JPH0829840B2 - Automatic paper feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic paper feeder for supplying paper to a printer printing section.

[Conventional technology]

Generally, a printer is provided with an automatic paper feeder for supplying paper to a printer printing unit.

FIG. 9 and FIG. 10 show such an automatic sheet feeding device, and in the figure, reference numeral 101 is a sheet feeding device for stacking sheets 102 on a bearing surface 103 and storing the sheets 102 in a leaning state. A paper stacker is shown.

The paper stacker 101 includes a right stacker 104 and a left stacker.
105 and pressure plates 104a and 105a, respectively.
The left and right stackers 104 and 105 are movable along the bearing surface 103.

The left and right stackers 104 and 105 are the coil spring 1
It is urged forward by the pressing means consisting of 06 and acts as a pressure plate.

The brackets 109 of the corner separators 108 are rotatably supported on the side plates 107 of the left and right stackers 104 and 105, respectively, and the corner separators 108 are arranged so as to project forward from the lower surface of the bearing surface 103.

Then, one end of the paper feed roller shaft 110 is inserted into the side plates 107 of the left and right stackers 104 and 105, respectively.
Are arranged horizontally, and the paper feed roller shaft 110 is
A paper feed roller 1 that separates the paper sheets 102 stored in the paper feed stacker 101 one by one and sends them to the platen 112 of the printer printing unit 1.
11,111 is stuck.

In front of the paper feed roller 111, a paper output stacker 1 for accommodating the printed paper 102 that has passed through the platen 112 and is stacked on the rear wall 113 for the paper output stacker while being stacked at a predetermined interval.
14 are arranged.

In the paper feed stacker 101, the lower end of the paper 102 is supported by the bearing surface 10 while supporting the paper 102 on the left and right stackers 104 and 105 that act as pressure plates in a leaning state.
3 is placed on the left and right stackers 104, 10 when the paper 102 is fed.
The sheet 102 stacked on the sheet 5 is pressed against the sheet feeding rollers 111, 111 by the coil spring 106.

Then, the paper 102 stacked on the paper feed stacker 101 is
By the rotation of the sheet feeding roller 111, the sheet is separated by the corner separator 108 and printed while passing through the platen 112.
The paper 102 is output to the paper output stacker 11 by the rotation of the paper output roller 117.
It is sent to 4, where it is laminated.

And in the automatic paper feeder configured as described above,
The left and right stackers 10 are used to supply paper 102 to the paper feed stacker 101.
After the left and right stackers 104 and 105 are retracted and locked with 4,105 left and right slightly wider than the width of the paper 102, the lower end of the stacked paper 102 is placed on the bearing surface 103, and the paper 102 is placed on the left and right stackers 104 and 105. It is done by leaning against it.

However, in such a conventional automatic paper feeder,
When the above-described paper 102 is supplied to the paper feed stacker 101, the opening 115 is formed between the bearing surface 103 and the paper feed roller 111 as shown in FIGS.
When replenishing the paper, the paper 102 on the side of the paper feed roller 111
There is a problem that it may fall down from 5 and fall into the paper guide path 116.

In particular, in order to easily replenish the paper 102, when the left and right stackers 104, 105 are expanded wider than the width of the paper 102,
This tendency was remarkable.

Therefore, the paper 102 from the bearing surface 103 of the paper feed stacker 101
In order to reliably prevent the falling of the sheet, the applicant of the present invention has previously shown the automatic sheet feeder shown in FIGS. 11 and 12 (Japanese Patent Application No. 1-135572).
No.) was filed.

In FIGS. 11 and 12, reference numeral 121 indicates a paper feed stacker that stacks the stacked sheets 102 on the support surface 122 and stores the sheets 102 in a leaning state.

This paper stacker 121 consists of a right stacker 123 and a left stacker.
The pressure plates 123a and 124a, respectively.
The left and right stackers 123 and 124 are movable along the bearing surface 122.

Also, these left and right pressure plates 123a, 124a
Is urged forward by a pressing means such as a coil spring 125, and has an action of pushing the paper 102 forward.

The brackets 128 of the corner separators 127 are rotatably supported on the side plates 126, 126 of the left and right stackers 123, 124, and the corner separators 127 are arranged so as to project forward from the lower surface of the bearing surface 122.

Then, one end of the paper feed roller shaft 129 is inserted into the side plates 126 of the left and right stackers 123 and 124, respectively.
Are arranged horizontally, and the paper feed roller shaft 129 has
A paper feed roller 1 that separates the paper sheets 102 stored in the paper feed stacker 121 one by one and sends them to the platen 130 of the printer printing unit
31,131 is stuck.

In front of the paper feed roller 131, a paper output stacker 1 for accommodating the printed paper 102 that has passed through the platen 130 at a predetermined interval in a state of leaning against the rear wall 132 for the paper output stacker in a stacked state.
33 are arranged.

A lower end portion 134 of the paper feed roller shaft 129 is arranged with an opening / closing member 135 urged toward the end of the bearing surface 122 so as to be axially movable and rotatable. This opening / closing member 13
The opening / closing member main body 136 is integrally formed with triangular side plates 137 which are tapered downward.

Then, on the opposite side of the side plate 137 of the opening / closing member main body 136, support pieces 138 are formed so as to project on both sides thereof, and a pyramid 139 made of, for example, metal is fixed between these support pieces 138. With this cone 139, the lower end portion 13 of the opening / closing member 135 is
4 is biased towards the end of bearing surface 122.

Therefore, when the paper 102 is supplied to the paper feed stacker 121, the opening / closing member 135 surely closes the opening formed between the paper 102 and the paper feed roller 131, so that the paper feed stacker 121 is supported. It is possible to reliably prevent the paper 102 from falling off the surface 122.

[Problems to be Solved by the Invention]

However, in the automatic sheet feeder having the structure shown in FIGS. 11 and 12, when the opening / closing member 135 has a large urging force, the sheet 1
The effect of preventing falling is great regardless of the thinness of 02. However, when feeding a thin and weak paper 102, there may be a case where the paper 102 cannot be sent out against the biasing force of the opening / closing member 135.
Since the second side is always biased, if the balance between the biasing force of the opening / closing member 135 and the strength of the waist of the paper 102 is improper, the paper 1
02 may wrinkle or cause skew.

On the other hand, if the biasing force of the opening / closing member 135 is small, it may not be possible to prevent the thick paper 102 from falling off. in short,
If the opening / closing member 135 and the change in the quality and humidity of the paper sheet 102 do not always match, the resistance of the opening / closing member 135 prevents reliable feeding.

Further, as shown in FIG. 13, to prevent skewing, the paper 102 caught in the platen 130 is once returned in reverse to form a loop between the paper feed roller 131 and the platen 130, and the platen 130
At this time, the paper 10
Since the opening / closing member 135 is provided regardless of the width of the opening / closing member 2, the opening / closing member 135 does not contact the entire width of the sheet 102, and thus the returned sheet 102 has wrinkles on both sides of the opening / closing member 135. it can.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent paper from falling off from the support surface of the paper feed stacker when the paper is supplied into the paper feed stacker, and It is an object of the present invention to provide an automatic paper feeding device that does not cause wrinkles or skew in the paper at the time of feeding.

[Means for solving the problem]

In order to achieve the above object, the invention according to claim 1 is
Place the paper feed roller fixed to the paper feed roller shaft in the opening in front of the paper feed stacker that stacks the stacked paper on the pressure plate while placing the bottom edge of the paper on the bearing surface. In an automatic paper feeding device which is arranged to form and stacks sheets on a pressure plate by a pressing means to press and feed the paper to a feeding roller, a holding means for locking the pressure plate at its maximum retracted position. One side of the opening / closing member that allows the opening to be closed / opened is swingably supported, and is maximally retracted by being locked by the holding means between the opening / closing member and the lower end side of the pressure plate. The opening / closing member is brought close to the pressure plate by the maximum amount corresponding to the pressure plate, and the opening / closing member is moved when the pressure plate released by the holding means advances from the maximum retracted position. It is provided with a restricting means for restricting a relative range between the connecting bar and linking opening and closing member and the pressure plate away from the train plate.

According to a second aspect of the present invention, a sheet feeding roller fixed to a sheet feeding roller shaft is provided in front of a sheet feeding stacker that stacks the stacked sheets on a pressure plate and places the lower end of the sheets on a supporting surface. Are arranged so as to form an opening between them and the bearing surface, and a rear wall for the paper discharge stacker is arranged in front of the paper feed roller, and the stacked paper on the pressure plate is pressed by the paper feed roller. In an automatic paper feeding device that presses and feeds the paper, the holding means for locking the pressure plate at its maximum retracted position is provided, and the opening / closing member that freely closes / opens the opening is swingable on the paper feeding roller shaft. Pivotally supported between the lower end side of the pressure plate and the opening / closing member, one end side of which is pin-connected to one end of the lower end side of the pressure plate or the opening / closing member and is formed in the elongated hole formed on the other end side. Pre The connecting bar pin provided on the other Sha plate or closing member is inserted and linking
A biasing means for rotating the opening / closing member away from the pressure plate is provided on the paper feed roller shaft, and when the opening / closing member is rotated away from the pressure plate, the opening / closing member or the rear wall of the stacker for discharging the paper is ejected. Provide a stopper that contacts the rear wall of the paper stacker or the opening / closing member, and make the interlocking range of the pressure plate and the opening / closing member equal to the value obtained by subtracting the maximum retracted amount of the pressure plate from the maximum thickness of stacked sheets. Or it is made smaller.

Further, according to a third aspect of the present invention, a sheet feeding roller fixed to a sheet feeding roller shaft is provided in front of a sheet feeding stacker that stacks the stacked sheets on a pressure plate and places the lower end of the sheets on a supporting surface. Are arranged so as to form an opening between them and the bearing surface, and a rear wall for the paper discharge stacker is arranged in front of the paper feed roller, and the stacked paper on the pressure plate is pressed by the paper feed roller. In an automatic paper feeding device that presses and feeds the paper, the holding means for locking the pressure plate at its maximum retracted position is provided, and the opening / closing member that freely closes / opens the opening is swingable on the paper feeding roller shaft. The lower end of the pressure plate is pivotally supported, and one end of the opening and closing member is pin-connected to the opening and closing member and the pin provided on the lower end of the pressure plate is inserted into the long hole formed on the other end. The connecting bar is linked and the biasing means for rotating the opening / closing member away from the pressure plate is provided on the paper feeding roller shaft, and the opening / closing member is moved away from the pressure plate on the opening / closing member or the rear wall of the paper discharge stacker. A stopper that abuts against the rear wall for the sheet discharge stacker or the opening / closing member when rotated in this manner is provided, and the length of the long hole of the connecting bar is made longer than the maximum thickness of the stacked sheets.

[Work]

According to the first aspect of the invention, when the pressure plate is fully retracted, the opening / closing member is advanced by the maximum amount so as to approach the pressure plate, and the opening / closing member closes the opening between the sheet feeding roller and the bearing surface.

On the other hand, when the holding means releases the locked state of the pressure plate at the maximum retracted position, the pressure plate advances, but when the pressure plate advances, the opening / closing member interlocks to open the opening so as to move away from the pressure plate. To do.

When the feeding is started and the paper is reduced, only the pressure plate is moved forward by the pressing means while the opening / closing member remains stationary.

In the invention according to claim 2 or 3, like the invention according to claim 1, when the retaining state releases the locked state of the pressure plate at the maximum retracted position, the pressure plate advances, but this pressure plate moves forward. As the plate moves forward, the opening / closing member retracts by the biasing means so as to move away from the pressure plate.

The retractable opening / closing member comes into contact with the rear wall for the paper discharge stacker via the stopper, and is in a stationary state even if the force from the urging means is received. At that time, the connecting bar is also in a stationary state, and the long hole of the connecting bar is also in a stationary state. In this state, the pin of the pressure plate advances in the elongated hole of the connecting bar. As a result, only the pressure plate advances while the opening / closing member remains stationary, and the paper on the pressure plate comes into contact with the paper feed roller.

When the feeding is started and the paper is reduced, only the pressure plate is moved forward by the pressing means while the opening / closing member remains stationary.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 to 8 show an automatic paper feeder according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a paper feed stacker in which stacked sheets P are placed on the bearing surface 2 and the sheets P are accommodated in a leaning state.

The paper stacker 1 includes a right stacker 1a and a left stacker 1b.
And the left and right stackers 1a and 1b, which have a pressure plate 3 and a side plate 4, respectively, are movable along the bearing surface 2 in the width direction. Each pressure plate 3 is swingably supported on the upper end of the side plate 4.

The paper feed roller shaft 5 is fixed to the side plate F ₁ of the frame body F through the side plates 4 and 4, and the side plate 4 is movable along with the pressure plate 3 in the width direction according to the width of the paper P. There is. The side plate 4 is formed with a long hole 4A, and each side plate 4
A pressure plate shaft 6 is bridged between the elongated holes 4A of the pressure plate 3, and the pressure plate shaft 6 is inserted through a support portion 3A provided on the back surface side of the pressure plate 3. A pressing means composed of a coil spring 7 is interposed between the rear wall of the stacker 1 and the lower surface of the lower end of the pressure plate 3.

As shown in FIGS. 1 and 6, the frame body F side plate F ₁
The release lever 8 is rotatably supported around the stacker slide shaft 9. A plate-shaped bracket 10 is integrally fixed to the release lever 8, and a long hole 10A is formed at the center of the plate-shaped bracket 10. A small-diameter convex portion provided at the tip of the pressure plate shaft 6 is formed in the long hole 10A. 6A is slidably engaged. Further, an engaging portion 10B is formed at the tip of the plate-shaped bracket 10, and when the release lever 8 is rotated in the B direction, the pressure plate shaft 6 moves in the C direction,
The engaging portion 10B of the bracket 10 integrally with the release lever 8 when maximum rotation engages the locking pin F2 provided on the side surface of the frame body side plate F _1, is held in this position. The above-mentioned release lever 8, bracket 10, locking pin F2, etc. constitute a holding means H.

1 and 2, a pair of paper feed rollers 11 and 11 are fixed to the paper feed roller shaft 5, and opening / closing members 12 and 12 located outside each paper feed roller 11 and 11. Is loosely fitted. The opening / closing member 12 is configured as a wedge-shaped small piece that becomes narrower downward, and a stopper 13 is fixedly provided on a side surface 12A of the opening / closing member 12 on the pressure plate 3 side. A torsion spring 14 is provided between the end plate 12B side of the opening / closing member 12 and the side plate 4.
The opening / closing member 12 is a torsion spring.
It is biased by 14 so as to rotate in the direction opposite to A.

15 A connecting bar made of a V-shaped plate, one end of which is 15A
Is integrally connected to a pin 16 provided on the end surface 12B of the opening / closing member 12, and a slot 15C is formed in the other end side 15B. This long hole
A pin 17 implanted at the tip of the pressure plate 3 is inserted into 15C.

In FIG. 2, reference numeral 18 is a rear wall for the paper discharge stacker with which the stopper 13 of the opening / closing member 12 abuts. Also in FIG.
Brackets 20 of corner separators 19 are rotatably supported on the side plates 4, 4 of the left and right stackers 1a, 1b, respectively, and the corner separators 19 are arranged so as to project forward from the lower surface of the bearing surface 2.

Here, in FIG. 3 and FIG. 4, the pressure plate 3 and the opening / closing member 12 are interlocked with each other through the connecting bar 15, and the interlocking area is shown as a. Further, the thickness of the maximum number of sheets of paper P set in the stacker 1 is l _m , the maximum retreat amount of the pressure plate 3 from the paper feed roller 11 is L, and the length of the long hole 15C of the connecting bar 15 is l. If so, L-l _m ≧ a l> l _m is set.

 Next, the operation of this embodiment will be described.

FIG. 2 shows a state at the time of paper supply, FIG. 3 shows a state without paper, FIG. 4 shows a state in which the pressure plate is retracted and locked, and FIG.
The process proceeds in the order of Fig. → Fig. 4 → Fig. 2 → Fig. 5.

FIG. 3 shows a state in which the paper P is not set in the stacker 1. In this state, as shown in FIG. 8, the engagement between the engaging portion 10B of the bracket 10 integral with the release lever 8 and the engagement pin F2 is released. As shown in FIG. 6, when the release lever 8 is rotated in the B direction, the small diameter convex portion 6A of the pressure plate shaft 6 moves in the long hole 4A, and the pressure plate shaft 6 moves in the long hole 4A in the C direction. Moving. As a result, as shown in FIG. 3, the pressure plate 3
Moves backwards against the biasing force of the coil spring 7 (shown in FIG. 2). As the pressure plate 3 moves backward, the pins 17 planted in the pressure plate 3 move in the elongated holes 15C of the connecting bar 15 in the C direction. At this time, the opening / closing member 15 is biased by the torsion spring 14 in the direction A, and the stopper 13 provided on the opening / closing member 15 is in contact with the rear wall 1 for the paper discharge stacker,
The quiescent state is held. Therefore, the connecting bar 15 is also stationary.

Then, the pin 17 of the pressure plate 3 moves in the long hole 15C, contacts the left end in the long hole 15C, and continuously moves in the C direction. Along with this, the pin 17 moves the opening / closing member 12 integrated with the connecting bar 15 in the C direction against the biasing force of the torsion spring 14. In this way, the pressure plate 3
Is the maximum amount of backward movement, and the maximum amount of backward movement is L. At the maximum retracted position of the pressure plate 3, as shown in FIG. 7, the engaging portion 10 of the bracket 10 integral with the release lever 8 is provided.
B engages with the locking pin F2, and the maximum retracted position of the pressure plate 3 is held.

The retracted state of the pressure plate is shown by the solid line of the pressure plate 3 in FIG.

While holding the pressure plate 3 in this state, the paper P is supplied to the paper feed stacker 1. That is, the lower end of the stacked paper P is placed on the bearing surface 2, and the paper P is leaned against the left and right pressure plates 3, 3.

In this way, as shown in FIG. 2, after the sheets P are replenished in the stacker 1 and the release lever 8 is rotated in the anti-B direction as shown in FIG. The engagement of 10B and the locking pin F2 is released, and the locking of the pressure plate 3 is released.

As a result, the pressure plate 3 receives the biasing force of the coil spring 7, and its lower end moves in the counter C direction. In the range of the initial interlocking region a, the opening / closing member 12 is biased in the anti-A direction by the biasing force of the torsion spring 14, so that the connecting bar
15 is also biased in the anti-A direction. Therefore, as the pin 17 moves, the connecting bar 15 also moves in the counter C direction.

With the rotation of the opening / closing member 12, the stopper 13 of the opening / closing member 12 comes into contact with the rear wall 18 for the paper discharge stacker, and the opening / closing member 12 is in a stationary state.

Here, when the maximum amount of paper P is set in the stacker 1 at one time, there is a slight gap between the uppermost paper P and the paper feed roller 11, and therefore the uppermost paper P is the paper feed roller. 11 does not abut, and the biasing force of the torsion spring 14 for the opening / closing member 12 does not act on the paper feed roller 11 via the pressure plate 3 at the time of paper feed.

Further, the pressure plate 3 moves in the anti-C direction by the urging force of the coil spring 7, and as shown in FIG.
The top of the sheet comes into contact with the sheet feeding roller 11. At this time, since the opening / closing member 12 is in the stationary state as described above, the connecting bar 15 is also in the stationary state, the pin 17 moves in the elongated hole 15C of the connecting bar 15, and the pressure plate 3 moves in the counter C direction. can do.

In this way, by releasing the locking of the left and right pressure plates 3,3, the left and right pressure plates 3,3 are pushed forward by the coil spring 7 and moved forward, and by this forward movement, the uppermost sheets of the stacked paper P are stacked. Paper P is the paper feed roller
The sheet is abutted against the sheet 11 in a pressed state, and the automatic sheet feeder is ready to feed.

Then, feeding is started, the paper P is reduced, and
The pressure plate 3 moves in the counter C direction by the urging force of the coil spring 7. As a result, the pin 17 moves within the long hole 15C of the connecting bar 17.

According to the above-described structure, firstly, when the sheets P are replenished in the stacker 1, the pressure plate 3 is locked by the holding means H in a state of being retracted rearward, and when the pressure plate 3 is retracted, it is opened and closed. The member 12 is in the advanced state, and the opening 21 is closed by the opening / closing member 12. Therefore, it is possible to reliably prevent the paper P from falling off the support surface 2 of the paper feed stacker 1 when the paper P is supplied.

Secondly, when the holding means H is released and the pressure plate 3 moves forward after the paper supply is completed, the opening / closing member 12 is retracted rearward, and the opening 21 is formed. Therefore, when the paper P is fed, the opening 21 is always opened, and the fed paper P is not subject to the resistance of the opening / closing member 12. Therefore, the sheet P can be smoothly fed without skewing.

Thirdly, the interlocking range a between the pressure plate 3 and the opening / closing member 12 is set to be equal to or smaller than a value obtained by subtracting the maximum retreat amount L of the pressure plate 3 from the maximum thickness l _m of the stacked sheets P. Therefore, when the pressure plate 3 moves forward from the maximum retracted position, the paper P stacked on the pressure plate 3 may come into contact with the paper feed roller 11 while the pressure plate 3 and the opening / closing member 12 are interlocked. Absent. Therefore, the biasing force of the torsion spring 14 is not added to the pressing force of the coil spring 7 against the pressure plate 3 via the opening / closing member 12 and the connecting bar 15. As a result, the contact pressure between the paper P and the paper feed roller 11 can be secured at a predetermined value, and the contact pressure is kept constant without changing depending on the amount of the paper P, so that the wrinkles and skew of the paper P can be maintained. The cause of can be removed.

Fourthly, since the length l of the long hole 15C is larger than the thickness l _m of the maximum number of sheets P, the pin 17 is located at the center of the long hole 15C while the sheets P are being fed. It is located and is not in contact with the end. Therefore, the biasing force of the torsion spring 14 is
It is not added to the biasing force of the coil spring 7 with respect to the pressure plate 3 via the opening / closing member 15. As a result, the contact pressure of the paper P on the paper feed roller 11 does not become high, and the contact pressure does not change depending on the amount of the paper P and is kept constant. Furthermore, if the biasing forces of the torsion springs 14, 14 for the left and right opening / closing members 15 are different between the left and right, the pressure on the left and right paper feed rollers 11, 11 will be different, but even in such a case, Since the biasing forces of the torsion springs 14 and 14 are cut off, the contact pressure of the paper P on the paper feed roller 11 becomes constant. In short, the contact pressure between the paper P and the paper feed roller 11 can be secured at a predetermined value, the cause of wrinkles and skew of the paper P can be removed, and the paper P in the stacker 1 is the last one. Up to the number of sheets, the pressure plate 3 reliably presses the sheet feed roller 11 to feed the sheets.

In this embodiment, the opening / closing member 12 has a stopper 13
Although the stopper 13 is fixed, the stopper 13 may not be fixed to the opening / closing member 12, and the stopper 13 may be fixed to the paper discharge stopper rear wall 18.

Further, in this embodiment, one end side of the connecting bar 15 is pin-connected to the opening / closing member 12, and the pin 17 provided on the lower end side of the pressure plate 3 is inserted into the elongated hole 15C formed on the other end side of the connecting bar 15. However, without being limited to such a structure, one end side of the connecting bar is pin-connected to the lower end side of the pressure plate 3, and a long hole is formed at the other end of the connecting bar on the opening / closing member 12 side. Opening / closing member in this slot
It is also possible to insert the pin provided on 12.

Further, in this embodiment, the pressure plate 13
Between the lower end side and the opening / closing member 12, one end side is pin-connected to the opening / closing member 12 and the pin 17 provided on the lower end side of the pressure plate 3 is inserted into the elongated hole 15C formed on the other end side. The bar 15 is linked, and the paper feed roller shaft 5 is provided with an urging means composed of a torsion spring 14 for rotating the opening / closing member 12 away from the pressure plate 3.
When the opening / closing member 12 is provided with a stopper 13 that comes into contact with the rear wall 188 for the paper ejection stacker when the 12 is rotated away from the pressure plate 3, the connecting bar 15 is opened / closed.
And the lower end side of the pressure plate 3 are linked to each other, and the opening / closing member 12 is brought close to the pressure plate 3 by a maximum amount in correspondence with the pressure plate 3 which is locked by the holding device H and maximally retracted. When the released pressure plate 3 moves forward from the maximum retracted position, the opening / closing member 12 is moved away from the pressure plate 3, but the pressure plate 3, the opening / closing member 12,
The series of interlocking movements of the connecting bar 15 is not limited to the above-mentioned structure. For example, the forward / backward state of the pressure plate 3 is appropriately detected by a sensor, and the stopper 13 and the torsion spring (biasing means) 14 are Even if it is not provided, the opening / closing member 1 is instructed by the sensor according to the forward / backward position of the pressure plate 3.
2, the connecting bar 15 can also be controlled via a suitable actuator.

And in this embodiment, the pressure plate 3
And the interlocking range a between the opening / closing member 12 and the maximum retreat amount L of the pressure plate 3 when the maximum number of stacked sheets P is the thickness
The length l of the long hole 15C of the connecting bar 15 is made longer than the thickness l _m when the maximum number of sheets P to be stacked is equal to or smaller than the value (L-l _m ) minus l _m. All the effects of the present embodiment are achieved under the two conditions. However, even if one of the two conditions or the two conditions are not provided, the first, second It is possible to achieve the effect of.

〔The invention's effect〕

As described above, according to the automatic paper feeding device of the first aspect of the present invention, when replenishing paper into the stacker,
The pressure plate is locked by the holding means in a state of being retracted rearward, and when the pressure plate is retracted,
The opening / closing member is in the advanced state, and the opening is closed by the opening / closing member. Therefore, it is possible to reliably prevent the sheets from falling off the support surface of the sheet stacker.

Further, when the pressure plate moves forward from the maximum retracted position after the paper supply is completed, the paper stacked on the pressure plate does not come into contact with the paper feed roller while the pressure plate and the opening / closing member are moving. . Therefore,
The biasing force of the biasing means is not added to the pressing force of the pressing means against the pressure plate via the opening / closing member and the connecting bar. As a result, the contact pressure between the paper and the paper feed roller can be maintained at a predetermined value, and the contact pressure remains constant regardless of the amount of paper, eliminating the cause of paper wrinkles and skew. be able to.

According to the automatic sheet feeding device of the second aspect of the invention, as in the first aspect of the invention, when the locked state of the pressure plate at the maximum retracted position is released, the pressure plate moves forward, Interlocking with the advancement of the pressure plate, the opening / closing member is retracted by the urging means so as to move away from the pressure plate. When the pressure plate moves forward from the maximum retracted position, the interlocking range of the pressure plate and the opening / closing member is equal to or less than the maximum retracted amount of the pressure plate minus the thickness of the maximum number of stacked sheets. While the pressure plate and the opening / closing member are interlocked, the sheets stacked on the pressure plate do not come into contact with the paper feed roller. Therefore, the urging force of the urging means is not added to the pressing force of the pressing means against the pressure plate via the opening / closing member and the connecting bar. As a result, the contact pressure between the paper and the paper feed roller can be secured at a predetermined value, and the contact pressure does not change depending on the amount of paper and is kept constant.
The cause of paper wrinkles and skew can be eliminated.

According to the automatic sheet feeding device of the third aspect of the invention, like the invention of the first aspect, when the pressure plate is released from the locked state at the maximum retracted position and the pressure plate moves forward, the opening / closing member is opened. It moves backwards in conjunction with each other, but becomes stationary due to the action of the stopper. In this state, when the pin of the pressure plate advances in the long hole of the connecting bar, the length of the long hole of the connecting bar is made longer than the thickness of the maximum number of stacked sheets, so that the paper is fed. During this time, the pin of the pressure plate is located at the center of the slot and does not abut the end. Therefore, the urging force of the urging means is not added to the urging force of the pressing means with respect to the pressure plate via the opening / closing member and the connecting bar. As a result, the contact pressure between the paper and the paper feed roller can be maintained at a predetermined value, and the contact pressure remains constant regardless of the amount of paper, eliminating the cause of paper wrinkles and skew. be able to.

[Explanation of symbols of main parts]

 1 ... Paper feeding stacker 2 ... Bearing surface 3 ... Pressure plate 5 ... Paper feeding roller shaft 6 ... Pressure plate shaft 7 ... Coil spring (pressing means) 11 ... Paper feeding roller 12 ... Opening / closing member 13 ... … Stopper 14 …… Torsion spring (biasing means) 15 …… Coupling bar 15C …… Elongated hole 17 …… Pin 18 …… Rear wall 21 for paper output stacker …… Opening H …… Holding means P …… Paper.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B65H 3/56 330 S S 8712-3F

Claims (3)

[Claims] 1. A paper feed roller fixed to a paper feed roller shaft is provided as a bearing surface in front of a paper feed stacker for placing the lower end of the paper on the bearing surface while leaning the stacked paper sheets on a pressure plate. In an automatic paper feeding device that is arranged so as to form an opening between them and presses the stacked sheets on the pressure plate against the paper feeding roller by the pressing means to feed the paper, the pressure plate is set at its maximum retracted position. One side of an opening / closing member that has a holding means for locking the opening / closing portion is swingably supported, and is locked by the holding means between the opening / closing member and the lower end side of the pressure plate. The opening / closing member is moved closer to the pressure plate by a maximum amount corresponding to the maximum retracted pressure plate, and the pressure plate released by the holding means advances from the maximum retracted position. Closing member automatic sheet feeder, characterized in that provided limiting means for limiting the relative range of the connecting bar away from the pressure plate and linking opening and closing member and the pressure plate. 2. A paper feed roller fixed to a paper feed roller shaft is provided as a bearing surface in front of a paper feed stacker for placing the lower end of the paper on the bearing surface while leaning the stacked paper sheets on a pressure plate. In addition to arranging so as to form an opening between them, a rear wall for the paper discharge stacker is arranged in front of the paper feed roller, and the stacked sheets on the pressure plate are pressed against the paper feed roller by the pressing means. In an automatic paper feeder for feeding, a holding means for locking the pressure plate at its maximum retracted position is provided, and an opening / closing member for closing / opening the opening is swingably supported on the paper feeding roller shaft, Between the lower end side of the pressure plate and the opening / closing member, one end side is pin-connected to one of the lower end side of the pressure plate or the opening / closing member, and the pressure plate or the pressure plate is provided in a long hole formed on the other end side. Is a link bar to which a pin provided on the other side of the opening / closing member is inserted, and a biasing means for rotating the opening / closing member away from the pressure plate is provided on the paper feed roller shaft. A stopper is provided on the rear wall for use that abuts against the rear wall for the stacker or the opening / closing member when the opening / closing member rotates away from the pressure plate. An automatic sheet feeder, which is equal to or smaller than a value obtained by subtracting the thickness of the maximum number of stacked sheets from the amount. 3. A paper feed roller fixed to a paper feed roller shaft is provided as a bearing surface in front of a paper feed stacker for placing the lower end of the paper on the bearing surface while leaning the stacked paper sheets on a pressure plate. In addition to arranging so as to form an opening between them, a rear wall for the paper discharge stacker is arranged in front of the paper feed roller, and the stacked sheets on the pressure plate are pressed against the paper feed roller by the pressing means. In an automatic paper feeder for feeding, a holding means for locking the pressure plate at its maximum retracted position is provided, and an opening / closing member for closing / opening the opening is swingably supported on the paper feeding roller shaft, Between the lower end side of the pressure plate and the opening / closing member, one end side is connected to the opening / closing member by a pin, and a connecting bar into which a pin provided on the lower end side of the pressure plate is inserted is inserted into an elongated hole formed on the other end side. Bound, the paper feed roller shaft, the biasing means for rotating the closing member away from the pressure plate is provided, the opening and closing member or after a discharge stacker wall,
When the opening / closing member rotates away from the pressure plate, a stopper is provided that contacts the rear wall of the paper ejection stacker or the opening / closing member, and the length of the long hole of the connecting bar is set to the maximum thickness of the stacked sheets. An automatic paper feeder characterized by being made longer than that.