Patent GB-1198943-A (GB)
Title: Method and Apparatus for Splitting Tapes and Films
IPC: D01G1/08
Filed: 1968-02-06
Abstract: 1,198,943. Film fibrillation; slitting webs. MITSUBISHI JUKOGYO K.K. 6 Feb., 1968 [9 Feb., 1967], No. 5950/68. Headings B4B and B5B. Apparatus for splitting tapes preparatory to making filamentary or network structures comprises two sets of rollers adapted for feeding a film or tape or plurality of substantially parallel films or tapes under tension through a feed path, and a plurality of splitting rollers arranged adjacent said feed path and each capable of forming a split or splits in a film or tape brought into contact therewith, and deflecting means for deflecting the film(s) or tape(s) into operative engagement with at least one of said splitting rollers whereby in use, a split or splits is formed in the or each film or tape. Thus in Figures 1 to 3 a tape splitting device includes a forward set of rollers 42 and 16 and a rear set of rollers 40 and 11 forming nips between which a plurality of substantially parallel tapes of film-forming material, e.g. polyethylene, polypropylene, or polyester may be transported, the forward set of rollers 42 and 16 being rotated faster than the rear set so as to maintain the tape between the roller sets under tension. Tapes 10 may be positioned in operative engagement with one or both splitting rollers 12 1  and 12 2  which are mounted on shafts (44), (46) (Fig. 3, not shown) at opposite ends of a rotatable arm 14 affixed to a shaft (48) for rotation therewith. In operation arm 14 is advantageously located along a vertical axis Y-Y to position one of the cutters 12 1  or 12 2  in a position facing the tape 10. With arm 14 so positioned, guide roller 13 is shifted upwardly to engage the tapes 10 from below and to cause them to engage a portion of the periphery of the operating splitting roller 12 1 . Roller 13 is freely rotatable about its axis and is mounted on shaft (54) carried on lever (G) an intermediate portion of which is pivoted to a rod (56) which may be reciprocated under the control of fluid cylinder (H) to cause the desired shifting of roller 13 towards or away from tapes 10 and so effect a suitable angle of tape contact with respect to the cutter. Other possible positions of the guide roller 13 are shown at 13<SP>1</SP> and 13<SP>11</SP> in Fig. 2. Rollers 12 1  and 12 2  may be oriented in any of the dotted line positions shown by shifting arm 14 so that it lies on any of the axes X-X, W-W, Y-Y, or Z-Z. A feature of the invention is that splitting can be restarted after the tape is trained over the guide rollers without winding the tape directly around the splitting cutter in the event that any tape becomes broken or entangled with the splitting cutter. For this purpose a tape engaging bar 15 is disposed below splitting cutter 12 1  during operation. Bar 15 is so positioned by actuating fluid cylinder (J) to cause outward movement i.e., at right angles to the plane of the paper in Fig. 2. The bar need not be rotatable. The position of guide roller 13 is initially adjusted by actuating cylinder (H) and thereafter it is held at a given winding angle by means of winding angle adjusting apparatus (I), including a fixed plate member (70) and a threaded adjusting screw (72) which bears against an angle portion (74) of lever (G). During starting, arm 14 is held in position X-X, as in Fig. 2, and guide roller 13 in the position of 1311. Arm 14 is then rotated to the position of line Y-Y and held thereat during splitting. Guide roller 13 is then swung so as to provide a suitable contact angle of tape 10 with respect to splitting cutter 12 1 , and held in this position. When breakage of the tape occurs, arm 14 may be rotated through 180 degrees, so that the tape which is not broken is engaged by cutter 12 2 . The mechanism may also be operated so that the tape is contacted first by cutter 12 1  and then by cutter 12 2 . Any tape which becomes entangled or is cut off falls down on engaging bar 15 and may be manually returned to the guide roller 13 and the forward rollers 16 and 42 so that the splitting operation can be restarted. As one of the cutting rollers 12 1  or 12 2  is always in an idle position, it is possible to work on this idle roller, e.g. to replace its cutting knives, even when the other roller is operating. In Fig. 4, similar parts are similarly designated but with the addition of 100. In this embodiment, two splitting rollers 112 1  and 112 2  are provided mounted on fixed spaced journals located between rollers 116 and 142 and rollers 111 and 140. Two sets of guide rollers 113 1  and 113 2  are arranged adjacent the respective outboard sides of splitting rollers 112 1  and 112 2 . Each guide roller is freely rotatable and is carried on a supporting lever 118 1  pivoted about the centre 0. The position of guide lever 118 1  is controlled by a fluid cylinder (H<SP>1</SP>) (Fig. 5, not shown) which acts to move a piston rod (156) to shift the associated guide lever about its pivot. Guide rollers 113 1  and 113 2  are mounted so as to be movable through the path of the tape 10 to tension the tape between the rear rollers 111 and 140 and the associated cutter 112 1  or the forward rollers 116 and 142 and the associated cutting roller 112 2 . Tape engaging bars 115 1  and 115 2  are provided; 115 1  is operated by fluid cylinder (J<SP>1</SP>). When the tape is set, tape engaging bars 115 1  and 115 2  are moved backwardly to the retracted position shown in solid lines in Fig. 5 (not shown). Arms 118 1  and 118 2  are held in a position indicated by lines O-Y and O-X in Fig. 4. Arm 118 1  is then rotated to the position O-X or arm 118 2  is maintained in its initial position. Contact of the tape with cutter 112 1  is thus maintained and the splitting operation will be effected by this cutter. When breakage or entanglement of the tape occurs during the operation, the broken tape is cut off in proximity of the discharge side of nip rollers 111 and 140 and then the supply to splitting cutter 112 1  is cut off. Thereafter the splitting operation is transferred to splitting roller 112 2  by shifting arm 118 1  back to position O-Y and shifting arm 118 2  to position O-X at which the tape will be guided around cutting rollers 112 2 . Splitting roller 112 1  can then be fully examined and removed for maintenance. Where it is desired to effect a double splitting operation, both arms 118 1  and 118 2  may be oriented in an upward position in which they guide the tape around their associated splitting rollers 112 1  and 112 2 . In the embodiment of Fig. 2 it is necessary to shift the position of the splitting rollers so that the idle roller becomes effective. In that of Fig. 4 shifting from one splitting roller to the other may be effected by merely displacing the associated guide roller to cause the tape to bear against whichever roller is desired for operation.