| 摘要 |
1,096,571. Thermoplastic containers. V. FLAX. Nov. 19, 1964 [Nov. 21, 1963; Feb. 28, 1964; May 8, 1964; Oct. 22, 1964], No. 47150/64. Heading B8D. [Also in Division B5] Two parts of thermoplastic material are welded together by pressing the parts together and holding one of the parts stationary whilst the other is rapidly rotated until sufficient frictional heat has been generated to produce local fusion of the thermoplastic material and then discontinuing the rotation of the second part, whilst maintaining the pressure between the parts so that the parts become welded together. In one embodiment, Fig. 1, to join a cap or neck 7 to a tube 8, the cap 7 is placed on a double-frusto-conical head 5 of a rotary mandrel 1 coupled to a driving member (not shown) and is centred by a boss 6 forming an extension of the head 5. The tube 8 is threaded on to a fixed tubular sleeve 2 surrounding the mandrel 1 to contact a fixed but adjustable abutment 19. A pressure member (not shown), e.g. an hydraulic jack, is set into motion to bring a socket 3, preferably made of nylon, closer to the fitment comprising the mandrel 1 and the sleeve 2 so that a lip 17 is formed on the tube 8 and is pressed against the cap 7. The mandrel 1 is then rotated so that the cap 7 is rotated and friction is set up between the external periphery of the cap 7 and the lip 17. As shown, grooves 10 are provided in the bearing surface 9 of the head 5 to facilitate gripping the cap 7. The sleeve 2 is formed with a collar 12 and is shaped to leave a continuous passage 14 between the head 5 and the sleeve 2 to enable any particles torn away during welding to be discharged to a chimney 15. The socket 3, which is fixed against rotation, has an annular channel 22 so that a bead is formed at the junction between the lip 17 and the collar of the cap 7 and has a metal ring 23 around the neck thereof. In one embodiment of the cap 7, Fig. 2 (not shown), projecting ribs 24 are formed on the internal face of the collar 7.1 thereof. The ribs 24 may be continuous or discontinuous. The ring 23 projects into an annular channel 26 of triangular cross-section provided around the threaded neck of the cap 7. In a second embodiment of the cap 7, Figs. 3 and 4 (both not shown), a projecting annular shoulder 31 is formed on the face 25 of the cap and the ribs 24 either terminate on each side of the shoulder or are extended on to the shoulder. |
