摘要 |
1,253,956. Anchor nut. TOLEDO WOODHEAD SPRINGS Ltd. 6 July, 1970 [11 July, 1969], No. 32645/70. Heading F2H. A pierce nut 10 comprises a flat end surface 14 with at least one groove 16 extending into the nut at opposite sides of the threaded bore 12 having an inner side wall 18 perpendicular to the end surface, an undercut outer wall 20 terminating in a flat abutment surface 22 parallel to the flat end surface 14, the abutment surface defining approximately the outer half of the bottom of the groove, the inner portion 26 of the bottom of the groove, being recessed further inwardly of the nut body from the abutment surface, the depth d of perpendicular wall 18 being greater than and the depth b of the abutment surface being less than the width a of groove 16. To prevent rotation of the nut when in position in a panel of sheet metal 28, it may have an annular groove, with a plurality of recesses (38, Fig. 4, not shown), a groove with an annular inside wall and an elliptical outer wall (Fig. 11, not shown) or two parallel straight grooves (Fig. 4, not shown). The nut is locked to a panel 28 by holding the nut in place with an anvil (not shown) and pressing the panel with a tool 30 which just clears the inner wall of the groove. The panel metal shears, is stretched over the outer shoulder of the groove and pressed under the undercut sidewall of the groove. |