JP2011230882A - Conveying device, and image forming device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying device that allows a roller assembly to be replaced relatively simply, and an image forming device including the same.SOLUTION: The conveying device has: a driving source; a driving shaft; a driven shaft; and a roller assembly that is detachably mounted on the driving shaft and the driven shaft. The roller assembly has a roller and a support shaft. The support shaft includes a first protruding part and a second protruding part. A first groove and a second groove extending in an arc shape are formed in a third end surface of the driving shaft. A third groove and a fourth groove extending in an arc shape are formed in a fourth end surface of the driven shaft. The first protruding part inserted into the first groove is moved along the second groove. The second protruding part inserted into the third groove is moved along the fourth groove. Consequently, the support shaft is connected to the driving shaft and the driven shaft.

Description

  The present invention relates to an apparatus for transporting a sheet and an image forming apparatus incorporating the transport apparatus.

  An apparatus for applying a desired process to a conveyed sheet is used in many fields. Examples of such an apparatus include an image forming apparatus typified by a copier, a printer, a facsimile machine, or a multifunction machine having these functions.

  In many cases, a cylindrical roller is used as an element for conveying a sheet. The sheet is conveyed in the apparatus by a frictional force generated between the roller peripheral surface and the sheet surface. The frictional force generated between the roller peripheral surface and the sheet surface inevitably causes roller wear. Therefore, it is preferable that the roller used for conveying the sheet is formed to be replaceable. Patent Document 1 discloses a structure of a replaceable roller assembly.

  The roller assembly of Patent Document 1 includes a roller that contacts a sheet and a support shaft that supports the roller. The support shaft includes a cylindrical shaft, a pair of inner shafts that are detachably attached from the end of the support shaft, and a coil spring that urges the inner shaft in a direction in which the inner shaft is pushed out from the cylindrical shaft. The user can make the rotation center axis of the inner shaft coincide with the rotation center axis of the drive shaft after the inner shaft is immersed in the cylindrical shaft. Thereafter, when the user releases the hand from the inner shaft, the inner shaft is pushed out of the cylindrical shaft and connected to the drive shaft.

JP-A-11-227963

  Large mating tolerances between the support shaft and the drive shaft reduce the quality of the sheet transport process. Therefore, in many cases, the fitting tolerance between the support shaft and the drive shaft is set to be relatively small.

  For this reason, the user who installs the roller assembly of patent document 1 needs to make the rotation center axis | shaft of a support shaft correspond with the rotation center axis | shaft of a drive shaft with comparatively high precision. This makes the user feel troublesome to replace the roller assembly.

  The present invention has been made in order to solve the above-described problem, and a transport apparatus capable of replacing a roller assembly relatively easily even by a person other than a professional worker, and the transport apparatus An object of the present invention is to provide an image forming apparatus in which is incorporated.

  A conveying device for conveying a sheet according to one aspect of the present invention is a conveying device for conveying a sheet, a driving source for generating a driving force, a driving shaft to which the driving force is transmitted, A driven shaft disposed opposite to the drive shaft, and a roller assembly that is detachably attached to the drive shaft and the driven shaft, and that rotates together with the drive shaft and the driven shaft. The solid body includes a roller that conveys the sheet, a first end surface connected to the drive shaft, and a second end surface connected to the driven shaft, and a support shaft that supports the roller. The shaft includes a first projecting portion projecting from the first end surface, and a second projecting portion projecting from the second end surface. A third end surface facing the first end surface, the outer peripheral surface of the drive shaft being a base end toward the rotation center axis of the drive shaft so that the first protrusion is inserted into the third end surface; A first groove portion that extends and a second groove portion that extends in an arc shape with a middle portion of the first groove portion as a base end are formed, and the driven shaft includes a fourth end surface facing the second end surface, The end surface includes a third groove portion extending toward the rotation center axis of the driven shaft with the outer peripheral surface of the driven shaft as a base end so that the second projecting portion is inserted, and a middle portion of the third groove portion. A fourth groove portion extending in an arc shape is formed as an end, and the first projecting portion inserted into the first groove portion is moved along the second groove portion and the first groove portion inserted into the third groove portion. 2 by moving the protrusion along the fourth groove, Supporting shaft, characterized in that it is connected to the drive shaft and the driven shaft (claim 1).

  According to the above configuration, the driving force generated by the driving source is transmitted to the driving shaft. The driven shaft is disposed opposite the drive shaft. The roller assembly is detachably attached to the drive shaft and the driven shaft, and rotates together therewith. The roller assembly includes a roller and a support shaft that supports the roller. A 1st protrusion part protrudes from the 1st end surface of a support shaft, and a 2nd protrusion part protrudes from the 2nd end surface of a support shaft. A first groove extending toward the center of the drive shaft with the outer peripheral surface of the drive shaft as a base end is formed in the third end surface of the drive shaft facing the first end surface. Therefore, the first groove opens the outer peripheral surface of the drive shaft, and the support shaft is connected to or removed from the drive shaft without the first protrusion being caught by the drive shaft. A second groove extending toward the center of the driven shaft with the outer peripheral surface of the driven shaft as a base end is formed in the fourth end surface of the driven shaft. Therefore, the second groove opens the outer peripheral surface of the driven shaft, and the support shaft is connected to or removed from the driven shaft without the second protrusion being caught by the driven shaft. Therefore, even a person other than a specialized worker can replace the roller assembly relatively easily. The third end face is further formed with a second groove portion extending in an arc shape with the middle portion of the first groove portion as a base end. In addition, a fourth groove portion that extends in an arc shape is formed on the fourth end surface with the middle portion of the third groove portion as a base end. Thus, the user can move the first protrusion along the second groove and move the second protrusion along the fourth groove by rotating the support shaft. As a result, unintentional dropping of the support shaft from the drive shaft and the driven shaft is suppressed.

  The said structure WHEREIN: It is preferable that a said 2nd groove part and a said 4th groove part are extended in the reverse direction with respect to the rotation direction of the said drive shaft.

  According to the said structure, a 2nd groove part and a 4th groove part are extended in the reverse direction with respect to the rotation direction of a drive shaft. Therefore, unintentional dropping of the support shaft from the drive shaft and the driven shaft during rotation of the drive shaft is suitably suppressed.

  In the above configuration, the support shaft includes a cylindrical shaft to which the roller is attached, an inner shaft that is inserted into the cylindrical shaft, and a biasing member that biases the inner shaft in a direction in which the inner shaft is pushed out from the cylindrical shaft. The drive shaft includes a first bottom surface that forms a bottom surface of the second groove portion, and the first protrusion portion that moves along the second groove portion is inserted into the first bottom surface. A first fixing hole is preferably formed (claim 3).

  According to the said structure, the inner shaft inserted in the cylindrical shaft to which the roller was attached is urged | biased in the direction pushed out from a cylindrical shaft by an urging | biasing member. Therefore, when the 1st protrusion part which moves along a 2nd groove part reaches | attains the 1st fixing hole of the 1st bottom face which forms the bottom face of a 2nd groove part, a 1st protrusion part is inserted in a 1st fixing hole. It will be. Therefore, unintentional dropping of the support shaft from the drive shaft and the driven shaft during rotation of the drive shaft is suitably suppressed.

  In the above configuration, the driven shaft includes a second bottom surface that forms a bottom surface of the fourth groove portion, and the second protrusion portion that moves along the fourth groove portion is inserted into the second bottom surface. Two fixing holes are preferably formed (claim 4).

  According to the above configuration, when the second protruding portion that moves along the fourth groove portion reaches the second fixing hole of the second bottom surface that forms the bottom surface of the fourth groove portion, the second protruding portion is the second fixing hole. Will be inserted. Therefore, unintentional dropping of the support shaft from the drive shaft and the driven shaft during rotation of the drive shaft is suitably suppressed.

  In the above configuration, the first projecting portion includes a tip portion that contacts the first bottom surface, and the first bottom surface is directed from the middle portion of the first groove portion toward the first fixing hole. It is preferable to incline so that a groove part may become shallow (Claim 5).

  According to the said structure, a 1st bottom face inclines so that a 2nd groove part may become shallow toward the 1st fixing hole from the middle part of a 1st groove part. Therefore, the first bottom surface can push the inner shaft into the cylindrical shaft while being in contact with the tip of the first projecting portion that moves along the second groove portion. Therefore, it is not necessary for the user to insert the inner shaft into the cylindrical shaft in order to obtain a connection between the first fixing hole and the first protrusion. Thus, when replacing the roller assembly, an unnecessarily large biasing force from the biasing member is not transmitted to the user's hand, and an efficient replacement operation is achieved.

  In the above configuration, the second projecting portion includes a tip portion that contacts the second bottom surface, and the second bottom surface faces the second fixing hole from the middle portion of the second groove portion to the fourth fixing hole. It is preferable to incline so that a groove part may become shallow (Claim 6).

  According to the said structure, a 2nd bottom face inclines so that a 4th groove part may become shallow toward the 2nd fixing hole from the middle part of a 2nd groove part. Therefore, the second bottom surface can push the inner shaft into the cylindrical shaft while being in contact with the tip of the second protrusion that moves along the fourth groove. Therefore, it is not necessary for the user to insert the inner shaft into the cylindrical shaft in order to obtain a connection between the second fixing hole and the second protrusion. Thus, when replacing the roller assembly, an unnecessarily large biasing force from the biasing member is not transmitted to the user's hand, and an efficient replacement operation is achieved.

  The said structure WHEREIN: The said cylindrical shaft contains the surrounding wall part in which the guide hole extended along the urging | biasing direction of the said urging | biasing member was formed, and while the said inner shaft protrudes from the said guide hole, the said cylindrical shaft It is preferable that a restricting member for restricting displacement of the inner shaft in a direction pushed out from the inner side is included.

  According to the said structure, the guide hole extended along the urging | biasing direction of an urging | biasing member is formed in a surrounding wall part at a cylindrical shaft. The inner shaft includes a regulating member that projects from the guide hole and regulates the displacement of the inner shaft in the direction of being pushed out from the cylindrical shaft. Thus, unintentional dropping of the inner shaft is preferably suppressed.

  An image forming apparatus according to another aspect of the present invention includes the transport device according to any one of claims 1 to 7 and an image forming unit that forms an image on the sheet transported by the transport device. (Claim 8).

  According to the above configuration, since the image forming apparatus incorporates the above-described conveyance device, even a person other than a professional worker can replace the roller assembly relatively easily.

  As described above, the present invention can provide a transport apparatus that can be replaced relatively easily even by a person other than a professional worker, and an image forming apparatus incorporating the transport apparatus.

It is a top view which shows roughly the conveying apparatus which concerns on one Embodiment of this invention. It is a figure which shows schematically the roller assembly of the conveying apparatus shown by FIG. FIG. 3 is a schematic cross-sectional view of the roller assembly shown in FIG. 2. It is a perspective view which shows roughly the front-end | tip part of the drive shaft and driven shaft of the conveying apparatus shown by FIG. FIG. 5 is a cross-sectional development view schematically showing shapes of second and fourth groove portions formed in the drive shaft and the driven shaft shown in FIG. 4. FIG. 2 is a perspective view of an image forming apparatus to which the principle of the conveying device shown in FIG. 1 is applied. It is a figure which shows the internal structure of the image forming apparatus shown by FIG. FIG. 7 is a perspective view of a paper feed structure incorporated in the image forming apparatus shown in FIG. 6.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that terms used in the following description, such as “up”, “down”, “left”, “right” and the like, are merely for the purpose of clarifying the explanation and do not limit the present invention. Not what you want. In the following description, the term “sheet” is subjected to an image forming process such as copy paper, coated paper, an OHP sheet, cardboard, a postcard, and tracing paper, and an optional process other than the image forming process. Includes other sheet materials.

(Principle of transfer device)
FIG. 1 is a schematic plan view for explaining the principle of a transport apparatus according to an embodiment of the present invention. The principle of the conveying apparatus shown in FIG. 1 can be used notably for a copying machine, a printer, a facsimile machine, or a multifunction machine having these functions, but also for any apparatus that is required to convey a sheet. It can be suitably applied to.

  A conveying device 300 shown in FIG. 1 is constructed on a support plate 301 that supports the sheet S. The transport apparatus 300 includes a driving source 310 (for example, a motor) that generates a driving force. The drive source 310 includes a rotation shaft 311.

  The conveying device 300 further includes a first gear 312 attached to the tip of the rotary shaft 311, a second gear 321 that meshes with the first gear 312, and a substantially cylindrical shape that extends from the second gear 321 in the width direction of the sheet S. Drive shaft 320. In the description of this embodiment, the term “the width direction of the sheet S” means a direction orthogonal to the conveyance direction of the sheet S. The drive shaft 320 is supported above the support plate 301 by a bearing portion 322 erected on the upper surface of the support plate 301. The connection structure between the drive source 310 and the drive shaft 320 is not limited to the structure shown in the figure, and any structure that can transmit the drive force generated by the drive source 310 to the drive shaft 320 can be driven. It may be constructed between the source 310 and the drive shaft 320.

  The conveyance device 300 further includes a substantially cylindrical driven shaft 330 disposed to face the drive shaft 320. The base end portion of the driven shaft 330 is supported by the bearing portion 331, and the rotation center axis of the driven shaft 330 is aligned substantially in line with the rotation center axis of the drive shaft 320.

  The conveyance device 300 further includes a roller assembly 340 that is detachably attached to the drive shaft 320 and the driven shaft 330. The roller assembly 340 includes a pair of substantially cylindrical rollers 341 and a support shaft 342 that supports the rollers 341. The number of rollers 341 may be singular or may be three or more. The roller assembly 340 rotates with the drive shaft 320 and the driven shaft 330.

  The circumferential surface of the roller 341 is in contact with the upper surface of the sheet S. The sheet S is conveyed by the rotation of the roller 341. The support shaft 342 supports a pair of disc-shaped knobs 343 in addition to the roller 341. One knob 343 is disposed between the roller 341 located on the right side and the bearing 322. The other knob 343 is disposed between the roller 341 located on the left side and the bearing 331. The user can pick both knobs 343 and attach / detach the roller assembly 340 to / from the drive shaft 320 and the driven shaft 330. Therefore, unnecessary contact of the user's finger with the peripheral surface of the roller 341 is prevented, and contamination of the peripheral surface of the roller 341 by the user's sebum is suppressed. Since the knob 343 is formed with a smaller diameter than the roller 341, the knob 343 does not interfere with the conveyance of the sheet S.

  In the following description, the end surface of the support shaft 342 connected to the drive shaft 320 is referred to as a first end surface. The end surface of the support shaft 342 connected to the driven shaft 330 is referred to as a second end surface. Furthermore, the end surface of the drive shaft 320 facing the first end surface is referred to as a third end surface. The end surface of the driven shaft 330 facing the second end surface is referred to as a fourth end surface.

  FIG. 2 schematically illustrates the roller assembly 340. FIG. 2A is a plan view of the roller assembly 340. FIG. 2B is a side view of the roller assembly 340 as viewed from the second end face side. FIG. 2C is a side view of the roller assembly 340 as viewed from the first end face side.

  The support shaft 342 includes a pair of first protrusions 345 that protrude from the first end surface 344. The first protrusions 345 are formed in alignment on the diameter of the first end surface 344. A substantially intermediate position between the pair of first projecting portions 345 becomes a rotation center axis of the support shaft 342.

  The support shaft 342 includes a pair of second protrusions 347 that protrude from the second end surface 346. The second protrusion 347 is formed in alignment on the diameter of the second end surface 346. A substantially intermediate position between the pair of second projecting portions 347 serves as a rotation center axis of the support shaft 342.

  FIG. 3 is a schematic longitudinal sectional view of the roller assembly 340. The roller assembly 340 is further described with reference to FIG. 1 in conjunction with FIG.

  The support shaft 342 includes a substantially cylindrical tubular shaft 348 and a substantially cylindrical inner shaft 349 inserted into the tubular shaft 348. The cylindrical shaft 348 includes a peripheral wall 351 that fits with the knob 343 and the roller 341, and an outer end wall 352 that closes one end of the peripheral wall 351. The outer surface of the outer end wall 352 forms a second end surface 346.

  The inner shaft 349 has a substantially cylindrical peripheral wall portion 353 that forms an outer contour that is substantially complementary to the space surrounded by the inner peripheral surface of the cylindrical shaft 348, and a peripheral wall portion 353 that is disposed inside the cylindrical shaft 348. An inner wall portion 354 formed so as to close the opening portion of the inner wall portion 354, an outer wall portion 355 disposed on the opposite side of the inner wall portion 354 and formed so as to close the opening portion of the peripheral wall portion 353 of the inner shaft 349, ,including. An outer surface of the outer wall portion 355 forms a first end surface 344. The diameter of the substantially disk-shaped outer wall portion 355 is larger than the diameter of the peripheral wall portion 353 of the inner shaft 349 and is substantially equal to the peripheral wall portion 351 of the cylindrical shaft 348.

  The cylindrical shaft 348 includes a substantially cylindrical protrusion 356 that protrudes from the inner surface 357 of the outer end wall 352. The inner shaft 349 includes a substantially cylindrical protruding portion 358 protruding from the surface of the inner wall portion 354 facing the inner surface 357 of the outer end wall 352. The support shaft 342 includes a coil spring 359 including one end portion that fits with the protruding portion 356 and the other end portion that fits with the protruding portion 358. The coil spring 359 is used as a biasing member that biases the inner shaft 349 in a direction in which the inner shaft 349 is pushed out from the cylindrical shaft 348.

  As shown in FIG. 1, a guide hole 361 having a substantially rectangular shape in plan view is formed in the peripheral wall portion 351 of the cylindrical shaft 348. The guide hole 361 extends in the biasing direction of the coil spring 359 (that is, the longitudinal direction of the support shaft 342).

  As shown in FIG. 3, the peripheral wall portion 353 of the inner shaft 349 includes a regulating member 362 that projects from the guide hole 361. As shown in FIG. 1, the restricting member 362 has a width substantially equal to the width of the guide hole 361. Therefore, the displacement of the inner shaft 349 in the rotational direction with respect to the cylindrical shaft 348 is suitably suppressed by fitting the restriction member 362 into the guide hole 361.

  As shown in FIG. 3, the cross section of the restricting member 362 has a substantially right trapezoidal shape. The slope 363 in the cross section of the regulating member 362 is gently curved downward. When the inner shaft 349 is inserted into the opening of the cylindrical shaft 348 formed on the side opposite to the outer end wall 352, the inclined surface comes into contact with the cylindrical shaft 348, and the regulating member 362 faces the inside of the inner shaft 349. Gradually bends and deforms. Thereafter, when the regulating member 362 reaches the guide hole 361, the regulating member 362 is restored and protrudes from the guide hole 361. The inner shaft 349 can be displaced toward the outer end wall 352 of the cylindrical shaft 348 by the compression deformation of the coil spring 359 and the guide hole 361 extending in the longitudinal direction of the support shaft 342. As described above, the displacement of the inner shaft 349 toward the outer end wall 352 is restricted by the outer wall portion 355 having a larger diameter than the peripheral wall portion 353 of the inner shaft 349. By the restoration of the coil spring 359, the displacement of the inner shaft 349 in the direction pushed out from the cylindrical shaft 348 is regulated by the regulating member 362.

  FIG. 4 is a perspective view schematically showing the structure of the tip portions of the drive shaft 320 and the driven shaft 330. FIG. 4A shows the tip of the drive shaft 320 having a third end face connected to the roller assembly 340. FIG. 4B shows the distal end portion of the driven shaft 330 having a fourth end face connected to the roller assembly 340. The drive shaft 320 and the driven shaft 330 will be described with reference to FIG. 3 in conjunction with FIG.

  The third end surface 323 of the drive shaft 320 is formed with a first groove portion 324 extending toward the rotation center axis C of the drive shaft 320 with the outer peripheral surface of the drive shaft 320 as a base end. The base end portion of the first groove portion 324 forms an insertion port 325 for inserting the first projecting portion 345 on the outer peripheral surface of the drive shaft 320. The first groove 324 does not completely cross the third end surface 323 and passes through the rotation center axis C of the drive shaft 320 and then forms an end between the rotation center axis C and the periphery of the third end surface 323. The edge 326 of the drive shaft 320 that forms the insertion port 325 (the edge 326 extending in parallel with the rotation center axis C) is chamfered, and the insertion port 325 is connected to the other of the first grooves 324. It is expanded more than the part. Thus, the user can insert the first protrusion 345 into the first groove 324 relatively easily. The depth of the first groove portion 324 (depth dimension in the direction along the rotation center axis C) is preferably substantially equal to the protrusion amount of the first protrusion portion 345. Thus, the user can attach the roller assembly 340 to the drive shaft 320 without shrinking the support shaft 342.

  After the first protrusion 345 is inserted into the first groove 324 through the insertion port 325, the movement of the first protrusion 345 in the insertion direction is stopped by the end of the first groove 324. At this time, the rotation center axis of the support shaft 342 is substantially aligned with the rotation center axis C of the drive shaft 320 (that is, the support shaft 342 is coaxial with the drive shaft 320).

  The third end surface 323 is further formed with a second groove portion 327 extending in an arc shape with the middle portion of the first groove portion 324 as a base end. In the present embodiment, a pair of second groove portions 327 is formed. A connection portion between the pair of second groove portions 327 and the first groove portion 324 is provided at a position corresponding to the first protruding portion 345 of the support shaft 342 attached coaxially to the drive shaft 320. The second groove portion 327 extends from the connection portion with the first groove portion 324 in an arcuate locus in a direction opposite to the rotation direction of the drive shaft 320.

  The fourth end surface 333 of the driven shaft 330 is formed with a third groove portion 334 extending toward the rotation center axis C of the driven shaft 330 with the outer peripheral surface of the driven shaft 330 as a base end. The base end portion of the third groove portion 334 forms an insertion port 335 for inserting the second projecting portion 347 on the outer peripheral surface of the driven shaft 330. The third groove portion 334 does not completely cross the fourth end surface 333 and passes through the rotation center axis C of the driven shaft 330 and then forms an end portion between the rotation center axis C and the peripheral edge of the fourth end surface 333. The edge 336 of the driven shaft 330 that forms the insertion port 335 (the edge 336 extending parallel to the rotation center axis C) is chamfered, and the insertion port 335 is connected to the other grooves 334. It is expanded more than the part. Thus, the user can insert the second protrusion 347 into the first groove 324 relatively easily. The depth of the third groove 334 (depth dimension in the direction along the rotation center axis C) is preferably substantially equal to the amount of protrusion of the second protrusion 347. Thus, the user can attach the roller assembly 340 to the driven shaft 330 without shrinking the support shaft 342.

  After the second protrusion 347 is inserted into the third groove 334 via the insertion port 335, the movement of the second protrusion 347 in the insertion direction is stopped by the end of the third groove 334. At this time, the rotation center axis of the support shaft 342 is substantially aligned with the rotation center axis C of the driven shaft 330 (that is, the support shaft 342 is coaxial with the driven shaft 330).

  The fourth end surface 333 is further formed with a fourth groove portion 337 extending in an arc shape with the middle portion of the third groove portion 334 as a base end. In the present embodiment, a pair of fourth groove portions 337 is formed. A connection portion between the pair of fourth groove portions 337 and the third groove portion 334 is provided at a position corresponding to the second projecting portion 347 of the support shaft 342 attached coaxially to the driven shaft 330. The fourth groove portion 337 extends from the connecting portion with the third groove portion 334 while drawing an arcuate locus in a direction opposite to the rotation direction of the driven shaft 330 (that is, the rotation direction of the drive shaft 320).

  FIG. 5 is a schematic diagram for explaining the shapes of the second groove portion 327 and the fourth groove portion 337. Fig.5 (a) is an expanded view of the cross section of the drive shaft 320 in the direction in alignment with the AA line shown by Fig.4 (a). In addition, the AA line shown by Fig.4 (a) follows the 2nd groove part 327. FIG. FIG. 5B is a development view of a cross section of the driven shaft 330 in the direction along the line BB shown in FIG. The line BB shown in FIG. 4B is along the fourth groove 337. The 2nd groove part 327 and the 4th groove part 337 are demonstrated, referring FIG.3 and FIG.4 in combination with FIG.

  The drive shaft 320 includes a first bottom surface 328 that is gently inclined from the bottom of the first groove 324 toward the third end surface 323. The first bottom surface 328 forms the bottom surface of the second groove portion 327. A first fixing hole 329 is formed in the first bottom surface 328 at the terminal end portion of the second groove portion 327 located on the opposite side to the connection portion with the first groove portion 324.

  The tip of the first protrusion 345 inserted into the first groove 324 is in contact with the bottom surface of the first groove 324. Thereafter, when the roller assembly 340 is rotated in a direction opposite to the rotation direction of the drive shaft 320, the first protrusion 345 moves along the second groove 327. At this time, the tip of the first protrusion 345 is in contact with the first bottom surface 328. Since the first bottom surface 328 is inclined toward the third end surface 323 and the second groove portion 327 is gradually shallowed, the inner shaft 349 is pushed into the cylindrical shaft 348. When the first protrusion 345 reaches the first fixing hole 329, the first protrusion 345 is fitted into the first fixing hole 329 by the biasing force of the coil spring 359. Thus, the support shaft 342 is connected to the drive shaft 320.

  The driven shaft 330 includes a second bottom surface 338 that gently slopes from the bottom of the third groove 334 toward the fourth end surface 333. The second bottom surface 338 forms the bottom surface of the fourth groove portion 337. A second fixing hole 339 is formed in the second bottom surface 338 at the terminal end of the fourth groove 337 located on the side opposite to the connection with the third groove 334.

  The tip of the second protrusion 347 inserted into the third groove 334 contacts the bottom surface of the third groove 334. Thereafter, when the roller assembly 340 is rotated in the direction opposite to the rotation direction of the drive shaft 320, the second protrusion 347 moves along the fourth groove 337. At this time, the distal end portion of the second projecting portion 347 contacts the second bottom surface 338. The second bottom surface 338 is inclined toward the fourth end surface 333 and the fourth groove portion 337 is gradually shallowed, so that the inner shaft 349 is pushed into the cylindrical shaft 348. When the first protrusion 345 reaches the second fixing hole 339, the second protrusion 347 is fitted into the second fixing hole 339 by the biasing force of the coil spring 359. Thus, the support shaft 342 is connected to the driven shaft 330.

(Image forming device)
FIG. 6 is a perspective view of an image forming apparatus in which the conveyance device 300 described with reference to FIGS. 1 to 5 is incorporated. The image forming apparatus shown in FIG. 6 is a so-called in-body discharge type copier. However, the present invention is not limited to this, and a printer, a facsimile machine, a multifunction machine having these functions, and a toner image are used. Another apparatus for forming a sheet on a sheet may be used.

  The image forming apparatus 1 includes a housing 2 having a substantially rectangular parallelepiped shape. The casing 2 includes a substantially rectangular parallelepiped lower casing 21, a substantially rectangular parallelepiped upper casing 22 disposed above the lower casing 21, and a connection that connects the lower casing 21 and the upper casing 22. And a housing 23. The connection housing 23 extends along the right edge and the back edge of the housing 2. The sheet subjected to the printing process is discharged into a discharge space 24 surrounded by the lower casing 21, the upper casing 22, and the connecting casing 23.

  The operation unit 221 protruding in the front direction of the upper housing 22 includes, for example, an LCD touch panel 222. The operation unit 221 is formed so as to be able to input information related to the image forming process. For example, the user can input the number of sheets to be printed, the print density, and the like through the LCD touch panel 222. Housed in the upper housing 22 are mainly an apparatus for reading an image of a document and an electronic circuit that controls the entire image forming apparatus 1.

  A pressing cover 223 disposed on the upper housing 22 is used for pressing the document. The presser cover 223 is attached to the upper housing 22 so as to be rotatable up and down. The user rotates the holding cover 223 upward to place the document on the upper housing 22. Thereafter, the user can operate the operation unit 221 to cause the device for reading the document disposed in the upper housing 22 to read the image of the document.

  The lower casing 21 accommodates a cassette 211 formed so as to accommodate sheets. The cassette 211 can be pulled out from the lower housing 21 in the front direction. The sheets stored in the cassette 211 are subjected to an image forming process in the lower housing 21 based on an instruction input by the user through the operation unit 221, and are discharged into the discharge space 24.

  A tray 212 is rotatably attached to the right surface of the lower housing 21. As shown in FIG. 6, when the tray 212 is in a position protruding to the right of the lower housing 21, the user can place a sheet on the tray 212. The sheet on the tray 212 is drawn into the lower housing 21 based on an instruction input by the user through the operation unit 221, is subjected to image forming processing, and is discharged into the discharge space 24. When the tray 212 is rotated upward, the tray 212 is accommodated in the accommodation space 213 that is recessed in the right surface of the lower casing 21, and the supply port for drawing the sheet into the lower casing 21 is closed.

  The lower housing 21 accommodates various devices for forming an image on a sheet. Further, the connection housing 23 accommodates various devices for discharging the sheet subjected to the image forming process to the discharge space 24.

  FIG. 7 schematically shows the internal structure of the image forming apparatus 1 shown in FIG. The image forming apparatus 1 will be further described with reference to FIG. 6 in conjunction with FIG.

The upper housing 22 accommodates the scanning mechanism 224. The user can cause the image forming apparatus 1 to read an image of a desired document through the scanning mechanism 224. A contact glass 225 attached to the upper surface of the upper housing 22 is disposed on the scanning mechanism 224. The pressing cover 223 is used for pressing a document placed on the contact glass 225.
And a pressing cover 162 that rotates on the contact glass 161. When the user operates the image forming apparatus 1 through the operation unit 221, the scanning mechanism 224 scans and reads an image of the document on the contact glass 225. Analog information of the image read by the scanning mechanism 224 is converted into a digital signal. The image forming apparatus 1 forms an image on a sheet based on the digital signal.

  The lower housing 21 includes toner containers 900Y, 900M, 900C, 900Bk, an intermediate transfer unit 92, an image forming unit 93, an exposure unit 94, a fixing unit 97, and a paper discharge unit 96.

  The image forming unit 93 includes a yellow toner container 900Y, a magenta toner container 900M, a cyan toner container 900C, and a black toner container 900Bk. Below these containers, developing devices 10Y, 10M, 10C, and 10Bk corresponding to the respective colors of YMCK are disposed.

  The image forming unit 93 includes a photosensitive drum 17 (a photosensitive member on which a latent image is formed by an electrophotographic method) that carries a toner image of each color. As the photosensitive drum 17, a photosensitive drum using an amorphous silicon (a-Si) material can be used. The photosensitive drums 17 are supplied with yellow, magenta, cyan, and black toner from the toner containers 900Y, 900M, 900C, and 900Bk, respectively.

  Around the photosensitive drum 17, a charger 16, a developing device 10 (10Y, 10M, 10C, 10Bk), a transfer roller 19, and a cleaning device 18 are disposed. The charger 16 uniformly charges the surface of the photosensitive drum 17. The surface of the photosensitive drum 17 after charging is exposed by the exposure unit 94 to form an electrostatic latent image. The exposure unit 94 emits laser light based on the digital signal generated by the scanning mechanism 224 described above. The developing devices 10Y, 10M, 10C, and 10Bk develop the electrostatic latent images formed on the respective photosensitive drums 17 using the toners of the respective colors supplied from the toner containers 900Y, 900M, 900C, and 900Bk, respectively ( Visualization). The transfer roller 19 forms a nip portion with the photosensitive drum 17 across the intermediate transfer belt 921, and primarily transfers the toner image on the photosensitive drum 17 onto the intermediate transfer belt 921. The cleaning device 18 cleans the peripheral surface of the photosensitive drum 17 after the toner image is transferred.

  Each developing device 10Y, 10M, 10C, 10Bk includes a housing 20. A two-component developer having a magnetic carrier and toner is accommodated in the housing 20. In the housing 20, two agitating rollers 11 and 12 (developer agitating members) are rotatably arranged in parallel near the bottom of the housing 20 with the longitudinal direction as an axial direction.

  A developer circulation path is set on the inner bottom surface of the housing 20, and the stirring rollers 11 and 12 are disposed in the circulation path. A partition wall 201 erected from the bottom of the housing 20 is provided in the axial direction between the stirring rollers 11 and 12. The partition wall 201 divides the circulation path. A circulation path is formed so as to circulate around the partition wall 201. The two-component developer is charged while being stirred and conveyed on the circulation path by the stirring rollers 11 and 12.

  The two-component developer circulates in the housing 20 while being stirred by the stirring rollers 11 and 12, and the toner is charged. The two-component developer on the stirring roller 11 is attracted and conveyed by the magnetic roller 14 located on the upper side. The sucked two-component developer forms a magnetic brush (not shown) on the magnetic roller 14. The layer thickness of the magnetic brush is regulated by the doctor blade 13. The toner layer on the developing roller 15 is formed by a potential difference between the magnetic roller 14 and the developing roller 15. The electrostatic latent image on the photosensitive drum 17 is developed by the toner layer.

  The exposure unit 94 includes various optical system devices such as a light source, a polygon mirror, a reflection mirror, and a deflection mirror. To form an electrostatic latent image.

  The intermediate transfer unit 92 includes an intermediate transfer belt 921, a driving roller 922, and a driven roller 923. On the intermediate transfer belt 921, toner images are overcoated from a plurality of photosensitive drums 17 (primary transfer). The overcoated toner image is secondarily transferred to a sheet supplied from the cassette 211 or the tray 212 by the secondary transfer unit 98. A driving roller 922 and a driven roller 923 that rotate the intermediate transfer belt 921 are rotatably supported by the lower housing 21.

  The fixing unit 97 performs a fixing process on the toner image on the sheet secondarily transferred from the intermediate transfer unit 92. The sheet with the color image that has been subjected to the fixing process is discharged toward a paper discharge unit 96 formed in the upper part of the fixing unit 97 (in the connection housing 23).

  The paper discharge unit 96 discharges the sheet conveyed from the fixing unit 97 onto the upper surface 214 of the lower housing 21 used as a paper discharge tray.

  The cassette 211 stores a sheet bundle formed by stacking a plurality of sheets on which images are formed. As described above, the cassette 211 is detachably attached to the lower housing 21. When the pickup roller 40 provided in the cassette 211 is driven, the uppermost sheet of the sheet bundle in the cassette 211 is taken out one by one, fed out to the paper feed conveyance path 133, and introduced into the image forming unit 93. The

  The tray 212 is disposed above the cassette 211. The tray 212 shown in FIG. 7 is in a closed position for closing the paper feed port. The lower end portion of the tray 212 serves as a rotation shaft, and the tray 212 is rotated rightward so that a sheet bundle formed by stacking a plurality of sheets can be supported. In the vicinity of the lower end portion of the tray 212, a paper feed structure 500 including the transfer device 300 described with reference to FIGS. The conveyance device 300 plays a role as a sheet feeding device that feeds sheets placed on the tray 212 one by one to the image forming unit 93. The image forming unit 93 forms an image on the sheet sent into the lower housing 21 by the conveying device 300.

  FIG. 8 is a schematic perspective view of the conveying device 300 exposed by rotating the tray 212 downward. A conveying apparatus 300 applied to the image forming apparatus 1 will be described with reference to FIGS. 1 to 6 in conjunction with FIG.

  1 to 5 is disposed in a region between the lower casing 21 and the base end edge serving as the rotation axis of the tray 212. The roller 341 contacts the leading edge of the sheet placed on the tray 212. In response to the driving force from the driving source 310 transmitted through the driving shaft 320, the roller 341 rotates and feeds the sheet into the lower housing 21. Thereafter, as described with reference to FIG. 7, the sheet fed into the lower housing 21 by the conveying device 300 is subjected to an image forming process in the image forming unit 93.

  As described with reference to FIGS. 1 to 5, the roller assembly 340 can be removed from the drive shaft 320 and the driven shaft 330 with relative ease. Thus, as the roller 341 wears, the roller assembly 340 is replaced without the need for skilled skills.

  In the above-described embodiment, the inner shaft 349 is connected to the drive shaft 320 and the cylindrical shaft 348 is connected to the driven shaft 330. However, the inner shaft 349 is connected to the driven shaft 330, and the cylindrical shaft 348 is connected to the drive shaft. 320 may be connected.

  The present invention can be applied to a printer, a copier, a facsimile machine, a multi-function machine having these functions, various apparatuses that form an image on a sheet, and any apparatus that applies a desired process to a sheet.

300 ... Conveying device 310 ... Drive source 320 ... Drive shaft 323 ... Third end face 324 ... First groove 327 ... Second groove 328 ... First bottom 329 ... 1st fixed hole 330 ... driven shaft 333 ... 4th end surface 334 ... 3rd groove part 337 ... 4th groove part 338 ... 2nd bottom face 339 ... 2nd fixed hole 340 ... Roller assembly 341 ... Roller 342 ... Support shaft 344 ... First end face 345 ... First protrusion 346 ... Second end face 347 ... Second protrusion 348 ... Tubular Shaft 349 ... Inner shaft 351 ... Peripheral wall 359 ... Coil spring (biasing member)
361 ... Guide hole 362 ... Regulating member C ... Rotation center axis S ... Sheet

Claims (8)

A conveying device for conveying a sheet,
A driving source for generating a driving force;
A drive shaft to which the driving force is transmitted;
A driven shaft disposed opposite the drive shaft;
A roller assembly that is detachably attached to the drive shaft and the driven shaft, and that rotates together with the drive shaft and the driven shaft,
The roller assembly is
A roller for conveying the sheet;
A support shaft including a first end face connected to the drive shaft and a second end face connected to the driven shaft and supporting the roller;
The support shaft includes a first protrusion protruding from the first end face, and a second protrusion protruding from the second end face,
The drive shaft includes a third end surface facing the first end surface;
The third end surface includes a first groove portion extending toward the rotation center axis of the drive shaft with the outer peripheral surface of the drive shaft as a base end so that the first protrusion is inserted, and a middle portion of the first groove portion A second groove portion extending in an arc shape with the portion as a base end,
The driven shaft includes a fourth end surface facing the second end surface;
The fourth end surface includes a third groove portion extending toward the rotation center axis of the driven shaft with the outer peripheral surface of the driven shaft as a base end so that the second protrusion is inserted, and a middle portion of the third groove portion And a fourth groove extending in an arc shape with the base as a base,
The first protrusion inserted into the first groove is moved along the second groove, and the second protrusion inserted into the third groove is moved along the fourth groove. Thereby, the support shaft is connected to the drive shaft and the driven shaft.   The conveying device according to claim 1, wherein the second groove portion and the fourth groove portion extend in a direction opposite to a rotation direction of the drive shaft. The support shaft includes a cylindrical shaft to which the roller is attached, an inner shaft that is inserted into the cylindrical shaft, and a biasing member that biases the inner shaft in a direction of pushing the inner shaft from the cylindrical shaft. ,
The drive shaft includes a first bottom surface that forms a bottom surface of the second groove portion,
3. The transport device according to claim 1, wherein a first fixing hole into which the first projecting portion that moves along the second groove portion is inserted is formed in the first bottom surface. The driven shaft includes a second bottom surface that forms a bottom surface of the fourth groove portion,
The second fixing hole into which the second protrusion that moves along the fourth groove is inserted is formed in the second bottom surface. Conveying device. The first protrusion includes a tip that contacts the first bottom surface,
The transport apparatus according to claim 3, wherein the first bottom surface is inclined so that the second groove portion becomes shallower from the middle portion of the first groove portion toward the first fixing hole. The second protrusion includes a tip portion that contacts the second bottom surface,
5. The transport device according to claim 4, wherein the second bottom surface is inclined so that the fourth groove portion becomes shallower from the middle portion of the second groove portion toward the second fixing hole. The cylindrical shaft includes a peripheral wall portion formed with a guide hole extending along a biasing direction of the biasing member,
The conveying device according to claim 3, wherein the inner shaft includes a restricting member that protrudes from the guide hole and restricts displacement of the inner shaft in a direction of being pushed out from the cylindrical shaft. A transport device according to any one of claims 1 to 7,
An image forming apparatus comprising: an image forming unit that forms an image on the sheet transported by the transport apparatus.

Images