JP4829907B2 - Medium supply apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a medium supply device and an image forming apparatus.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction machine, for example, a printer, a sheet feeding device as a medium supply device is provided to feed sheet-like paper as a medium. . The sheet feeding device is provided with a sheet feeding roller as a rotating body at least having a surface layer formed of a material having a high friction coefficient, for example, rubber, and the sheet feeding roller is accommodated in a sheet feeding cassette. By rotating the sheet while being pressed against the upper surface of the sheet, the sheet is continuously fed.

  By the way, since the paper feed roller is made of rubber, it has low wear resistance and is worn by repeated paper feeding. Therefore, when the paper feed roller wears and the degree of deterioration increases, it is replaced with a new paper feed roller.

In this case, the paper feed roller is detachably disposed with respect to a main body of the printer, that is, a shaft supported by a cantilever structure with respect to the apparatus main body. Therefore, when replacing the paper feed roller, the paper feed roller is inserted and removed on the free end side of the shaft (see, for example, Patent Document 1).
Japanese Utility Model Publication 2-79334

  However, in the conventional paper feeding device, when the paper feeding roller is inserted into and removed from the shaft, a space for moving the paper feeding roller in the axial direction is required on the free end side of the shaft. Therefore, the size of the paper feeder becomes large.

  The present invention provides a medium supply device and an image forming apparatus that can solve the problems of the conventional paper feeding device, reduce the space required for replacing the rotating body, and reduce the size. The purpose is to do.

For this purpose, in the medium supply device of the present invention, a rotating body for transporting the medium, an axially movable body, and a removably disposed shaft hole of the rotating body are disposed, and a driving unit. A shaft for transmitting the rotation generated by the rotating body to the rotating body, a stopper attached at a predetermined position in the axial direction of the shaft, the shaft rotatably supporting the shaft, and being removed from the rotating body And a support portion that is movably supported to a position.
The stopper is moved between the two restricting members as the shaft is moved in the axial direction, abuts against one restricting member, and the shaft is placed at the first restricting position. One end portion is inserted into the shaft hole in a state supported by the support portion, contacts the other restricting member, places the shaft at the second restricting position, and supports the one end portion of the shaft as the support portion. The shaft hole is pulled out while being supported by the portion.

According to the present invention, in the medium supply device, the rotating body for transporting the medium, the axially movable body, and the insertion section that is detachable with respect to the shaft hole of the rotating body are provided. A shaft for transmitting the rotation generated by the rotating body to the rotating body, a stopper attached at a predetermined position in the axial direction of the shaft, the shaft rotatably supporting the shaft, and being removed from the rotating body And a support portion that is movably supported to a position.
The stopper is moved between the two restricting members as the shaft is moved in the axial direction, abuts against one restricting member, and the shaft is placed at the first restricting position. One end portion is inserted into the shaft hole in a state supported by the support portion, contacts the other restricting member, places the shaft at the second restricting position, and supports the one end portion of the shaft as the support portion. The shaft hole is pulled out while being supported by the portion.

  In this case, since the shaft is rotatably supported by the support portion and is supported so as to be movable to the position where the shaft is removed from the rotating body, when the rotating body is inserted into and removed from the shaft, the rotating body is axially moved. The space for moving to is no longer necessary. Therefore, the space required for exchanging the rotating body can be reduced, and the medium paper feeding device can be reduced in size.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, a printer as an image forming apparatus will be described.

  FIG. 2 is a schematic view of the printer according to the first embodiment of the present invention.

  As shown in the figure, the printer 11 has a paper feed cassette 12 as a medium storage unit for storing paper P as a medium in the lower side, an image forming unit 15 and a transport path for transporting the paper P in the upper side. 31, a fixing unit 41, a discharge unit 51, and the like.

  The paper P accommodated in the paper feed cassette 12 is pushed up by a spring 14 as an urging member disposed in front of the paper feed cassette 12 and stacked on a sheet receive 13 as a medium receiver, and above the front end. It is made to contact | abut to the paper supply roller 17 as a rotary body arrange | positioned in this. A separation pad 18 as a separation member is pressed against the paper feed roller 17 by a spring 19 as an urging member, and the paper P is a portion where the paper feed roller 17 and the separation pad 18 abut, that is, At the contact portion, as the sheet feeding roller 17 rotates, the sheet is separated one by one from the sheet receive 13 to the conveying path 31 and conveyed.

  Then, the paper P fed out from the paper feed cassette 12 is sent between the registration roller 22 and a pressure roller 23 disposed to face the registration roller 22, and the registration roller 22 and the pressure roller 23 rotate. Accordingly, it is sent to the image forming unit 15.

  The image forming unit 15 includes a photosensitive drum 25 as an image carrier, a charging roller (not shown) as a charging device, a developing roller (not shown) as a developer carrier, a cleaning blade (not shown) as a cleaning member, and the like. Is done. Further, an LED head 20 as an exposure device is opposed to the photosensitive drum 25 above the image forming unit 15, and a transfer as a transfer member is opposed to the photosensitive drum 25 below the image forming unit 15. A roller 26 is provided.

  The photosensitive drum 25 is uniformly charged by a charging roller, and the surface of the photosensitive drum 25 is exposed by the LED head 20 to form an electrostatic latent image as a latent image. The electrostatic latent image is developed by a developing roller, and a toner (not shown) as a developer is attached to form a toner image as a developer image. Subsequently, when the paper P passes between the photosensitive drum 25 and the transfer roller 26, the toner image is transferred to the paper P by the transfer roller 26, and the paper P on which the toner image is transferred is fixed to the fixing device 41. Sent to.

  The fixing device 41 is provided with a heat roller 42 as a first roller and a backup roller 44 as a second roller, and a lamp 43 is used as a heating body for heating the heat roller 42 in the heat roller 42. Is disposed.

  When the paper P passes between the heat roller 42 and the backup roller 44, the paper P is heated by the heat roller 42 and pressurized by the backup roller 44, and as a result, the toner image is fixed on the paper P. Then, the sheet P on which the toner image is fixed is conveyed by the discharge rollers 51 a and 51 b and is discharged to the stacker 52 disposed on the upper portion of the main body unit 10. In order to detect the position of the paper P, the sensor 21 as the first medium detection unit is interposed between the separation pad 18, the registration roller 22 and the pressure roller 23, and the sensor 24 as the second medium detection unit. Between the registration roller 22 and the pressure roller 23 and the photosensitive drum 25 and the transfer roller 26, a sensor 46 as a third medium detection unit is disposed between the fixing device 41 and the discharge roller 51a.

  Next, the arrangement state of the paper feed roller 17 will be described.

  FIG. 1 is a cross-sectional view showing a support structure for a paper feed roller in the first embodiment of the present invention, FIG. 3 is a perspective view of a medium supply device in the first embodiment of the present invention, and FIG. It is sectional drawing which shows the principal part of the support structure of the paper feed roller in 1st Embodiment.

  In the figure, 17 is a paper feed roller, 22 is a registration roller, 26 is a transfer roller, and 28 is rotatably supported by a frame 29 as a structure of the printer 11 for rotating the paper feed roller 17. The shaft 35 is an electromagnetic clutch as an engagement / disengagement element that receives rotation transmitted from a motor (not shown) as a drive unit via a rotation transmission mechanism (not shown) and selectively transmits the rotation to the paper feed roller 17. The shaft 28 is detachably disposed with respect to the shaft hole h 1 of the paper feed roller 17, and transmits the rotation from the electromagnetic cut latch 35 to the paper feed roller 17. The electromagnetic clutch 35 constitutes a shaft driving element. The medium feeding device is constituted by the sheet feeding cassette 12, the sheet feeding roller 17, the separation pad 18, the spring 19, the sensor 21, the registration roller 22, the shaft 28, the electromagnetic clutch 35, and the like.

  The frame 29 is suspended from a horizontal member 101, a predetermined portion of the horizontal member 101, and two vertical supporting members 102 and 103 as parallel supporting walls formed parallel to each other, and the horizontal member between the vertical members 102 and 103. Ribs 29a and 29b as two restricting members that are suspended from a predetermined portion of the member 101 and are formed in parallel to each other, and the shaft 28 penetrates the vertical members 102 and 103 and has a shaft It is arranged to be movable in the direction.

  Cylindrical support portions 27 and 30 are attached to the vertical members 102 and 103, respectively, and the feed roller 17 is connected to the other end of the shaft 28 by the support portion 27 at one end portion (free end) of the shaft 28. The electromagnetic clutch 35 is supported by a cantilever structure at the end (free end) of the.

  Therefore, both ends of the shaft 28 are projected through the support portions 27 and 30. The support portion 27 includes a cylindrical portion 27a and a flange portion 27b formed to project radially outward at a predetermined position of the cylindrical portion 27a. The flange portion 27b is formed in the vertical member 102. It is attached in contact with the surface facing the paper feed roller 17. The support portion 30 includes a cylindrical portion 30a and a flange portion 30b formed to project radially outward at a predetermined location of the cylindrical portion 30a, and the flange portion 30b is a vertical member. 103 is attached in contact with the surface facing the electromagnetic clutch 35.

  An annular groove 28a is formed at a predetermined position of the shaft 28, and a stopper 34 is attached by engaging with the groove 28a. The stopper 34 includes a cylindrical portion 34a, a flange portion 34b formed by projecting radially outward at a predetermined portion of the cylindrical portion 34a, and one end of the cylindrical portion 34a on the radially inner side. And a locking portion 34c that is formed so as to protrude toward the side and is engaged with the groove 28a. The stopper 34 is moved between the ribs 29a and 29b together with the shaft 28, contacts the rib 29a, places the shaft 28 in the first restricting position, contacts the rib 29b, and moves the shaft 28 to the second restricting position. Put. When the stopper 34 is placed at the first restricting position, one end of the shaft 28 is inserted into the paper feed roller 17. When the stopper 34 is placed at the second restricting position, the shaft One end of 28 is removed from the paper feed roller 17. That is, the shaft 28 is rotatably supported by the support portions 27 and 30, and is supported so as to be movable to a position where the shaft 28 is pulled out from the paper feed roller 17.

  Further, a cylindrical spacer 36 is disposed between the support portion 30 and the electromagnetic clutch 35 as a restricting member that restricts the electromagnetic clutch 35 from moving in the direction of the paper feed roller 17. Further, an E-ring 37 as a fall prevention portion is fixed to the end portion of the shaft 28 protruding from the electromagnetic clutch 35 so that the electromagnetic clutch 35 does not move and disengage from the other end portion of the shaft 28. The paper feed roller 17 is composed of a structure 17a and a rubber material as a covering for covering the surface of the structure 17a, that is, a rubber agent 17b.

  The paper feed roller 17 and the shaft 28 are rotated integrally. Therefore, a predetermined shape, in the present embodiment, a “D” -shaped cross section is formed near one end of the shaft 28. The relative rotation restricting engaging portion 28b is formed. In addition, a portion corresponding to the engaging portion 28b of the shaft hole h1 as an insertion portion into which the shaft 28 is inserted in the paper feed roller 17 is engaged with the relative rotation restricting engaged portion 17c having a “D” -shaped cross section. Is formed. Therefore, when the shaft 28 is inserted into the shaft hole h1 and the engaging portion 28b and the engaged portion 17c are engaged, the relative rotation between the paper feed roller 17 and the shaft 28 is restricted.

  In addition, an arc-shaped notch 17d is formed at a predetermined position on the peripheral edge of the shaft hole h1, that is, on the side away from the engaged portion 17c by 180 [°], and is formed in the notch 17d. The operation piece 61 is formed integrally and freely deformable. An engagement protrusion 38 is formed at a predetermined position on the inner peripheral surface side of the operation piece 61, and an annular engagement groove 39 is formed in the vicinity of one end of the shaft 28. By engaging the mating groove 39, the paper feed roller 17 can be prevented from being detached from one end of the shaft 28.

  In order to improve the operability of the operation piece 61, the tip of the operation piece 61 is formed so as to protrude from the end portion of the paper feed roller 17. Further, the structure 17a is formed of a flexible material so that the operation piece 61 can be deformed to disengage the engagement protrusion 38 from the engagement groove 39. 4 shows a state in which the operating piece 61 is deformed to disengage the engaging protrusion 38 from the engaging groove 39.

  Next, a method for inserting and removing the paper feed roller 17 with respect to the shaft 28 will be described.

  FIG. 5 is a view showing a state in which the shaft is removed from the paper feed roller according to the first embodiment of the present invention.

  When a predetermined tool, for example, a flat-blade screwdriver is used from above the paper feed roller 17 to be deformed by pushing down the operation piece 61, the engagement between the engagement protrusion 38 and the engagement groove 39 is released. Thus, the shaft 28 can be pulled out from the shaft hole h1 of the paper feed roller 17. At this time, when the stopper 34 is moved from the first restricting position in contact with the rib 29a to the second restricting position in contact with the rib 29b, one end of the shaft 28 is supported in the support portion 27. Placed in.

  In this way, when the shaft 28 is removed from the paper feed roller 17, the paper feed roller 17 comes off the mounting position of the main body 10 and falls.

  When the new paper feed roller 17 is set at the mounting position, the shaft piece h1 of the paper feed roller 17 is in a state where the operation piece 61 is deformed to disengage the engagement protrusion 38 from the engagement groove 39. The shaft 28 is inserted thereinto, and the engagement protrusion 38 and the engagement groove 39 are engaged.

  When the surface of the locking projection 38 on the shaft 28 side is inclined, when the shaft 28 is inserted into the shaft hole h1, the locking projection 38 is pushed by one end of the shaft 28, and the operation piece 61 is pressed. Can be deformed. Therefore, the paper feed roller 17 can be set at the mounting position without pushing down the operation piece 61 using a minus driver or the like.

  As described above, in this embodiment, when the paper feed roller 17 is inserted into and removed from the shaft 28, a space for moving the paper feed roller 17 in the axial direction on one end side of the shaft 28. Is no longer necessary. Accordingly, since the space necessary for replacing the paper feed roller 17 can be reduced, the size of the medium supply device can be reduced, and the printer 11 can be reduced in size.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the same code | symbol is provided and the effect of the same embodiment is used about the effect of the invention by having the same structure.

  FIG. 6 is a cross-sectional view showing a paper feed roller support structure according to the second embodiment of the present invention, and FIG. 7 is a cross-sectional view showing a main part of the paper feed roller support structure according to the second embodiment of the present invention. It is.

  In this case, in the first embodiment, the support roller 27 supports the paper feed roller 17 as a rotating body in a cantilever structure, whereas in the second embodiment, a cylindrical support The paper feed roller 17 is supported by the both-side support structure by the portions 27 and 71.

  For this purpose, the frame 72 includes a horizontal member 101, a vertical member 102 to 104 as three supporting walls formed in parallel to each other, suspended from a predetermined portion of the horizontal member 101, and between the vertical members 102 and 103. Ribs 72 a and 72 b as two restricting members that are suspended from a predetermined portion of the horizontal member 101 and formed in parallel to each other, and the support portion 71 is attached to the vertical member 104. The shaft 28 is disposed so as to penetrate the vertical members 102 to 104 and be movable in the axial direction.

  In addition, the support portion 71 protrudes radially outward at a cylindrical portion 71a and a predetermined portion of the cylindrical portion 71a, in this embodiment, an end portion on the vertical member 102 side. A flange portion 71b is formed, and the flange portion 71b is attached in contact with the surface of the vertical member 104 facing the paper feed roller 17.

  Next, a method for inserting and removing the paper feed roller 17 with respect to the shaft 28 will be described.

  FIG. 8 is a view showing a state in which the shaft is removed from the paper feed roller in the second embodiment of the present invention.

  When a predetermined tool, for example, a flat-blade screwdriver is used from above the paper feed roller 17 to be deformed by pushing down the operation piece 61, the engagement between the engagement protrusion 38 and the engagement groove 39 is released. Thus, the shaft 28 can be pulled out from the shaft hole h1 of the paper feed roller 17.

  In this way, when the shaft 28 is removed from the paper feed roller 17, the paper feed roller 17 comes off the mounting position of the main body 10 and falls.

  When the new paper feed roller 17 is set at the mounting position, the shaft piece h1 of the paper feed roller 17 is in a state where the operation piece 61 is deformed to disengage the engagement protrusion 38 from the engagement groove 39. The shaft 28 is inserted into the inner portion and the support portion 71, and the engagement protrusion 38 and the engagement groove 39 are engaged.

  As described above, in this embodiment, when the paper feed roller 17 is inserted into and removed from the shaft 28, a space for moving the paper feed roller 17 in the axial direction on one end side of the shaft 28. Is no longer necessary. Accordingly, since the space necessary for replacing the paper feed roller 17 can be reduced, the size of the medium supply device can be reduced, and the printer 11 can be reduced in size.

  In each of the above embodiments, the printer as the image forming apparatus has been described. However, the present invention can be applied to a copying machine, a facsimile machine, a multifunction machine, and the like.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention, and they are not excluded from the scope of the present invention.

It is sectional drawing which shows the support structure of the paper feed roller in the 1st Embodiment of this invention. 1 is a schematic diagram of a printer according to a first embodiment of the present invention. 1 is a perspective view of a medium supply device according to a first embodiment of the present invention. It is sectional drawing which shows the principal part of the support structure of the paper feed roller in the 1st Embodiment of this invention. It is a figure which shows the state which pulled out the shaft from the paper supply roller in the 1st Embodiment of this invention. It is sectional drawing which shows the support structure of the paper feed roller in the 2nd Embodiment of this invention. It is sectional drawing which shows the principal part of the support structure of the paper feed roller in the 2nd Embodiment of this invention. It is a figure which shows the state which pulled out the shaft from the paper supply roller in the 2nd Embodiment of this invention.

Explanation of symbols

12 Feed cassette 17 Feed roller 18 Separation pad 19 Spring 21 Sensor 22 Registration rollers 27, 30, 71 Support 28 Shaft 35 Electromagnetic clutch h1 Shaft hole P Paper

Claims (5)

(A) a rotating body for conveying a medium;
(B) movable in the axial direction, and is removably disposed with respect to the axis hole of the rotary body, a shaft for transmitting the rotation generated by the drive for moving parts in the rotating body,
(C) a stopper attached at a predetermined location in the axial direction of the shaft;
(D) rotatably supporting said shaft, and which has a support portion that movably supports to the position withdrawn from said rotary member,
(E) The stopper is moved between the two restricting members as the shaft is moved in the axial direction, abuts against one restricting member, and the shaft is placed at the first restricting position. One end of the shaft is inserted into the shaft hole in a state of being supported by the support portion, and the shaft is placed in a second restricting position in contact with the other restricting member, and the one end of the shaft is placed in the second restricting position. A medium supply device , wherein the medium supply device is pulled out from the shaft hole in a state of being supported by a support portion .   The medium supply device according to claim 1, wherein the rotating body is supported by the support portion in a cantilever structure.   The medium supply device according to claim 1, wherein the rotating body is supported by the support portion in a doubly supported structure. The medium supply device according to claim 1, wherein the two regulating members are disposed on a frame of the image forming apparatus.   An image forming apparatus on which the medium supply device according to claim 1 is mounted.

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