JP3498518B2 - Paper feeder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus, and more particularly, to a sheet feeding apparatus for feeding a plurality of sheets stacked in a stacking unit one by one to the next step. .

[0002]

2. Description of the Related Art As an image forming apparatus for forming images corresponding to sheets of different sizes, one capable of feeding sheets of different sizes with one sheet feeder is adopted.

A sheet feeding device 13 shown in FIGS. 13 and 14.
No. 0 (see Japanese Utility Model Laid-Open No. 55-16903), two pairs of feeding rolls 134 and 136 having different diameters are provided on the drive shaft 132.
Is attached. When a wide sheet is conveyed, only the outer feeding roll pair 134 contacts the uppermost sheet as shown in FIG. At this time, the pair of feeding rolls 13
4 and the separation claw 138, there is a predetermined space (a space in the left-right direction in the drawing) in which the conveyed paper can be looped. On the other hand, as shown in FIG. 14, when a narrow sheet is conveyed, the separation claw 138 and the side plate 140 are brought close to each other according to the width of the sheet. The paper does not contact the outer feed roll pair 134, but only the inner feed roll pair 136. At this time, there is a predetermined space between the feeding roll pair 136 and the separating claw 138 so that the paper can be looped, and the feeding roll pair 13 on the outer side is present.
No. 4 is not in contact with the paper.

However, in this paper feeding device 130, since the feeding roll pair 134 and the feeding roll pair 136 have different radii, the conveyance speed differs between the wide paper and the narrow paper. For this reason, in order to convey the sheet at a constant speed in the main body of the image forming apparatus, it is necessary to separately provide a mechanism for keeping the conveying speed constant, which causes an increase in cost and an increase in the number of parts.

A sheet feeding device 150 shown in FIG. 15 has been proposed (see Japanese Patent Publication No. 58-113045).

In this sheet feeding device 150, the drive shaft 15 is provided on both sides of a placing plate (not shown) on which a sheet is placed in the width direction.
2 and the driven shaft 154 are erected. Pulleys 156 and 158 are attached to the upper ends of the drive shaft 152 and the driven shaft 154, and an endless belt 160 is stretched around the pulleys 156 and 158. In addition, the endless belt 160
Are blocks 162, 164 arranged above the mounting plate.
Through the insertion hole 166. Of the endless belt 160, the portion located on the upper side of the paper is fixed to the block 162 but not fixed to the block 164.
On the contrary, the portion of the endless belt 160 located on the lower side of the paper surface is fixed to the block 164 and not fixed to the block 162. The blocks 162 and 164 are provided with a feed roll 168 that conveys a sheet.

Therefore, by rotating the drive shaft 152 by a drive means (not shown), the blocks 162, 1
64 can be brought into and out of contact with each other to accommodate sheets of different widths. Since one conveyance roll 168 conveys sheets of different widths, the conveyance speed of the wide sheet and the narrow sheet becomes constant.

However, in the paper feeding device 150, the drive shaft 152, the driven shaft 154, the endless belt 160, the blocks 162, 164, etc. are required, so that the number of parts is increased. Further, a driving means for driving the drive shaft 152 is also required, which complicates the structure and increases the cost.

[0009]

SUMMARY OF THE INVENTION In consideration of such a fact, the present invention has an object to obtain a sheet feeding device which can convey sheets of different sizes at a constant speed with a simple mechanism. To do.

[0010]

According to a first aspect of the present invention, there is provided a sheet feeding device which feeds a plurality of sheets placed in a stacked state on a placing section one by one to the next step. A plurality of feeding rolls arranged along the width direction of the sheets placed on the placing section to feed the sheets by rotation, and a feeding of the sheets placed in a stacked state on the placing section. In the corner on the downstream side in the direction,
The separation claw that comes into contact with the stacking part from the opposite side, and the sheet between the separation claw of the plurality of feeding rolls corresponding to the width of the sheets stacked in the stacking part. Selective means for selecting and rotating the feeding roll that causes a loop on the paper, and the width of these multiple papers located at the widthwise edge of the paper.
A width aligning member that restricts directional movement,
A step is disposed between the width aligning member and the feeding roll.
And the width aligning members contact each other,
Rotate this feed roll by engaging it with a specific feed roll
It becomes impossible and the feed roll is rotated by separating the width alignment member.
It is a link member that enables it .

[0011] The sheets stacked on the stacking unit
However, the width alignment member is positioned in the width direction of the paper,
Limit the movement in the width direction. Further , the separation claw comes into contact with the corner of the sheet on the downstream side in the feeding direction from the side opposite to the placing section. Aligned width
When the link member contacts the link member, the link
The locking member engages with a specific feed roll to
Disables rotation. Also, if the width alignment member is a link member
When separated from this, the feeding roll can be rotated. others
Therefore, among the plurality of feeding rolls arranged in the width direction of the sheet, the feeding roll that causes a loop in the sheet is rotated. As a result, a loop occurs in the portion of the sheet between the feeding roll and the separation claw, and the sheet in which the loop occurs can be separated from other sheets. When the width of the sheets placed on the placing section is different, the selecting unit rotates the feeding roll that causes a loop between the sheets and the separating claw in accordance with the width. Therefore, even if the widths of the sheets are different, it is possible to cause a loop in the sheet and separate the sheet from other sheets. Since the radius of the plurality of feeding rolls can be made constant, the sheet conveying speed becomes constant without providing a means for making the feeding speed of the paper to the next process constant. Further, since the interval between the transport rolls is not expanded or contracted in accordance with the width of the paper, a member for that is not required, the number of parts is reduced, and the structure is simplified. Moreover, just move the width alignment member
The feed roller via the link member according to the width of the paper.
The lever can be rotatable or non-rotatable.

According to a second aspect of the present invention, in the first aspect of the invention, the link member is a wide sheet.
When transporting, the feed roll on the outside of the paper width direction and the paper width
The feed roll on the inside in the direction can be rotated, and narrow paper can be
When feeding, do not rotate the feeding roll on the outer side in the paper width direction.
Only the feed roll inside the paper width direction can be rotated.
Characterized in that that.

[0013]

Although the link member may directly engage the feed roll to make the feed roll non-rotatable, it may be indirectly engaged with the feed roll via another member, and the feed roll may be rotated. May be non-rotatable.

[0015]

[0016]

[0017]

1 to 3 show a sheet feeding device 10 according to an embodiment of the present invention.

The sheet feeding device 10 is formed in a substantially box shape,
It has a cassette 12 whose top surface is open. Cassette 1
2 is slid from the right side of FIGS. 1 and 2 and is accommodated in an accommodating portion (both not shown) provided in the image recording apparatus.

One or more sheets P or sheets Q (see FIG. 6) narrower than the sheets P are accommodated in the cassette 12, and the sheets P or the sheets Q are used in the image recording apparatus. It is fed one by one. Hereinafter, the direction in which the sheets P and Q are fed is indicated by arrow A, and the width direction of the sheets P and Q is indicated by arrow B. Further, when simply referred to as “feed direction”, it means the feed direction of the sheets P and Q, and when simply referred to as “width direction”, it means the width direction of the sheets P and Q. (Note that in FIGS. 1 to 5, the paper P is the cassette 1
2 shows the state of being housed in the cassette 2, and FIGS. 6 to 11 show the state of the sheet Q being housed in the cassette 12. ) At the bottom of the cassette 12, a mounting plate 14 on which the sheets P are stacked is placed. As shown in FIGS. 1 and 2, a shaft support plate 16 is erected on the upstream side of the mounting plate 14 in the feeding direction, substantially vertically upward from both sides in the width direction. The cassette 1 is inserted into the shaft hole 18 (see FIG. 2) formed in the shaft support plate 16.
A projecting shaft 22 that projects inward from the second side plate 20 is accommodated, and the mounting plate 14 is swingably supported about the projecting shaft 22. Also, the bottom plate 2 of the cassette 12
The compression coil spring 26 attached to the mounting plate 14
Is urged to rotate in the counterclockwise direction (arrow C direction) in FIG. When the cassette 12 is pulled out from the accommodating portion, rotation of the mounting plate 14 in the counterclockwise direction in FIG. 2 is restricted by a stopper (not shown), but when the cassette 12 is accommodated in the accommodating portion, the stopper is removed, Mounting plate 1
4 is rotated counterclockwise in FIG. 2 by the urging force of the compression coil spring 26. This rotation causes the uppermost sheet P1 among the sheets P.
Is stopped by hitting a separating claw 38 described later.

At the center of the mounting plate 14 in the width direction (arrow B direction), a rectangular recess 28 is formed from the end portion on the upstream side (left side in FIG. 1) in the feeding direction toward the downstream side. The rear end aligning plate 32 is accommodated in the recess 28 so as to be slidable in the feeding direction (direction of arrow A) and the opposite direction. The trailing edge of the sheet P placed on the placing plate 14 is the trailing edge aligning plate 32.
Will be aligned. By sliding the trailing edge aligning plate 32 in the feeding direction, sheets of different lengths (for example, sheet Q)
Can be placed on the placing plate 14 and housed in the cassette 12 (see FIG. 6).

A rectangular recess 30 is formed in the mounting plate 14 substantially in the center in the feeding direction (arrow A direction) from both ends in the width direction (arrow B direction) toward the center. In this recess 30, the feeding direction is the longitudinal direction, and the cassette 12
A width aligning plate 34 that is erected vertically upward from the bottom surface 24 of the is accommodated. The width aligning plate 34 contacts both ends in the width direction of the paper P placed on the placing plate 14 and aligns the paper P in the width direction.
Further, the width aligning plate 34 is slidable in the width direction along a guide rail (not shown) formed on the bottom plate 24 of the cassette 12, and by sliding in this manner, the gap between the width aligning plates 34 is increased. By expanding and contracting, sheets of different widths can be placed on the placing plate 14 and housed in the cassette 12.

The upper end of the width aligning plate 34 is bent inwardly at a substantially right angle to form a height limiting plate portion 36, and the height limiting plate portion 36 allows the paper P placed on the placing plate 14 to be conveyed. Maximum height is fixed.

Of the sheets P placed on the placing plate 14, a separation claw 38 having a substantially triangular shape in plan view is in contact with a corner of the uppermost sheet P1 on the downstream side in the feeding direction. The left and right separating claws 38 are connected to each other by the connecting plate portions (not shown) that extend from the left and right width aligning plates 34 to the lower side of the mounting plate 14 and extend downstream. The separation claw 38 and the separation claw 38 slide together. Therefore, when the space between the width aligning plates 34 is expanded or contracted, the separation claw 3
The intervals between the eight widths are also expanded / contracted while matching the intervals between the width alignment plates 34.

The separation claw 38 is a pair of paper feed rolls 4 which will be described later.
When the arcuate surfaces 46 and 48 of the pair of paper feed rolls 42 and 44 come into contact with the uppermost sheet P1 by the rotation of 2, 44, and the sheet P1 is conveyed in the feeding direction (direction of arrow A), the sheet P1 hits the sheet P1. It causes resistance to the conveyance of P1. Thus, for example, in the case of wide paper, as shown in FIG.
Both ends of the paper P1 on the downstream side in the feeding direction are provided with the paper feed roll pair 42.
While being left on the upstream side in the feeding direction with respect to the contacting portion of the circular arc surface 46, it is guided inward by the hypotenuse 38A of the separating claw 38 and both ends of the sheet P1 on the downstream side in the feeding direction and the pair of paper feed rolls. A loop PR is generated in the sheet P1 by curving upward between the portion in contact with 42. At this time, the paper P
The paper P below 1 may also have a loop, but the frictional force between the paper P1 and the paper P below the paper P1 is
Since the frictional force between 1 and the circular arc surface 46 is smaller than the frictional force between the circular arc surface 46 and the circular arc surface 46, the sheets P other than the sheet P1 are dropped and the sheet P1 is separated. When the paper feed roll pair 42 is further rotated, both ends of the paper P1 on the downstream side in the feeding direction are separated from the separation claw 38 and jumped up, and the paper P1 can be fed.

In the case of a narrow sheet, both ends of the uppermost sheet Q1 on the downstream side in the feeding direction are guided inward by the oblique side 38A of the separating claw 38, and as shown in FIG. 11, the sheet Q1 is fed in the feeding direction. Since the space between the both ends on the downstream side and the portion where the pair of paper feed rolls 44 are in contact with each other is curved upward to form a loop QR on the sheet Q1, the uppermost sheet Q1 is separated.

A paper feed roll shaft 40 having a longitudinal direction in the width direction (arrow B direction) is provided above the cassette 12 on the downstream side in the feeding direction. This paper feed roll shaft 40
Is rotated in the counterclockwise direction (arrow D direction) in FIG. 4 by a driving unit such as a motor (not shown).

On the paper feed roll shaft 40, two pairs of paper feed rolls 42 and 44 are arranged. As shown in FIGS. 2 and 4, these paper feed roll pairs 42 and 44 are substantially semicircular in side view (in FIGS. 2 and 4, the feed roll pair 44 is shown in FIG. 2 and FIG. 4).
Is omitted from the drawing), which is a so-called half-moon roll having a predetermined thickness in the same direction as the longitudinal direction of the paper feed roll shaft 40 (width direction of the paper B). Further, the four half-moon rolls forming the paper feed roll pair 42, 44 have the same shape.

A spring clutch 50 that allows the paper feed roll pair 42 to rotate integrally with the paper feed roll shaft 40 or does not rotate is attached to the outer paper feed roll pair 42 coaxially with the paper feed roll pair 42. Has been. As shown in detail in FIG. 12, the spring clutch 50 includes a spring winding tightening portion 76 formed by enlarging a diameter of a part of the paper feed roll shaft 40 and a half-moon roll forming a pair of paper feed rolls 42 to the side. And a spring winding portion 78 having an outer diameter equal to that of the spring winding tightening portion 76, while the paper feeding roll shaft 42 is loosely inserted inside.
Spring winding tightening portion 76 and spring winding portion 78
Are adjacent to each other, and both are surrounded by a cylindrical collar 80 from the outside. Further, the collar 80 is fixed to the paper feed roll pair 42 and rotates integrally with the paper feed roll pair 42. A single torsion coil spring 82 is wound around the spring winding tightening portion 76 and the spring winding portion 78 to tighten both the spring winding tightening portion 76 and the spring winding portion 78, and the paper feed roll shaft 40 and the paper feed. The roll pair 42 and the roll pair 42 rotate together. One end of the torsion coil spring 82 is fixed to the spring winding portion 76 and the other end is fixed to the collar 80.
The paper feed roll shaft 40 rotates, and together with this, the paper feed roll pair 4
When the rotation of the collar 80 is stopped in a state where the collar 2 is rotating, one end of the torsion coil spring 82 rotates together with the spring winding portion 76, but the other end fixed to the collar 80 stops rotation. The torsion coil spring 82 loosens and separates from the spring winding portion 78. For this reason, the paper feed roll pair 42 is also separated from the paper feed roll shaft 40, and the rotation is stopped.

As shown in FIGS. 2 and 4, a plurality of gears 52 are formed on the outer periphery of the collar 80 of the spring clutch 50. A link 60, which will be described later, is attached to the gear 52.
The engaging piece 72 of is engaged to stop the rotation of the collar 80,
The rotation of the paper feed roll pair 42 is also stopped.

The paper feed roll pair 42, as shown in FIG.
A wide paper P is accommodated in the cassette 12, and the paper P1 between the separation pawl 38 and the paper feed roll pair 42 is in a state where the separation pawl 38 is in contact with the corner of the uppermost paper P1 on the downstream side in the feeding direction.
It is set at a position where a predetermined interval is formed in which a loop can be generated. That is, when the paper feed roll pair 42 rotates in this state and the paper P1 is conveyed by the friction between the arcuate surface 46 and the paper P1, the part of the paper P1 that the separation claw 38 contacts and the part that the arcuate surface 46 contacts. A loop PR occurs between and. The spring clutch 50 is immovable in the axial direction of the paper feed roll shaft 40. For this reason,
The paper feed roll pair 42 also does not move in the axial direction of the paper feed roll shaft 40 and is maintained at a predetermined position.

On the other hand, the inner paper feed roll pair 44 is shown in FIG.
As shown in FIG. 6, the narrow sheet Q is accommodated in the cassette 12, and the separation claw 38 and the transport roll pair 44 are in a state where the separation claw 38 is in contact with the corner of the uppermost sheet Q1 on the downstream side in the feeding direction.
Is fixed to the paper feed roll shaft 40 at a position where a predetermined interval is formed between the sheet Q1 and the sheet Q1 where a loop can be generated.
That is, when the paper feed roll pair 44 rotates in this state and the sheet Q1 is conveyed by the friction between the arc surface 48 and the sheet Q1, the portion of the sheet Q1 where the separation claw 38 is in contact with the portion where the arc surface 48 is in contact. A loop QR occurs between and.

Further, the paper feed roll pair 42, 44 is made up of the paper P.
Alternatively, when the sheet Q is not conveyed, the arcuate surfaces 46 and 48 are on standby while facing upward, but when the pair of paper feed rolls 42 and 44 is rotated by the rotation of the paper feed roll shaft 40, the arcuate surfaces 46 and 48 are lowered. The sheets P, Q located on the side and lifted upward by the compression coil spring 26 come into contact. An anti-slip material formed in a corrugated shape with rubber or the like is attached to the arc surfaces 46 and 48, and the arc surfaces 46 and 48 come into contact with the paper sheets P and Q to rotate, whereby the paper sheets P and Q are rotated. Be transported. When the pair of paper feed rolls 42, 44 is further rotated, the circular arc surface 46,
48 separates from the papers P and Q, but at this time, the leading ends of the papers P and Q have already been sandwiched by, for example, a pair of conveyor rolls provided in the image recording apparatus, and therefore the papers are continuously conveyed.
Further, a motor (not shown) for rotating the paper feed roll shaft 40 does not fail to rotate the arc surface 4 in the standby state of the paper feed roll pair 42, 44.
The control means (not shown) controls so that the reference numerals 6 and 48 face upward.

As shown in FIGS. 1, 2 and 4, two supporting columns 56 are provided so as to project downward from a ceiling plate 54 which constitutes a housing portion of an image recording apparatus (not shown). A support shaft 58 is formed at the lower end of the support column 56 in the same direction as the width direction of the paper P (arrow A direction), and the support shaft 58 is provided at a substantially middle portion of the link 60. The link 60 is rotatable around the support shaft 58.

From the axially outer end of the support cylinder 62, an upstream arm 64 extends toward the upstream side in the feeding direction, and the tip of the upstream arm 64 is widened downward and is lowered. A contact portion 66 having a rounded edge is formed. As shown in FIG. 6, a narrow sheet of paper Q is placed on the placing plate 14.
9 is placed and the width aligning plates 34 hit both sides of the sheet Q, and as shown in FIG. 9, a substantially trapezoidal projection protruding upward from the downstream end of the height limiting plate 36. Abutting part 6 on 68
The length of the upstream arm 64 and the position of the support column 56 are determined so that the 6 contacts.

On the other hand, a downstream arm 70 extends from the inner end of the support tube 62 toward the downstream side in the feeding direction. At the tip of the downstream arm 70, an engaging piece 72 that is bent downward at a substantially right angle and that engages with the gear 52 of the collar 80 that constitutes the spring clutch 50 is formed. Figure 9
As shown in FIG.
In the state where 6 is in contact, the engagement piece 72 engages with the gear 52 to prevent the collar 80 from rotating. As a result, the rotation of the paper feed roll pair 42 is also stopped.

The link 60 is heavier on the upstream side in the feeding direction than on the downstream side in the feeding direction, and the link 60 tries to rotate in the counterclockwise direction (arrow E direction) in FIG. 8 from the horizontal state. This rotation is stopped by hitting the tip of the downstream arm 70 against the pressing protrusion 74 protruding downward from the ceiling plate 54. Therefore, in a normal state, the tip end portion of the upstream arm 64 has the uppermost sheet P placed on the placing plate 14.
It does not hit 1 or Q1 or enter the movement track of the width aligning plate 34. An elastic body that rotates the link 60 in the counterclockwise direction in FIG. 8 (direction of arrow E) may be provided.

Next, the sheet feeding device 1 according to the present embodiment
The action of 0 will be described. As shown in FIGS. 1 to 5, when a wide sheet P is conveyed, the cassette 12 is pulled out from a storage unit (not shown), the sheet P is placed on the placing plate 14, and then the trailing edge aligning plate 32 is placed. And slide it against the rear end of the paper P in the feeding direction. Similarly, the width aligning plate 34 is slid and applied to both ends of the paper P in the width direction. Alternatively, the trailing edge aligning plate 32 and the width aligning plate 3 are preliminarily adjusted to the size of the paper P.
It is also possible to set the sheet 4 at a predetermined position, bend the sheets P appropriately in an aligned state, and place the sheet P on the placing plate 14. At this time, the separation claw 38 is in contact with the corner of the uppermost sheet P1 on the downstream side in the feeding direction.

When the cassette 12 is accommodated in the accommodating portion, a stopper (not shown) is removed, and the placing plate 14 is rotated counterclockwise in FIG. 2 (arrow C direction) by the urging force of the compression coil spring 26. The rotation is stopped by the uppermost sheet P1 hitting the separation claw 38.

In this state, the projection 68 formed on the height limiting plate portion 36 of the width aligning plate 34 is not in contact with the contact portion 66 of the upstream arm 64 which constitutes the link 60. Therefore, the link 60 rotates counterclockwise in FIG. 2 (arrow E direction) due to its own balance. This rotation is
The tip of the downstream arm 70 hits the pressing protrusion 74 and is stopped. Therefore, the engagement piece 72 of the downstream arm 70
Is not engaged with the gear 52 of the collar 82 that constitutes the spring clutch 50, the paper feed roll pair 42 is rotatable integrally with the paper feed roll shaft 40.

Here, when the paper feed roll shaft 40 is rotated once or a plurality of times in the counterclockwise direction in FIG. 4 (direction of arrow D),
This rotation is transmitted to the paper feed roll pair 42 via the spring clutch 50, and the paper feed roll pair 42 rotates. Also,
The rotation of the paper feed roll shaft 40 is also directly transmitted to the transport roll pair 44, and the transport roll pair 44 rotates. by this,
The arc surfaces 46 and 48 of the pair of paper feed rolls 42 and 44 come down and come into contact with the uppermost sheet P1, and the friction between the arc surfaces 46 and 48 and the sheet P1 causes the sheet P1 to move in the feeding direction (arrow A).
Direction).

As shown in FIG. 5, when the paper P1 is conveyed, the paper feed roll pair 42 and the separating claw 3 of the paper P1 are conveyed.
8 and the portion located between 8 and 8 bends upward to form a loop. Therefore, the uppermost sheet P1 is the other sheet P
And is conveyed to an image recording device (not shown).

As shown in FIGS. 6 to 11, a narrow sheet Q
Similarly to the case of conveying a wide sheet P, the cassette 12 is pulled out from the accommodating portion (not shown), the sheet Q is placed on the placing plate 14, and the rear end of the sheet Q in the feeding direction is conveyed. Apply the rear end aligning plate 32 to the width aligning plate 3 at both ends in the width direction.
Hit 4 The trailing edge aligning plate 32 and the width aligning plate 34 may be set at predetermined positions according to the size of the sheet Q in advance, and the sheets Q may be placed on the placing plate 14 in an aligned state. At this time, the separation claw 38 is in contact with the corner of the uppermost sheet Q1 on the downstream side in the feeding direction.

As shown in FIG. 8, when the cassette 12 is slid from the right side to the left side in FIG. 8 to be accommodated in the accommodating portion, the projection 68 of the height limiting plate portion 36 of the width aligning plate 34 is linked to the protrusion 68 in the middle thereof. The contact portion 66 of the downstream arm 70 of 60 abuts. When the cassette 12 is further slid,
As shown in FIG. 8, since the contact portion 66 rides on the protrusion 68, the link 60 slightly rotates clockwise in the counterclockwise direction (arrow E direction) in FIG. 8 due to its own balance. The engaging piece 72 of the downstream arm 70 engages with the gear 52 of the collar 80. As a result, the paper feed roll pair 42 cannot rotate.

When the paper feed roll shaft 40 is rotated counterclockwise in FIG. 9 (direction of arrow D), the paper feed roll pair 42 does not rotate, and the rotation is transmitted only to the transport roll pair 44, so that the transport roll pair 44 is formed. Rotate. As a result, the transport roll pair 4
The circular arc surface 48 of 4 comes down to contact the uppermost sheet Q1, and the friction between the circular surface 48 and the sheet Q1 causes the sheet Q1.
Are conveyed in the feeding direction (arrow A direction).

As shown in FIG. 11, when the sheet Q1 is conveyed, a portion of the sheet Q1 located between the paper feed roll pair 44 and the separating claw 38 is curved upward to form a loop. It At this time, since the paper feed roll pair 42 does not rotate, the arc surface 46 of the paper feed roll pair 42 does not come into contact with the portion where the loop is formed from above to prevent the occurrence of the loop. Therefore, the uppermost sheet Q1 is separated from the other sheets Q and conveyed to the image recording apparatus (not shown).

As described above, in the sheet feeding device 10 according to the present embodiment, the width aligning plate 3 is adjusted according to the width of the sheet to be conveyed.
When the cassette 12 is accommodated in the accommodating portion simply by sliding 4 to expand / contract the space, the link 60 is rotated, and the outer paper feed roll pair 42 is rotatably or unrotatably mounted on the mounting plate 14. A loop can be generated in the uppermost sheet of the placed sheets. Unlike the conventional case, since the space between the pair of paper feed rolls 42 or 44 is not expanded or contracted, a mechanism therefor is not required and the structure of the paper feeding apparatus 10 is simplified.

Further, since the pair of paper feed rolls 42 and 44 are composed of half-moon rolls having the same diameter, the case where the wide paper P is conveyed by the pair of paper feed rolls 42 and 44 and the narrow paper Q is conveyed. The sheet conveyance speed is the same as when the sheet is conveyed only by the pair of conveyance rolls 44. Therefore, it is not necessary to separately provide a mechanism for keeping the sheet conveyance speed constant.

In the present embodiment, the link 6
With the rotation of 0, the engagement piece 72 moves the spring clutch 50.
The outer paper feed roll pair 42 is non-rotatable by engaging with the gear 52 of the collar 80 constituting the above, but the means for making the outer paper feed roll pair 42 non-rotatable is the link 60 that rotates in this way. However, the present invention is not limited to this, as long as the conveyance roll pair that causes a loop between the separation claw 38 and the separation claw 38 can be rotated and the conveyance roll pair that prevents the occurrence of the loop cannot be rotated according to the width of the sheet. Good. For example, when the link 60 slides in the feeding direction, the collar 80 of the spring clutch 50
The gear 52 may be engaged. Alternatively, the link 60 may hit or engage to make a specific transport roll pair rotatable among a plurality of transport roll pairs that are normally incapable of rotation.

Further, all the pairs of feeding rolls are provided with the spring clutch 50, and the links 6 are correspondingly provided.
A plurality of 0s may be provided, and all the feed roll pairs may be controlled to be rotatable or non-rotatable according to the width of the paper, the distance between the feed roll pairs and the separation claws, and the like.

Further, in the present embodiment, two pairs of paper feed rolls 42 and 44 are attached to the paper feed roll shaft 40 so that papers of two kinds of widths (a wide paper P and a narrow paper Q) are provided. ) And the sheet feeding device 10 capable of transporting, are shown, but more pairs of transport rolls are attached to the drive shaft,
You may make it possible to correspond to the paper of various widths. Further, it is not necessary to form a pair of feeding rolls by pairing two half-moon rolls, one feeding roll is formed by one half-moon roll, and this feeding roll is, for example, in the axial direction of the feeding roll shaft 40. It may be provided on only one side. Further, the width aligning plate 34 and the separation claw 38 do not have to slide in the width direction and may be fixed.

In addition, the pair of paper feed rolls 42, 44 need not be constituted by a half-moon roll, but may be anything that comes into contact with or separates from the uppermost paper at a predetermined rotation angle.

[0052]

Since the present invention is constructed as described above, it is possible to convey sheets of different sizes at a constant speed with a simple mechanism.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which wide sheets are accommodated in a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a side view showing a state in which wide sheets are accommodated in the sheet feeding device according to the embodiment of the present invention.

FIG. 3 is a front view showing a state in which wide sheets are accommodated in the sheet feeding device according to the embodiment of the present invention.

FIG. 4 is an enlarged side view of the main part of the sheet feeding device according to the embodiment of the present invention in which wide sheets are accommodated.

FIG. 5 is a front view showing a state in which wide sheets are fed by the sheet feeding device according to the embodiment of the present invention.

FIG. 6 is a plan view showing a state in which a narrow sheet is accommodated in the sheet feeding device according to the embodiment of the present invention.

FIG. 7 is a side view of a sheet feeding device according to an embodiment of the present invention in which narrow sheets are accommodated.

FIG. 8 is an enlarged view of a main part of a process of accommodating the cassette of the sheet feeding device in the accommodating portion of the image forming apparatus in a state where the narrow sheet is accommodated in the sheet feeding device according to the embodiment of the invention. It is a side view.

FIG. 9 is an enlarged side view of a main portion of a sheet feeding device according to an embodiment of the present invention in which narrow sheets are accommodated.

FIG. 10 is a plan view showing a state where a narrow sheet is fed by the sheet feeding device according to the embodiment of the present invention.

FIG. 11 is a front view showing a state in which a narrow sheet is fed by the sheet feeding device according to the embodiment of the present invention.

FIG. 12 is a cross-sectional view of a spring clutch used in the sheet feeding device according to the embodiment of the invention.

FIG. 13 is a plan view of a conventional sheet feeding device.

FIG. 14 is a front view of a conventional sheet feeding device.

FIG. 15 is a front view of a conventional sheet feeding device.

[Explanation of symbols]

10 Paper feeder 34 Width alignment plate (width alignment member) 38 Separated nail 42 Paper feed roll pair (feed roll) 44 Paper feed roll pair (feed roll) 50 Spring clutch (selection means) 60 links (link members, selection means) 68 Protrusion (selection means)

Claims (2)

(57) [Claims] 1. A sheet feeding device for feeding a plurality of sheets placed in a stacked state on a placing section to the next step one by one, the sheet feeding apparatus comprising: A plurality of feeding rolls arranged along the width direction to feed the paper by rotation, and a corner on the downstream side in the feeding direction of the sheets stacked in the above-mentioned stacking section, opposite to the stacking section. A sheet is looped between the separation claw that comes into contact with the side and the separation claw of the plurality of feeding rolls corresponding to the width of the sheets stacked in the stacking unit. Selection means for selecting and rotating the feeding roll, and a width direction of the plurality of sheets positioned at an end portion in the width direction of the sheet.
A width aligning member for restricting movement , wherein the selecting means has a width aligning member and the feed roll.
Placed in between, the width alignment members contact each other to feed
This feed roll engages with a specific feed roll of the rolls.
Of the feed roller by making the roll non-rotatable and separating the width alignment member.
A sheet feeding device, wherein the sheet feeding device is a link member that allows the roll to rotate . 2. The link member conveys a wide sheet.
Paper roll in the paper width direction and inside the paper width direction
Side feed roll can be rotated to convey narrow paper
Paper feed roll outside the paper width direction
The sheet feeding device according to claim 1, wherein only the feeding roll inside the sheet width direction is rotatable .