Patent GB-1423071-A (GB)
Title: Apparatus for packing product material in a length of foil
IPC: B65H23/16
Filed: 1973-05-10
Abstract: 1423071 Apparatus for wrapping products in foil H KUPER [trading as HEINRICH KUPER] 10 May 1973 [17 May 1972 9 March 1973 (2)] 22301/73 Heading B8C An apparatus for packing products in a length of foil 55 comprises a separating device 13 displaceable transversely to the direction of movement of the length of foil 10, 11, and a welding device 14 for welding the separated ends of the foil, or one end of the length of foil and the beginning of another length of foil, in association with a bearing 12, in the drawing-off direction of the length of foil and carrying a roll of foil 10a, 11a and driven by a motor 29, a guide surface 15 for carrying the end of the length of foil connected to the roll of foil after the separating operation or, during the replacement of a roll of foil located between the bearing 12 and the separating device 13, and a member 16 for retaining the separated length of foil extending to the consumer located downstream of the welding device in the direction of movement of the :length of foil. As shown, a machine for wrapping products 52, supplied at intervals, by a belt conveyer 51a in lengths of plastics foil 10, 11 which is preferably shrinkable comprises two pairs of bearing rollers 27, 27 which are drivable by motors 29 at the required times and which support rolls of foil 10a, 11a foil from each of which is directed through separating rewelding, retaining and foil-storage devices 13, 14, 16 and 33-38 respectively and is joined to the other foil 11 or 10 to form a curtain 55 of foil across the path of the advancing product 52. The foil is draped over the product 52 as the latter advances on to a second belt conveyor 51b, the foils being brought together at the trailing edge of the product 52 between a fixed roller 56 and a lowered, vertically moveable, roller 57 and operated upon by a welding unit 53 which severs the foils between two parallel seals to seal the foils along the rear lower edge of the product 52 and reform the curtain 55. The motors 29 are not energized to feed foil 10, 11 until the weight of foil between rollers 35-37 on spring-loaded and pivoted arms 33 is small enough to allow the arms 33 to rotate upwardly and actuate switches 38 to energize the motors 29 which supply more foil to the storage rolls 36, 37. To exchange one roll 10a, 11a for another, a hot-wire cutter 17, 20, pivotally mounted with a guide plate 15 at 18, is rotated downwardly, by a handle 21, to transversely sever the foil 10, 11 the foil-end 59b connected to the roll 10a, 11a, Fig. 2, dropping on to the downwardly pivoted guide plate 15 to overlap the other, downstream, end 54a of foil resting upon the lower welding bar 41 of the welding unit 14. The bar 41, accommodated in a groove 43 in a guide beam 39, is vertically displaced, by pressure-operated cylinders 42 to co-operate with a fixed counter bar 49 and seal the two ends 54a, 54b together, the bars 41, 49 each being provided with, one, or more, heatconducting bands. The guide beam 39, pivotally mounted at 45, can be rotated through a quadrant so that the bar 41 can be replaced easily. The beam 39 being lockable in its vertical position by a screw 46, Fig. 3. The foil guide pulleys 56, 57 are in driving engagement with the conveyor belt 51b to assist the drawing of foil from the rolls 10a, 11a, the drive to the pulley 57, which is vertically moveable in a guide groove 65, being effected by a contact belt drive 59 which is tensioned by a pulley 61. At least the upper guide pulley 57 and preferably both guide pulleys 56, 57, are provided with a free wheel mechanism (66), Fig. 5 (not shown), to allow for drawing off more foil while the upper welding beam 53b of the welding device 53 is descending. Free-wheel return locks 69, 70, pivotally mounted at 76, are operable by pneumatic motors 72. The belt conveyers 51a, 51b may be replaced by roller conveyers, and the guide plate 15 may be replaced by adjacent guide bars.