| 摘要 |
981,653. Attaching handles; welding by pressure. METAL CONTAINERS Ltd. March 15, 1963 [March 15, 1962], No. 10325/63. Headings B3A and B3R. In electric resistance welding a metal attachment to a metal base having an insulating coating facing the attachment, the attachment is provided with at least one projection having a thin edge on its surface to engage the base, the attachment is pressed against the base and the projection is progressively partly collapsed or flattened under the action of the pressure alone and current is supplied to the parts, the pressure being applied at its maximum value before full current is applied. A bail ear having a central portion 17, Fig. 2, to receive one end of a bail and lateral tabs 19 is to be secured to a container 11, Fig. 1, having an insulating, e.g. painted, coating thereon. A hole 20 with a projecting burr with a ragged or serrated edge is formed in each tab by punching with a cylindrical punch and oversize die. With a tab engaged on the surface of the container an electrode 23, Fig. 4, is applied to the container wall and the other is applied lightly to the tab so that the coating 21 is not penetrated. The pressure of the movable electrode is increased to a maximum so that penetration of the coating and some deformation of the projection occurs as shown in Fig. 6. Current is then supplied initially at a low value but increasing to a maximum so that the projection starts to fuse and flows radially outwards culminating in complete flattening of the. projection as shown in Fig. 8. Current flow is discontinued before the pressure is released. The pressure is applied by a positively moved member free of inertial effects, e.g. by cams on a rotary shaft or by a stiff spring from a mechanical source or by an hydraulic source. It is stated that metal parts may be secured to rust-proofed motor vehicle bodies. |
