GB2323566A - A folding groove applying machine with endless belts - Google Patents

Abstract

Folding grooves are applied to both faces of corrugated boards 42 by passage between upper and lower endless belts 10,12 having groove applying members 26,28 attached thereto.

Description

FOLDING GROOVE APPLYING MACHINE BACKGROUND OF THE INVENTION The present invention relates to a folding groove applying machine which is improved so that, when applying folding grooves necessary to produce corrugated boxes from corrugated board, paper (liner and medium paper) is not cracked (no folding grooves are broken).

DESCRIPTION OF THE RELATED ART Double faced corrugated board which is produced by adhering a liner to both the sides of medium paper to which corrugations are given, and double wall corrugated board which is produced by adhering a single faced corrugated board to the double faced corrugated board are continuously produced by a corrugating machine in which various units such a single facer, double facer, etc. are disposed in series. Since most of corrugated boards are finally assembled as corrugated boxes, the preparation activities necessary to produce corrugated boxes are carried out in the final process of said corrugating machine and in the processes coming thereafter.

For example, at the most downstream side of a corrugating machine, a corrugated board is cut off to an appointed dimension in the direction orthogonal to the corrugations by a slitter unit as shown by symbols a 1, r 2 in Fig.7(a). Similarly, as shown in Fig.7(a), two scores 92 are applied to the corrugated board 42 thus cut off with an appointed interval in the direction orthogonal to the corrugations. The corrugated board 42 to which the scores 92 are applied is piled in many layers in a stacking area 82 of a feeder 80 in the subsequent process shown in Fig.6 and the corrugated boards 42 are supplied one by one by an incorporated kicker to the first printer 84 and second printer 86 in the further downstream side. The corrugated board 42 which are printed in multi-color by these printers is caused to pass through a creaser unit 88 installed at the downstream side of the second printer 86, wherein as shown in Fig. 7(b), four creases 94 are given with appointed intervals in the direction parallel to the corrugations.

The corrugated board 42 to which the creases 94 are applied is caused to pass through a slotter unit 90 shown in Fig.6, wherein the corrugated board 42 is given slots 94 and corner slots 96 at appointed places on the creases 94 as shown in Fig.7(b), thereby flaps 99 necessary to produce a corrugated box are formed.

As described above, a folding groove applied to a corrugated board is classified into (1) a score which is orthogonal to the corrugations and (2) a crease which is parallel to the corrugations. A scorer unit which is used for applying the former score to a corrugated board and a creaser unit which is used for applying the latter crease thereto are called "Folding groove applying machine" as the general term.

A brief description is given of a folding groove applying machine with respect to the creaser unit. As shown in Fig.8, disks 15,17 are disposed opposite each other at a pair of rotating shafts vertically disposed in parallel.

An annular groove 15a is formed on the outer circumference of the upper disk 15, and an annular projection 17a is formed on the outer circumference of the upper disk 17. Said annular projection 17a is caused to face said annular groove 15a with an appointed clearance G. The clearance G is set to a dimension smaller than the thickness of double faced corrugated board or double wall corrugated board 42 to which creases are given. Therefore, in a case where said corrugated board 42 is forcibly caused to pass between the upper disk 15 (groove 15a) and the lower disk 17 (projection 17a), a crease is given to the corrugated board 42 in parallel to the corrugations. The principle of the scorer unit is identical to that of the creaser unit in that a score is given to a corrugated board by causing the same to pass between a pair of rotating disks although there are a few differences with respect to the shape of groove and projection.

Hereupon, with a conventional creaser unit (and scorer unit), there exist some shortcomings by which so-called cracks are caused on corrugated boards when applying folding grooves to the corrugated boards. That is, since with said conventional unit a corrugated board is caused to pass between a pair of rotating disks, the groove and projection formed on the rotating disks are brought into contact with the surface and back of a corrugated board at almost all the areas. Accordingly, when applying a folding groove, a mechanical stress given to a corrugated board is concentrated at the part roughly equivalent to a point on both the sides of the corrugated board, whereby cracks arise at the folding groove applied part conjointly with the paper quality and moisture of medium paper and liners, and various factors such as production speed, etc., and finally defective products result therefrom.

SUMMARY OF THE INVENTION In view of the shortcomings and problems described above, the present invention was proposed in order to preferably solve the abovementioned shortcomings and problems, and it is therefore an object of the invention to provide a folding groove applying machine by which folding grooves are applied to corrugated boards without any cracks when applying folding grooves to corrugated boards.

The invention which is able to preferably achieve the abovementioned object proposes a folding groove applying machine used for applying folding grooves to corrugated boards, wherein a pair of endless members, between which a channel through which corrugated boards pass is put, are disposed so as to travel, folding groove applying members are correspondingly secured on each of these endless members, and by causing the corrugated board to pass between the two corresponding endless members putting the corrugated board passing channel therebetween, both the surface and back of the corrugated board are pinched by the folding groove applying members, thereby causing folding grooves to be applied to appointed positions of the corrugated board.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.l is a partially cut off perspective view showing a preferred embodiment of a folding groove applying machine according to the invention.

Fig.2 is a longitudinally sectional view taken along the line II-II of Fig.2, which shows a state of feeding a corrugated board while being pinched by the upper and lower groove and projection.

Fig.3 is an explanatory view showing an example in which the upper endless belt is elevated with the parallelism secured with respect to the lower endless belt in a folding groove applying machine according to the preferred embodiment.

Fig.4 is an explanatory view showing an example in which the upper and lower endless belts are caused to swing in a folding groove applying machine according to the preferred embodiment.

Fig.5 is a longitudinally sectional view showing a brief construction of a mechanism for elevating and lowering the upper endless belt in a folding groove applying machine according to the preferred embodiment.

Fig.6 is an explanatory view showing a construction in which a creaser unit is disposed at the downstream side of the printer unit in series.

Fig.7(a) is a plan view of a corrugated board to which scores are applied by a scorer unit.

Fig.7(b) is a plan view showing a state where a corrugated board is given slots and corner slots after creases are applied to the corrugated board to which the scores are already applied.

Fig.8 is a front elevational view showing a brief construction of a folding groove applying mechanism of a creaser unit according to the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a description is given of a preferred embodiment of a folding groove applying machine according to the invention with reference to accompanying drawings. Although, in the preferred embodiment illustrated, a description is given of a folding groove applying machine in a creaser unit as an example, it is needless to say that the invention is applicable to a scorer unit as it is since the same aims at a folding groove applying machine.

Furthermore, since it is necessary to apply four creases onto a corrugated board with a creaser unit, four folding groove applying mechanisms are disposed as shown in Fig. 1. Herein, a detailed description is given of only one of the four folding groove mechanisms.

Endless belts 12,10 are disposed at a horizontal travelling channel S of corrugated boards in the creaser unit so that the travelling unit S is put therebetween. Both the belts are driven in the feeding direction of said corrugated boards. Recessed segments 28 are secured on the upper endless 12 belt at an appropriate interval while projected segments 26 are correspondingly secured on the lower endless belt 10 at an appropriate interval. Said recessed segments 28 and projected segments 26 cause a corrugated board 42 to be pinched in a linear contacting state, whereby creases are applied to the corrugated board.

That is, a drive side toothed pulley 18 (upper side) fixed at a drive shaft 34 is disposed above the board travelling channel S, and simultaneously a drive-side toothed pulley 14 (lower side) is secured at a drive shaft 30 beneath said board travelling channel S. Corresponding to the toothed pulleys 18,14, a toothed pulley 20 (upper side) fixed at the driven shaft 36 and a toothed pulley 16 (lower side) fixed at the driven shaft 36 are disposed at an appropriate interval above and beneath of the board travelling channel S in the downstream. An upper toothed belt 12 is applied between the upper drive side toothed pulley 18 and the driven side toothed pulley 20. Accordingly, the upper belt 12 is driven in the board feeding direction by rotation actions of the toothed pulley 18.

Furthermore, the lower belt 10 is applied between the lower toothed pulleys 30,16, whereby the lower belt 10 is driven in the board feeding direction by rotation actions of the toothed pulley 30. At the upper belt 12, a toothed pulley 24 for tensioning is disposed between both the toothed pulleys 18 and 20, thereby causing the tension of the belt 12 to be adjusted. Similarly, a toothed pulley 22 for tensioning is disposed between the toothed pulleys 14 and 16 to thereby adjust the tension of the belt 10.

A number of projected segments 26 are provided on the outer circumference of the lower belt 10 along the lengthwise direction at an appropriate interval. That is, the projected segment 26 is a small member which is a reversed V-shaped projection 26a extending in the belt direction as one of the examples is shown in Fig.2. The projected segment 26 is made of synthetic hard rubber, synthetic hard resin or other metallic material. For example, a dovetail 26b forming a reversed trapezoid is provided at the rear side of the projected segments 26, and a dovetail groove 10a which is able to house the dovetail 26a is provided on the surface of the lower belt 10. The respective projected segments 26 are retained without dropping or slipping off by inserting the dovetails 26b into the dovetail grooves 10a of the lower belt 10.

The lengthwise direction of the projected segments 26 and interval between the adjacent segments are suitably defined to such a degree that they do not disturb smooth travelling of the lower belt which retains the segments.

Furthermore, a number of recessed segments 28 on the outer circumference of the upper belt 28 at an appropriate interval in the lengthwise direction thereof. That is, as one of the examples is shown in Fig.2, the recessed segment 28 is a small member which is a trapezoidal recess 28a extending in the lengthwise direction of the upper belt. Similarly, they are made of synthetic hard rubber, synthetic hard resin or other appropriate metallic material. The recessed segments 28 are provided with a dovetail 28b at the rearside thereof, and are provided with a dovetail groove 12a which is able to house the dovetail 28b. The respective recessed segments 28 are retained without dropping or slipping off by inserting the dovetails 28 into the dovetail grooves 12a of the upper belt 12.

As shown in Fig.2, a reversed V-shaped projection 26a of the respective projected segments 26 is set to a dimension by which the same is able to slightly enter the recess 28a of the corresponding recessed segments 28. As described later, a corrugated board 42 of an appointed thickness is caused to pass between the two vertically corresponding belts 10,12, wherein a crease is applied to the corrugated board. In this case, it is preferable that back-up guide members 38,40 are correspondingly disposed along the inside of the belts 10,12 as shown in Fig. 1 in order to prevent the pinching force from being lowered due to outward deflections of the belts 10,12 by the projected segments 26 and recessed segments 28 being brought into contact with the corrugated board 42.

A folding groove applying machine according to the preferred embodiment drives the upper side endless belt 12 by an appointed mechanism as shown in Fig.5 and simultaneously elevates and lowers the upper side belt 12, whereby the interval G between the two endless belts 10,12 can be adjusted (Fig.2). For example, in Fig.5, the perpendicular main frame 44 has a sub frame 46 parallel to the main frame thereinside so that the sub frame 46 is suspended and retained so as to be elevated and lowered, wherein the upper belt 12 and a drive mechanism of the upper belt 12 are secured on the sub frame. That is, a fluid cylinder 50, the piston rod 52 of which is oriented downward, is supported at appropriate upper and lower positions inside the main frame 44, and the clevis 54 of the piston rod 52 is connected to the sub frame 46 via a linkage member 56. Although not illustrated in Fig.5, fluid cylinders 50 are also provided at this side or the deep side of the main frame 44 in a similar upper and lower relationship, whereby with the cylinders 50 the sub frame 46 is suspended and supported. Furthermore, at the left side of Fig.5, another main frame is correspondingly disposed, where another sub frame is suspended and supported by a mechanism similar thereto. Therefore, if a plurality of fluid cylinders 50 are synchronously operated normally or reversely, the corresponding sub frames 46,46 are able to be elevated and lowered only a necessary distance with respect to the main frames 44,44.

Furthermore, a movable frame 48 which incorporates the abovementioned upper belt 12 is disposed in parallel to the sub frames at the middle between the sub frames 46,46, and the movable frame 48 is able to shift laterally as necessary. That is, motors 60,60 for lateral shift are disposed on the sub frames at the upper and lower positions thereof, wherein a threaded shaft 62 is attached to the rotating shaft of each of the motors 60 and horizontally extends. Sliders 64,64 are disposed on the movable frame 48 at the upper and lower positions thereof, and the upper and lower threaded shafts 62 are correspondingly screwed in the female threaded part internally provided in these sliders 64,64. The drive shaft 34 of the toothed pulley 18 (upper side) described with reference to Fig.1 is rotatably supported, and the upper belt 12 is applied to the toothed pulley 18. Furthermore, a drive gear 78 is fixed at the drive shaft 34.

The main drive motor 66 is secured at the sub frame 46 shown in Fig.5, and the first gear 70 is fixed at the rotating shaft 68 of the motor 66. As in the above, a spline shaft 74 is rotatably supported in parallel to the threaded shaft 62, and the second gear 72 fixed at the spline shaft 74 is engaged with the first gear 70. Furthermore, a movable gear 76 is attached to the spline shaft 74 in such a manner that the same is axially slidable and non-rotatable in the circumferential direction, and the movable gear 76 is engaged with a drive gear 78 fixed at the drive shaft 34 which drives the upper belt 12. Therefore, if the main motor is caused to rotate in an appointed direction, power is transmitted in the order of the first gear 70, second gear 72, spline shaft 74, movable gear 76 and drive gear 78, whereby the upper belt 12 is driven in the corrugated board 42 feeding direction. If the motors 60,60 for lateral shift are caused to synchronously rotate normally or reversely, the sliders 64,64 are moved by rotation actions of the threaded shafts 62,62 and cause the upper belt 12 to laterally shift along with the movable frame 48. Although not illustrated, a mechanism similar to the above is employed with respect to the drive of the lower belt 10.

In the mechanism shown in Fig.5, if the fluid cylinders 50 are rotated normally or reversely as described above, the sub frames 46,46 opposite to each other are elevated and lowered a necessary distance with respect to the main frames 44,44. Therefore, as shown in Fig.3, with a folding groove applying machine according to the preferred embodiment, it is possible to elevate and lower the upper endless belt 12 with the parallel posture thereof retained with respect to the lower endless belt 10. By carrying out fine adjustment of the interval between the upper and lower endless belts 12, 10, it is possible to set the depth of creases and application degree thereof given to a corrugated board 12 to optimal values. Furthermore, in the preferred embodiment illustrated in Fig.4, it is possible to swing both the upper endless belt 12 and lower endless belt 10 centering around the driven shafts 36,32 located at the downstream thereof. That is, it is possible to set the interval between the upper and lower endless belts 12,10 to a large value at the inlet side of corrugated boards 42 and to set the same to a small value at the outlet side of the corrugated boards. In this case, it is possible to set the depth of creases and application degree thereof given to the corrugated boards to optimal values.

Thus, by starting the main drive motor 66 after the interval between the endless belts 10,12 is set to the optimal value, these endless belts 10,12 are driven in the feeding direction of corrugated boards 42. As shown in Fig. 1, a corrugated board 42 which horizontally comes in on the board travelling channel S is fed between the endless belts 10,12 which are thus driven, whereby the corrugated board 42 is fed to the downstream side while being pinched by the recessed segments 28 and projected segments 26 correspondingly disposed at each of the belts and creases 94 are given to appointed positions of the corrugated board in the course as shown in Fig.2.

At this time, since the recessed segments 28 and projected segments 26 are linearly brought into contact with the surface and rearside of the corrugated board 42, no so-called cracks are produced even though the quality of the medium paper and liners which compose a corrugated board 42 is lowered and the moisture thereof is not adequate. Therefore, the preferred embodiment has an advantage by which stabilized creasing can be carried out.

Furthermore, in the example illustrated, although toothed belts are used as the upper and lower endless belts, they may be any of endless members, which are able to travel, carrying a pair of segments which can apply folding grooves to a corrugated board in a linear contact with the corrugated board.

Therefore, they are not limited to toothed belts. For example, endless chains may be applied to a pair of sprockets disposed left and right, which may carry recessed segments and projected segments, or a so-called V-belt may be applied to a pair of left and right pulleys, and the V-belt may carry recessed segments and projected segments.

Furthermore, although the illustrated example shows that folding grooves are applied to a corrugated board by a combination of recessed segments and projected segments, one of the segments may be provided with projections and the other may be formed to be flat. The sectional shape of the respective segments which function as folding groove applying members can be adequately chosen, depending upon purposes and uses, etc. such as (1) whether the folding groove applying machine is a scorer unit with which scores are applied or a creaser unit with which creases are applied, and (2) whether or a corrugated board to which folding grooves are applied is a double faced corrugated board or a double wall corrugated board.

Furthermore, each of the segments forming a pair is constructed to be easily detachable with respect to endless members such as belts and chains, according to the difference of corrugated boards to which folding grooves are applied (for example, whether the corrugated board is a double faced corrugated board or a double wall corrugated board) and a wearing degree of the segments. Still furthermore, as a mechanism which makes the segments detachable with respect to endless members, as illustrated in the cross section in Fig.2, it is already proposed that a reversed trapezoidal dovetail is provided at the rearside of the segments and a dovetail groove is provided on the surface of the endless members. In this case, by inserting the dovetail of segments into the dovetail groove of the endless members, the segments can be detachably retained at the endless members without dropping and/or slipping.

It is not necessary that the segments described above are detachable for replacement with respect to the belts, chains, etc. They may be made integral with the endless members from the beginning. For example, when producing endless belts using, for example, synthetic hard resin, it is proposed that a folding groove applying member, the section of which constitutes a projection, and a folding groove applying member, the section of which constitutes a recess, are molded integrally with the portions at the surface of the belts.

Claims (9)

What is claimed is:

1 A folding groove applying machine used for applying folding grooves to corrugated boards, wherein a pair of endless members (10,12), between which a channel (S) through which corrugated boards (42) pass is put, are disposed so as to travel, folding groove applying members (26,28) are correspondingly secured on each of said endless members (10,12), and by causing the corrugated board to pass between the two corresponding endless members (10,12) putting the corrugated board passing channel (S) therebetween, both the surface and back of the corrugated board (42) are pinched by the folding groove applying members (26,28), thereby causing folding grooves (92,94) to be applied to appointed positions of the corrugated board (42).

2 A folding groove applying machine as set forth in claim 1, wherein said pair of endless members are endless toothed belts (10,12) and these toothed belts (10,12) are applied to toothed pulleys (14,16, 18,20) each making a pair at the left and right sides.

3 A folding groove applying machine as set forth in claim 1, wherein said pair of endless members are endless chains (10,12) and these chains (10,12) are applied onto sprockets (14,16,18,20) each making a pair at the left and right sides.

4 A folding groove applying machine as set forth in claim 1, wherein said pair of endless members are endless V-belts (10,12), and these V-belts (10,12) are applied to pulleys (14,16,18,20) each making a pair at the left and right sides.

5 A folding groove applying machine as set forth in any of claims 1 through 4, wherein said folding groove applying members are composed of segments (26), the section of which constitutes a projection, and segments (28), the section of which constitutes a recess.

6 A folding groove applying machine as set forth in any of claims 1 through 4, wherein said folding groove applying members are composed of segments (26), the section of which constitutes a projection, and segments (28), the section of which are made flat.

7 A folding groove applying machine as set forth in claim 1, wherein folding groove applying members (26,28) making a pair at the upper and lower parts is made movable bynchronously in the direction crossing the feeding direction of corrugated boards in response to changes of the positions of folding grooves (92,94) to be applied to said corrugated boards (42).

8 A folding groove applying machine as set forth in claim 1, wherein said folding grooves applying members are detachable for replacement as necessary with respect to each of the corresponding endless members (10,12).

9. A folding groove applying machine substantially as hereinbefore described with reference to Figs. 1 - 7 of the accompanying drawings.