摘要 |
This method relates to the production of connectors each embodied by a row of substantially U-shaped clips formed in their curved part with a row of regularly spaced-apart apertures which separate the hinge elements from one another. The following metal deep drawing and pressing operations are performed consecutively in the central part of a metal strip, forming an aperture of reduced cross-section in the center of the place intended for each aperture required to be present between two hinge elements; widening each such aperture and pressing in the edges to form a collar which projects from a surface of the strip; bending the sides of each collar around on to the corresponding surface of the metal strip; and bending the strip round into a U-shape by the surface towards which the collar edges have been bent round being inwardly directed. The inside surface of each hinge element is, therefore, strengthened by two metal strips which are disposed one beside another and which correspond to the bent-round contiguous sides of the two collars previously formed at the apparatus and extending around the particular hinge element. |