Patent GB-1498822-A (GB)
Title: Closing an opening in an upholstery cover
IPC: B29C65/20
Filed: 1974-12-16
Abstract: 1498822 Seaming non-metallic sheet material OPTI PATENT - FORSCHUNGS - UND FABRIKATIONS AG 16 Dec 1974 [27 Dec 1973] 54177/74 Heading B5K An opening 1 defined in an upholstery cover by two marginal portions 4, 5 each having a projection 7 extending away from one surface of the cover and part of one at least of the portions 4, 5 comprises a synthetic plastics material, is closed by guiding the projections 7 to a predetermined relationship adjacent one another and softening the synthetic plastics material to bond or fuse the portions 4, 5 together. In one embodiment, Figs. 1 and 2, the portions 4, 5 are of thermoplastics material in the form of extruded flat strips 6 having integral projections 7 comprising circular section ribs. A closure device 8 comprises jaws 9, 10 pivoted at 11 and having operating handles 12. The jaw 10 has a resistance heating element 13. A passage 14 is defined between the jaws 9, 10 and tapers from an inlet 15 to an outlet 16 so as to bring together the two ribs 7 during movement of the device 8 along the opening 1. As the ribs 7 pass beneath the element 13, the thermoplastic material is softened and the ribs are fused together. In modifications of the shape of the projections, (a) the ribs (17) are of square section, Figs. 2a and 2b (both not shown), (b) the ribs (18) are circular and lie symmetrically with respect to the plane of the strips (6), Fig. 2c (not shown); (c) a circular section rib (19) is provided on each side of each strip, Fig. 2d (not shown); (d) elliptical ribs (20) extend across the plane of the strips, Fig. 2e (not shown); and (e) the ribs are replaced by shaped flanges (21), Figs. 2f, 2g, 2h and 2i (all not shown). In a second embodiment, Figs. 3 and 4, marginal portions 22, 23 comprise extruded strips 24, 26 having square section ribs 25, 27 located internally of the opening, the rib 25 being disposed mid-way across the width of the strip 24. In the finished closure, overlapping portions of the strips are fused together with the ribs 25, 27 lying adjacent each other without being fused together. A closure device 28 comprises jaws 29, 30 and a heating element 31 on the jaw 29. A passage 32 between the jaws 29, 30 brings the portions 22, 23 into the desired positions with the ribs 25, 27 being located in recesses 34 at the outlet 33. In modifications of the marginal portions, (a) each strip has a square section rib (35), (36) located midway across the width thereof, Fig. 4a (not shown); (b) ribs (37), (38), (39), (40) are disposed on oppsite sides of the strips, Figs. 4b and 4c (both not shown); (c) circular section ribs ribs 41, Fig. 4d, or square section ribs (42), Fig. 4e (not shown), overlap and are fused together, (d) one strip 43, Fig. 4f, has bifurcated ends 44 terminating in ribs 45 which are fused to the portion of the other strip 46 lying between two ribs 47, and (e) a bifurcated unbeaded end(48) on one strip engages an edge rib (50) on the other strip, Figs. 4g and 4h (both not shown). In modifications of the devices 8, 28 of Figs. 1 and 3, respectively, one or each jaw is provided with passages for cooling fluid to assist setting of the welded plastics material. In further modifications (not shown), instead of using heat and pressure, welding is effected using ultrasonic or radio frequency techniques or a solvent may be used to soften the marginal portions so as to fuse them together. The marginal portions with the synthetic plastics material may be reinforced with a natural textile core or covering. Preferably, the strips of the marginal portions are preformed and are attached to the upholstery cover by sewing or the use of adhesives. In another modification (not shown), stringers of a sliding clasp fastener with plastics coupling members are used as the marginal portions and the coupling members are closed in the normal way and fused together in the. coupled condition by heat and pressure.