ROTARY DRUM TYPE CUTTING APPARATUS

Abstract: The improvements reside in that the respective drums (3) are severed in their axial directions into two drum sections (3a, 3b), respectively, and the two left and right pairs of severed drum sections are respectively driven in an independent manner. After cutting the web (2) longitudinally, the two parts (2a, 2b), can be cut according to different lengths.

Description: The present invention relates to a rotary drum type cutting apparatus as defined in the preamble of claim 1 for cutting a continuously fed sheet-like article such as, for example, a corrugated cardboard sheet, various kinds of paper sheets, a thin steel sheet or the like into predetermined lengths. Such a cutting apparatus is known from US-A-3 107 589. In the following, description will be made on a further rotary type drum shear applicable to a corrugate machine which is a corrugated cardboard making equipment representative as a prior art of such kind. A general structure and functions of a cut-off section of the known type equipped in a corrugate machine are shown in Figs. 5 to 8. Rotary type drum shears 3, 3 equipped at a cut-off section are apparatuses for cutting a corrugated cardboard sheet 1 continuously fed from the preceding stage nearly at right angles to the direction of traveling, and its general structure is as shown in Fig. 8. More particularly, the rotary type drum shear 3 in the prior art includes a pair of upper and lower hollow knife cylinders 4 and 5 disposed rotatably, onto the circumferential surfaces of these knife cylinders 4 and 5 are fixedly secured elongated knives 6 and 7, respectively, of linear or spiral shape nearly in parallel to their axial directions, also the upper and lower knife cylinders 4 and 5 are rotated in the opposite directions to each other so that the respective knives 6 and 7 may engage once during one revolution, and thereby the corrugated cardboard sheet 1 fed between the upper and lower knife cylinders 4 and 5 can be sheared. The knife cylinders 4 and 5 having the knives 6 and 7 fixedly secured thereto are rotatably mounted to their respective shafts 9 and 10 via bearings 8 interposed at the opposite end portions of the cylinders, and these shafts 9 and 10 are supported via taper sleeves 11 from frames 12 and 13 provided uprightly at the opposite ends of the width of the apparatus. In addition, at the both end portions of the above-described knife cylinders 4 and 5 are respectively mounted gears 14 and 15, and they are meshed with each other. Furthermore, the lower gear 15 is meshed with a gear 19 which is fixedly secured to a tip end of a drive shaft 18 that is connected to an output shaft of a prime mover 16 via a coupling 17. The above-described gears 14 and 15 have an equal number of teeth, and so, the knife cylinders 4 and 5 are rotated in the opposite directions with a same phase angle as driven by the prime mover 16. In Fig. 8, reference numeral 24 designates bearings for rotatably supporting the drive shaft 18 from the frame 13. Since the knives 6 and 7 in the rotary type drum shear 3 in the prior art are mounted to the knife cylinders 4 and 5, respectively, over their almost entire lengths, in the case where two kinds of product sheets 2a and 2b having different lengths are to be produced from a single corrugated cardboard sheet 1, it is necessary to provide two sets of rotary type drum shears 3 having the above-described structure as disposed at two, upper and lower levels, and normally they are equipped as shown in Figs. 6 to 9. Next, description will be made on setting of a traveling corrugated cardboard sheet and functions (control for cutting) of the apparatus. Figs. 5 to 7 illustrate the case where two kinds of product sheets 2a and 2b having different lengths are produced from a single corrugated cardboard sheet 1. As shown these figures, a continuously traveling corrugated cardboard sheet 1 is subjected to scoring work (K) by scoring rolls 25 in a slitter-scorer just preceding the cut-off section, and thereafter it is slitted by slitter knives 26 to be severed into two sheets 2a and 2b. The severed sheet 2a on one side is fed in the horizontal direction through a lower traveling route, and is cut into lengths ℓ₂ in Fig. 5 by a rotary type drum shear 3a at the lower position. On the other hand, the severed sheet 2b on the other side has its traveling route diverted upwards by an assorting device 27, and then it is cut into lengths ℓ₁ in Fig. 5 by the other rotary type drum shear 3b positioned at the upper level. In Figs. 5 and 6, reference numeral 22a and 22b designate rollers having predetermined diameters for measuring traveling speeds of the severed respective sheets 2a and 2b, which rollers pinch the corrugated cardboard sheets 2a and 2b, respectively, jointly with opposed receiver rolls 28, numbers of revolutions per unit time of the revolving rollers 22a and 22b are detected by encoders 29a and 29b, and fed back to the prime mover 16, and thereby drive and stoppage of the prime mover 16 are controlled so that the knives 6 and 7 may act at the timing corresponding to the respective product lengths ℓ₁ and ℓ₂, respectively. The product sheets 2a and 2b cut into the predetermined lengths ℓ₁ and ℓ₂ are transported to the next step of the process via transport conveyors 23a and 23b, respectively, and at an auto-stacker which forms the final stage, they are carried out to the outside as a bundle of stacked sheets. Nowadays, frequently product sheets 2a and 2b having different lengths are simultaneously produced in a same corrugate machine for the purpose of achieving improvement in productivity. However, as the rotary type drum shear 3 in the prior art is constructed and operates in the above-described manner, in view of the structure of the apparatus, there still remain a lot of inconveniences such as rise of a manufacturing cost, increase of an installation area (volume) and the like. As described above, the rotary type drum shear equipped at the cut-off section in the prior art is provided with long knives constructed so as to be able to cut the maximum width of a corrugated cardboard sheet which can travel through the shear, and for instance, in the case of making two kinds of sheets having different lengths, not only an assorting device for diverting a traveling route of the sheet is necessitated, but also two sets of cutting apparatuses to be disposed at two, upper and lower levels become necessary. Furthermore, in this connection, sheet transport means such as sheet guide rolls, belt conveyors and the like are all necessitated to be installed two sets, and this was the cause of great rise of the installation expense. Also, upon diverting a traveling route of the sheet, since there may occur an inconvenience such as breaking of the sheet, it is impossible to design an extremely acute bending angle, hence an interval between a slitter and a cut-off section must be chosen large, and hence there is a shortcoming that installation lengths (floor area) or a volume of the apparatus is enlarged. It is therefore one object of the present invention to provide a novel rotary drum type cutting apparatus which is free from the above-described shortcomings in the prior art. A more specific object of the present invention is to provide an improved rotary drum type cutting apparatus in which an installation expense is reduced and space saving can be achieved. According to one feature of the present invention, there is provided a rotary drum type cutting apparatus in which a continuously traveling sheet-like article is cut into predetermined lengths by making the sheet-like article pass between a pair of drums which have elongated knives on their circumferential surfaces and are synchronously rotating in the opposite directions to each other, and in which the respective drums are severed in their axial directions into two drum sections, respectively, and the two, left and right pairs of severed drum sections are respectively driven in an independent manner. Preferably, the above-featured rotary drum type cutting apparatus is fixedly secured to a movable member, and the movable member can be set as moved in the widthwise direction of the cutting apparatus so as to be adapted to a slitted slot position on the traveling sheet-like article. According to the present invention, when it is contemplated to produce simultaneously two kinds of products having different lengths from an elongated sheet-like article that is being fed continuously, the main body of the rotary drum type cutting apparatus is preset so as to be aligned with a slitting position (position of a slitted slot) on the sheet-like article, and the two, left and right pairs of severed drum sections are actuated so as to match with the lengths of the respective products. Then in the same sheet traveling route, two kinds of products having different lengths can be produced simultaneously. Thereby, simplification of various equipments which may be associated as a result of change of the traveling route of the sheet, as well as reduction of an installation space can be realized. The above-mentioned and other objects, features and advantages of the present invention will become more apparent by reference to the following description of one preferred embodiment of the invention taken in conjunction with the accompanying drawings. In the accompanying drawings: Fig. 1 is a plan view showing an operating state of a rotary type drum shear for corrugated cardboard sheets according to one representative embodiment of the present invention; Fig. 2 is a side view of the same; Fig. 3 is a front view of the same; Fig. 4 is a cross-section view showing a detailed structure of the same apparatus, taken along line A-A in Fig. 2 as viewed in the direction of arrows; Fig. 5 is a plan view showing an operating state of a rotary type drum shear for corrugated cardboard sheets in the prior art; Fig. 6 is a side view of the same; Fig. 7 is a front view of the same; and Fig. 8 is a cross-section view showing a detailed structure of the same apparatus taken along line B-B in Fig. 6 as viewed in the direction of arrows. Figs. 1 to 4 illustrate a general structure and functions of a cut-off section provided in a corrugate machine according to one preferred embodiment of the present invention. The illustrated cut-off section is similar to the already described apparatus in the prior art with respect to the point that it cuts a corrugated cardboard sheet 1 continuously fed from the preceding stage nearly at right angles to the traveling direction of the sheet 1. A characteristic feature of the present invention resides in that the cutting apparatus has such construction that when two kinds of product sheets 2a and 2b having different lengths are to be produced from a traveling single corrugated cardboard sheet 1, it can be achieved without branching the traveling route of the sheet into upper and lower routes as is the case with the heretofore known apparatus. Now description will be made in greater detail on the structure in connection to the illustrated embodiment. A rotary type drum shear 3 according to this preferred embodiment is provided with two sets of drum shears 3a and 3b severed nearly at the center as illustrated in Fig. 4, and the respective drum shears can be driven individually. The respective ones of the two sets of rotary type drum shears 3a and 3b comprise pairs of upper and lower hollow cylinders 4a, 5a and 4b, 5b, onto their circumferential surfaces are fixedly secured linear or spiral knives 6a, 7a and 6b, 7b, respectively, nearly in parallel to their axial directions, the respective knives 6a, 7a and 6b, 7b are engaged with each other by rotating the respective upper and lower hollow cylinders 4a, 5a and 4b, 5b in the opposite directions to each other, and thereby the corrugated cardboard sheet 1 can be sheared. The respective hollow knife cylinders 4a, 5a and 4b, 5b having the knives 6a, 7a and 6b, 7b fixedly secured thereto, are rotatably supported from two upper and lower shafts 9 and 10 via bearings 8, 8, 8, 8 interposed at the both end portions of the respective cylinders, and the respective shafts 9 and 10 are supported via taper sleeves 11 from frames 12 and 13 provided uprightly at the opposite ends of the width of the apparatus. In addition, gears 14a, 14b and 15a, 15b are respectively mounted to the respective frame side end portions of the above-mentioned left and right knife cylinders 4a, 4b and 5a, 5b, and the respective upper and lower gears 14a, 15a and 14b, 15b are meshed with each other. Furthermore, the lower gears 15a and 15b are respectively meshed with drive gears 19a, 19b fixedly secured to the tip ends of shafts 18 which are connected via couplings 17 to shafts of separate prime moves 16a, 16b. The above-mentioned gears 14a and 15a, and the gears 14b and 15b respectively have equal numbers of teeth. The rotary type drum shear 3 constructed in the above-described manner is installed on a base 21 which is movable via traversing means such as traveling wheels 20 or the like, so that it can move in the widthwise direction of the traveling corrugated cardboard sheet 1 to make setting of a slitting position. It is to be noted that scoring rolls 25 and slitter knives 26 similar to those in the heretofore known apparatus shown in Figs. 5 to 8 are provided on the upstream side in the sheet traveling direction of the drum shear 3. Next, description will be made on setting of the traveling corrugated cardboard sheet 1 and functions (control for cutting). Figs. 1 to 4 illustrate the case of double size production where two kinds of product sheets 2a, 2b having different lengths are produced from a single corrugated cardboard sheet 1. As shown in these figures, after a continuously traveling corrugated cardboard sheet 1 has been subjected to scoring work (K) in a slitter-scorer, it is severed into two slitted sheets. The severed sheet on one side has its traveling speed detected by means of a measuring roller 22a, and it is cut into the lengths ℓ₂ by actuation of the rotary type drum shear 3a as controlled by feedback of the detection signal. On the other hand, the severed sheet on the other side has its traveling speed detected by a measuring roller 22b disposed in juxtaposition to the above-mentioned measuring roller 22a, and it is cut into the lengths ℓ₁ by actuation of the rotary type drum shear 3b on the other side as controlled by feedback of the detection signal. The product sheets 2a and 2b cut in the above-described manner are transported to the subsequent stage at the downstream via transport conveyors 23a and 23b. Since the cutting apparatus according to the present invention is constructed and operates in the above-described manner, if the position in the sheet widthwise direction of the rotary type drum shear 3 is preset so as to be adapted to the position of the slitting slot S on the sheet, then many kinds of different product sheets 2a, 2b can be produced simultaneously. In addition, as a matter of course, if the operation timings of the two sets of drum shears 3a and 3b are adjusted, it is also possible to achieve cutting over the entire width of the corrugated cardboard sheets. As will be seen from the detailed description, since the rotary drum type cutting apparatus according to the present invention is equivalent in structure to two, left and right sets of rotary drum type cutting apparatus having a pair of upper and lower shafts used in common and placed in juxtaposition to each other, if the cutting apparatus mainbody is disposed at the slitting slot position on the traveling sheet-like article and the respective ones of two pairs of upper and lower drums are operated independently in correspondence to the respective sheet traveling speeds and the product lengths, then two kinds of products can be produced simultaneously in the same sheet traveling route. As a result, the present invention affords the following advantages: (1) Various equipments resulted from change of a traveling route of a sheet-like article can be simplified, and a manufacturing cost of the apparatus can be lowered. (2) Especially in the case of a corrugated cardboard sheet, counter-measures against bending resulted from change of a traveling route become unnecessary, and in this connection a distance between a slitter and a cut-off section can be shortened. That is, reduction of installation area and volume can be achieved. (3) Not only the cut-off sections, but also the entire manufacturing installation including the preceding and succeeding stages can be small-sized and light-weighted, carrying to the field and installation at the field become easy, and so, reduction of the relevant expense becomes possible.

Claims: A rotary drum type cutting apparatus, in which a continuously traveling sheet-like article (1) is cut into predetermined lengths (l₁,l₂) by making said sheet-like article pass (1) between a pair of drums (4,5) which have elongated cutting knives (6a,7a,6b,7b) on their circumferential surfaces and are synchronously rotating in the opposite directions to each other; characterized in that said respective drums (4,5) are severed in their axial directions into two drum sections (4a,4b,5a,5b), respectively, and the two, left and right pairs of severed drum sections are respectively driven in an independent manner. A rotary drum type cutting apparatus as claimed in Claim 1, characterized in that gears meshing (15a) with each other are provided on the frame side (12) of one pair of severed drum sections (4a,5a) on one side and also on the frame side (13) of one pair of severed drum sections (4b,5b) on the other side, and the numbers of teeth of the gear meshing with each other are made identical. A rotary drum type cutting apparatus as claimed in Claim 1, characterized in that said rotary drum cutting apparatus is mounted on a movable member (21), said movable member (21) being movable in the width direction of said cutting apparatus so as to be adapted to a slitted slot position on the traveling sheet-like article (1).

Inventors: SEKI, YUKUHARU, SEKI, YUKUHARU, C/O MIHARA MACHINERY WORKS
Applicants: MITSUBISHI JUKOGYO KABUSHIKI KAISHA
Application year: 1990
Main classification: B26D1
IPC codes: B25B3, B26D11, B26D1, B31B1, B23D25