| 摘要 |
1,166,229. Making corrugated tubes. KOPPY TOOL CORP. 28 Feb., 1968 [9 March, 1967], No. 9566/68. Heading B3A. A corrugated tube 50 is made by squeezing a series of continuous grooves 12 in spaced parallel relationship in a sheet of flat stock to form a grooved blank having a leading edge 40 and a trailing edge 42 which extend transversely to the grooves, the grooves being formed in timed progression laterally outwardly from a centre groove 14, joining the leading edge to the trailing edge so that the grooved blank forms a tube of uniform cross-section with the grooves forming closed rings about the axis, and radially expanding the tubular blank in the area of selected grooves to form annular sections 48 with greater diameter than that of the first-formed tube. The grooves are preferably made by a series of dies on a common surface of a continuous strip of flat stock which may be trimmed at 26, Fig. 2, perforated with holes, preferably elongated, 36 before being cut into sections of predetermined length 38. |
