Patent GB-891462-A (GB)
Title: Improvements in the manufacture of composite wrappers, and apparatus therefor
Inventor: MEER DOUWE VAN DER
IPC: B31B39/00
Filed: 1957-08-30
Abstract: 891,462. Laminating. DOUWE EGBERTS KONINKLIJKE TABAKSFABRIEK KOFFIEBRANDERIJEN - THEEHANDEL N.V. Aug. 29, 1958 [Aug. 30, 1957], No. 27324/57. Class 140. Composite wrappers are formed by feeding a predetermined length of tubular wrapping material in flattened form from a continuous web, severing the length from the web to form an outer tubular wrapper, opening the wrapper to form an open tube of flat cross-section, feeding an inner wrapper into position within the tube and collapsing the tube on to the inner wrapper. The tubular web may be of thermoplastic film material, and may be stretched laterally slightly before the feeding of the inner wrapper, the tube subsequently being released to revert to substantially its original width. This permits the use of an inner wrapper of substantially the same width as the tube. The inner wrapper may be of paper bearing appropriate printed matter. As shown in Fig. 1, a tubular web of polythene 11 is fed over a guide roll 12 and down towards a cutting device by reciprocating grippers 14. Oscillating trapping members 16 grip the web during the return motion of the grippers 14. The cutting device comprises two opposed knives 31 movable across the web during the dwell of the grippers 14. Opening plates 32 each with a multiplicity of suction apertures are movable towards and away from one another. The two members of each pair of grippers 14, trapping members 16, knives 31 and opening plates 32 are operatively connected by arcuate racks. Sideways movement of the grippers 14 and the opening plates 32 is controlled by rollers 24 and 39 engaging bars 26 and 37 respectively. These bars and the knives 31 and opening plates 32 are all separately mounted on parallel motion links. The various parts of the apparatus are operated and timed through the links shown by means of cams (not shown). As the grippers 14 reach the end of their feeding stroke, the plates 32 close to grip the web, the knives then operate to cut it, and the plates 32 then open, to form the severed web into an open tube, and carry it downwards. As shown in Fig. 2, supports 51 are mounted on carriers which are mounted on rods 52 slidably mounted in the hubs 48, and are also slidably mounted on guide rods 53 secured in the hubs 48. The ends of rods 52 carry rollers 54 which engage cam tracks 56 axially movable on the shaft 49 by cam-operated arms 57. The hubs 48 are intermittently rotatable in timed relation with the movement of the opener so that supports 51 receive the open tube on downward movement of plates 32. Cam track 56 is then retracted and the supports 51 move outwards to engage and stretch slightly the tube. Suction is cut off from the plates 32 leaving the tubular wrapper on the supports 51. The plates 32 then move upwards to receive the next wrapper. The carrier 45 is then rotated through 90 degrees (in a clockwise direction as seen in Fig. 1) to a position where an inner wrapper in sheet form is fed into the interior of the tube by means not shown, and finally positioned by an oscillating arm 72. The light blade springs 73 hold it in place until, after further movement through 180 degrees (in two stages), the composite wrapper is removed from the supports 51 by the reciprocating grippers 74 which take it to a conveyer (not shown) for further processing. Specification 861,281 is referred to.