elastic member. Yes.

In Patent Document 2, as a configuration for restricting the rotation of such a pickup roller, with respect to the intermediate conveyance roller of the sheet feeding device, a solenoid is operated to operate a flapper that engages with the stopper gear. Also disclosed is a configuration that regulates the rotation of the intermediate transport roller (see Patent Document 2).
JP-A-6-115730 JP-A-11-157694

  However, in the configuration disclosed in Patent Document 1 or Patent Document 2 described above, it is difficult to adjust the balance between the attracting force of the solenoid and the elastic force of the elastic member. It was the cause. As described above, the conventional paper feeding apparatus has not been high in the accuracy of the rotation control of the pickup roller.

  That is, if the elastic force of the elastic member is too larger than the attracting force of the solenoid, the lever cannot be operated. On the other hand, if the elastic force of the elastic member is too small than the attracting force of the solenoid, even if the solenoid is turned off, the lever cannot be returned to the position where it abuts against the rotating body. When there is an extra load, the lever may not be quickly returned to the contact position with the rotating body only by the elastic force of the elastic member.

  Therefore, the present invention relates to a sheet feeding device that solves the above-described conventional problems and aims to improve the accuracy of rotation control of the pickup roller with a simple configuration.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect of the present invention, a pickup roller that carries out the paper and a locking member that restricts the rotation of the pickup roller are provided, and the locking member is supported so as not to rotate relative to the pickup roller. A rotating body, a lever that is locked to the rotating body and restricts the rotation of the rotating body, a solenoid that displaces the lever, and an elastic member that constantly urges the lever in a direction to contact the rotating body. In the paper feeding device provided, an auxiliary elastic member is interposed between the lever and the solenoid, and the auxiliary elastic member urges the lever in a direction in contact with the rotating body.

  According to a second aspect of the present invention, the auxiliary elastic member is pressed by the lever and the solenoid when the lever is attracted by the solenoid.

  According to a third aspect of the present invention, the auxiliary elastic member is not in contact with either the lever or the solenoid when the lever is in contact with the rotating body.

  As effects of the present invention, the following effects can be obtained.

  With the configuration shown in claim 1, the lever operation by the solenoid is ensured by using the elastic force of the auxiliary elastic member, and the accuracy of the rotation control of the pickup roller can be improved with a simple configuration.

  Since the auxiliary elastic member is pressed one by one when the lever is operated by switching the solenoid, the lever operation by the solenoid is further performed using the elastic force of the auxiliary elastic member. Can be sure.

  Since the structure shown in claim 3 is adopted, the locking between the lever and the rotating body can be quickly eliminated, and the timing deviation from when the solenoid is excited until the pickup roller is started to rotate can be reduced.

Next, the best mode for carrying out the invention will be described.
FIG. 1 is a perspective view showing an overall configuration of a multi-function peripheral including a paper feeding device according to the present embodiment, FIG. 2 is a side sectional view of FIG. 1, FIG. 3 is a plan view of the paper feeding device, and FIG. Is an enlarged perspective view of the pick roller and the locking device, FIG. 5 is a side view of FIG. 4, and FIG. 6 is a side view of the solenoid excited in FIG.

  Hereinafter, as an image forming apparatus including the paper feeding device 7 according to the present invention, a multifunction machine 1 having a facsimile function and a copying function of a copying machine will be described. However, the present embodiment is not limited to this, The present invention can be applied to a simple facsimile machine or a copying machine. In the following description, for the sake of convenience, the front-rear and left-right positions of each structure will be described with the left side of the multifunction device 1 shown in FIG. 2 as the front side and the right side as the rear side. The same applies to the front / rear and left / right positions of each structure in other drawings.

First, the overall configuration of the multifunction machine 1 will be described below.
As shown in FIGS. 1 and 2, the multifunction machine 1 includes a recording unit 2, a reading unit 3, a recording device 4, a paper feeding device 7, an automatic document feeder 8, and the like. The reading unit 3 is disposed above the recording unit 2, and the recording unit 2 includes a recording device 4 and a paper feeding device 7 in the vertical direction. The paper stored in the paper feeding cassette 5 is carried out to the recording device 4 by the paper feeding device 7, transferred by the recording device 4, and discharged from the recording paper discharge tray 11.

  The reading unit 3 stores a reading device (not shown) for reading the contents of a document or the like in the reading case 6, and scans the document placed on the upper surface of the reading case 6 by the reading device, thereby The image information is read. On the other hand, an automatic document feeder 8 that automatically feeds a document is attached to one end of the reading case 6, and the document placed on the document supply tray 9 is one sheet by the automatic document feeder 8. The paper is picked up one by one and conveyed to one end of the upper surface of the reading case 6, and the content is read by the stationary reading device and then discharged to the document discharge tray 10.

  The reading unit 3 is used as a flat bed type image scanner that scans a reading device to read a stationary document, and is also used as a sheet feed type scanner that reads a document while fixing the position of the reading device. Configured to be able to.

  In the multifunction machine 1 according to the present embodiment, when a document placed on the automatic document feeder 8 is sent by fax, the document is placed on the document supply tray 9, and the documents are separated one by one and automatically documented. The image is taken into the transport device 8, and the image information of the original is read by the reading device on the apparatus main body side, and then discharged from the paper discharge port and stacked on the original discharge tray 10. Image information read by the reading device is converted into an electric signal and transmitted to the other party through a telephone line. On the other hand, when receiving a fax, the signal received from the other fax machine is converted into image information, and the paper stored in the paper feed cassette 5 is carried out to the recording device 4 by the paper feed device 7 and the image is received. Then, it is discharged to the recording paper discharge tray 11.

Next, the configuration of the sheet feeding device 7 will be described in detail below.
As shown in FIGS. 1 to 3, in the paper feeding device 7 according to the present embodiment, a substantially rectangular parallelepiped paper feeding cassette 5 having an open upper surface is slidably disposed on a casing 12. The cassette 5 is configured to be drawable from the casing 12 in the longitudinal direction of the machine body. The casing 12 is formed integrally with the apparatus main body, but the apparatus main body and the casing 12 may be configured separately. The casing 12 can be provided in a plurality of stages in the vertical direction. In this case, the apparatus main body is placed and fixed above the uppermost casing 12.

  In the paper feed cassette 5, a flapper 13 as a bottom plate for setting paper is supported so as to be driven, and this flapper 13 is urged upward by a spring (not shown) arranged on the paper feeding side. In order to set paper in the paper cassette 5, the paper cassette 5 is pulled out from the casing 12 and a plurality of papers are placed on the flapper 13. When the paper is placed on the flapper 13, the flapper 13 is driven upward by a spring, and the leading end (front end) of the upper surface of the paper is formed at two left and right corners of the paper feed cassette 5. 15 is pressed against the lower surface. In this state, the paper feed cassette 5 is housed in the casing 12 with the paper being locked to the separation claws 15.

  Pickup rollers 16 and 16 are provided above the separation claws 15 and 15, and a feed roller 17 and a press roller 18 are arranged on the rear side of the pickup rollers 16 and 16 and on the downstream side in the paper unloading direction. It is installed.

  Two pickup rollers 16, 16 are arranged along the left-right direction of the paper feed cassette 5, and are supported at substantially equal intervals above the flapper 13 by a drive shaft 19 that is supported and fixed to the casing 12 so that both ends can be driven. ing. The drive shaft 19 can be driven via a drive mechanism (not shown) disposed on the casing 12 side. The pick-up rollers 16 and 16 are formed in a substantially fan shape when viewed from the side, and when one rotation is made, the roller surface comes into contact with the upper surface of the uppermost sheet among the plurality of sheets set on the flapper 13, It is configured to retract to the rear of the aircraft. Note that only one pickup roller 16 may be disposed on the drive shaft 19, and the number and arrangement position thereof are not limited.

  The paper carry-out mechanism by the pickup rollers 16 and 16 will be described in detail. When the pickup rollers 16 and 16 are rotated, the uppermost sheet among the sheets stored in the paper feed cassette 5 starts to be fed. At this time, the paper on the paper feed cassette 5 is regulated at both ends by the separation claws 15 and 15, so that a certain resistance is generated against such retraction, but the coefficient of friction between the papers is small, Only the uppermost sheet in contact with the pickup rollers 16 and 16 is fed out while sliding with respect to the other sheets. When the paper is carried out, the corner of the paper is first raised to the convex portion while the corner is locked to the separation pawls 15 and 15, and the corner jumps up from the separation pawls 15 and 15 before being removed. It is released from the paper feeder 7.

  The feed roller 17 and the press roller 18 are rotationally driven through a drive mechanism (not shown) disposed in the casing 12, and the paper carried out by the pickup rollers 16 and 16 is above the paper feeding device 7. It is configured to be carried out into the recording device 4 on the downstream side in the paper carrying-out direction.

  As shown in FIGS. 3 to 5, the paper feeding device 7 according to the present embodiment is provided with a cam 20 and a lever 21 as a locking member 14 that restricts the rotation of the pickup roller 16. A solenoid 22 that is displaced by moving operation is provided. The lever 21 is attached with an elastic member 23 that constantly urges the lever 21 in a direction in which the lever 21 abuts against the cam surface of the cam 20. Between the lever 21 and the solenoid 22, an auxiliary elastic member 26 for returning the lever 21 displaced by the solenoid 22 to a position where it abuts against the cam 20 is disposed.

  In this embodiment, the locking member 14 (cam 20 and lever 21), solenoid 22 and the like are disposed only on the right and left pickup rollers 16 of the left and right pickup rollers 16. However, the disposition position of the cam 20 and the like is not limited to this, and may be disposed approximately in the middle between the left and right pickup rollers 16.

  The cam 20 is mounted on the drive shaft 19 on the side of the pickup roller 16 and is fixed so that the relative position cannot be varied so as to rotate in conjunction with the pickup roller 16 in the same direction. The cam 20 is formed as a non-circular cam having a substantially “6” shape in a side view, and the radial length is gradually shortened from the position where the radial length is maximum around the drive shaft 19. Is formed. The cam surface of the cam 20 is formed with a locking portion 20a to which the lever 21 is locked, and this locking portion 20a is formed at a step at a boundary portion between the maximum radial position and the minimum radial length. Has been.

  The cam 20 is rotated in the same direction as the drive shaft 19 and the pickup roller 16 in the direction of the arrow in FIG. 4 (rightward in FIG. 5). The cam 20 is attached in such a direction that the radial length at the rotation start position of the locking portion 20a continuously shortens during one rotation. In a state where the lever 21 is locked to the cam 20, the pickup roller 16 is stopped with the substantially fan-shaped portion positioned above (see FIG. 4).

  By forming the locking portion 20a with the cam surface continuous in this manner, the cam 20 and the pickup roller 16 can be smoothly rotated, and the lever 20 can reliably rotate and stop the cam 20 and the pickup roller 16. Can be regulated. The shape of the cam 20 is not particularly limited as long as it is a rotating body that is supported so as not to rotate relative to the pickup roller 16. For example, the cam 20 may be a gear that can be locked with the lever 21. The stop portion 20a may be formed by protruding in the radial direction.

  The lever 21 is disposed at a position overlapping the cam 20 in a plan view, and is supported by a support shaft 25 so as to be swingable back and forth. The lever 21 has an arm portion 21a extending obliquely downward and forward with the support shaft 25 as a center, and a distal end portion 21b that is bent downward and locked to the locking portion 20a of the cam 20. Is formed. The front end portion 21 b is engaged with the engaging portion 20 a of the cam 20, so that the rotation of the cam 20 is restricted and the rotation of the pickup roller 16 disposed on the drive shaft 19 is restricted.

  The lever 21 is provided with a contact portion 21c extending upward from the base portion of the arm portion 21a, and the contact portion 21c is configured to press an auxiliary elastic member 26 described later from the front of the body. (See FIG. 6). A connection portion 21d, in which the plunger 24 of the solenoid 22 is locked, is cut out in a part of the contact portion 21c.

  The solenoid 22 is disposed behind the lever 21 and at a position overlapping the cam 20 and the lever 21 in plan view. A plunger 24 that extends and contracts in the longitudinal direction of the machine body is attached to the solenoid 22 toward the front of the machine body. The plunger 24 is contracted in a state in which the solenoid 22 is “ON”, that is, when the solenoid 22 is energized, the direction in which the plunger 22 is accommodated in the main body of the solenoid 22. On the other hand, when the solenoid is in the “OFF” state, that is, when the excitation of the solenoid 22 is cut off, the solenoid 22 is extended in a direction protruding from the main body.

  The end of the plunger 24 on the lever 21 side is provided with a groove 24a that is recessed in the radial direction from the circumferential surface. The groove 24a is engaged with the connecting portion 21d of the lever 21, and the lever 21 and the plunger 24 is linked and linked. When the plunger 24 is expanded and contracted with respect to the main body of the solenoid 22, the lever 21 is swung around the support shaft 25 via the connecting portion 21d locked to the groove portion 24a. The connecting mechanism between the lever 21 and the plunger 24 is not limited to that described above, and any mechanism that swings the lever 21 in conjunction with the expansion and contraction of the plunger 24 may be used.

  The elastic member 23 is formed as a torsion spring in which one side comes into contact with the support shaft 25 and the other side comes into contact with the lever 21, and is attached inside the lever 21 (see FIG. 5). The elastic member 23 always urges the lever 21 in the direction in which the lever 21 rotates in the direction of the arrow in FIG. 4 (rightward in FIG. 5) so that the tip 21 b comes into contact with the cam surface of the cam 20. The elastic member 23 is not limited to a torsion spring, and a coil spring or the like may be used.

  When the solenoid 22 is in the “OFF” state, the plunger 24 is extended from the main body of the solenoid 22 and urged by the elastic member 23 so that the distal end portion 21 b of the lever 21 contacts the cam surface of the cam 20. When the solenoid is turned “ON”, the plunger 24 contracts to the solenoid 22 body, the lever 21 is attracted against the elastic force of the elastic member 23, and the tip 21 b does not contact the cam surface of the cam 20. Displaced to position. That is, in the state where the solenoid is “ON”, the rotation of the cam 20 is allowed and the pickup roller 16 is rotated.

  In the present embodiment, since the sheets stored in the sheet feeding cassette 5 are carried out one by one while the pickup roller 16 makes one rotation, the solenoid 22 has the tip 21b of the lever 21. And the locking portion 20a of the cam 20 need only be switched to “ON” while the locking is released. If the lever 21 is brought into contact with any one of the cam surfaces of the cam 20, the tip portion 21b slides on the cam surface during one rotation of the cam 20, and is eventually locked by the locking portion 20a.

  As shown in FIGS. 5 and 6, the auxiliary elastic member 26 is interposed between the lever 21 and the solenoid 22, specifically, the front surface of the solenoid 22 and the rear surface of the contact portion 21 c of the lever 21. And is attached to the front wall surface of the solenoid 22. In this embodiment, the auxiliary elastic member 26 is formed in a substantially rectangular parallelepiped shape, and is attached so that the front surface is substantially parallel to the front wall surface of the solenoid 22.

  The auxiliary elastic member 26 is formed of a member having an elastic force. Specifically, it is formed from a member having elasticity with respect to the expansion / contraction direction of the plunger 24 with respect to the solenoid 22 body, and in this embodiment, is formed from a sponge material such as rubber sponge or urethane foam. By forming the auxiliary elastic member 26 from a sponge material, even if the contact portion 21c is brought into contact with the front surface of the auxiliary elastic member 26 from an oblique direction, this can be effectively biased, which is preferable. However, the material of the auxiliary elastic member 26 is not limited to a sponge material, and may be formed from rubber, a spring, or the like.

  When the solenoid 22 is switched to “ON” and excited, the auxiliary elastic member 26 is pressed by the contact portion 21 c of the lever 21 that is swung around the support shaft 25. When the solenoid 22 is in the “ON” state, the auxiliary elastic member 26 is held in a state of being pressed from the front by the contact portion 21c and biases the contact portion 21c in a direction against the pressing of the contact portion 21c. ing. When the solenoid 22 is switched to the “OFF” state and the excitation is cut off, the pressing of the auxiliary elastic member 26 by the contact portion 21 c is released, and the lever 21 contacts the cam surface of the cam 20 by the auxiliary elastic member 26. Repelled in the direction. That is, when the solenoid 22 is switched to the “OFF” state, the lever 21 is immediately returned to the position where it abuts against the cam surface of the cam 20 by the elastic force that the elastic member 23 and the auxiliary elastic member 26 cooperate. .

  As described above, the auxiliary elastic member 26 is interposed between the lever 21 and the solenoid 22 in addition to the elastic member 23. When the excitation of the solenoid 22 is cut off, the lever 21 is brought into contact with the cam 20 by the auxiliary elastic member 26. By configuring so as to be urged in the contacting direction, the lever 21 can be quickly and reliably returned to the position where the lever 21 contacts the cam 20 by using the elastic force of the auxiliary elastic member 26. Therefore, rotation / stop of the pickup roller 16 can be easily regulated, and the accuracy of rotation control of the pickup roller 16 can be improved with a simple configuration.

  By providing the auxiliary elastic member 26 in addition to the elastic member 23, it is sufficient that the elastic member 23 is provided with an elastic force that causes at least the tip 21b of the lever 21 to contact the cam surface of the cam 20. It can be configured such that an elastic force for returning 21 is applied to the auxiliary elastic member 26. Therefore, the balance between the force of attracting the lever 21 of the solenoid 22 and the elastic force of the elastic member 23 and the auxiliary elastic member 26 can be easily adjusted by selecting and changing the auxiliary elastic member 26 and attaching it. Even when the solenoid 22 is in the “OFF” state, even if the magnetic force remains in the solenoid 22, the lever 21 is repelled by the elastic force of the auxiliary elastic member 26, and the solenoid 22 The operation of the lever 21 can be ensured.

  Further, in this embodiment, as shown in FIGS. 5 and 6, the auxiliary elastic member 26 is pressed by the lever 21 and the solenoid 22 in a state where the solenoid 22 is excited and the lever 21 is attracted. Composed. With this configuration, when the lever 21 is operated by switching the “ON / OFF” of the solenoid 22, the auxiliary elastic member 26 can be pressed one by one. Therefore, by using the elastic force of the auxiliary elastic member 26, the lever 21 attracted by the solenoid 22 can be reliably returned to the position where it abuts on the cam 20, and the operation of the lever 21 by the solenoid can be made more reliable. it can.

  Further, in this embodiment, as shown in FIGS. 5 and 6, when the solenoid 22 is in the “OFF” state, the front surface of the auxiliary elastic member 26 and the rear surface of the contact portion 21c of the lever 21 are not in contact with each other. Has been. When the solenoid 22 is switched to the “ON” state, first, the rear surface of the contact portion 21c contacts the front surface of the auxiliary elastic member 26, and then the auxiliary elastic member 26 is pressed. The separation between the auxiliary elastic member 26 and the lever 21 can cancel the engagement between the distal end portion 21b of the lever 21 and the engaging portion 20a of the cam 20 until the lever 21 is swung and comes into contact with the auxiliary elastic member 26. It may be a distance.

  With this configuration, the solenoid 22 only needs to attract the lever 21 against only the elastic force of the elastic member 23 while the rear surface of the contact portion 21c contacts the front surface of the auxiliary elastic member 26. The load due to the elastic force of the auxiliary elastic member 26 can be reduced, and the engagement between the distal end portion 21b of the lever 21 and the engagement portion 20a of the cam 20 can be quickly eliminated. For this reason, it is possible to reduce a deviation in timing for starting the pickup roller 16 after the solenoid 22 is excited, and to improve the accuracy of rotation control of the pickup roller 16.

  In the above-described embodiment, the configuration in which the auxiliary elastic member 26 is attached to the front surface of the solenoid 22 has been described. However, the present invention is not limited to this, and the auxiliary elastic member 26 is disposed on the rear surface of the contact portion 21c of the lever 21. The contact portion 21c itself may be formed from a member having an elastic force.

1 is a perspective view illustrating an overall configuration of a multifunction machine including a sheet feeding device according to an embodiment. The side sectional view of FIG. The top view of a paper feeder. The expansion perspective view of a pick roller and a locking device. The side view of FIG. 4 similarly. FIG. 5 is a side view showing a state where the solenoid is excited in FIG. 4.

Explanation of symbols

7 Feeding Device 14 Locking Member 16 Pickup Roller 20 Cam (Rotating Body)
21 Lever 22 Solenoid 23 Elastic member 26 Auxiliary elastic member

Claims (3)

  A pickup roller for carrying out the paper; and a locking member for restricting the rotation of the pickup roller. The locking member is supported by the rotating body so as not to rotate relative to the pickup roller. In a paper feeding device comprising a lever that locks and restricts rotation of the rotating body, a solenoid that displaces the lever, and an elastic member that constantly urges the lever in a direction to contact the rotating body. An auxiliary elastic member is interposed between the lever and the solenoid, and the auxiliary elastic member urges the lever in a direction in contact with the rotating body.   The sheet feeding device according to claim 1, wherein the auxiliary elastic member is pressed by the lever and the solenoid when the lever is attracted by the solenoid.   The sheet feeding device according to claim 1, wherein the auxiliary elastic member is not in contact with either the lever or the solenoid when the lever is in contact with the rotating body.

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