Patent GB-1277669-A (GB)
Title: Methods and apparatus for friction welding synthetic plastic container parts and the like
IPC: B29C65/06
Filed: 1969-12-29
Abstract: 1277669 Seaming non-metallic sheet material KOEHRING CO 29 Dec 1969 [2 Jan 1969] 63122/69 Heading B5K Apparatus for friction welding thermoplastic parts 10, 11 comprises holders 38, 43 for the parts 11, 10, respectively; means for moving at least one of the holders 38, 43 from a removed position toward the other holder to engage the respective surfaces to be welded of the parts 10, 11; and eccentric motion producing drive means for oscillating the holder 43 and the part 10 relative to the holder 38 and the part 11 in the plane of engagement of the surfaces, and while the relative orientation of the parts is maintained, to friction weld the parts 10, 11 together. In the embodiment described, the parts 10, 11 are rectangular in section and are friction welded together to form a vehicle gasoline tank. The part 11 is held in a vacuum chuck 38 fixed to a plate 34 mounted on a plate 23 on rubber blocks 33 by bolts 35 having ball ends 36 received in sockets 37 on the plate 23 to permit lateral shifting movement of the plate 34 relative to the plate 23. The plate 23 is vertically slidable on fixed rods 26 and a fixed post 30 by pneumatic cylinders 20. The part 10 is held in a vacuum chuck 43 fixed to a plate 49 mounted on rubber blocks 50 secured to a plate 52 secured to a fixed plate 53a by an assembly 54 comprising a shaft 55 rotatable in bearings 56, 57 and rings 58, 59 to restrict axial movement of the shaft 55. The shaft 55 has an axially projecting eccentric portion 55a received within a roller bearing 60 in a block 61 on the plate 49. The shaft 55 is driven by a belt 63, Figs. 1 and 2, which is movable into and out of engagement with a pulley 62 on the upper end of the shaft 55. The belt 63 is trained around pulleys 64, 65, the pulley 64 being supported on an arm 66 pivoted at 66a by a bolt 69 acted on by a pneumatic cylinder 71 to move the belt 63 into and out of engagement with the pulley 62. The pulley 65 is driven by a combined motor and speed reduction unit 76. The chucks 38, 43 are provided with parts 39a, 46 leading to openings 40, 45 connected to a suction pump by lines having solenoid-operated valves 42, 48 therein. In operation, the parts 10, 11 are located in the chucks 43, 38 and the valves 42, 48 are operated so that suction is applied to the chucks. Simultaneously, the cylinders 20 advance the chuck 38 towards the chuck 43. The cylinder 71 swings the arm 66 forwardly so that, by the time the parts 10, 11 are in engagement, the belt 63 is in driving engagement with the pulley 62 and the part 10 is oscillated thereby in an eccentric path relative to the part 11. After the weld has been achieved, the plate 34 moves with the plate 49 and closes a normally-open switch 79. The cylinder 71 withdraws the belt 63 sharply from the pulley 62. Simultaneously, the valves 42, 48 are operated so that the parts 10, 11 are no longer held by suction. The cylinders 20 lower the chuck 38. When the plate 23 reaches the bottom of its downward travel, it contacts a time-delay switch 80 which provides sufficient time for the operator to unload the welded parts and re-load new parts. An electrical control circuit for the operation is described, Fig. 5 (not shown).