JPH11314785A - Paper feeder for corrugated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely feed a corrugated sheet by making a proper pressing force act on this corrugated sheet irrespective of the size. SOLUTION: This paper feeder of a corrugated sheet 1a, is equipped with a delivery roll 5a delivering a corrugated sheet 1a stacked on a paper feeding part hopper being equipped with a front stop plate 23 in order from the lowermost layer, and two feed rolls 11a and 11b to be installed at the downstream side of the delivery roll 5a. The front stop plate 23 is constituted so as to make it positionally adjustable in the vertical direction, is equipped with a presser member 34 being installed so as to be opposed to the feed rolls 11a and 11b, and pressing the corrugated sheet 11a to these feed rolls 11a and 11b, and then the presser member 34 is attached to the front stop plate 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cardboard sheet feeding device provided in a cardboard sheet box making machine or the like.

[0002]

2. Description of the Related Art A conventional corrugated sheet feeding apparatus provided in a conventional corrugated sheet box making machine includes a paper feed unit hopper on which corrugated cardboard sheets are stacked, and a pair of feeders disposed above and below a sheet path line. And a roll.
The paper feed unit hopper includes a front guide, a back stop, a paper feed table, and the like. Then, the corrugated cardboard sheets stacked in the paper feeding unit hopper are sequentially sent out one by one from the lowermost layer through a gap at the lower end of the front guide plate of the front guide, and are passed through a pair of feed rolls provided up and down. The paper is transferred to the downstream printing unit.

In such a conventional cardboard sheet feeding apparatus, a cardboard sheet stacked on a sheet feeding table is fed through a gap formed at a lower end of a front contact plate of a front guide by rotation of a feed roll. A sheet feeder of a lead edge feeder type configured to sequentially feed one sheet at a time from the lowermost sheet and carry it out to the downstream side, and reciprocate corrugated cardboard sheets stacked on a sheet feed table at a predetermined timing. There is a kicker type sheet feeding device configured to pass a gap formed at a lower end portion of a front guide by a moving kicker, sequentially feed one sheet at a time from the lowermost layer, and carry it out downstream.

[0004]

However, in such a cardboard sheet feeding apparatus, the cardboard sheet is transported to the downstream printing section while being crushed by being pinched by a pair of feed rolls. The rigidity (accumulation strength) of the corrugated cardboard sheet is reduced, and it is necessary to adopt a higher quality (high strength) base paper as the material of the corrugated cardboard sheet in consideration of such a decrease in rigidity. Become.

[0005] Further, since the gap between the pair of feed rolls is set so as to be narrower than the thickness of the corrugated cardboard sheet so that the corrugated cardboard sheet is transported while being pinched and crushed by the pair of feed rolls, When the front end of the sheet is inserted into the gap between the rolls, a load acts instantaneously in the vertical direction, causing the feed roll to bounce (vibrate), thereby causing extreme sheet collapse and slip due to insufficient conveyance force. Will be.

For this reason, the present applicant has proposed various cardboard sheet feeding apparatuses in order to solve such a problem and to enable safe and reliable transfer of the cardboard sheets. For example, a paperboard feeding device proposed in Japanese Patent Application Laid-Open No. 9-295719 will be described with reference to FIG. 8. Such a paperboard feeding device as shown in FIG. A paper feed unit hopper 15 formed by a front guide 2, a back stop 3, and a side guide (not shown) is provided on the paper table 4, and inside the paper feed unit hopper 15, a downstream print unit (not shown) is provided. The cardboard sheets 1 to be fed are stacked.

Further, below the paper feed unit hopper 15,
A plurality of delivery rolls 5 are provided so as to protrude slightly above the paper supply table 4, and a suction box 6 is attached to the delivery rolls 5. The suction box 6 is connected to a suction blower 8 via a duct 7. Then, the cardboard sheets 1 stacked in the paper feed unit hopper 15 are sucked downward,
The lower surface of the lowermost cardboard sheet 1a is brought into contact with the delivery roll 5 so as to increase the frictional force between the lower surface of the cardboard sheet 1a and the outer peripheral surface of the delivery roll 5.

A receiving plate 10 supported by a lifting device (not shown) is attached below the paper feeding unit hopper 15. The receiving plate 10 is moved up and down by a lifting device (not shown), and the lowermost corrugated cardboard is provided. The sheet 1a is separated from the feed roll 5 and the upper outer peripheral surface, and the relative height position between the lower side surface of the lowermost corrugated cardboard sheet 1a and the upper outer peripheral surface of the feed roll 5 can be changed in a cycle for each sheet feeding. It is possible to be.

Next, the feeding operation of such a cardboard sheet by the feeding device will be described. In the cardboard sheet feeder, first, the receiving plate 10 is lowered by an elevating device (not shown) to bring the lowermost cardboard sheet 1 a into contact with the outer peripheral surface of the feed roll 5. At this point, the delivery roll 5 has not yet rotated.

Next, the delivery roll 5 is rotated to increase its rotation speed, and the lowermost corrugated cardboard sheet 1a is delivered in synchronization with the peripheral speed of the feed rolls 11a and 11b provided on the downstream side. The paper is transferred from the side 5 to the feed rolls 11a and 11b. The feed rolls 11a and 11b are rotating at a constant speed. In this case, air is sucked from a gap between the feed rolls 11a and 11b and a table plate 18 provided on the upper surface of the suction box 12, and the lowermost corrugated cardboard sheet 1a to be transferred is sucked on the outer peripheral surfaces of the feed rolls 11a and 11b. Thus, the cardboard sheet 1a is transferred to the printing section 9 in the next step by the frictional force generated between the outer peripheral surfaces of the feed rolls 11a and 11b and the lower surface of the cardboard 1a.

In this manner, the corrugated cardboard sheet 1a reaches the feed rolls 11a and 11b and is further transported, but at an appropriate time before the rear end of the corrugated cardboard sheet 1a passes through the most downstream delivery roll 5a. And receiving plate 10
Is raised, and the lowermost corrugated cardboard sheet 1a or the corrugated cardboard sheet 1b to be transferred next and the delivery roll 5
Then, the feed roll 5 is decelerated and stopped until the next sheet feeding. When the receiving plate 10 is raised, the corrugated cardboard sheet 1a is fed by the feed rolls 11a, 11
b will be transferred only.

However, in such a cardboard sheet feeding device, there is a case where the sheet cannot be fed reliably depending on the size of the cardboard sheet 1. For example, when a corrugated cardboard sheet 1 having a short length (length in the sheet conveying direction) is fed, there are the following problems. Here, FIG. 9 is a view for explaining the transfer of a corrugated cardboard sheet having a short length.

As shown in FIG. 9, when the length of the corrugated cardboard sheet 1 is short, even if the receiving end of the corrugated cardboard sheet 1a rises and the conveying force of the delivery roll 5a is lost, the corrugated cardboard sheet 1a is still in the position. The tip is slightly applied to the upstream feed roll 11a. In this case, a gap between the downstream feed roll 11b and the table plate 18, a gap between the lower surface of the corrugated cardboard sheet 1a and the table plate 18, and a gap between the upstream feed roll 11a and the table plate 18 Through the suction box 12
Is released to the atmosphere, air flows into the suction box 12 from the atmosphere, and the degree of vacuum in the suction box 12 is not sufficiently increased.

Further, since the sheet area to which the suction pressure is applied is small and the force for sucking the corrugated cardboard sheet 1a and pressing it against the upstream feed roll 11a is weak, it is sufficient to pull out the corrugated cardboard sheet 1a from the paper feed unit hopper 15. Sheet pulling output cannot be obtained. Therefore, the air leakage in the suction box is reduced and the negative pressure is increased, so that the corrugated cardboard sheet 1a and the feed roll 11 are reduced.
It is conceivable to arrange a sheet guide for guiding the corrugated cardboard sheet 1a above the feed rolls 11a and 11b in order to increase the frictional force between the sheet rolls 11a and 11b. Since the pressing force applied to the corrugated cardboard sheet 1a cannot be adjusted, it is difficult to press the corrugated cardboard sheet 1a with the proper pressing force to feed the feed rolls 11a and 11b. Sheet output cannot be obtained.

In particular, for example, when the thickness of the corrugated cardboard sheet 1a is changed, the pressing force acting on the corrugated cardboard sheet 1a cannot be adjusted, so that the corrugated cardboard sheet 1a is pressed against the feed rolls 11a, 11b with an appropriate pressing force. Therefore, an appropriate sheet pulling output cannot be obtained. The present invention has been made in view of such a problem, and regardless of the size of a corrugated cardboard sheet, an appropriate pressing force is applied to the corrugated cardboard sheet so that the corrugated cardboard can be fed reliably. An object of the present invention is to provide a sheet feeding device.

[0016]

According to the first aspect of the present invention, there is provided a sheet feeding apparatus for a cardboard sheet according to the present invention, in which the cardboard sheets stacked on a sheet feeding section hopper having a front contact plate are sequentially fed from the lowest layer. A feed roll, and a feed roll disposed downstream of the feed roll, in a corrugated sheet feeding device for feeding the corrugated sheet, the front contact plate can be adjusted vertically. And a pressing member arranged to face the feed roll and pressing the fed corrugated cardboard sheet against the feed roll, wherein the pressing member is attached to the front contact portion. .

According to a second aspect of the present invention, there is provided the cardboard sheet feeding apparatus according to the first aspect, wherein the pressing member is constituted by a pressing plate urged in a pressing direction by an elastic member. The pressing force of the plate against the feed roll is adjusted by the elastic force of the elastic member. According to a third aspect of the present invention, there is provided the paper feeding apparatus for corrugated cardboard sheets according to the first aspect, wherein the pressing member is urged in a pressing direction by an elastic member, and is formed by a spring plate formed by bending a plate member. And the pressing force of the spring plate against the feed roll is:
It is characterized by being adjusted by the spring force of the spring plate and the elastic force of the elastic member.

According to a fourth aspect of the present invention, there is provided a sheet feeding apparatus for corrugated cardboard sheets according to the first aspect, wherein the pressing member is constituted by a pressing roll.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First, a cardboard sheet feeder according to a first embodiment of the present invention will be described with reference to FIGS. Since the cardboard sheet feeder according to the present embodiment is configured in the same manner as that already described with reference to FIG. 8, only the characteristic portions of the present embodiment will be described here. .

First, a description will be given of the front abutment plate 23 of the front guide 2 provided in the present cardboard sheet feeding device. FIG. 3 is a front view of the front guide 2 (only the upper portion of the front guide 2 is shown), and FIG. FIG. 5 is a sectional view taken along the line CC of FIG. 3, and FIG. 5 is a sectional view taken along the line DD of FIG. In the present cardboard sheet feeding device, as shown in FIG. 3, a beam 21 is stretched between frames 20, 20 extending on both sides along the sheet conveying direction. Front guides 2 (here, two sets) are arranged side by side. These front guides 2 can move in the sheet width direction crossing the sheet conveying direction in accordance with the size of the corrugated cardboard sheet 1, and their positions can be adjusted appropriately.

As shown in FIG. 4, the beam 21 is formed in a C-shaped cross section. Edges 21a and 21b are formed at upper and lower ends in a band shape in the sheet width direction. A bracket 22 is attached to the portions 21a and 21b so as to be slidable in the sheet width direction crossing the sheet conveying direction. In addition, as shown in FIG.
A dovetail groove 22a is formed, and a front contact plate 23 is attached to the bracket 22 via the dovetail groove 22a so as to be vertically slidable.

For this purpose, a motor 25 is mounted on the front contact plate 23 via a mounting stand 24. A screw 25a is formed at the shaft end of the motor 25.
Is a screw hole 2 formed in the projection 22b of the bracket 22.
2c. Thus, by rotating the motor 25, the front contact plate 23 can be slid vertically in the dovetail groove 22a.

As described above, the front guide 2 can be arranged at an arbitrary position in the sheet width direction crossing the sheet conveying direction according to the size of the corrugated cardboard sheet 1. The gap between the lower end of the front contact plate 23 and the paper feed table 4 can be adjusted accordingly. In the present embodiment, below the front abutment plate 23 of the front guide 2 thus configured, a sheet pressing device 50 that presses the corrugated cardboard sheet 1 to be sent to the downstream printing unit against the feed rolls 11a and 11b is provided. ing.

This sheet pressing device 50 is shown in FIGS.
As shown in FIG. 1, the bracket 31 includes a pair of brackets 31 and a pressing plate 34 as a pressing member attached to the brackets 31 via the lever 32. Here, the pair of brackets 31, 31 are fixed by, for example, bolts or the like so as to protrude downstream in the sheet conveying direction.

A lever 32 is rotatably attached to the pair of brackets 31 via a pin 33. Here, two levers 32, 32 are arranged in series on the upstream side and the downstream side in the sheet conveying direction. Further, a flat pressing plate 34 is attached to these levers 32, 32 via pins 35.
The pressing plate 34 is disposed so as to face the feed rolls 11a and 11b. The holding plate 34
Is formed such that the upstream portion in the sheet conveying direction is in a warped state.

A pair of brackets 31, 31 is supported by a support plate 36, and a pin 36 A attached to the support plate 36 and a pin 37 attached to the lever 32.
And a tension spring (elastic member) 38 is interposed therebetween.
Bolts 3 are provided in screw holes 36B formed in the support plate 36.
9 is screwed, and the tip of the bolt 39 is in contact with the upper surface of the lever 32.

The cardboard sheet feeder according to the first embodiment of the present invention is configured as described above, and has the following operations and effects. First, in the present cardboard sheet feeding device, the vertical position of the front contact plate 23 is set so that only the lowermost cardboard sheet 1a can pass through.
The gap between the lower end of the sheet and the feed table 4 is
It is set slightly wider than the thickness of a.

On the other hand, the vertical position of the holding plate 34 is adjusted by the bolt 39 abutting on the lever 32 to which the holding plate 34 is attached.
The gap between the cardboard sheets 1a and 11b is set to be smaller than the thickness of the cardboard sheet 1a. And the holding plate 34
Presses the cardboard sheet 1a against the feed rolls 11a and 11b by its own weight and the tensile force of the tension spring 38 adjusted by the bolt 39.

Further, since the pressing plate 34 is attached to the front contact plate 23 via the bracket 31, even if the thickness of the corrugated cardboard sheet 1 is changed, the gap is adjusted according to the thickness. Holding plate 34 together with the front contact plate 23
Also moves up and down, whereby the gap between the holding plate 34 and the feed rolls 11a and 11b is adjusted.

Therefore, once the gap between the holding plate 34 and the feed rolls 11a and 11b is set, the gap between the holding plate 34 and the feed rolls 11a and 11b is always adjusted without any special adjustment. The cardboard sheet 1a is pressed against the feed rolls 11a and 11b with a constant pressing force. Therefore, according to the cardboard sheet feeding device according to the present embodiment, the vertical position of the front abutment plate 23 can be arbitrarily adjusted.
Since the sheet pressing device is attached to the sheet 3, even if the size of the corrugated cardboard sheet 1a, that is, the length or thickness of the corrugated cardboard sheet 1a is different, an appropriate pressing force by the pressing plate 34 on the corrugated cardboard sheet 1a. Can act. For this reason, when the cardboard sheet 1a is pulled out from the paper feed unit hopper 15, an appropriate sheet pulling output is obtained, whereby the cardboard sheet 1a can be reliably fed to the downstream printing unit. There are advantages.

In particular, the length of the corrugated cardboard sheet 1a is short,
Even if the leading end of the corrugated cardboard sheet 1a is slightly applied to the feed roll 11b, the negative pressure of the suction box 12 is not sufficiently increased, and even if the suction force is not sufficiently obtained, the corrugated cardboard sheet is used. Since the sheet 1a can be pressed against the feed roll 11, the sheet pulling output can be increased when the cardboard sheet 1a is pulled out from the paper feed unit hopper 15, and the cardboard sheet 1a is reliably fed to the downstream printing unit. There is also the advantage that it can be done.

Further, even when the type of the corrugated cardboard sheet is changed and the thickness of the corrugated cardboard sheet is changed, even if the gap between the pressing plate 34 and the feed rolls 11a and 11b is not adjusted, the front contact plate 23 can be formed. Since the corrugated cardboard sheet 1a can be pressed against the feed rolls 11a and 11b with a constant pressing force only by adjusting only the vertical position, there is an advantage that the pressing force by the pressing plate 34 can be easily adjusted.

Next, a second embodiment will be described with reference to FIG. As shown in FIG. 6, the cardboard sheet feeding device according to the present embodiment is different from the above-described first embodiment in the pressing member of the sheet pressing device 50. That is, in the present embodiment, a plurality of (here, two) spring plates 40, 40 formed by bending a plate-shaped member are used as the pressing members. And these spring plates 4
0,40 spring force (returning force) and bolt 39
And the tension of the tension spring 38 adjusted by
The cardboard sheet 1 is pressed against the feed rolls 11a and 11b.

In this embodiment, similarly to the above-described first embodiment, the sheet pressing device 50 mounts the bracket 31 on the front contact plate 23 and rotatably supports the lever 32 to the bracket 31 via the pin 33. At the same time, the lever 32 is suspended by a tension spring 38. Then, the spring plate 4 is connected to these levers 32 via bolts 41.
0 is fixed.

Therefore, according to the cardboard sheet feeding device of the present embodiment, the same operation and effect as those of the above-described first embodiment can be obtained. That is, according to the cardboard sheet feeding device according to the present embodiment, the front contact plate 23 is provided.
The height of the corrugated cardboard sheet 1a, that is, the length and thickness of the corrugated cardboard sheet 1a are different, since the vertical position of the corrugated cardboard sheet 1a can be adjusted arbitrarily and the sheet pressing device is attached to the front contact plate 23. Even with this, an appropriate pressing force by the spring plate 40 can be applied to the corrugated cardboard sheet 1a. For this reason, when the cardboard sheet 1a is pulled out from the paper feed unit hopper 15, an appropriate sheet pulling output is obtained, whereby the cardboard sheet 1a can be reliably fed to the downstream printing unit. There are advantages.

Further, since the pressing member of the sheet pressing device 50 is constituted by the spring plate 40, there is an advantage that the manufacturing is easy with a simple structure and the cost can be reduced. Next, a third embodiment will be described with reference to FIG.
This will be described with reference to FIG. As shown in FIG. 7, the sheet feeding device of the present embodiment differs from the above-described second embodiment in the pressing member of the sheet pressing device 50. That is, in the present embodiment, the bracket 31 is attached to the front abutment plate 23 as in the above-described second embodiment.
A plurality of shafts 42 (here, two) are inserted,
A pressing roller 4 as a pressing member is provided on these shafts 42.
3, 43 are rotatably supported. A soft rubber 44 is wound around the outer circumference of the pressing roller 43. Then, the cardboard sheet 1 is pressed against the feed rolls 11a and 11b via the rubber 44 wound around the pressing roller 43.

Therefore, according to the cardboard sheet feeder of the present embodiment, the same operation and effect as those of the above-described second embodiment can be obtained. That is, according to the cardboard sheet feeding device according to the present embodiment, the front contact plate 23 is provided.
The height of the corrugated cardboard sheet 1a, that is, the length and thickness of the corrugated cardboard sheet 1a are different since the vertical position of the corrugated cardboard sheet 1a can be adjusted arbitrarily and the sheet pressing device 50 is attached to the front contact plate 23. Even in this case, an appropriate pressing force by the pressing roller 43 can be applied to the cardboard sheet 1a. For this reason, the paper feed unit hopper 15
When the corrugated cardboard sheet 1a is pulled out from the printer, an appropriate sheet pulling output can be obtained, thereby providing an advantage that the corrugated cardboard sheet 1a can be reliably fed to the downstream printing unit.

Further, since the pressing member of the sheet pressing device 50 is constituted by the pressing roller 43 around which the rubber 44 is wound, there is an advantage that the structure is simple, the manufacturing thereof is easy, and the cost can be reduced. is there. In the third embodiment, the pressing roller 43 is provided as a pressing member in the cardboard sheet feeding device. However, the pressing roller 43 is combined with the spring plate 40 according to the second embodiment. Is also good.

In the first and second embodiments described above, the pressing force of the pressing members 34 and 40 can be arbitrarily adjusted by the elastic force of the tension spring 38 adjusted by the bolt 39. The sheet pressing device 50 only needs to be attached to the front contact plate 23, and the pressing force of the pressing member does not necessarily need to be arbitrarily adjustable.

Further, in each of the above-described embodiments, the suction rolls 12 and 6 are attached to the feed rolls 11a and 11b and the feed roll 5, respectively. However, it is not essential to provide the suction boxes.

[0041]

As described above in detail, according to the cardboard sheet feeding apparatus of the present invention, the vertical position of the front contact plate can be adjusted arbitrarily. Since the holding member is attached to the front contact plate, even if the size of the corrugated cardboard sheet, that is, the length or thickness of the corrugated cardboard sheet is different, it is necessary to apply an appropriate pressing force by the pressing member to the corrugated cardboard sheet. Can be. For this reason, when the corrugated cardboard sheet is pulled out from the paper feeding unit hopper, an appropriate sheet pulling output is obtained, and as a result,
There is an advantage that the cardboard sheet can be reliably fed from the paper feed unit hopper to the downstream printing unit.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a sheet holding device of a cardboard sheet feeding device according to a first embodiment of the present invention.

FIG. 2 is a schematic front view of a sheet holding device of the cardboard sheet feeding device according to the first embodiment of the present invention, and is a view as viewed in the direction of arrow A in FIG.

FIG. 3 is a schematic front view for explaining a front abutment plate of a front guide provided in the cardboard sheet feeding device according to the first embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view for explaining a front contact plate of a front guide provided in the cardboard sheet feeding device according to the first embodiment of the present invention, and is a cross-sectional view taken along the line CC of FIG. FIG.

FIG. 5 is a schematic cross-sectional view for explaining a front contact plate of a front guide provided in the cardboard sheet feeding device according to the first embodiment of the present invention, and is a cross-sectional view taken along the line DD of FIG. FIG.

FIG. 6 is a schematic cross-sectional view of a sheet pressing device of a cardboard sheet feeding device according to a second embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view of a sheet holding device of a sheet feeding device for corrugated cardboard sheets according to a third embodiment of the present invention.

FIG. 8 is a schematic diagram showing a conventional cardboard sheet feeding device.

FIG. 9 is a schematic diagram for explaining a problem of a conventional cardboard sheet feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Corrugated cardboard sheet 1a Lowermost corrugated cardboard sheet 2 Front guide 3 Backstop 4 Feeding table 5 Delivery roll 5a Downstream delivery roll 6 Suction box 7 Duct 8 Suction blower 9 Printing unit 10 Receiving plate 11 Feed roll 11a Downstream side 11b Upstream Side 12 Suction box 15 Paper feed unit hopper 18 Table plate 20 Frame 21 Beam 21a Guide portion 22 Bracket 22a With groove 22b Projection 22c Screw hole 23 Forehead plate 24 Mounting stand 25 Motor 25a Screw 31 Bracket 32 Lever 33 Pin 34 Press plate (Pressing member) 35, 36A, 37 Pin 36 Support plate 38 Tension spring (elastic member) 39 Adjusting bolt 40 Spring plate (pressing member) 41 Bolt 42 Shaft 43 Pressing roller (pressing member) 44 Rubber 5 Sheet holding device

Claims (4)

[Claims] 1. A corrugated cardboard comprising: a feed roll for sequentially feeding corrugated cardboard sheets stacked on a feeder hopper provided with a front contact plate from a lowermost layer; and a feed roll disposed downstream of the feed roll. In a sheet feeding device for a cardboard sheet for feeding a sheet, the front contact plate is configured to be able to adjust a position in a vertical direction, and is disposed so as to face the feed roll and feeds the cardboard sheet to be fed. A sheet feeding device for a corrugated cardboard sheet, comprising: a pressing member that presses against the feed roll, wherein the pressing member is attached to the front contact portion. 2. The pressing member is constituted by a pressing plate urged in a pressing direction by an elastic member, and the pressing force of the pressing plate against the feed roll is adjusted by the elastic force of the elastic member. The sheet feeding device for corrugated cardboard sheets according to claim 1, characterized in that: 3. The pressing member is urged in a pressing direction by an elastic member, and is constituted by a spring plate formed by bending a plate-like member. The pressing force of the spring plate against the feed roll is adjusted by the spring plate. 2. The sheet feeding device for a corrugated cardboard sheet according to claim 1, wherein the feeding is adjusted by a spring force of the elastic member and an elastic force of the elastic member. 4. The sheet feeding device for a corrugated cardboard sheet according to claim 1, wherein said pressing member is constituted by a pressing roll.