| 摘要 |
921,195. Seaming non-metallic sheet material. H. GUBELA. Sept. 15, 1959 [Sept. 16, 1958; Sept.23, 1958], No.31348/59. Class 42(1). A method of manufacturing a fluid-tight hollow body of plastic material comprises welding together at their outer peripheral edges two mating parts which co-operate to form the hollow body, to cause material of the edges when made molten by the welding operation to enter a peripheral recess within the hollow body, subsequently removing the edges leaving the parts joined at the recess and smoothing the exterior of the body at the joint. As shown two shaped parts 1, 2, made of a plastic, and each provided with a flange-like edge 3, 4 having recesses, are brought together so that there is a hollow space 5 between them. The edges 3 and 4 are welded together by electrodes 6, 6<SP>1</SP> and the liquefied material of the edges is thereby pressed into the hollow space 5 so that when it hardens the two parts 1 and 2 are firmly held together in an airtight and watertight manner. The edges 3 and 4 may be broken off during or after welding. The recess may be formed by simply chamfering the inside edge of one or both body parts. Both parts are preferably warmed prior to the welding operation to prevent tensions being set up. In Fig. 9 the invention is applied to welding an internal spigot 13 to backing piece 16 in the manufacture of a reflexreflector. |
