Patent GB-1525410-A (GB)
Title: Manufacture of tampons
IPC: A61F13/20
Filed: 1975-12-23
Abstract: 1525410 Tampon manufacture PROCTER & GAMBLE CO 23 Dec 1975 [27 Dec 1974] 52624/75 Heading A5R [Also in Divisions B5 and B8] In the manufacture of tampons comprising flexible sacks filled with absorbent material, a length of flexible tubing 85, Fig. 3, which has preferably been pre-printed with transverse stripes of adhesive, is brought into contact with the periphery of a transfer wheel assembly 59 where it is pinched together by lugs 75a, b, c whose positions correspond to those of the adhesive stripes, the sequence of operations being such that the tube is pinched together at a first point, a measured charge of filling material is introduced into the tubing and the tubing is then pinched together at a second point spaced rearwardly from the first point. The tubing is formed around a hollow mandrel 4 and the charges of filling material are propelled through the centre of the mandrel into the tubing. The transfer wheel assembly, Fig. 8, comprises a frusto-conical body portion 62 and spaced-apart upper and lower discs 68, 65 rotatably mounted on a hollow shaft 61. The lugs 75 for sealing the flexible tubing are mounted on an endless belt 70 passing around idler rolls 71 and 72 and the lugs engage in corresponding grooves 66 and 69 around the peripheries of the lower and upper discs respectively so that the belt is driven by the rotation of the transfer wheel assembly. The periphery of the transfer wheel assembly comprises a series of hollow plates 78, each of which is pivotally mounted at its leading end between adjacent pairs of spacer bars 67 between the upper and lower discs. The outer surfaces of the plates are provided with perforations 81 and their hollow interiors open upwardly for communication with vacuum parts 82 in the upper disc 68; the parts communicate with a vacuum manifold 83 on top of the upper disc and a vacuum is applied at the lower end of the hollow shaft 61 so that the contents of the tubing are subjected to a vacuum through the perforations 81. The filled tubing passes from the lugged belt assembly into a tube (87), Fig. 2 (not shown), where the filling material is compressed, and the filled tubing may then be transferred to apparatus for gathering and sealing the tubing at the points which were previously pinched together, followed by the attachment of a withdrawal string to each sack and the severance of the tubing into individual sacks. The speed of travel of the tubing around the transfer wheel may be varied independently of the rotation of the latter by causing the plates 78 to pivot inwardly or outwardly under the influence of springs (90), Fig. 9 (not shown); this movement may be controlled by a sensor (95), Fig. 2 (not shown) mounted on the tube (87), which detects the location of the transverse strips of adhesive on the tubing and actuates a servo-mechanism 94 which in turn actuates a cam track 92. In the apparatus of Fig. 1, filling material is delivered from a feed hopper 9 via a screw feeder 11 and a head box 13 to a rotary loading turret assembly 16 from which measured quantities of filling material are discharged through a nozzle 44 into the mandrel 4, and a web of tube-forming material 2 is folded about the mandrel and overlapped with the application of adhesive from an applicator 6 forming a longitudinal seam for the tubing, the adhesive being set by a chilled roll 7. The loading turret assembly comprises a rotatable loading wheel (23), Fig. 4 (not shown), mounted in a stationary shroud 20, the rear wall of which is a vacuum plenum 27 provided with a vent port (37) and vacuum manifolds (35, 36, 38) Fig. 6 (not shown) in communication with respective vacuum conduits (39, 40, 41). The loading wheel (23) is provided with a series of pockets (33) extending therethrough, the ends facing the vacuum plenum being covered by screening (34). In use, filling material is drawn into a pocket as it passes the vacuum manifold (35) and is expelled through the nozzle 44 as the pocket passes the vent part (37). The nozzle assembly, Fig. 7 (not shown) comprises a tapered induction nozzle (49) mounted within a block 45 and compressed air is introduced through an annular passageway between the induction nozzle (49) and a frusto-conical cavity (48) in the block 45, thereby causing air to be drawn through the pockets as they pass the vent port (37) and propelling the charges of filling material through the nozzle and into the mandrel.