Patent GB-1290517-A (GB)
IPC: B29C48/03
Filed: 1969-12-19
Abstract: 1290517 Flattening and haul-off apparatus WINDMOLLER & HOLSCHER 19 Dec 1969 [7 Jan 1969 3 June 1969] 62003/69 Heading B5B Flattening and haul-off apparatus for blown tubular plastics film produced on a stationary blowhead comprises flattening means and hauloff rolls mounted for oscillation about the longitudinal axis of the arriving tubular film, a turning bar, preferably non-rotary with a lowfriction surface, located downstream of the haul-off rolls and disposed at substantially 45 degrees to the axis of oscillation, a first directionchanging roll located downstream of the turning bar and disposed substantially parallel to the axis of oscillation, both the turning bar and the first direction-changing roll being mounted to oscillate with the haul-off rolls, and a non- oscillatory second direction-changing roll located downstream of the first direction-changing roll and disposed substantially parallel to the said axis of oscillation. A second, stationary turning bar may be located downstream of the second direction-changing roll and disposed at substantially 45 degrees to the axis of oscillation. In Fig. 1, tubular plastics film 3, made by extruder 1 and blowhead 2, is flattened by flattening plates 4 and withdrawn by a pair of haul-off rolls 5 driven by motor 6. The flattened film 7 is then diverted by direction-changing roll 8, turned sideways through 90 degrees by non-rotary turning bar 9, fed upright over direction-changing roll 10, guided through the longitudinal axis of unflattened film 3 by rotary direction-changing rolls 16 defining a nip in line with the axis of oscillation, passed over non- oscillatory direction-changing roll 17, second turning bar 18 and direction changing roll 19 and by means of one or more guide rolls 20 reaches winder 21. Haul-off rolls 5 and direction-changing rolls 8 and 10 are carried by turntable 11 which is oscillated by means of ball-race 12, elevated platform 13 and motor 14. Direction-changing rolls 16, 17 and 19 and turning bar 18 are all carried by stationary support 15. For oscillation through substantially 360 degrees deflecting rolls 25 and 26 (Fig. 4, not shown) carried by pivotable levers 22 and 23 hingedly interconnected by member 24 may follow rolls 16. In an alternative embodiment (Fig. 5, not shown) features (101) to (107), (109) to (115), (117) to (121) correspond to features 1 to 7, 9 to 15, 17 to 21, respectively, the main differences being that turning bar (109) is located above the haul-off rolls (105) and the first directionchanging roll (110) is one of a pair of rolls adjacent turning bar (109). The second direction-changing roll (117) is eccentric to the axis of oscillation. A deflecting roll (116) is mounted for rotation and oscillation adjacent turning bar (109) on the opposite side thereof to rolls (110). A film winder driven through a slip clutch may be provided to compensate fluctuations in film speed downstream of rolls (110). A dancer roll or similar film take-up device may be located between direction-changing roll (117) and winder (121). A further direction-changing roll 124 may be provided (see Fig. 8) at the hinge connection of levers 122, 123 pivoted to rolls 110 and 117, respectively.