Method of and apparatus for folding and shaping sheet

Abstract: A method of folding and shaping a sheet, by which a sheet formed with a single or a plurality of mountain-shaped folds and a single or a plurality of valley-shaped folds, the first and second folds being parallel and alternate, can be rapidly and smoothly folded and shaped, and an apparatus therefor. The method comprises the steps of supplying a sheet (1) in a naturally developed state onto a support guide (3), and applying a light pressing pressure on the sheet (1) in a direction, in which folds (10, 11) are increased in bent angles, by means of a pressing guide (6), which acts in a direction of moving toward and away from a support surface of the support guide (3) when a pair of bending tools (5a, 5b) begin to apply bending pressures on the sheet (1) or are in the course of applying bending pressures on the sheet (1) while applying bending pressures on the sheet (1) in a direction, in which the sheet (1) is bent along the respective folds (10, 11). The sheet (1) can be correctly and smoothly folded and shaped along the respective folds (10, 11).

Description: Technical Background This invention relates to, in general, a method of folding and shaping a sheet and an apparatus for folding and shaping a sheet. More specifically, it relates to a method of manufacturing a predetermined block body by folding and shaping a sheet formed with a single or a plurality of ridge-like fold(s) to which directional permanency of inward folding is imparted and a single or a plurality of valley-like fold(s) to which directional permanency of outward folding is imparted in parallel and alternately, and an apparatus therefor. Related Art of Invention It has been proposed to manufacture a block body by forming ridge-like folds to which directional permanency of inward folding (folding habit) is imparted and valley-like folds to which directional permanency of outward folding is imparted in parallel and alternately on a sheet having a hardness of some extent and capable of being folded easily such as a pasteboard or a corrugated cardboard and folding the sheet in zigzag along the above-mentioned folds. Such a manufacture method and apparatus are known from WO 95 31 330 A, which forms the basis of the preamble of claims 1 and 4. It has been also proposed to manufacture a hollow block body by forming a plurality of ridge-like folds and a plurality of valley-like folds on a sheet as mentioned above in parallel and alternately and folding the sheet along the folds (Japanese Patent Application No. 7-237405). In the inventions of the above-mentioned prior applications, it is proposed that the above-mentioned block bodies are used for a frame body or cushioning member for packaging, a core member of an adiabatic panel, a supporting material for various kinds of adsorbent or the like. In addition, it is proposed that the sheet is preferably pressed in the direction of folding along the respective folds in order to fold the sheet formed with the folds as mentioned above in zigzag or shape into a block body. It is, however, a problem that the sheet can not be folded and shaped smoothly and quickly when the sheet formed with the folds as mentioned above is placed on a predetermined plane and the folding pressure is added to the sheet in the direction of folding along the respective folds by a suitable pressing means, because the part of the sheet is raised from the surface or bounds upward due to resilience of the folds of the sheet. Disclosure of the Invention An object of the present invention is to provide a method of folding and shaping a sheet, which enables to manufacture a block body by quickly and smoothly folding the sheet formed with a single or plural ridge-like fold(s) to which directional permanency of inward folding is imparted and a single or plural valley-like fold(s) to which directional permanency of outward folding is imparted in parallel and alternately. Another object of the present invention is to provide an apparatus for folding and shaping a sheet, in which the method capable of solving the above-mentioned problem is performed more efficiently. In order to attain the above object, the method of folding and shaping a sheet according to the present invention is constituted as defined in claim 1. According to the method of folding and shaping a sheet of the first mode, in the process of applying the folding pressure to the sheet in the direction of folding along the ridge-like folds and the valley-like folds to which directional permanency of folding is imparted, addition of the light pushing pressure to the sheet in the direction of widening the folding angles of the ridge-like folds and the valley-like folds prevents the part of the sheet to be raised from the working position or bound toward the direction of the ridge-like folds. Therefore, the sheet can be folded and shaped along the respective ridge-like folds and the valley-like folds accurately, quickly and smoothly. Further embodiments of the method are defined in dependent claims 2 and 3. In order to attain the above-mentioned object, an apparatus for folding and shaping a sheet according to the present invention is constituted as defined in claim 4. Further embodiments of the apparatus are defined in dependent claims 5 to 12. Brief Description of Drawings Figure 1 is a schematic front view of a sheet folding and shaping apparatus according to one embodiment of the present invention. Figure 2 is a schematic plan view of support guides and a drive system associated therewith in the apparatus shown in Figure 1. Figure 3 is a schematic plan view of pressing guides and a drive system associated therewith in the apparatus shown in Figure 1. Figure 4 is a schematic plan view of lower pressing guides and a drive system associated therewith. Figure 5 is a partial right side view of the apparatus in Figure 1. Figure 6 illustrates a schematic partial view of a sheet used in a method of folding and shaping a sheet according to the first embodiment. Figure 7 is a schematic front view of the apparatus for explanation of the method for folding and shaping a sheet in accordance with the first embodiment of the present invention. Figure 7(a) is a partial front view showing that a sheet is supplied onto the support guide, and Figure 7(b) is the same showing that the sheet is folded and shaped. Figure 8 illustrates a schematic partial view of a sheet used in a method of folding and shaping a sheet according to the second embodiment. Figure 9 is a schematic front view of the apparatus for explanation of the method for folding and shaping a sheet in accordance with the first embodiment of the present invention. Figure (e) is a partial front view showing that a sheet is supplied onto the support guide, and Figure (f) is the same showing that the sheet is folded and shaped. Figure 10 illustrates a schematic partial view of a sheet used in a method of folding and shaping a sheet according to the third embodiment. Figure 11 illustrates the states before and after shaping the sheet used in a method of folding and shaping a sheet according to the third embodiment. Figure (g) is a side view of the sheet in spontaneously developed state, and Figure (h) is a side view of a block body obtained by folding the sheet. Figure 12 is an oblique view of the block manufactured by the method of folding and shaping a sheet according to the first embodiment of the present invention. Figure 13 is an oblique view of a block body of Figure 12 made into three-dimension for a frame body for packaging. Detailed Description of Preferred Embodiments The sheet folding and shaping apparatus according to preferred embodiments of the present invention will now be explained with reference to accompanying drawings. [Embodiment 1] Figure 1 is a schematic front view of a sheet folding and shaping apparatus according to the present invention, Figure 2 is a schematic plan view of support guides and a drive system associated therewith in the apparatus shown in Figure 1, Figure 3 is a schematic plan view of pressing guides and a drive system associated therewith in the apparatus shown in Figure 1, Figure 4 is a schematic plan view of lower pressing guides and a drive system associated therewith, Figure 5 is a partial right side view of the apparatus in Figure 1, Figure 6 illustrates a schematic partial view of a sheet, and Figures 7(a) and 7(b) are a schematic front view of the apparatus showing a method for folding and shaping a sheet in accordance with the present invention. Figure 7(a) is a partial front view showing that a sheet is supplied onto the support guide, and Figure 7(b) is the same showing that a sheet is folded and shaped. A side portion (upper portion in Figure 2) of a sheet folding and shaping apparatus of the present embodiment is provided with a pasting apparatus (not shown). A sheet 1, both sides of which paste is applied to, is supplied along an arrow c in Figure 2 onto a support guide 3 which is a working position d of the sheet folding and shaping apparatus in a spontaneously developed state. The sheet 1, which is a work to be processed by the folding and shaping apparatus, is a corrugated cardboard. As shown in Figure 6, the sheet 1 is formed with folds 10 to which directional permanency of ridge-like folding is imparted and folds 11 to which directional permanency of valley-like folding is imparted alternately and in parallel. These ridge-like and valley-like folds 10, 11 intersect corrugations of the corrugated cardboard. When applying paste in a preliminary treatment, the both sides of the sheet 1 are formed with non-paste portions 13 at given intervals in a direction intersecting the ridge-like and valley-like folds 10, 11. The portions other than the non-paste portions 13 become paste portions 12. In the sheet 1 shown in Figure 6, the paste portions 12 and non-paste portions 13 of both sides are positioned back to back. However, they need not be positioned back to back. Since the above mentioned folds 10, 11 of the sheet 1 have elasticity to some extent, each of the folds 10, 11 spontaneously developed is bent in a direction where directional permanency of folding is applied slightly, and therefore, the whole sheet 1 corrugates slightly. In this embodiment, as shown in Figures 1 and 2, the support guide 3 is consisting of 6 (six) rod-shaped support guides 30, 31, 32, 33, 34 and 35. These support guides 30 to 35 are positioned on a base 2 along a direction which intersects the folds 10, 11 of the supplied sheet 1. Each of support guides 30 to 35 in this embodiment, as shown in Figures 1 and 2, is arranged to be guided by two of guide rails 20, 21, 22 and 23 fixed on the base 2 in a state that they intersect support guides 30 to 35, and to be moved by one of the respective adjusting drive means 40, 41, 42, 43, 44 and 45 along the guide rails 20 to 23. In this embodiment, the support guides 30, 32 and 35 are supported by the guide rails 20 and 21 via linear bearings 24 and 25 (see Figure 1), and the other support guides 31, 33 and 34 are guided by the guide rails 22 and 23 via linear bearings 26 and 27. The adjusting drive means 40 to 45 consist of respective motors 400, 410, 420, 430, 440 and 450 fixed to one side of the base 2 and screw shafts 401, 411, 412, 413, 414 and 415, which are rotatably supported by the respective bearing members 402, 412, 422, 432, 442 and 452 having tips fixed to the other side of the base 2 and are connected to the respective motors 400 to 450. The screw shafts 401, 411, 421, 431, 441 and 451 penetrate through respective screw guides 403, 413, 423, 433, 443 and 453. The screw guides 403, 413, 423, 433, 443 and 453 are connected to the support guides 30, 31, 32, 33, 34 and 35, respectively. Accordingly, each of the motors 400 to 450 operate so as to make the respective one of the support guides 30 to 35 move along the guide rails 20 and 21 or the same 22 and 23, whereby the distances between and positions of support guides 30 to 35 are adjusted. In this embodiment, although servo motors are used as the above mentioned motor 400, 410, 420, 430, 440 and 450, stepping motor or the like may be used. As shown in Figure 2, the support guides 30, 32 and 35 are provided with pushers, which are folding tools 5a, at one side thereof. Each of the pushers 5a reciprocates by the moving drive means 5 provided in association with the respective support guides 30 ,32 and 35 such that it moves toward a stopper which is the other folding tool 5b described later and thereafter returns to the illustrated original position. In this embodiment, each of the support guides 30, 32 and 35 is fixed to base plates 3a and 3b at both ends thereof. Each of moving drive means 5 includes a servo motor 50 mounted on the base plate 3a, a geared pulley (or a sprocket) 51 mounted on the base plate 3a, a geared pulley (or a sprocket) 52 mounted on the other base plate 3b, a timing belt (or a chain belt) 53 wound around the geared pulleys 51, 52 and connected to the pusher 5a, and a guide rail 54 positioned over the base plates 3a and 3b along the timing belt 53. The pusher 5a is guided by the guide rail 54 via a linear bearing (not shown). Accordingly, clockwise or counterclockwise rotation of each of the servo motor 50 makes the respective one of pushers 5a reciprocate along the guide rail 54 at a predetermined stroke. A pressing guide 6 is located above the support guide 3. As shown in Figure 3, the pressing guide 6 includes rod-shaped pressing guides 60, 61, 62, 63, 64 and 65 facing the respective support guides 30, 31, 32, 33, 34 and 35. As shown in Figures 1 and 3 to 5, at the 4 (four) corners on the base 2, columns 2b stand vertically, and frames 2a, 2a are fixed to the respective columns 2b like bridges. A pair of columns 2c, 2c stand vertically on the frames 2a, 2a. The columns 2c, 2c are connected via a bridge-like frame 2d at their upper ends. The columns 2c, 2c are provided with a drive mechanism 7 which makes each of the pressing guides 60 to 65 rise and fall in such a way that it moves toward and away from the support guides 30 to 35. The drive mechanism 7 is provides with a servo motor 70 mounted to the upper portion of one of the columns 2c via a bracket 2e, screw shafts 71, 71 rotatably supported along the respective columns 2c, 2c, and a speed reducer 72 which reduces the rotation speed of the servo motor 70 and transfers the reduced rotation to the one screw shaft 71 and via a transfer shaft 73 and rotation transform means 74 to the other screw shaft 71. The drive mechanism further includes screw guides 75, 75 through which the respective screw shafts 71, 71 penetrate, rail-like guides 76, 76 positioned vertically along the respective columns 2c, 2c, and a movable frame 78 linked to the guides 76, 76 via linear bearings 77, 77 and connected to the screw guides 75, 75. Pairs of vertical bars 600, 610, 620, 630, 640 and 650 are connected, at their lower ends, to the respective pressing guides 60 to 65. The vertical bars 600, 610, 620, 630, 640 and 650 of the pair are connected with each other, at the upper end thereof, by horizontal bars 601, 611, 621, 631, 641 and 651 respectively. The horizontal bars 601 to 650 are connected to the movable frame 78. Accordingly, when the screw shafts 71, 71 are rotated as the servo motor 70 rotates, the screw guides 75, 75 rises and falls accompanied with the pressing guides 60 to 65 and the movable frame 78. Each of the pressing guides 60 to 65 according to this embodiment is constituted so that it is guided by one pair of guide rails 2f, 2h or 2g, 2I which are mounted so as to intersect the pressing guides 60 to 65, and moved along the guide rails 2f to 2I by the respective one of the adjusting drive means 80, 81, 82, 83, 84 and 85. In this embodiment, rod-shaped movable bases 602, 612, 622, 632, 642 and 652 are provided corresponding to the pressing guides 60, 61, 62, 63, 64 and 65. The movable bases 602, 622 and 652 are guided by the upper guide rails 2f and 2h shown in Figures 1 and 3 via linear bearings (not shown). On the other hand, the other movable bases 612, 632 and 642 are guided by the lower guide rails 2g and 2i shown in Figures 1 and 4 via linear bearings (not shown). The adjusting drive means 80 to 85 includes motors 800, 810, 820, 830, 840 and 850 fixed to one of the frames 2a and screw shafts 801, 811, 821, 831, 841 and 851 rotatably supported by the bearing members 802, 812, 822, 832, 842 and 852, which are connected, at their ends, to the other of the frames 2a, and connected to the motors 800 to 850, respectively. The screw shafts 801, 811, 821, 831, 841 and 851 penetrate through the respective screw guides 803, 813, 823, 833, 843 and 853. The screw guides 803, 813, 823, 833, 843 and 853 are connected to the movable bases 602, 612, 622, 632, 642 and 652, respectively. The vertical bars 600, 610, 620, 630, 640 and 650, shown in Figures 3 and 4, connected to the respective pressing guides 60 to 65 connect with the respective movable bases 602, 612, 622, 632, 642 and 652 so as to enable them to move in a vertical direction. Accordingly, the respective pressing guides 60 to 65 are moved along the pair of guide rails 2f, 2h or 2g, 2i by operation of the motors 800 to 850 and, thereby, the distances therebetween or positions thereof are adjusted as desired. In this embodiment, although the servo motors are used as the motors 800, 810, 820, 830, 840 and 850, stepping motors or the like may be used. In the apparatus according to this embodiment, as shown in Figures 1 and 3, the stoppers, which are the other folding tools 5b, are mounted to the respective movable bases 602, 622 and 652 via the brackets 5d so as to be horizontally moved together with the respective pressing guides 60, 62 and 65, and rise and fall to a predetermined extent along the guides 5e using the respective actuators 5c constituted by respective air cylinders. [First Working Example of Sheet Folding and Shaping Method] A working example of the sheet folding and shaping method will now be explained as well as the operation of the folding and shaping apparatus according to the above mentioned embodiment. Before the apparatus starts working, each of the motors 400 to 450 and 800 to 850 is operated so as to adjust the distances between the adjacent support guides 30 to 35 and pressing guides 60 to 65 according to a design of the folds 10, 11, paste portions 12 and non-paste portions 13 of sheet 1 shown in Figure 6. As adjusting these distances, the pushers 5a, moving drive means 5 and stoppers 5b are moved. At this moment, if the number of streaks of the non-paste portions in sheet 1 is small, or if the width of sheet 1 (i.e. the length in a direction of folds 10, 119) is narrow, and therefore, some of the support guides 30 to 35 and the pressing guides 60 to 65 are unnecessary, the unnecessary ones in the support and pressing guides 30 to 35 and 60 to 65 are moved upward in the apparatus shown in Figures 2 and 3. The sheet 1 is supplied to the working position d in such an orientation that each of the folds 10, 11 is perpendicular to the support guides 30 to 35 and the pressing guides 60 to 65. When the sheet 1 is supplied to working position d , namely, onto the support guides 3, the support guide 3 comes into contact with the non-paste portions 13 of sheet 1 and the pressing guide 6 positions just above the non-paste portions 13. After the sheet 1 is supplied onto the support guide 3, the actuators 5c lower the stoppers 5d, while the servo motor 70 lowers the pressing guide 6 as shown in Figure 7 (a) so as to apply a light pressing pressure to the spontaneously developed sheet 1 in a direction in which bent (folding) angles of the folds 10, 11 are widen. At this situation, the servo motor 50 shown in Figure 2 is activated to move the pusher 5a toward the stopper 5b. Since the sheet 1 is gradually folded in a way that the bent angles of the folds 10, 11 are narrowed by means of the movement of pusher 5a, the servo motor 70 is rotated in a reverse direction to gradually raise the pressing guide 6 synchronously with the folding of sheet 1. When the sheet 1 is folded as shown in Figure 7(b), an encoder (not shown) provided within the servo motor 50 detects a working size L indicative of the size of folded sheet 1. In response to this detection, the servo motor 50 stops. In a folded state shown in Figure 7(b), one surface of the sheet 1 adheres to other surface thereof facing the former, thereby obtaining a block body 1a in a desired shape. The stopper 5b is raised by means of the actuator 5c while the pressing guide 6 is raised so as to convey the worked out block body 1a to a next process (e.g. drying process). The thus described operation and control are repeated. If neither of the surface of sheet 1 is adhesive, the sheet 1 is shrink-packaged in a folded state shown in Figure 7 (b) using a shrink film or is banded together using suitable means to maintain the block shape. Suppose that the block body 1a is intended to be used as a frame body for packaging or cushioning member, or a core of insulation panel, and the folding of sheet 1 is worked out in a process of packaging line of the article or manufacturing line of the panel, the sheet 1 is not pasted before the folding, and is packed in a box or pushed into a hollow panel in the folded state. According to this working example of sheet folding and shaping method, when a bending (folding) pressure is applied to the sheet 1 in the folding direction along the folds 10, 11, a light pressure is applied in a direction in which the bent angles of the folds 10, 11 are widen. Accordingly, it is possible to prevent portions of the sheet 1 from rising upward from the working position d or bounding in a direction towards the ridge-like folds 10. Therefore, it is possible to fold and shape the sheet 1 along each of the folds 10, 11 accurately, quickly and smoothly. According to this working example of sheet folding and shaping method, a bending pressure to the sheet 1 is supplied by the pressing guide 6 which operates from a state in which it is in the vicinity of the support surface of support guide 3 intervened by the sheet 1, toward a state in which it is away from the sheet 1 as the sheet 1 is folded. Accordingly, the bending pressure to the sheet 1 is gradually decreased as the sheet 1 is folded, thereby enabling the sheet 1 to be shaped into the folded state more smoothly and quickly. In addition, since the bending pressure is certainly applied to the sheet 1 by the pair of bending working tools 5a, 5b, one of which move toward and away from the other, the sheet 1 can be fold surely without folding failure. According to this working example of sheet folding and shaping method, in case of the both surface of sheet 1 being pasted, the support guide 3, pressing guide 6 and folding tools 5a, 5b are in contact with the non-paste portions 13 of sheet 1. Accordingly, it is possible to accomplish the folding and shaping more smoothly without interference with adhesive. The method for folding and shaping the sheet 1 of the present invention can be performed surely and smoothly according to this working example of sheet folding and shaping apparatus. The support guide 3 and the pressing guide 6 respectively consist of a plurality of guides positioned at given intervals so as to intersect the folds 10, 11 of sheet 1 supplied onto the working position d and one of the folding tools 5a, 5b is the pusher 5a, which is provided at one end of the support guide 3. Accordingly, if some of the support guide 3, pressing guide 6 or pusher 5a is damaged, the apparatus can be repaired by merely exchanging the damaged elements or components. Besides, regarding the moving drive means 5, since only the pusher 5a is reciprocated, it is possible to simplify the structure of apparatus. The support guides 30 to 35 face the respective bending guides 60 to 65 and the light pressing pressure and the bending pressure are applied to the sheet 1 at the same position, and therefore excess pressure is not applied to the sheet 1. Accordingly, it is possible to fold and shape the sheet 1 more smoothly. The support and pressing guides 30 to 35 and 60 to 65 can be individually moved along the folds 10, 11 of sheet 1 by means of the respective adjusting drive means 40 to 45 and 80 to 85. Accordingly, it is possible to adjust the distances between the adjacent guides constituting the support guide 3 and pressing guide 6 according to the design including the size of sheet 1, the position of adhesive. Further, simultaneously with the adjustment of distances between the support guide 3 and pressing guide 6, the positions of pusher 5a and stopper 5b can be adjusted. The adjusting drive means 80 to 85, which move the respective pressing guide 60 to 65, include the respective screw shafts 801, 811, 821, 831, 841 and 851, the respective motors 800, 810, 820, 830, 840 and 850 which drive the respective screw shafts 801, 811, 821, 831, 841 and 851, and the respective screw guides 803, 813, 823, 833, 843 and 853 through which the respective screw shafts 801, 811, 821, 831, 841 and 851 penetrate. Accordingly, the position of pressing guides 60 to 65 can be adjusted more smoothly, even very small amount can be adjusted easily and accurately. Each of the respective screw guides 803, 813, 823, 833, 843 and 853 are linked to the respective pressing guides 60 to 65 in a direction perpendicular to the support surfaces of the support guides 30 to 35, and the respective pressing guides 60 to 65 are indirectly guided by the pair of guide rails 2f, 2h or 2g, 2i in a direction of moving. Accordingly, the respective pressing guides 60 to 65 are moved smoothly when the positions thereof are adjusted. The same advantages can be obtained for the adjusting drive means 40 to 45 associated with the support guides 30 to 35. Since the sheet folding and shaping apparatus of the above mentioned embodiment is provided with the actuator 5c which retracts the stopper 5b from a suitable position for restricting the movement of sheet 1 to other position, and return it to the suitable position, it is possible to easily handle the block body 1a after folding the sheet 1. The moving drive means 5 of the pusher 5a includes the servo motor 50, the pair of geared pulleys or sprockets 51, 52, the timing belt or chain 53 wound around the pair or geared pulleys or sprockets 51, 52 and connected to the pusher 5a, and the guide rail 54 positioned along the timing belt or chain 53, and the pusher 5a is guided by the guide rail 54. Accordingly, it is possible to control the movement of pusher 5a more smoothly. The sheet folding and shaping apparatus of the above mentioned embodiment includes the movable frame 78 which can move perpendicular to the support surface of support guide 3 along the suitable guide 76 and the drive mechanism 78 which operates the movable frame 78 along the guide 76 using the servo motor 70, and the respective pressing guides 60 to 65 are linked to the movable frame 78. Accordingly, it is possible to control the movement of the pressing guides 60 to 65 toward and away from the support guide 3 more smoothly. [Second Working example of Sheet Folding and Shaping Method] In this working example, a sheet 1, which is a work to be processed, is a corrugated cardboard. As shown in Figure 8, it is formed with two streaks of parallel ridge-like folds 10, 10 and two streaks of parallel valley-like folds 11, 11 alternately along a direction which intersects the corrugation. A directional permanency of inward folding is imparted to each of the ridge-like folds 10, whereas a directional permanency of outward folding is imparted to each of the valley-like folds 11. Both the distance w1 between the adjacent ridge-like folds 10, 10 and the distance w2 between the adjacent valley-like folds 11, 11 equal approximately 40 mm. The width w3 of a shoulder 14 formed between the ridge-like folds 10 and the valley-like folds 11 equals approximately 75 mm and the width w4 of another shoulder 15 formed therebetween equals approximately 85mm. The sheet 1 is formed, on a surface of the shoulder 14, with paste portions 12 (shown by thin shaded lines) adjacent to the ridge-like folds 10, and on the opposite surface, with paste portions 12 (shown by dotted lines) adjacent to the valley-like folds 11. Non-paste portions 13 are formed with along a direction which intersects the ridge-like and valley-like folds 10, 11. As shown in Figure 9, after adjusting the intervals of the support and pressing guides 3 and 6, the sheet 1 is supplied onto the support guide 3 of the sheet folding and shaping apparatus as shown in Figure 9(e). The pusher 5a, stopper 5b and pressing guide 6 are operated in the same way as the first working example. The pusher 5a applies the bending pressure to the sheet 1 while the pressing guide 6 applies the pressing pressure to the same in a direction in which the bent angles of the folds 10, 11 are widen. The sheet 1 is processed such that bent angles of the ridge-like and valley-like folds 10, 11 are narrowed, and finally the adjacent ridge-like and valley-like folds 10, 11 are adhered by the paste portion 12. Thus a hollow block body 1b can be obtained as shown in Figure 9(f). The servo motor 50 stops in the same way as the first working example, which follows the detection of a working size L of the block body 1b by an encoder (not shown). According to the second working example of the sheet folding and shaping method, it is possible to manufacture the hollow block body 1b having a pseudo honeycomb-like end face smoothly and quickly according to its design. The other features of sheet folding and shaping method according to the second working example, and operations and advantages obtained thereby are substantially the same as those of the first working example. Accordingly, the description thereof is omitted. [Third Working Example of Sheet Folding and Shaping Method] A sheet 1 used in the third working example is a corrugated cardboard shown in Figure 10. It is formed with two streaks of parallel valley-like folds 11, 11 and three streaks of parallel ridge-like folds 10, 10, 10 positioned at equal intervals, alternately along a direction which intersects the corrugation of the core. The distance w1 between the adjacent ridge-like folds 10, 10 equals approximately 25. The width w3 of a shoulder 14 formed between the ridge-like folds 10 and the valley-like folds 11 equals approximately 75 mm and the width w4 of another shoulder 15 formed therebetween equals approximately 85mm. Both sides of the sheet 1 are formed with paste portions 12 and non-paste portions 13 in the substantially same position as in the sheet 1 shown in figure 8. After adjusting the distances of the support and pressing guides 3 and 6 shown in Figure 9(e) in accordance with the design of the sheet 1 shown in Figure 10, the sheet 1 in a spontaneously developed state is supplied onto the support guide 3, where the sheet 1 retain a state shown in Figure 11(g). The pusher 5a, stopper 5b and pressing guide 6 are operated in the same way as the second working example, and the pusher 5a applies the bending pressure to the sheet 1 while the pressing guide 6 applies the light pressing pressure to the same in a direction in which the bent angles of the folds 10, 11 are widen. The hollow block body 1b having a pseudo honeycomb-like end face shown in Figure 11(h) is thus manufactured. As can be seen from this working example, in the sheet folding and shaping method according to the present invention, when the sheet 1 includes plural streaks of ridge-like folds 10 and plural streaks of valley-like folds 11, the number of streaks of the former is not necessarily same as that of the latter. In addition, the number or a set of ridge-like folds or that of valley-like folds needs not be constant. The other features of sheet folding and shaping method according to the third working example, and operations and advantages obtained thereby are substantially the same as those of the first working example. Accordingly, the description with respect thereto is omitted. Besides, it is possible to manufacture a hollow block body 1b from a single sheet by suitably designing the sheet 1 as shown in Figure 12. The block body 1b may be constituted by a bottom block piece 1c and side block pieces 1d and 1e, which are linked with each other by sheet pieces 1f and 1g. By standing the side block pieces 1d and 1e along arrows in Figure 12, a frame body for packaging (or cushioning member for packaging) 11h is thus obtained. This frame body 11h is suitable for as a corner frame body for protecting a corner of goods such as a television or the like (not shown) having three-dimensional angle. [Other Embodiments or Working Examples] Although, in the above mentioned exmples, the pressing guides 60 to 65 slightly press the sheet 1 from the beginning of the pusher 5a moving toward a direction of folding of the sheet 1, the pressing guides 60 to 65 may start pressing the sheet 1 after the pusher 5a moves. This is because, only if the pressing guides 60 to 65 are positioned in the vicinity of the sheet 1, it is possible to prevent the portions of the sheet 1 from rising away from the support guide 3 or bounding no matter how the timing of pressing is shifted. Although, in the above mentioned embodiment, the pressing guide 6 which moves toward and away from the support surface of support guide 3 applies the pressing pressure in a direction in which the ridge-like and valley-like folds 10, 11 are increased in bent angles, a suitable weight member (not shown) may substitute for the pressing guides 6 operating in the above mentioned manner and may apply the pressing pressure to the sheet 1. Alternatively, a bar or bars (not shown) may impart a pressure to the sheet 1 using an air cylinder (not shown) of a suitable elasticity whose air pressure or the like is adjustable. Although the apparatus of the above mentioned embodiment is arranged so that one of folding tools 5a, 5b can be moved, it is possible to provide the apparatus with moving drive means arranged such that both of the folding tools 5a and 5b moves toward and away from the other. Regarding to the moving drive means 5, adjusting drive means 40 to 45 of the support guide 3, adjusting drive means 80 to 85 of the pressing guide 6, and drive mechanism 7 which moves the pressing guide 6 toward and away from the support surface of support guide 3, other constitutions than the disclosed in the embodiment or working examples may be used.

Claims: Amethod of folding and shaping a sheet (1) comprising : a first step of supplying the sheet (1) formed with a single or a plurality of ridge-like folds (10) and a single or a plurality of valley-like folds (11) alternately and in parallel to a predetermined working positioned (d) in a spontaneously developed state and a second step of applying a folding pressure to the sheet (1) in the direction of bending along the respective ridge-like folds (10) and the valley-like folds (11) characterized in that it further comprises a step of imparting a pushing pressure to the sheet (1) lightly so as to widen the folding angles of the ridge-like folds and the valley-like folds from the beginning or in the course of applying the folding pressure. The method of folding and shaping a sheet of claim 1 characterized in that the sheet (1) is supplied onto a predetermined support guide (3) in the first step and, in the second step, the pushing pressure is applied to the sheet (1) by a pressing guide (6) which moves away from the sheet (1) from a position close to the supporting surface of the support guide (3) with the sheet (1) sandwiched between itself and the support guide (3) while the sheet (1) is being folded and the folding pressure is applied to the sheet (1) by a pair of working tools (5a, 5b) each of which moves toward and away from the other or one of which moves toward or away from the other. The method of folding and shaping a sheet of claim 2, characterized in that paste portions (12) and non-paste portions (13) lying along the direction orthogonal to the ridge-like folds (10) and the valley-like folds (11) are formed on opposite sides of the sheet (1), and the support guide (3), the pressing guide (6) and the folding working tools (5a, 5b) make contact with the non-paste portions (13) of the sheet (1). An apparatus for folding and shaping a sheet (1) comprising: a support guide (3) for supporting the sheet (1) formed with a single or a plurality of ridge-like folds (10) and a single or a plurality of valley-like folds (11) alternately and in parallel in a spontaneously developed state, a pair of folding working tools (5a, 5b) disposed to oppose each other across a predetermined distance so as to apply a folding pressure to the sheet (1) supported by the support guide (3) in the folding direction and along the respective ridge-like folds (10) and valley-like folds (11) and moving drive means (5) for reciprocating at least one of the folding working tools (5a, 5b) toward and away from the other, characterized in that it further comprises a pressing guide (6) operating to move toward or away from the supporting surface of the support guide (3) with the sheet (1) sandwiched between itself and the support guide (3). The apparatus for folding and shaping a sheet of claim 4, wherein the support guide (3) and the pressing guide (6) are each provided as a plurality of guides disposed at predetermined distances so as to intersect the ridge-like folds (10) and the valley-like folds (11) of the sheet (1) supplied to the supporting surface of the support guide (3), one of the folding working tools (5a, 5b) is a pusher (5a) and is installed at the end portion of at least one support guide (3), the other of the folding working tools (5a, 5b) is a stopper (5b) for stopping the motion of the sheet (1), and the moving drive means (5) is disposed in association with the each support guide (3) installed with a pusher (5a) so as to reciprocate the pusher (5a). The apparatus for folding and shaping a sheet of claim 5, wherein the individual support guides (3) and the individual pressing guides (6) are disposed opposite each other. The apparatus for folding and shaping a sheet of claim 5 further comprising: adjusting drive means (40-45, 80-85) for moving the respective support guides (3) and the respective pressing guides 6 independently in the direction of the ridge-like folds 10 and the valley-like folds (11) of the sheet (1). The apparatus for folding and shaping a sheet of claim 7, wherein the adjusting drive means (80-85) for moving the respective pressing guides (6) consists of screw shafts (801, 811, 821, 831, 841 and 851) disposed orthogonal to the pressing guides (6), screw motors (810, 820, 830, 840 and 850) for driving the screw shafts (801, 811, 821, 831, 841 and 851), and screw guides (803, 813, 823, 833, 843, 853) through which the screw shafts (801, 811, 821, 831, 841, 851) penetrate, the screw guides (803, 813, 823, 833, 843 and 853) are associated with the respective pressing guides (6) to move the pressing guides (6) in the direction perpendicular to the supporting surfaces of the support guide (3), and the pressing guides (6) are guided directly of indirectly by guide rails (2f, 2g, 2h, 2i) disposed along the direction orthogonal to the pressing guide (6). The apparatus for folding and shaping a sheet of claim 7, wherein the adjusting drive means (40 to 45) for moving the respective support guides (3) consists of screw shafts (401, 411, 412, 431, 441 and 451) disposed orthogonal to the support guides (3), motors (400, 410, 420, 430, 440 and 450) for driving the screw shafts (401, 411, 412, 431, 441 and 451), and screw guides (403, 413, 423, 433, 443 and 453) through which the screw shafts (401, 411, 412, 431, 441 and 451) penetrate, the screw guides (403, 413, 423, 433, 443 and 453) are connected to the support guides (3), and the support guides (3) are guided directly or indirectly by the guide rails (20 to 23) disposed along the direction orthogonal to the support guides (3). The apparatus for folding and shaping a sheet of claim 5, further comprising an actuator (5c) which retracts the stopper (5b) from the position suitable for suppressing the motion of the sheet (1) to another position and returns the same to the suitable position. The apparatus for folding and shaping a sheet of claim 5, wherein the moving drive means (5) consists of a pair of geared pulleys or sprockets (51, 52), a timing belt or chain belt (53) mounted on the pair of geared pulleys or sprockets (51, 52) and connected with the pusher (5a), a guide rail (54) disposed along the timing belt or chain belt (53) and a servo motor (50) for driving the geared pulleys or sprockets (51, 52), and the pusher (5a) is guided directly or indirectly by the guide rail (54). The apparatus for folding and shaping a sheet of claim 4, further comprising a movable frame (78) which moves along a predetermined guide (76) in the direction perpendicular to the support surface of the support guide (3), and a drive mechanism (7) for operating the movable frame (78) along the guide (76) using the servo motor (70), wherein the pressing guides (6) are connected to the movable frame (78) to be moved toward and away from the support surface of the support guide (3).

Inventors: YAMAMOTO MASAHIRO, YOKOYAMA YOSHIMASA, YAMAMOTO, MASAHIRO, YOKOYAMA, YOSHIMASA, YAMAMOTO, Masahiro, Hitachi Zosen Corporation, YOKOYAMA, Yoshimasa, 1379-4, Aza-Shinotsubo
Applicants: HITACHI SHIPBUILDING ENG CO, YOKOYAMA SANKOH CO LTD, HITACHI ZOSEN CORPORATION, YOKOYAMA SANKOH CO., LTD.
Application year: 1997
Main classification: B65H45
IPC codes: B31F1, B65H45, B31D3