GB2270304A

GB2270304A - Corrugated board feeding and folding apparatus.

Info

Publication number: GB2270304A
Application number: GB9318090A
Authority: GB
Inventors: Kenji Mizuno
Original assignee: HOTOKU KOGYO KK
Current assignee: HOTOKU KOGYO KK
Priority date: 1992-09-04
Filing date: 1993-09-01
Publication date: 1994-03-09
Anticipated expiration: 2013-09-01
Also published as: IT1272571B; JPH0687176A; ITMI931904A1; GB9318090D0; ITMI931904A0; GB2270304B; DE4329701A1; FR2695863A1

Abstract

A corrugated board 10, to be folded by bars 36, is fed by endless belts 20, the board being securely held in place on the belts by suction generated within tubular members 16, the suction being communicated via apertures 16a in the tubular members, slots 18a in belt guides 18, and holes 20a in the belts themselves. Each belt guide 18 is of low friction material and extends the full length of the respective tubular member 16. The return run of the belt 20 is within the tubular member 16. Pressure rolls (figures 5 and 6) may act on the upper surface of the board. <IMAGE>

Description

2270304 CORRUGATED BOARD SHEET FOLDING APPARATUS 1W

BACKGROUND OF THE INVENTION

This invention relates to an apparatus for folding corrugated board sheets, more particularly to a folding apparatus which can perform accurate folding of corrugated board sheets along the creases as the sheets are fed being immobilized securely under suction on endless belts.

SUMMARY OF THE INVENTION

Folder gluer is known as an apparatus for folding corrugated board sheets, which automatically performs folding and gluing of corrugated board sheets having been subjected to required processes such as printing, creasing, slotting, etc. The folder gluer has a folding mechanism for folding the corrugated board sheets along the creases, a gluing mechanism for gluing the overlap widths and a feeding mechanism. In the folder gluer, a corrugated board sheet fed out of an upstream apparatus (e.g. printer slotter) is designed to be glued at the overlap widths by a gluing mechanism and also to be folded along the creases by the folding mechanism, as the corrugated board sheet is fed downstream by the feeding mechanism. The feeding mechanism consists of a pair of conveyor belts extending along the direction of feeding the corrugated board sheet parallel to and spaced from each other with a predetermined distance therebetween in the direction orthogonal to the direction of feeding the corrugated board sheet; and a plurality of pressure rolls disposed above (provided that the corrugated board sheets are to be folded upward) the respective belts correspondingly, so that the corrugated board sheet may be fed as it is held between the belts and the pressure rolls.

In the above feeding mechanism, it is necessary that the - 2 corrugate board sheet be fed in a right posture so that the sheet may be folded accurately by the folding mechanism. For such purpose, the pressure rolls are employed to press the sheet firmly against the conveyor belts so as to prevent displacement of the sheet. However, it can be pointed out that the flutes of the corrugated board sheet are collapsed to reduce strength of the sheet, if the pressurizing force of the pressure rolls is set to a high level; whereas if it is set to a low level, on the contrary, it happens occasionally that the corrugated board sheet cannot securely be held between the rollers and the conveyor belts, causing readily slippage of the corrugated board sheet in the direction diagonal to the feeding direction, resulting in the failure of accurate folding along the creases and causing the sheet to be glued and pasted at improper portions to produce unacceptable articles.

When a lot of corrugated board sheets having different thickness are to be processed in accordance with an order change and the like, the pressurizing force of the pressure rolls must be readjusted to a proper level so that the sheets may be fed in a right posture without causing collapse of flutes. Accordingly, it can be pointed out that the prior art feeding mechanism suffers disadvantages in that it requires the skill of an expert for such readjustment of pressure rolls in a short time, and that it takes an unexperienced operator much time for the readjustment operation in accordance with every order change, resulting in tremendous loss time.

Further, the pressure rolls cannot be allowed to be present in the zone on the conveyor belts where the corrugated board sheet is to be folded by at least 900 along the creases, and thus the sheet is fed unstably in such zone and sometimes slips out of position to frequently provide unacceptable articles.

Since the corrugated board sheet fed out of the printer slotter is then fed being held between the conveyor belts and the pressure rolls, the belts are brought into contact with the undried printed portions of the sheet, and the ink at such portions is transferred to the belts, in turn, to the following sheets, disadvantageously. Thus, such corrugated board sheets having inaccurate folding, scumm ng on the printed surface, etc. are rejected as unacceptable articles, leading to reduction in production efficiency.

This invention is proposed in view of the problems inherent in the prior art and for the purpose of solving them successfully, and it is an object of the invention to provide a folding apparatus which can fold a corrugated board sheet accurately along the creases as it is fed in the right posture without collapsing of the flutes thereof.

In order to overcome the above problems and attain the intended object of the invention, this invention provides a corrugated board sheet folding apparatus in which an unfolded corrugated board sheet having been subjected to slotting and creasing processes can be fed and folded along the creases, the apparatus comprising a cylindrical holder extended along the direction of feeding the corrugated board sheet at least over the zone including the folding start position to the folding end position; a plurality of through holes defined along the longitudinal direction of the holder with predetermined intervals therebetween; suction means communicably connected to the holder so as to provide a negative pressure within the holder; and an endless belt having a plurality of through holes defined along the longitudinal direction with predetermined intervals therebetween and extended across a pair of rollers rotatably supported on each longitudinal outer end of the holder; wherein the endless belt is designed to run externally along the surface of the holder having through holes defined therein during its downstream stroke, and to run internally within the holder during its upstream stroke, so that the corrugated board sheet can be fed as it is securely immobilized on the surface of the endless belt in the downstream stroke with the aid of the suctional action exerted in the holder.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows in vertical cross-section a front view of the folding apparatus according to one embodiment of the invention; 15 Fig. 2 shows schematically in side view the entire constitution of the folding apparatus; Fig. 3 shows schematically in perspective view the major 20 portion of the folding apparatus; Fig. 4 shows in vertical cross-sectional front view the major portion of the folding apparatus; Fig. 5 shows schematically in side view the entire constitution of the folding apparatus according to another embodiment of the invention; and Fig. 6 shows in cross-sectional front view the major 30 portion of the folding apparatus shown in Fig. 5.

DETAILED DESCRIPTION OF THE INVENTION

The folding apparatus for corrugated board sheets according 35 to the invention will now be described by way of preferred embodiments referring to the attached drawings. Fig. 1 shows in vertical crosssection a front view of the folding apparatus according to a preferred embodiment of the invention; and Fig. 2 shows schematically in side view the entire constitution of the folding apparatus. 5 As shown in Figs. 1 and 2, a folding apparatus 14 referred to as folder gluer is disposed downstream a printer slotter 12 which carries out necessary processes of printing, creasing, slotting, etc. against a corrugated board sheet 10. The folding apparatus 14 has a pair of elongated holders 16 disposed over the full length thereof parallel to and spaced from each other with a predetermined distance therebetween in the direction orthogonal to the direction of feeding the sheet 10. The holders 16 each have a cylindrical structure having an upstream open end and a downstream open end, with a plurality of through holes 16a defined on the upper surface along over the entire length thereof with a predetermined intervals therebetween. A guide 18 is extended on the upper surface of each holder 16 20 along the entire length thereof with a groove 18a communicating to the through holes 16a of the holder 16 being defined along the entire length thereof. The guide 18 has on the upper surface a couple of ridges 18b formed to be opposed to and spaced from each other with a distance 25 slightly greater than the width of an endless belt 20 to be described later so that the endless belt 20 may run between these two ridges 18b smoothly and safely without meandering. Incidentally, it is suggested that the guides 18 with which the endless belt 20 run in slide contact be 30 made of a material having a small coefficient of friction so as to realize smooth running of the belt 20. Each holder 16 has a plurality (two in the embodiment) suction blowers 26 connected thereto, so that the internal 35 space of the holder 16 may be maintained under a negative pressure. The corrugated board sheet 10 is designed to be immobilized securely on the endless belts 20 running on the upper surface of the guides 18 with the aid of the suctional action applied from the inside of the holder 16.

A drive roller 22 and a driven roller 24 are rotatably supported on each holder 16 at each longitudinal outer ends in the sheet feeding direction, as shown in Fig. 2, and an endless belt 20 is extended across these two rollers 22,24. The drive roller 22 is connected to a drive source not shown through a transmission means such as a series of gears or a belt, so that the endless belt may be driven by rotating the roller 22 in a predetermined direction.

The endless belt 20 is designed to run along the upper surface of the guide 18 during the downstream stroke and to run within the holder 16 during the upstream stroke. The endless belt 20 has a plurality of through holes 20a defined with predetermined intervals along the running direction thereof at the positions corresponding to the groove 18a of the guide 18, which are designed to communicate to the inside of the holder 16 while the belt 20 runs downstream (along the guide 18). Namely, if the suction blowers 26 are actuated to induce a negative pressure within the holder 16, a suction force is caused to be exerted onto the outer side of the endless belt 20 through the through holes 16a of the holders 16, grooves 18a of the guides 18 and the through holes 20a of the endless belts 20. Thus, the corrugated board sheet 10 transferred from the printer slotter 12 to the endless belts 20 can securely be immobilized on the surface of the endless belts 20 under such suctional action.

It should be noted here that the presence of the guide 18 with a groove 18a interposed between the holder 16 and the endless belt 20 prevents the endless belt 20 from being sucked strongly on the upper surface of the guide 18 under the suctional action, whereby preventing reduction in the efficiency of driving the endless belt 20, as well as, enabling use of a small output drive means.

A plurality of guide rollers 28 are rotatably supported in the holder 16 in such an arrangement as shown in Fig. 2, and the endless belt 20 is designed to run along a predetermined route with the aid of the guide rollers 28. At the junctions of the blowers 26 with the holder 16, the endless belt 20 running within the holders 16 are designed to locate below the junctions (see Fig 1), so that the suctional action to be applied to the endless belt 20 running along the upper surface of the guide 18 may not be affected.

The holders 16 are supported at several positions along the longitudinal direction thereof on carriages 32 respectively, and the carriages 32 are loaded on rails 30 which extend orthogonal to the sheet feeding direction so as to be able to run freely therealong, as shown in Fig. 4. Each opposing pair of carriages 32 are designed to be shifted closer to or farther from each other by means of adjust means 34 such as screws. In other words, if a lot of corrugated board sheets 10 with different outer dimensions are to be processed in accordance with an order change and the like, the adjust means are operated to bring the holders 16 in position relative to the corrugated board sheet 10. Incidentally, the reference number 36 denotes a guide bar 36 for folding both side portions 10a of the corrugated board sheet 10, and 38 a gluer.

The action of the folding apparatus according to the above embodiment of the invention will now be described.

The endless belts 20 are designed to run with a negative pressure being induced within the respective holders 16 by actuating the plurality of suction blowers 26. The corrugated board sheet 10 fed out of the printer slotter 12 is transferred to the pair of endless belts 20 running along the guides 18, where the sheet 10 is immobilized under suction on the upper surfaces of the endless belts 20 with the aid of the suctional action of the negative pressure exerted within the holders 16.

The corrugated board sheet 10 fed downstream as the endless belts 20 run, is then brought into press contact with upper holding belts or guide bars 36 at the lower surface of the predetermined side portions 10a of the corrugated board sheet 10 to be folded upward gradually along the creases (see Fig. 1). In this process, while an external force of folding is applied to the corrugated board sheet 10, the sheet 10 can be folded at the accurate position with no displacement since the sheet 10 is immobilized securely on the endless belts 20 with the aid of the suction force applied thereto. Thus, the overlap widths (not shown) glued by the gluer 38 can be pasted at accurate positions. Namely, the corrugated board sheet 10 is securely immobilized on the endless belts 20 by the suctional force applied thereto before the folding of the predetermined side portions 10a of the sheet 10 is started through and until folding of the side portions 10a is completed, so that accurate folding along the crease and accurate pasting of the glued overlap widths can be achieved.

The endless belts 20 which have completed transportation of the corrugated board sheet 10 having the side portions 10a folded to the discharge position are inverted by the drive rollers 22 and drawn into the inside of the holders 16, respectively. An air flow is generated by the suctional actions of the suction blowers 26 in the internal space of each holder 16, which serves to accelerate drying of the ink adhered to the endless belt 20 running therethrough.

Accordingly, the corrugated board sheets 10 to be fed anew to the endless belts 20 can effectively be prevented from being smudged with the ink which may otherwise be transferred thereto from the endless belts 20. Further, the paper dusts and the like transferred from the corrugated board sheet 10 to the endless belts 20 can be removed while the belts 20 pass through the inside of the respective holders 16.

In the above embodiment, in case of processing a lot of corrugated board sheets 10 with different thickness in accordance with an order change and the like, the operation of adjusting the pressure rolls which has been necessary in the prior art folding apparatus can be omitted, and thus the cycle time required in accordance with the order change can be reduced. Since the endless belts 20 are designed to run upstream within the holders 16, the drive section is not exposed at the lower portion of the apparatus, eliminating the danger the nearby operator may otherwise encounter. Moreover, the concealed movable section has a secondary effect of making the appearance of the apparatus simple and the design of the apparatus sophisticated.

Figs. 5 and 6 show another embodiment of the folding apparatus according to this invention, in which pressure rolls'42 are disposed over a predetermined upstream zone of each holder 16. In other words, a supporting plate 40 is disposed above and parallel to each holder 16, and a plurality of pressure rolls 42 are rotatably supported at predetermined intervals to the supporting plate 40 which is designed to be ascendable through an adjust mechanism not shown.

Accordingly, the corrugated board sheet 10 fed out of the printer slotter 12 is forwarded stably downstream as it is held between the pressure rolls 42 and the endless belts 20. In this process, the corrugated board sheet 10 is immobilized securely on the endless belts 20 under the suctional action, so that there is no fear of collapsing of the flutes of the corrugated board sheet 10, if the pressure of the pressure rolls 42 is set to an adequately small level. Meanwhile, in the zone where no pressure roll 42 is disposed, the corrugated board sheet 10 can be fed stably as immobilized securely on the endless belts 20 under the suctional action, as described above.

It should be noted that the folding apparatus described in the above embodiment is of a type where the required portions of the sheet are folded upward, but the present invention is not limited thereto, and a type where the required portions of the sheet are folded downward can also suitably be employed according to this invention. In the case of the latter folding apparatus where the required portions of the sheet are folded downward, it is recommendable that the guide bars be disposed below the level of the corrugated board sheet which is fed as securely immobilized on the endless belts under suction, whereby to prevent slippage of the sheet off the belts.

In the embodiments described above, while the corrugated board sheet forwarded from the upstream apparatus is designed to be folded along the creases, the apparatus of the invention can also be employed suitably when the unfolded corrugated board sheet is forwarded as such to the downstream apparatus securely with no displacement.

Claims

what is Claimed is:

1. A corrugated board sheet folding apparatus in which an unfolded corrugated board sheet (10) having been subjected to slotting and creasing processes can be fed and folded along the creases, said apparatus comprising:

a cylindrical holder (16) extended along the direction of feeding said corrugated board sheet (10) at least over the zone including the folding start position to the folding end position; a plurality of through holes (16a) defined along the longitudinal direction of said holder (16) with predetermined intervals therebetween; suction means (26) communicably connected to said holder (16) so as to provide a negative pressure within said holder (16); and an endless belt (20) having a plurality of through holes (20a) defined along the longitudinal direction with predetermined intervals therebetween and extended across a pair of rollers (22,24) rotatably supported on each longitudinal outer end of said holder (16); wherein said endless belt (20) is designed to run externally along the surface of said holder (16) having through holes (16a) defined therein during its downstream stroke, and to run internally within the holder (16) during its upstream stroke, so that said corrugated board sheet (10) can be fed as it is securely immobilized on the surface of the endless belt (20) in the downstream stroke with the aid of the suctional action exerted in said holder (16).

2. The corrugated board sheet folding apparatus according to Claim 1, wherein the communicable junction of said suction means (26) with said holder (16) is designed to be located on the same side where said through holes (16a) are defined relative to said endless belt (20) running within 12 said holder (26).

3. The corrugated board sheet folding apparatus according to Claim 1 or 2, wherein a guide (18) with a groove (18a) 5 communicating to the through holes (16a) of said holder (16) is disposed externally along the entire length of said holder (16), and said endless belt (20) is designed to run between a pair of ridges (18b) disposed to oppose to and spaced from each other with a predetermined distance in the direction orthogonal to the feeding direction of said corrugated board sheet (10) along the external surface of said guide (18).

4. The corrugated board sheet folding apparatus according to any of Claims 1 to 3, wherein a pair of said holders (16) are disposed parallel to and spaced from each other with a predetermined distance in the direction of feeding said corrugated board sheet (10), said holders (16) being designed to be approachable to each other with the aid of an adjust means (34).

5. A corrugated board sheet folding apparatus substantially as hereinbefore described with reference to Figs. 1 - 4, or Figs. 5 and 6 of the accompanying drawings.