Sheet feeding apparatus and recording apparatus

Information

  • Patent Grant
  • 6276680
  • Patent Number
    6,276,680
  • Date Filed
    Wednesday, August 25, 1999
    25 years ago
  • Date Issued
    Tuesday, August 21, 2001
    23 years ago
Abstract
Present invention relates to a sheet feeding apparatus comprising a first feeding rotary body for feeding sheets, a second feeding rotary body located in facing to the first feeding rotary body for feeding the sheets between the second feeding rotary body and the first feeding rotary body upon pressing the sheets, an elastic shaft serving as a rotary center of the second feeding rotary body for urging the second feeding rotary body toward the first feeding rotary body and restricting means for restricting movements of the second feeding rotary body in multiple directions by contacting with the second feeding rotary body.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to a sheet feeding apparatus for feeding sheets and, more particularly, to a sheet feeding apparatus for feeding recording media in a recording apparatus having a function such as a printer, a photocopier, a facsimile machine, or the like.




2. Description of Related Art




Recording apparatuses having a function such as a printer, a photocopier, a facsimile machine, or the like, and recording apparatuses used for output devices for hybrid electronics apparatuses such as computers and word processing apparatuses or workstations are structured to record images on recording media such as sheet papers and plastic thin plates based on image information. The recording apparatuses can be categorized, based on the recording method, into the inkjet type, the wire dot type, the thermal type, the laser beam type, or the like.




In a recording apparatus of a serial type using a serial scanning method in which a main scanning is made in a direction intersecting with a feeding direction of the recording medium (subsidiary scanning direction), the entire recording medium is recorded by repeating the processes of recording images (main scanning) by a recording means mounted on a carriage traveling along a recording medium feeding the sheet in a fixed amount (pitch feeding) after images of one line are recorded, and subsequently recording images of the next line (main scanning) on the recording medium stopped again. On the other hand, in a line type recording apparatus which does recording only in the subsidiary scanning direction, the entire recording medium is recorded by repeating the processes of setting a recording medium at a prescribed recording position. feeding the recording medium in a predetermined amount (pitch feeding) after the one line recording is made at one time, and recording the next line at one time.





FIG. 11

shows a perspective view showing a conventional inkjet recording apparatus. In the inkjet recording apparatus, the recording medium fed by a feeding apparatus


101


is held by a platen


122


constituted such that a feeding surface in the printing area is made flat and delivered by a delivery means


133


formed on a downstream side in the feeding direction after images are formed by a recording head


124


.




The delivery means


133


includes a delivery roller


134


, and a special paper pressing member (e.g., a spur having a gear teeth on circumferential surface)


136




d


located facing to the delivery roller


134


for feeding the recording medium in pressing the recording medium through point contacts. Rotation of those members makes the recording medium fed with applied inks not yet fixed right after printing.




The delivery roller


134


is freely rotatable where each opposite end of the shaft is attached to a bearing formed at the platen


122


. A recording medium feeding portion of the roller is rounded with a material such as a rubber or sponge-like material thereby rendering the recording medium hardly slip when fed.




The drive force given to the delivery roller


134


is transmitted from a paper feeding roller


132


via a transmission roller


135


attached to the platen. The transmission roller


135


is urged as to press both of the paper feeding roller


132


and the delivery roller


134


by an elastic shaft.




The spur


136


has a circumferential portion with gear teeth, which tend not to leave pressed marks or ink marks on the recording medium, so that such a spur is widely used for an inkjet recording apparatus.




The spur


136


functions for maintaining the printing quality in suppressing cockling of the recording medium in a direction perpendicular to the feeding direction when recording is made with high recording density or high duty and for protecting the recording head


124


by avoiding contacts between the recording head


124


and the recording medium.




The spur


136


is mounted on an attachment member with the elastic shaft go that the spur can move in substantially a perpendicular direction with respect to the feeding surface for the recording medium according to the thickness of the recording medium, and the attachment member may be formed with a restricting means for restricting the movement of the elastic shaft to restrict the movement of the spur


136


in substantially the perpendicular direction. This is for suppressing the movement of the spur


136


within a predetermined distance where the recording media is fed in a multiple number from the feeding apparatus


101


(duplicated feeding) to prevent the elastic shaft as a rotary shaft of the spur


136


from receiving damages.




With the conventional inkjet recording apparatus, as described above, no restricting means is provided for restricting the movement of the spur


136


, and even where such a restricting means is provided, the spur


136


is restricted by restricting the position of the elastic shaft serving as the rotary shaft of the spur


136


by means of the restricting means.




With the latter structure, however, the elastic shaft may come in contact with the restricting means where the extremely thick recording medium is fed from the feeding apparatus


101


or where multiple recording media are fed from the feeding apparatus


101


, thereby exerting large shear force to the elastic shaft, and possibly damaging the elastic shaft.




Furthermore, because the restricting means for restricting the movement of the spur


136


by restricting the movement of the elastic shaft is provided only in substantially the perpendicular direction with respect to the feeding surface of the recording medium, the elastic shaft may be damaged upon exertion of shear force in a direction that the recording medium is pulled out to the elastic shaft serving as the rotary shaft of the spur


136


when, e.g., the recording medium is pulled out due to occurrence of jamming of the recording media. Therefore, it is required to make the elastic shaft itself stronger, and this requirement may result in restriction on design.




As a structure to pull out the recording medium without exerting load to the spur


136


during paper jamming, a spur


136


may be conceivably attached to a cover portion that can be opened and closed as shown in

FIG. 11

, but in such a case, the structure may bring higher production costs and restriction on accuracy in assembling parts.




It is an object of the invention to provide a sheet feeding apparatus capable of preventing an elastic shaft of a spur from receiving damages due to force in multiple directions exerted to the spur during paper jamming or the like.




SUMMARY OF THE INVENTION




A representative structure of the invention in order to accomplish the above objects includes a first feeding rotary body for feeding sheets, a second feeding rotary body located opposing the first feeding rotary body for feeding the sheets between the second feeding rotary body and the first feeding rotary body upon pressing the sheets, an elastic shaft serving as a rotary center of the second feeding rotary body for urging the second feeding rotary body toward the first feeding rotary body, and restricting means for restricting movements of the second feeding rotary body in multiple directions by contacting with the second feeding rotary body.




According to the above structure, since the restricting means restricts movements of the second feeding rotary body in multiple directions by contacting with the second feeding rotary body, the elastic shaft serving as a rotary shaft of the second feeding rotary body can be prevented from inflicting damages because the movable range of the second feeding rotary body can be restricted not only in a substantially perpendicular direction with respect to the sheet feeding surface but also during a paper jamming, by, e.g., restricting the movements of the second feeding rotary body in a sheet thickness direction and in a direction toward an upstream side in the sheet feeding direction by means of the restricting means.




The second feeding rotary body is made of a tooth portion for feeding the sheets by pressing the sheets at point contacts to the sheets and a disc portion not in contact with the sheets, and the restricting means contacts with an outer round surface of the disc portion of the second feeding rotary body to restrict the movements. By such a structure, the second feeding rotary body contacts with the restricting means through larger contact areas, thereby further enhancing the above advantages.




Where the restricting means has at least one curving surface formed with a radius substantially the same length as a radius of an outer diameter portion of the disc portion of the second feeding rotary body, the outer diameter portion of the disc portion of the second feeding rotary body can suffer only from minimum damages due to contacts between the second feeding rotary body and the restricting means.




Where the restricting means is formed at a positioning member formed at a support member rotatively supporting the elastic shaft for positioning the body in an insertion direction of the elastic shaft, a number of parts can be reduced, so that a step number of the assembling process as well as production costs can be expectedly reduced.




Where a rib-shaped wall is formed in a range wider than the outer shape of the second feeding rotary body including the movable portion of the second feeding rotary body to the support member supporting the second feeding rotary body so that the elastic shaft is rotatable, the second feeding rotary body may not project outside from the contour of the rib-shaped wall during paper jamming or the like.




Moreover, for example, as a feeding means for feeding a recording medium on a downstream side of a recording means for recording images on a sheet as such as a recording medium, a structure in a recording apparatus having the above sheet feeding apparatus is so made that the support member for supporting the second feeding rotary body in a way that the elastic shaft is rotatable is molded in a united body with a platen for supporting a recording medium at a recording section in facing with the recording means, so that the steps of the assembling process and production costs can be expected in reducing the number of the parts.




The size deviations of the platen, the bearing of the first feeding rotary body, and the positioning member of the second rotary body can be managed within the same part, so that the pressure of the second feeding rotary body to the sheets can be set finely, and so that the sheets or recording media can be conveyed stably.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a front view showing a schematic structure of a recording apparatus according to a first embodiment;





FIG. 2

is a cross section showing the recording apparatus according to the first embodiment;





FIG. 3

is a top view showing a spur stay provided at a delivery section of the recording apparatus according to the first embodiment;





FIG. 4

is an enlarged cross section showing a delivery section (when a sheet is fed) of the recording apparatus of the first embodiment;





FIG. 5

is an enlarged cross section showing a delivery section (when a sheet is jammed) of the recording apparatus of the first embodiment;





FIG. 6

is an enlarged cross section showing a delivery section (when a sheet is pulled out) of the recording apparatus of the first embodiment;





FIG. 7

is an enlarged cross section showing a delivery section (when a sheet is fed) of the recording apparatus of the third embodiment;





FIG. 8

is an enlarged cross section showing a delivery section (when a sheet is jammed) of the recording apparatus of the third embodiment;





FIG. 9

is an enlarged cross section showing a delivery section (when a sheet is pulled out on an upstream side) of the recording apparatus of the third embodiment;





FIG. 10

is an enlarged cross section showing a delivery section (when a sheet is pulled out on a downstream side) of the recording apparatus of the third embodiment; and





FIG. 11

is a perspective view showing a conventional recording apparatus.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




Hereinafter, preferred embodiments of sheet feeding apparatuses to which this invention applies are described in detail. It is to be noted that in the embodiments below, sheet feeding apparatuses used for recording apparatuses are described as examples.




[First Embodiment]




Referring to

FIGS. 1

to


6


, a recording apparatus having a sheet feeding apparatus according to the first embodiment is described. In this embodiment. an inkjet recording apparatus is described.

FIG. 1

is a front view showing a schematic structure of an inkjet recording apparatus according to a first embodiment;

FIG. 2

is a cross section showing the inkjet recording apparatus;

FIG. 3

is a top view showing a spur stay provided at a delivery section of the inkjet recording apparatus;

FIGS. 4

to


6


are enlarged cross sections showing a delivery section of the inkjet recording apparatus.




The inkjet recording apparatus illustrated in this embodiment is a recording apparatus having a recording medium (hereinafter referred to as “sheet”) feeding apparatus as a united body, and has a sheet feeding apparatus


1


, a paper feeding section


13


, a delivery section


33


, a recording section


25


, a cleaning section


40


, and so on. Those structures are described below.




First, the structure of the sheet feeding apparatus


1


is described. The sheet feeding apparatus


1


is attached to an apparatus body in having a prescribed angle (about 30 to 60° in this embodiment) as shown in

FIG. 2

, and the sheets P having set are to be delivered substantially horizontally after recorded.




The recording head


24


is for recording images such as letters or the like made of inks on the sheet P, which is fed by a paper feeding roller


14


and a pinch roller


15


constituting the paper feeding section


13


. In this apparatus, as a recording means, an inkjet recording method in which a recording head sprays ink to record images is used. That is, the recording head has fine liquid outlets (orifices), liquid passages, energy operation portions formed at a part of each liquid passage, and energy generating means for generating energy for forming droplets to operate to the liquid in the energy operation portion.




The recording section


25


includes, as shown in FIG.


1


and

FIG. 2

, a carriage


26


for mounting the recording head


24


, a guide shaft


27


for reciprocally scanning the carriage


26


in a direction perpendicular to the sheet feeding direction, a guide


28


for maintaining a distance between the recording head


24


and the sheet P in holding the rear end of the carriage


26


, a timing belt


30


for transmitting drive of a carriage motor


29


to the carriage


26


, an idle pulley


31


for tensioning the timing belt


30


, a flexible substrate


32


for transmitting head drive signals from an electric board to the recording head


24


, and the like. The recording head


24


according to this embodiment is a recording head structured unitedly with an ink tank and can be replaced. The recording head


24


records images such as letters or the like by inks on sheets P conveyed over the platen


22


.




The cleaning section


40


includes, as shown in

FIG. 1

, a pump, not shown., for cleaning the recording head


24


, a cap, not shown, for suppressing drying of the recording head


24


, a drive switching arm, not shown, for switching the drive from the paper feeding roller


14


between the sheet feeding apparatus


1


and the pump, and the like.




The delivery section


33


includes, as shown in FIG.


2


and

FIG. 3

, a delivery roller


34


serving as a first feeding rotary body, a transmission roller


35


for transmitting drive of the paper feeding roller


14


to the delivery roller


34


, a plurality of spurs


36


serving as a second feeding rotary body located in facing to the delivery roller


34


for feeding the sheets upon pressing in point contacts with sheets, a plurality of spur cleaners


37


for absorbing the inks attached on the spur


36


, and so on. The delivery roller


34


and the spurs


36


make delivery of the sheets without messing the recording surfaces of the sheets after recording. In this embodiment, the spur


36


is mounted, so as to be rotatable around an elastic shaft


36




s


, on a spur stay


38


serving as a support member, and the pressure to the sheets P is generated by the elastic shaft


36




s.






In the delivery section


33


, the delivery roller


34


is constituted of a single shaft, and the drive for the roller


34


is given from the paper feeding roller


34


in the paper feeding section


13


through the transmission roller


35


. The transmission roller


35


is made in pressured contact with a drive force receiving section of the delivery roller


34


by means of an elastic shaft, not shown.




The spur


36


herein is constituted to have small contact areas in contact with the sheets and not to mess the recorded images on the sheets even where contacting to the sheet surfaces after recording is made, In this embodiment, as shown in

FIG. 4

to

FIG. 6

, there exemplifies the spur


36


including a tooth portion


36




a


for feeding sheets in pressured point contacts with the sheets and a molded portion


36




b


in a disc shape not in contact with the sheets.




The spur


36


is so formed, as shown in

FIG. 4

to

FIG. 6

, that the outer diameter of the disc shape molded portion


36




b


has a smaller outer diameter than the outer diameter of the tooth portion


36




a


. The spur


36


is formed with a shaft hole, not shown, for passing the elastic shaft


36




s


in the disc shaped molded portion


36




b


. This structure easily ensures the elastic shaft


36




s


and the spur


36


to slide.




Referring to

FIG. 4

to

FIG. 6

, states of the delivery section


33


when the sheet is fed, when the sheet is jammed, and when the sheet is pulled out, are described in detail next.

FIG. 4

shows a normal sheet feeding state;

FIG. 5

shows a sheet jamming state;

FIG. 6

shows a state when the sheet is pulled out on an upstream side in the sheet feeding direction. In each drawing, the tooth portion


36




a


of the spur


36


is shown by a broken line for illustrative purpose though it should have been shown by a solid line.




As shown in

FIG. 4

to

FIG. 6

, restricting means


39




a


,


39




b


for restricting movements of the spur


36


in multiple directions are provided at the spur stay


38


. In this embodiment, the restricting means


39




a


,


39




b


are formed on a positioning rib


41


in an insertion direction of the elastic shaft


36




s


molded unitedly as to extend from the spur stay


38


.




In this embodiment, the restricting means


39




a


is constituted of a curving surface formed with a radius substantially the same as that of the molded portion


36




b


of the spur


36


,and the restricting means


39




b


is constituted of two surfaces, a curving surface formed with a radius substantially the same as that of the molded portion


36




b


of the spur


36


and a vertical surface.




As shown in

FIG. 4

, the restricting means


39




a


,


39




b


are arranged at positions not in contact with the molded portion


36




b


of the spur


36


when the sheet P is fed where nipped by the delivery roller


34


and the spur


36


.




If the sheet P is jammed at the delivery section


33


, the jammed sheet P as shown in

FIG. 5

pushes up the spur


36


in arrow a direction. The molded portion


36




b


of the spur


36


at that time comes in contact with the restricting means


39




a


,


39




b


, thereby restricting the movements of the spur


36


. Therefore, the spur


36


cannot move any more in arrow a direction.




When the sheet P is pulled out on the upstream side in the sheet feeding direction from the delivery section


33


, the spur


36


is moved in arrow b direction as the upstream side in the sheet feeding direction from the normal position shown in

FIG. 4

by pulling force given to the sheet P. The molded portion


36




b


of the spur


36


at that time comes in contact with the restricting means


39




b


, thereby restricting the movements of the spur


36


. Therefore, the spur


36


cannot move any more in arrow b direction (the upstream side in the sheet feeding direction).




As described above, the restricting means


39




a


,


39




b


receive the molded portion


36


of the spur


36


to restrict the movements of the spur


36


in the multiple directions (in arrow a, b directions in

FIG. 4

to FIG.


6


), and therefore, the elastic shaft


36




s


serving as a rotary shaft of the spur


36


may not receive shear force which otherwise causes damages on the shaft even where jamming recovery or the like causes undue force exerted to the spur


36


,




In this embodiment, as shown in

FIG. 4

to

FIG. 6

, the positioning rib


41


serving as a rib-shaped wall formed unitedly with the spur stay


38


described above has a wider side shape than a movable maximum range of the tooth portion


36




a


of the spur


36


. This structure prevents the tooth portion


36




a


of the spur


36


from projecting outside the contour of the rib


41


even where the molded portion


36




b


of the spur


36


hits the restricting means


39




a


or the restricting means


39




b.






[Second Embodiment]




A sheet feeding apparatus according to the second embodiment is described in detail. It is to be noted that because the structural outline of the entire apparatus is substantially the same as that in the above embodiment, detailed descriptions are omitted. Hereinafter, the features of the sheet feeding apparatus according to this embodiment is described in detail. The members having the same functions as those in the above embodiment are described using the same reference numbers.




Although in the first embodiment the spur stay


38


is exemplified as a member separated from the platen


22


, the spur stay


38


in this embodiment is formed in a united body with the platen


22


. Other structures are substantially the same as those in the first embodiment. With this structure, the size deviation of the platen


22


, the bearing of the delivery roller


34


, and the positioning portion of the spur


36


can be managed as within the same part (a unitedly molded member of the spur stay


38


and the platen


22


), so that the pressure of the spur


38


to the sheet P can be set finely, and so that the sheets P can be delivered stably. Furthermore, such a molding to form those members in a united body expectedly makes production costs reduced.




[Third Embodiment]




Referring to

FIGS. 7

to


10


, a sheet feeding apparatus according to the third embodiment is described in detail.

FIGS. 7

to


10


are enlarged views of the essential portion of the sheet feeding apparatus (delivery section) according to the embodiment. It is to be noted that because the structural outline of the entire apparatus is substantially the same as that in the above embodiment, detailed descriptions are omitted. Hereinafter, the features of the sheet feeding apparatus according to this embodiment is described in detail. The members having the same functions as those in the above embodiment are described using the same reference numbers.




In the first embodiment, the restricting directions against the spur by the restricting means are the two directions (arrow a, b directions in

FIGS. 4

to


6


), but in this embodiment the restricting directions are three directions (arrow a, b, c directions shown in

FIG. 7

to FIG.


10


).




With respect to the restricting means according to this embodiment, one restricting means


39




a


′ is comprised of three surfaces: two curving surfaces formed with a radius substantially the same as that of the molded portion


36




b


of the spur


36


, and a vertical surface. The other restricting means


39




b


has the same shape as that in the above first embodiment. Other structural elements are substantially the same as those in the first embodiment except that no spur cleaner


37


is provided.





FIG. 7

shows a state of the normal sheet feeding of the delivery section


33


;

FIG. 8

shows a state where the sheet is jammed at the delivery section


33


;

FIG. 9

shows a state where the sheet is pulled out on the upstream side in the sheet feeding direction (arrow b direction in

FIG. 9

) from the delivery section


33


. The effects and advantages of each state are the same as those in the first embodiment as described above.





FIG. 10

shows a state where the sheet is pulled out on the downstream side in the sheet feeding direction (arrow c direction in

FIG. 9

) from the delivery section


33


. In such a situation, the spur


36


is moved in arrow c direction as the downstream side in the sheet feeding direction from the normal position shown in

FIG. 7

by pulling force given to the sheet P. The molded portion


36




b


of the spur


36


at that time comes in contact with the restricting means


39




a


′, thereby restricting the movements of the spur


36


. Therefore, the spur


36


cannot move any more in arrow c direction (the downstream side in the sheet feeding direction).




With this structure, the possibility that the elastic shaft inflicts damages is further reduced, and the flexibility to design the delivery section (sheet feeding apparatus) can be made higher.




[Other Embodiments]




In the above embodiments, exemplified are the deliver roller for feeding sheets serving as the first feeding rotary body and spurs for feeding sheets in pressing the sheets located in opposed relation to the delivery roller serving as the second feeding rotary body. This invention is not limited to those figures, and substantially the same effects can be obtained in application of this invention to an apparatus having a structure that a paper feeding roller for feeding the sheets to a recording means is a first feeding rotary body and that a pinch roller for feeding the sheets in pressing the sheets located in facing to the paper feeding roller is a second feeding rotary body.




In addition that the support member for supporting the spurs rotatively can be made of a molded part entirely as described in the above embodiment, any structure can be used such that where a spur stay may be formed by a sheet metal processing, a molded support member is fitted to the stay, or all members can be made by a sheet metal processing.




Although in the above embodiments the sheet feeding apparatus for feeding sheets (recording media) such as recording paper or the like as an item to be recorded is exemplified, the invention is not limited to this, and for example, the same advantages can be obtained where this invention applies to a sheet feeding apparatus for feeding sheet such as original documents as an item to be read.




Although in the above embodiments the inkjet recording apparatus using a single recording head is exemplified and described, this invention is not limited to this, and for example, this invention is applicable, notwithstanding the number of the recording heads, to, e.g., an inkjet recording apparatus for color recording using plural recording heads for making records with different colors, or an inkjet recording apparatus for grayscale recording using plural recording heads for recording with inks of the same color but different concentrations, thereby bringing substantially the same effects and advantages.




As a recording means (recording head), any structure or combination of the recording means and the ink tank, e.g., a cartridge type in which a recording head and an ink tank are formed unitedly, a structure in which a recording head and an ink tank are formed as separate bodies which are connected with each other through an ink supply tube, or the like can be applicable in the same way as the above, and substantially the same effects and advantages can be obtained.




When this invention applies to an inkjet recording apparatus, this invention is applicable to an apparatus using a recording means using an electromechanical converter or the like such as piezoelectric devices. This invention, inter alia, brings excellent advantages to an inkjet recording apparatus using a recording means of a type that sprays ink by utilizing thermal energy. According to this type, recording can be made with high definition and high density.




This invention is applicable effectively to a recording head of a full line type having a length corresponding to the maximum width of the recording medium that can be recorded by the recording apparatus. As a recording head used for such purposes, the head can be structured by a combination of plural recording heads as to fill the length or a single recording head formed unitedly. In addition, this invention is advantageous in using a recording head secured to an apparatus body, even though it is a serial type, a recording head of a chip type that can be replaced in which the electric connection to the apparatus body and ink supply from the apparatus body can be made upon attachment onto the apparatus body, or a recording head of a cartridge type in which a recording head itself is formed unitedly with an ink tank.




It is favorable to add recovery means for a recording head and preliminary and auxiliary means, which are formed as a structure of the recording apparatus of the invention, because the advantages of the invention can be obtained further stably. Such means are, e.g., a capping means for the recording head, a cleaning means, a pressing means, and absorbing means, preliminarily heating means made of thermoelectric converters or other heating devices or combinations of those. It is also effective to do a preliminary spraying mode for spraying inks in a different way from the recording for making recording stable.




The kind and number of the recording heads carried by a carriage can be, c.g., single in corresponding to a monochrome ink, or plural in corresponding to multiple inks having different colors and concentrations. That is, as a recording mode for the recording apparatus, this invention is applicable to an apparatus capable of use of not only a recording mode only of a major color such as a black color or the like but also at least one of multicolor made of different colors, full color made by mixing colors, which are created by a recording head of a combination of plural unitedly formed heads or other means.




In addition, as a feature of the above described inkjet recording apparatus, it can be an image output terminal apparatus such as an information processing apparatus such as a computer, an inkjet input and output apparatus capable of mounting a scanner or the like other than the recording head, a photocopier in combination with a reader or the like, a facsimile machine having a transmission function, and so on.




Although in the above embodiment, an inkjet recording method is exemplified as the recording method, this invention is not limited to this, and this invention is applicable to other recording methods such as a thermal transfer recording method, a thermal sensitive recording method, an impact recording method such as a wire dot recording method, and other electrophotographic methods.




As described above, according to the invention, because the restricting means is structured to restrict the movements of the second feeding rotary body in the multiple directions by contacting with the second feeding rotary body, for example, to restrict the movements of the second feeding rotary body in the sheet thickness direction and in the direction on the upstream side in the sheet feeding direction, the elastic shaft serving as a rotary shaft of the second feeding rotary body can be prevented from inflicting damages where the movable range of the second feeding rotary body is restricted not only in a direction substantially perpendicular to the sheet feeding surface but also during paper jamming. Furthermore, the design flexibility can be improved where such an apparatus is designed.



Claims
  • 1. A sheet feeding apparatus comprising:a first feeding rotary body for feeding sheets; a second feeding rotary body located in facing to the first feeding rotary body for feeding the sheets between the second feeding rotary body and the first feeding rotary body upon pressing the sheets; an elastic shaft serving as a rotary center of the second feeding rotary body for urging the second feeding rotary body toward the first feeding rotary body; and restricting means for restricting movements of the second feeding rotary body in multiple directions when contacting with the second feeding rotary body and allowing movement of a certain distance of the second feeding rotary body when in its normal state and out of contact with the second feeding rotary body.
  • 2. The sheet feeding apparatus according to claim 1, wherein the restricting means restricts the movements of the second feeding rotary body in a sheet thickness direction and in a direction toward an upstream side of the sheet feeding direction.
  • 3. The sheet feeding apparatus according to claim 1, wherein the second feeding rotary body includes a tooth portion for feeding the sheets by point contacts to press the sheets and a disc portion out of contact with the sheets, and wherein the restricting means restricts the movements of the second feeding rotary body by contacting with an outer round surface of the disc portion of the second feeding rotary body.
  • 4. The sheet feeding apparatus according to claim 3, wherein the restricting means has at least one curving surface formed with a radius substantially the same length as a radius of an outer diameter of the disc portion of the second feeding rotary body.
  • 5. The sheet feeding apparatus according to claim 3, wherein the second feeding rotary body has an outer diameter of the disc portion which is smaller than an outer diameter of the tooth portion.
  • 6. The sheet feeding apparatus according to claim 3, wherein the second feeding rotary body has a shaft hole for inserting the elastic shaft in the disc portion.
  • 7. The sheet feeding apparatus according to claim 1, wherein the second feeding rotary body is so supported by a support member that the elastic shaft is rotatable, and wherein the restricting means is formed in a united body with a positioning member for positioning the elastic shaft in an insertion direction of the elastic shaft.
  • 8. The sheet feeding apparatus according to claim 1, wherein the second feeding rotary body is so supported by a support member that the elastic shaft is rotatable, and wherein the support member is formed with, on a side of the second feeding rotary body, a rib-shape wall having a contour extending Outer than a contour in a movable range of the second feeding rotary body.
  • 9. A recording apparatus comprising:recording means for recording images on a recording medium; a platen located in facing with the recording means for supporting a recording medium at a recording section; and a feeding apparatus according to any of claims 1 to 8 for feeding the recording medium on a downstream side of the recording means in the feeding direction.
  • 10. The recording apparatus according to claim 9, wherein a support member for rotatively supporting the elastic shaft for the second feeding rotary body is molded in a united body with the platen.
  • 11. A sheet feeding apparatus comprising:a first feeding rotary body for feeding sheets; a second feeding rotary body located in facing to the first feeding rotary body for feeding the sheets between the second feeding rotary body and the first feeding rotary body upon pressing the sheets; an elastic shaft serving as a rotary center of the second feeding rotary body for urging the second feeding rotary body toward the first feeding rotary body; a support member for supporting the elastic shaft; and restricting means formed on and in a united body with the support member for restricting movements of the second feeding rotary body at least in a sheet thickness direction and in a direction toward an upstream side of the sheet feeding direction when contacting with a part of the second feeding rotary body when the second feeding rotary body moves and allowing movement of a certain distance of the second feeding rotary body when in its normal state and out of contact with the second feeding rotary body.
  • 12. A recording apparatus comprising:recording means for recording images on sheets; a platen located in facing with the recording means for supporting the sheets at a recording section; a first feeding rotary body for feeding the sheets; a second feeding rotary body located in facing to the first feeding rotary body for feeding the sheets between the second feeding rotary body and the first feeding rotary body upon pressing the sheets; an elastic shaft serving as a rotary center of the second feeding rotary body for urging the second feeding rotary body toward the first feeding rotary body; a support member formed in a united body with the platen for supporting the elastic shaft; and restricting means formed on and in a united body with the support member for restricting movements of the second feeding rotary body at least in a sheet thickness direction and in a direction toward an upstream side of the sheet feeding direction when contacting with a part of the second feeding rotary body when the second feeding rotary body moves and allowing movement of a certain distance of the second feeding rotary body when in its normal state and out of contact with the second feeding rotary body.
Priority Claims (1)
Number Date Country Kind
10-241789 Aug 1998 JP
US Referenced Citations (6)
Number Name Date Kind
4729557 Kiyohara Mar 1988
5606357 Bekki Feb 1997
5800076 Umeda Sep 1998
6007063 Park Dec 1999
6059287 Bae May 2000
6073927 Sako et al. Jun 2000
Foreign Referenced Citations (1)
Number Date Country
403243553A Oct 1991 JP