US20110241282A1 - Transportation apparatus - Google Patents

Transportation apparatus Download PDF

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Publication number
US20110241282A1
US20110241282A1 US13/081,137 US201113081137A US2011241282A1 US 20110241282 A1 US20110241282 A1 US 20110241282A1 US 201113081137 A US201113081137 A US 201113081137A US 2011241282 A1 US2011241282 A1 US 2011241282A1
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US
United States
Prior art keywords
feed roller
arm
pivotal portion
transported medium
transporting apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/081,137
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English (en)
Inventor
Hideki NISHINAKAMA
Satoshi Nakano
Shoichi Fukuyama
Kiyoshi Chinzei
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Original Assignee
Seiko Epson Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp filed Critical Seiko Epson Corp
Assigned to SEIKO EPSON CORPORATION reassignment SEIKO EPSON CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CHINZEI, KIYOSHI, NAKANO, SATOSHI, NISHINAKAMA, HIDEKI, FUKUYAMA, SHOICHI
Publication of US20110241282A1 publication Critical patent/US20110241282A1/en
Abandoned legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J13/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, specially adapted for supporting or handling copy material in short lengths, e.g. sheets
    • B41J13/02—Rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H3/00—Separating articles from piles
    • B65H3/02—Separating articles from piles using friction forces between articles and separator
    • B65H3/06—Rollers or like rotary separators
    • B65H3/0661—Rollers or like rotary separators for separating inclined-stacked articles with separator rollers above the stack
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H3/00—Separating articles from piles
    • B65H3/02—Separating articles from piles using friction forces between articles and separator
    • B65H3/06—Rollers or like rotary separators
    • B65H3/0684—Rollers or like rotary separators on moving support, e.g. pivoting, for bringing the roller or like rotary separator into contact with the pile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2220/00—Function indicators
    • B65H2220/09—Function indicators indicating that several of an entity are present
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2402/00—Constructional details of the handling apparatus
    • B65H2402/30—Supports; Subassemblies; Mountings thereof
    • B65H2402/31—Pivoting support means

Definitions

  • the present invention relates to a transporting apparatus used for, for example, an ink jet printer.
  • a printer includes a transporting apparatus configured to separate a bundle of sheets (transported media) placed on a placing tray of the printer into pieces and feed individual sheets one by one therefrom.
  • a transporting apparatus configured to maintain the feed roller in a state of being in press-contact with the sheets by urging the feed roller toward the sheets (see JP-A-2003-285936).
  • FIGS. 9A and 9B a configuration of the transporting apparatus in the related art will be described.
  • a transporting apparatus 100 includes a placing tray 110 configured to place sheets Q, and a feed roller 120 configured to transport the sheets Q placed on the placing tray 110 toward a printing unit of the printer.
  • the feed roller 120 is attached to a drive shaft 140 via an arm 130 .
  • the feed roller 120 is rotated by transmitting the rotation of the drive shaft 140 to the feed roller 120 via a gear train, not shown.
  • a torsion coil spring 150 configured to urge the arm 130 toward the sheets Q, that is, counterclockwise, in the drawings is mounted on the transporting apparatus 100 . Accordingly, the feed roller 120 is brought into press contact with the sheets Q. With the clockwise rotation of the feed roller 120 as shown by hollow arrows in the drawings, the sheets Q are fed in the direction of sheet transport indicated by arrows shown by alternate long and short chain lines.
  • the arm 130 and the feed roller 120 are allowed to pivot toward the placing tray 110 about the drive shaft 140 by being urged by the torsion coil spring 150 . Accordingly, the feed roller 120 maintains its press contact position with respect to the sheet Q in a topmost position of a bundle of sheets according to the number of the sheets Q.
  • the arm 130 is encouraged to pivot toward the sheets Q, that is, clockwise in the drawings by a frictional force f that the feed roller 120 receives from the sheets Q.
  • a frictional force f that the feed roller 120 receives from the sheets Q.
  • FIG. 9A if the amount of loaded sheets Q is large, an acute angle formed by an axial line LR which connects the center of rotation of the drive shaft 140 and the center of rotation of the feed roller 120 and a placing surface 111 of the placing tray 110 (hereinafter, referred to as “acute angle X” becomes smaller. Accordingly, a component of a force which tries to pivot the arm 130 toward the sheets Q by the frictional force f (f ⁇ sinX) becomes smaller. In contrast, as shown in FIG.
  • acute angle Y a component of a force which tries to pivot the arm 130 toward the sheets Q by the frictional force f (f ⁇ sinY) becomes larger than the same component with the acute angle X (f ⁇ sinX ⁇ f ⁇ sinY).
  • the feed roller 120 digs into the sheets Q and hence a frictional resistance between the feed roller 120 and the sheets Q becomes excessive. Consequently, an event such that the plurality of sheets Q are transported together at the time of transporting the sheet Q, so-called “multi feed” may occur.
  • An advantage of some aspects of the invention is that a transporting apparatus which can restrain multi feed of transported media.
  • a transporting apparatus including: a transporting apparatus body configured to transport a transported medium by a feed roller; a first arm to be mounted on the transporting apparatus body so as to be pivotable about a first pivotal portion with respect to the transporting apparatus body; a second arm mounted on the first arm so as to be pivotable about a second pivotal portion with respect to the first arm and fixed with the feed roller at a position opposite from the first pivotal portion with respect to the second pivotal portion; and an urging member acting on the second pivotal portion so as to urge the feed roller toward the transported medium.
  • the urging member exerts an urging force on the second pivotal portion by a restoration force of the urging member. Accordingly, the urging force increases so that the friction force that the feed roller receives from the transported medium and the force of the feed roller to transport the transported medium are balanced.
  • the urging force of the second urging member increases and the acute angle decreases in association with the movement of the second pivotal portion, so that the degree of increase in the frictional force which causes the feed roller to dig into the sheet becomes smaller than the degree of increase in the frictional force that the transported medium exerts on the feed roller. Consequently, the frictional force between the feed roller and the transported medium can be prevented from being excessive with respect to the frictional force between the two stacked transported media, whereby the multi feed of the transported media can be restrained.
  • a separating mechanism configured to separate a first transported medium in abutment with the feed roller from a second transported medium adjacent to the first transported medium in a stacking direction, and the second arm moves toward a direction in which a rotational force of the feed roller acts on the first transported medium against an urging force of the urging member when a load for separating the first transported medium and the second transported medium exerted by the separating mechanism is large, whereby the urging force of the feed roller with respect to the first transported medium increases.
  • the urging force of the feed roller with respect to the first transported medium increases when the load for separating the first transported medium and the second transported medium is large, whereby the urging force is adjusted according to the load.
  • the first transported medium is transported in a state in which the amount of increase in the urging force is relatively decreased.
  • the load is relatively large, the first transported medium is transported in a state in which the amount of increase in the urging force is relatively increased. Accordingly, since an urging force adequate for the load can be exerted on the feed roller, such event that the first transported medium and the second transported medium are transported simultaneously, that is, so-called multi feed of the transported media can be restrained.
  • a first inter-axis distance between the first pivotal portion and a second pivotal portion is smaller than a second inter-axis distance between the second pivotal portion and the axis of rotation of the feed roller.
  • the distance of the pivotal movement of the second pivotal portion is larger than that in the case where the first inter-axis distance is larger than the second inter-axis distance. Accordingly, a range of adjustment of the force that the urging member urges the feed roller toward the transported medium can be increased.
  • the second pivotal portion pivots so that an acute angle formed by an axial line connecting the axis of rotation of the feed roller and the second pivotal portion and the transported medium becomes minimum.
  • the frictional force between the two stacked transported media becomes maximum when a state in which the rotation of the feed roller is stopped is changed to a state in which the rotational force of the feed roller is transmitted to the transported medium, whereby the force to cause the second arm to rotate toward the direction of rotation of the feed roller becomes maximum.
  • the second pivotal portion pivots so that an acute angle formed by an axial line connecting an axis of rotation of the feed roller and a second pivotal shaft and the transported medium becomes minimum.
  • an obtuse angle formed by the direction of the urging force exerted by the urging member on the feed roller toward the transported medium and the direction of transport of the transported medium is reduced in comparison with that in the state in which the rotation of the feed roller is stopped. Accordingly, increase in the frictional force that the feed roller receives from the transported medium caused by the urging force of the urging member can be restrained. Therefore, the feed roller can be prevented from digging into the transported medium.
  • the transporting apparatus is provided with a placing surface for placing the transported medium at a position opposing the feed roller, a cover configured to cover the first pivotal portion from the outside thereof in the direction of the radius of the pivotal movement of the first pivotal portion, and restrict the number of the transported media to be placed by a gap formed in cooperation with the placing surface is provided at a portion of the first pivotal portion opposing the transported medium, and the cover is provided over a range of the pivotal movement of the first arm in association with the action of the feed roller which transports the transported medium.
  • the second pivotal portion When the second pivotal portion is provided with a mechanism which restricts the number of transported media to be placed, the second pivotal portion pivots about the first pivotal portion in association with the pivotal movement of the first arm and the second arm under the condition in which the feed roller transports the transported media. Therefore, the position of the second pivotal portion with respect to the placing surface changes. Consequently, the position to restrict the number of transported media to be placed varies as well. Accordingly, the extent of allowable amount of the transported media to be placed thereon cannot be defined accurately.
  • the cover since the cover covers the first pivotal portion from the outside in the direction of the radius of the pivotal movement of the first pivotal portion, the position of cover with respect to the placing surface does not change even when the first pivotal portion is pivoted. Therefore, the positions of the placing surface and the cover do not change in the circumstance in which the feed roller transports the transported medium. Therefore, the number of the transported medium to be placed can be defined accurately.
  • the cover is provided over the range of the pivotal movement of the first arm, the transported medium is restrained from deviating from the gap formed by the placing surface and the cover in the course of the pivotal movement of the first arm.
  • FIG. 1 is a schematic perspective view of a printer according to an embodiment.
  • FIG. 2 is a schematic perspective view of a transporting apparatus according to the embodiment.
  • FIG. 3 is an exploded perspective view of a pickup unit according to the embodiment.
  • FIG. 4 is a diagrammatic drawing showing a gear train of the pickup unit.
  • FIG. 5A is a side view of the transporting apparatus in a waiting state.
  • FIG. 5B is a diagrammatic drawing showing the transporting apparatus in FIG. 5A .
  • FIG. 6A is a side view showing the transporting apparatus just moments before the start of transport.
  • FIG. 6B is a diagrammatic drawing showing the transporting apparatus in FIG. 6A .
  • FIG. 7A is a side view showing the transporting apparatus in a state of transporting a sheet.
  • FIG. 7B is a diagrammatic drawing showing the transporting apparatus in FIG. 7A .
  • FIG. 8A is a side view showing the transporting apparatus just moments before the start of transport when using a thick sheet.
  • FIG. 8B is a diagrammatic drawing showing the transporting apparatus in FIG. 8A .
  • FIG. 9A is a diagrammatic drawing showing a transporting apparatus in the related art in a state in which a large number of sheets are loaded.
  • FIG. 9B is a diagrammatic drawing showing the transporting apparatus in the related art in a state in which a small number of sheets are loaded.
  • FIGS. 1 to 8B embodiments in which a transporting apparatus according to an aspect of the invention is embodied in an ink jet printer (hereinafter, referred to as “printer”) will be described.
  • the expressions “fore-and-aft direction”, “up-and-down direction”, and “left-and-right direction” indicate directions “fore-and-aft direction”, “up-and-down direction”, and “left-and-right direction” indicated by arrows in FIG. 1 unless otherwise specified.
  • the vertical direction is defined as the same direction as the vertical direction.
  • a printer 11 is a recording apparatus configured to record characters or images on sheets of paper (hereinafter, referred to simply as “sheet(s)”) as a recorded medium supplied from the rear side thereof.
  • the printer 11 includes a transporting apparatus 12 as an Automatic Sheet Feeder (ASF) which feeds sheets, a recording apparatus 13 configured to record an image or the like on a sheet transported by the transporting apparatus 12 , and a sheet discharging port 14 used for discharging the sheets on which the images or the like are recorded by the recording apparatus 13 .
  • ASF Automatic Sheet Feeder
  • the transporting apparatus 12 is provided with a placing tray 21 for placing the sheets thereon.
  • the placing tray 21 includes an inclined placing surface 21 a on which sheets P are placed and a supporting surface 21 b which is a flat surface extending along the fore-and-aft direction and the left-and-right direction.
  • a guide wall 22 fixed to the placing tray 21 and configured to perform positioning of the sheets is provided at a right end of the placing tray 21 .
  • a supporting shaft 23 as a transporting apparatus body, which extends leftward from the guide wall 22 and is connected to an electric motor, not shown, via a gear train is mounted on the guide wall 22 .
  • the supporting shaft 23 supports a pickup unit 24 , which transports the sheets P toward the recording apparatus 13 (see FIG. 1 ).
  • the placing surface 21 a is provided with a roller 25 (see FIGS. 5A and 5B ) which comes into abutment with a sheet which is in abutment with the placing surface 21 a.
  • the supporting surface 21 b is provided with a separation pad 26 as a separating mechanism for separating the sheets into pieces.
  • the separation pad 26 includes a rectangular box-shaped case 26 a to be mounted on the supporting surface 21 b, and a separating portion 26 b extending in the fore-and-aft direction of the case 26 a and provided in a center portion of the case 26 a in the left-and-right direction. member having a higher coefficient of friction than the case 26 a is employed for the separating portion 26 b.
  • the pickup unit 24 includes a first arm 31 to be pivotably mounted on the supporting shaft 23 , a second arm 32 to be pivotably mounted on a lower end of the first arm 31 , and a feed roller 33 to be mounted on a lower end of the second arm 32 .
  • a torsion coil spring 35 as an urging member is mounted on the second arm 32 . Accordingly, the feed roller 33 (the second arm 32 ) is urged toward the sheets P.
  • the torsion coil spring 35 also causes a rotational force of the supporting shaft 23 to be transmitted to the feed roller 33 via a transmitting mechanism 34 including driven gears 34 a to 34 c.
  • the first arm 31 includes a pair of first arm portions 41 apart from each other in the left-and-right direction and an upper cover portion 42 configured to connect the first arm portions 41 with each other and cover the supporting shaft 23 from above.
  • the first arm portions 41 each are provided with a first bearing portion 43 having a through hole penetrating therethrough in the left-and-right direction in upper portions thereof.
  • a first shaft portion 44 projecting rightward from the first arm portion 41 .
  • a second shaft portion 45 having a through hole penetrating therethrough in the left-and-right direction.
  • the supporting shaft 23 is slidably inserted through the first bearing portion 43 .
  • the supporting shaft 23 and the first bearing portion 43 constitute a “first pivotal portion 61 ”.
  • the upper cover portion 42 is provided with an arcuate shaped curved portion 42 a which surrounds the first pivotal portion 61 from the outside and is centered at the center of pivotal movement of the first pivotal portion 61 .
  • the curved portion 42 a is provided over the range of the pivotal movement of the first arm 31 .
  • a maximum amount of sheets to be loaded is defined here by a gap G (see FIG. 5A ) formed between the curved portion 42 a and the placing surface 21 a. Since the width of the gap G is not changed by the pivotal movement of the first arm 31 , the maximum amount of sheets to be loaded is maintained to be always constant by the pivotal movement of the first arm 31 .
  • the second arm 32 includes a pair of second arm portions 51 apart from each other in the left-and-right direction and a cover body 52 configured to cover upper portions and front portions of the second arm portions 51 .
  • a projection 53 having a through hole penetrating therethrough and projecting rightward from the second arm portion 51 .
  • a cylindrical-shaped second shaft portion 54 projecting leftward of the second arm portion 51 .
  • a third bearing portion 55 is provided in a lower portion of each of the second arm portions 51 , which is a through hole penetrating therethrough in the left-and-right direction.
  • the second arm 32 is mounted on the first arm 31 by the second shaft portion 54 slidably inserted into the second bearing portion 45 and the first shaft portion 44 slidably inserted into the projection 53 .
  • the second shaft portion 54 and the second bearing portion 45 constitute a “second pivotal portion 62 ” on the right side
  • the projection 53 and the first shaft portion 44 constitute a “second pivotal portion 62 ” on the left side.
  • the torsion coil spring 35 is fitted on the projection 53 so as to be coaxial with the second pivotal portion 62 .
  • One of the end portions of the torsion coil spring 35 is fitted to a locking portion 56 provided on the second arm portion 51 .
  • the other end portion of the torsion coil spring 35 is fitted to the upper cover portion 42 .
  • the feed roller 33 is provided with a roller body portion 33 a which is to be fitted to the third bearing portions 55 and is formed into a cylindrical shape.
  • a sliding contact member 33 b which comes into abutment with the sheet and is a cylindrical rubber member is mounted on an outer peripheral surface of the roller body portion 33 a.
  • a gear portion 33 c which engages with the driven gear 34 c (see FIG. 4 ).
  • the transmitting mechanism 34 includes the driven gears 34 a to 34 c.
  • the driven gear 34 a is fitted on the supporting shaft 23 so as to rotate integrally therewith.
  • the driven gear 34 b engages both the driven gears 34 a, 34 c.
  • the driven gear 34 c engages the gear portion 33 c.
  • the driven gear 34 a rotates counterclockwise in association with the counterclockwise rotation of the supporting shaft 23
  • the driven gear 34 b rotates clockwise by the rotation of the driven gear 34 a, and rotates the driven gear 34 c counterclockwise.
  • the feed roller 33 rotates clockwise in association with the rotation of the driven gear 34 c.
  • FIGS. 5A to 8B The drawings with a suffix of B are diagrammatic drawings showing a relation between a force exerted to a periphery of the pickup unit 24 and an angle of the pickup unit 24 , respectively.
  • FIGS. 5A to 7B “normal sheets” which are relatively thin and flexible sheets are used as the sheets P.
  • the pickup unit 24 Before placing the sheets P on the placing tray 21 , the pickup unit 24 is arranged so that the feed roller 33 abuts against the placing surface 21 a.
  • the pickup unit 24 is formed so that a first inter-axis distance D 1 , which is a length of a straight line connecting a center of pivotal movement of the first pivotal portion 61 and a center of pivotal movement of the second pivotal portion 62 , becomes smaller than a second inter-axis distance D 2 , which is a length of a straight line connecting a center of pivotal movement of the second pivotal portion 62 and an axis of rotation J of the feed roller 33 .
  • the first arm 31 and the second arm 32 of the pickup unit 24 pivot clockwise integrally about the first pivotal portion 61 .
  • the second arm 32 pivots about the first pivotal portion 61 while maintaining the angle of inclination with respect to the first arm 31 .
  • the feed roller 33 moves away from the placing surface 21 a and the sheets P pass through a gap between the feed roller 33 and the placing surface 21 a. Accordingly, the sheets P come into abutment with the separation pad 26 , and the feed roller 33 comes into abutment with the topmost surface of the sheets P.
  • the pickup unit 24 is inclined toward the front by the torsion coil spring 35 as the first arm 31 moves downward, and maintains its posture in a state of inclining rearward as the second arm 32 moves downward.
  • the pickup unit 24 changes its position from a state shown by the broken line in FIG. 5A to a state shown by the solid line in FIG. 5A under its own weight.
  • the pickup unit 24 moves in such a manner that the first arm 31 pivots about the first pivotal portion 61 so that the lower end thereof moves toward the sheets P (counterclockwise in FIG. 5A ).
  • the second arm 32 pivots while maintaining the angle of inclination with respect to the first arm 31 , that is, the first arm 31 and the second arm 32 pivot integrally toward the sheets P.
  • the torsion coil spring 35 has a natural length. Therefore, a force urging the second arm 32 counterclockwise by the torsion coil spring 35 is not generated. In other words, a force which urges the feed roller 33 toward a sheet P 1 as a first transported medium which is at the topmost position from among the sheets P exerted by the torsion coil spring 35 (hereinafter, referred to as “urging force S”) is not generated. Therefore, the feed roller 33 simply comes into abutment with the sheet P 1 . Since the feed roller 33 does not try to rotate, the frictional force f of the roller, which is a frictional force that the sheet P 1 exerts on the feed roller 33 is “0”.
  • an arm angle A which is an angle formed by the first arm 31 and the second arm 32 in the waiting state is defined as a reference angle A 1 .
  • An angle of inclination B which is an acute angle formed by a straight line JL connecting the second pivotal portion 62 and the axis of rotation J of the feed roller 33 and the placing surface 21 a, that is, an abutting surface of the sheet P 1 with respect to the feed roller 33 in the waiting state is defined as a reference angle B 1 .
  • an inter-sheet frictional force F generated between the sheet P 1 and a sheet P 2 as a second transported medium which comes into abutment with the sheet P 1 in the stacking direction (hereinafter, referred to as “inter-sheet frictional force F 1 ”) becomes maximum.
  • a separation load H which is a load exerted by the separation pad 26 for separating the sheet P 1 from the sheet P 2 (hereinafter, referred to as “separation load H 1 ”) becomes maximum.
  • transporting force T 1 a force T for transporting the sheet P 1 generated by the rotation of the feed roller 33 (hereinafter, referred to as “transporting force T 1 ”) becomes maximum.
  • the frictional force f of the roller corresponds to the reaction force of the transporting force T 1 , and hence is equal to the transporting force T 1 in the just-before-transport state.
  • the arm angle A becomes an angle A 2 , which is larger than the reference angle A 1 (A 1 ⁇ A 2 ), and the angle of inclination B becomes an angle B 2 , which is smaller than the reference angle B 1 (B 2 ⁇ B 1 ).
  • the feed roller 33 moves toward the downstream side in the direction of transport of the sheets P more than that in the waiting state as the arm angle A and the angle of inclination B vary. Accordingly, an urging force S 1 is applied toward the downstream side in the direction of transport more than the case where an imaginary urging force SK generated when assuming that the urging force S 1 is exerted in the waiting state.
  • the torsion coil spring 35 is bent in the opposite direction from an urging direction. Accordingly, a restoration force R 1 of the torsion coil spring 35 is exerted on the second arm 32 .
  • the urging force S 1 corresponding to the above-described restoration force R 1 is exerted on the second arm 32 . Accordingly, the torsion coil spring 35 is bent in the direction opposite from the urging direction as the arm angle A increases from the reference angle A 1 , and hence the restoration force R 1 of the torsion coil spring 35 increases.
  • a force which causes the feed roller 33 to dig into the sheet P 1 generated by the frictional force f of the roller is smaller than a force which causes the feed roller 33 to dig into the sheet P 1 generated when assuming that the frictional force f of the roller is generated also at the reference angle B 1 in the waiting state (f ⁇ sinB 2 ⁇ f ⁇ sinB 1 ).
  • a frictional force F 2 between the sheet P 1 and the sheet P 2 is smaller than the frictional force F 1 generated in the just-before-transport state shown in FIG. 5B (F 2 ⁇ F 1 ). Furthermore, since the sheet P 1 and the sheet P 2 are separated, the separation load H is “0”. Accordingly, since a force corresponding to the frictional force F 2 is required in order to maintain the transporting state of the sheet P 1 , a transporting force T 2 in the sheet-transporting state is smaller than a transporting force T 1 (T 2 ⁇ T 1 ). Accordingly, the frictional force f of the roller corresponds to the transporting force T 2 , and hence is smaller than that in the just-before-transport state.
  • the lower end of the first arm 31 pivots clockwise as the frictional force f of the roller decreases, and the upper end of the second arm 32 pivots counterclockwise. Accordingly, the second pivotal portion 62 moves away from the sheet P. Consequently, the arm angle A becomes an angle A 3 between the angle A 1 and the angle A 2 (A 2 ⁇ A 3 ⁇ A 1 ).
  • the angle of inclination B becomes an angle B 3 between the angle B 1 and the angle B 2 (B 1 ⁇ B 3 ⁇ B 2 ).
  • the feed roller 33 is moved toward more upstream side than in the just-before-transport state and toward more downstream side than in the waiting state as the arm angle A and the angle of inclination B vary.
  • the frictional force f of the roller, the transporting force T, the urging force S, and the angle of inclination B vary respectively with the transition thereof from the waiting state to the paper transporting state.
  • the urging force S increases and the angle of inclination B decreases with the increase in the transporting force T (the frictional force f of the roller).
  • the frictional force f of the roller, the urging force S, the transporting force T, and the angle of inclination B are also changed respectively with the difference of the thickness of the sheet P.
  • the separation load H is changed, and hence the frictional force f of the roller is changed correspondingly.
  • the separation load H as shown in FIGS. 8A and 8B is larger in the case of sheets P 3 which are thick like “photo sheets” or “postcards” than in the case of the sheets P 1 which are thin as the normal paper shown in FIGS. 6A and 6B .
  • the frictional force f of the roller is larger in the case where the sheet P 3 is transported in the just-before-transport state than in the case where the sheet P 1 is transported. Accordingly, the transporting force T 3 for transporting the sheet P 3 is larger than the transporting force T 1 , and hence an angle B 4 taken when the sheet P 3 is transported is smaller than the reference angle B 1 taken when the sheet P 1 is transported (B 4 ⁇ B 1 ).
  • the pickup unit 24 includes the first pivotal portion 61 and the second pivotal portion 62 , and also includes the torsion coil spring 35 which exerts an urging force to the second arm 32 , mounted on the second pivotal portion 62 . Accordingly, in the just-before-transport state and the sheet-transporting state, a component force of the frictional force f of the roller is exerted on the second arm 32 as a force to cause the second arm 32 to pivot clockwise. With the action of this force, the first arm 31 pivots counterclockwise about the first pivotal portion 61 and the second arm 32 pivots clockwise about the axis of rotation J of the feed roller 33 , so that the second pivotal portion 62 moves toward the sheets P. Consequently, the angle of inclination B is decreased with the movement of the second pivotal portion 62 in comparison with the waiting state.
  • a restoration force is generated in the torsion coil spring 35 by the movement of the second pivotal portion 62 , and the restoration force of the torsion coil spring 35 exerts an urging force in the direction toward the sheets P on the second arm 32 .
  • This urging force increases in proportion to the increase in the restoration force of the torsion coil spring 35 .
  • the urging force that the torsion coil spring 35 exerts on the second arm 32 is increased and the angle of inclination B is decreased, and hence the degree of increase in the frictional force f of the roller is smaller than the degree of increase in the urging force. Consequently, the frictional force f of the roller can be prevented from being excessive with respect to the inter-sheet frictional force F, whereby multi feed of the sheets P can be restrained.
  • the angle of inclination B corresponding to the above-described acute angle is decreased with increase in the frictional force f of the roller in conjunction with the pivotal movement of the second pivotal portion 62 without changing the position of the supporting shaft 23 . Therefore, occurrence of the digging as described above can be restrained. Therefore, both the downsizing of the transporting apparatus 12 and restraint of the digging are achieved.
  • the acute angle (the angle of inclination B) is set irrespective of the separation load and the inter-sheet frictional force of the sheet Q because the acute angle varies according to the amount of loaded sheets Q. Accordingly, if the amount of loaded sheets Q is small, the frictional force that the sheet Q exerts the feed roller 120 (the frictional force of the roller) is increased even though the separation load or the inter-sheet frictional force is not change.
  • the force to cause the feed roller 33 to dig into the sheet P 1 (f ⁇ sinB) generated by the frictional force f of the roller can be prevented from becoming excessive.
  • the magnitude of the separation load H is different depending on the type of the sheets even when the numbers of the sheets are the same. For example, when comparing the normal sheet and the postcard, the thickness of the postcard is larger than that of the normal sheet. Therefore, the separation load H of the postcard is higher correspondingly.
  • the position of the feed roller 120 can be adjusted according to the number of sheets, but a press-contact force of the feed roller 120 against the sheets cannot be changed according to the types of the sheets. Therefore, when the transporting apparatus 100 is set with reference to the separation load H for the postcard, for example, the multi feed may occur when transporting the normal sheets if the amount of normal sheets is small. In contrast, when the transporting apparatus 100 is set with reference to the separation load H for the normal paper, the feed roller 33 may turn free due to insufficient transporting force T thereof if the amount of thick sheets is small.
  • the transporting force T of the feed roller 33 increases correspondingly.
  • the urging force S of the pickup unit 24 decreases according to the decrease in the separation load H, when the sheets P are thin like the normal sheets, the transporting force T decreases correspondingly. Accordingly, even when the separation load H is different according to the difference in thickness of the sheets P, the multi feed of the sheets P and the free turning of the feed roller 33 can be restrained.
  • the second pivotal portion 62 When the second pivotal portion 62 is provided with a mechanism which restricts the number of sheets P to be placed, the second pivotal portion 62 moves toward or away from the sheets P in association with the pivotal movement of the first arm 31 and the second arm 32 in a circumstance in which the feed roller 33 transports the sheets P. Therefore, the position of the second pivotal portion 62 with respect to the placing surface 21 a changes. Consequently, the position to restrict the number of sheets P to be placed changes as well. Accordingly, the extent of allowable amount of the sheets P to be placed thereon cannot be defined accurately.
  • the curved portion 42 a of the upper cover portion 42 covers the first pivotal portion 61 from the outside in the direction of the radius of the pivotal movement of the first pivotal portion 61 , the position of the curved portion 42 a with respect to the placing surface 21 a does not change even when the first pivotal portion 61 is pivoted. Therefore, the positions of the placing surface 21 a and the curved portion 42 a do not change in the circumstance in which the feed roller 33 transports the sheet P. Accordingly, the maximum amount of sheets P to be loaded (the number of sheets P to be loaded) can be defined accurately.
  • the sheet P is restrained from deviating from the gap G formed by the placing surface 21 a and the curved portion 42 a in the course of the pivotal movement of the first arm 31 .
  • the urging force S is directed toward the downstream side as the urging force S increases, the degree of increase in the component force toward the upstream side of the urging force S becomes small with respect to the degree of increase in the urging force S. Accordingly, the degree of increase in the frictional force f of the roller with respect to the degree of increase in the urging force S decreases. Therefore, the feed roller 33 can be prevented from digging into the sheet P 1 .
  • the first inter-axis distance D 1 between the first pivotal portion 61 and the second pivotal portion 62 may be equivalent to or larger than the second inter-axis distance D 2 between the second pivotal portion 62 and the axis of rotation J of the feed roller 33 .
  • the separation pad 26 may be omitted.
  • the curved portion 42 a of the upper cover portion 42 may be provided over a range smaller than the range of pivotal movement of the first pivotal portion 61 .
  • the curved portion 42 a may also be omitted.
  • the direction of transport of the sheet P may be a direction along the fore-and-aft direction.
  • the feed roller 33 comes into abutment with an upper surface of the sheet P.
  • the second arm 32 is inclined upward as it goes to the upstream side in the direction of transport.
  • the first arm 31 is inclined downward as it goes to the upstream side in the direction of transport.
  • the arm angle A increases and the angle of inclination B decreases. Accordingly, the feed roller 33 moves toward the downstream side in the direction of transport.
  • the restoration force R of the torsion coil spring 35 increases in association with the movement of the feed roller 33 , the urging force S of the feed roller 33 increases.
  • the arm angle A decreases and the angle of inclination B increases in comparison with the just-before-transport state. Accordingly, the feed roller 33 moves toward the upstream side in the direction of transport. Accordingly, the restoration force R of the torsion coil spring 35 decreases, and hence the urging force S of the feed roller 33 decreases correspondingly.
  • the torsion coil spring 35 may be mounted on the first arm 31 .
  • the restoration force R of the torsion coil spring 35 increases and decreases in association with the pivotal movement of the second pivotal portion 62 by fitting both end portions of the torsion coil spring 35 to the first arm 31 an the second arm 32 , respectively.
  • a leaf spring may be employed instead of the torsion coil spring 35 .
  • the restoration force of the leaf spring increases and decreases because the leaf spring is bent in association with the pivotal movement of the second pivotal portion 62 by fitting the both end portions of the leaf spring to the first arm 31 and the second arm 32 , respectively.
  • a coil spring may be employed instead of the torsion coil spring 35 .
  • the restoration force of the coil spring increases and decreases because the leaf spring is expanded in association with the pivotal movement of the second pivotal portion 62 by fitting both end portions of the coil spring to the first arm 31 an the second arm 32 , respectively.
  • a configuration in which a shaft portion corresponding to the second shaft portion 54 is provided on the first arm 31 as a second fitting portion and a second shaft member, and a bearing portion corresponding to the second bearing portion 45 is provided on the second arm 32 is also applicable.
  • the pickup unit 24 may be provided on a part of the placing tray 21 or other portion of the printer 11 .
  • the above-described portion and the first bearing portion 43 constitute a first pivotal portion.
  • a configuration in which the above-described portion is formed into a shape corresponding to the first bearing portion 43 and a shaft potion to be fitted to the above-described portion is provided on the first arm 31 is also applicable.
  • sheets other than the normal sheets, the photo sheets, and the postcards such as OHP, for example may be transported as the transported media that the transporting apparatus 12 transports.
  • the transporting apparatus 12 is not limited to be applied to the ink jet printer 11 , and may be applied, for example, to a dot-impact printer, a laser printer, a thermal-transfer printer, and so on.
  • the application of the transporting apparatus 12 is not limited to the printer, and the transporting apparatus 12 may be applied to other apparatuses which transport the transported media.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
  • Delivering By Means Of Belts And Rollers (AREA)
US13/081,137 2010-04-06 2011-04-06 Transportation apparatus Abandoned US20110241282A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-088038 2010-04-06
JP2010088038A JP2011219203A (ja) 2010-04-06 2010-04-06 搬送装置

Publications (1)

Publication Number Publication Date
US20110241282A1 true US20110241282A1 (en) 2011-10-06

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ID=44708709

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/081,137 Abandoned US20110241282A1 (en) 2010-04-06 2011-04-06 Transportation apparatus

Country Status (3)

Country Link
US (1) US20110241282A1 (ja)
JP (1) JP2011219203A (ja)
CN (1) CN102211470A (ja)

Cited By (4)

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Publication number Priority date Publication date Assignee Title
US20130285308A1 (en) * 2012-04-27 2013-10-31 Seiko Epson Corporation Recording medium feeding device and recording apparatus
US20130320611A1 (en) * 2012-06-01 2013-12-05 Ricoh Company, Ltd Sheet conveying device, image reading device, and image forming apparatus
US20160169364A1 (en) * 2014-12-11 2016-06-16 Canon Kabushiki Kaisha Drive transmission device for transmitting rotary drive
CN112653804A (zh) * 2020-02-26 2021-04-13 虹光精密工业（苏州）有限公司 可感应媒体的影像形成装置以及相关的媒体感应机构

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6880927B2 (ja) * 2017-03-30 2021-06-02 ブラザー工業株式会社 シート給送装置

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US6503010B2 (en) * 2000-05-31 2003-01-07 Samsung Electronics Co., Ltd. Paper pickup apparatus for a printer
US20080150220A1 (en) * 2006-12-20 2008-06-26 Dean Alan Eltzroth Friction Backup Roller for Media Picking

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Publication number Priority date Publication date Assignee Title
JP3738497B2 (ja) * 1996-10-15 2006-01-25 ブラザー工業株式会社 給紙装置およびそれを備えた印字装置
US7370857B2 (en) * 2003-05-02 2008-05-13 Seiko Epson Corporation Paper feeding apparatus
KR100692573B1 (ko) * 2005-08-31 2007-03-13 삼성전자주식회사 화상형성기기의 급지장치

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6503010B2 (en) * 2000-05-31 2003-01-07 Samsung Electronics Co., Ltd. Paper pickup apparatus for a printer
US20080150220A1 (en) * 2006-12-20 2008-06-26 Dean Alan Eltzroth Friction Backup Roller for Media Picking

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130285308A1 (en) * 2012-04-27 2013-10-31 Seiko Epson Corporation Recording medium feeding device and recording apparatus
US8764005B2 (en) * 2012-04-27 2014-07-01 Seiko Epson Corporation Recording medium feeding device and recording apparatus
US20130320611A1 (en) * 2012-06-01 2013-12-05 Ricoh Company, Ltd Sheet conveying device, image reading device, and image forming apparatus
US8925913B2 (en) * 2012-06-01 2015-01-06 Ricoh Company, Limited Sheet conveying device, image reading device, and image forming apparatus
US20160169364A1 (en) * 2014-12-11 2016-06-16 Canon Kabushiki Kaisha Drive transmission device for transmitting rotary drive
US10502304B2 (en) * 2014-12-11 2019-12-10 Canon Kabushiki Kaisha Drive transmission device for transmitting rotary drive
CN112653804A (zh) * 2020-02-26 2021-04-13 虹光精密工业（苏州）有限公司 可感应媒体的影像形成装置以及相关的媒体感应机构

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Publication number Publication date
CN102211470A (zh) 2011-10-12
JP2011219203A (ja) 2011-11-04

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