| 摘要 |
The invention concerns a method for rigidly coupling a planar metal element (2) and a tubular element (1) with axis (ZZ') substantially perpendicular to said planar element. The invention is characterised in that it comprises the following steps: dimpling the planar element with radial cutouts (4) extending slightly beyond the periphery of the projection (11) of the tubular element on the planar element, in limited number to constitute between the ends of two successive cutouts (4) a folding line at 90 DEG (F) and on the same side (21) of the planar element for each sector (5) thus delimited, inserting by the inner side (22) of the planar element (2) the tubular element (1) in the dimple; then in driving back outwards the wall at the end of the element (1) to bend it rearwards (G) until it is urged to enclose by the outer side the dimpling sectors (5); finally driving back in the same direction the previous assembly by bending anew at 90 DEG (H) to securely counter-clamp the end (6) of the twice-bent tubular element. The invention is useful for automatically assembling metal ladders. |
