| 摘要 |
1,101,795. Riveted joints; attaching tabs. E. C. FRAZE. 28 April, 1965, No. 17921/65. Headings B3A and B3U. [Also in Division B8] A method of joining two metal sheets, e.g. the tab (38) and tear strip (62) of an aluminium or steel closure (20, Fig. 8) comprises forming hollow rivets (24, 40, Fig. 6) on the sheets, one rivet fitting within the other, and squeezing the end walls (36, 42) of the rivets between dies (44, 45, Fig. 7) so as to extrude the walls (36, 42) radially outwards to head and interlock the rivets without compressing them axially. The walls (36, 42) are impact-extruded between convex end surfaces of the dies, the end radius of outer die (44) being less than that of the inner die (45) in order to produce more radial displacement in the outer wall (42) than the inner wall (36) and prevent interference. Alternatively, the end of the inner die may be flat. The tab and closure may be formed separately to produce the rivets, or placed together and pressed simultaneously between two sets of dies, the first (Fig. 2, not shown) producing a shallow dimple in the part or parts, and the second set (Fig. 4, not shown) causing inward radial flow of the dimple-material to thicken the rivet.walls. The rivets may be formed outwardly or inwardly of the closure, between a single set of dies (Figs. 12 and 15, not shown,) after which they are interlocked between further dies. The line of weakness defining the tear strip, is formed on the upper or lower surface of the closure (Figs. 10, 11, not shown). |
