公开(公告)号：US3831415A

公开(公告)日：1974-08-27

申请号：US39831773

申请日：1973-09-18

Applicant: USM CORP

Inventor： SKIERSKI E

IPC: B21H3/02 ,  F16B25/00

CPC classification number: F16B25/0052 ,  B21H3/027

Abstract: A self tapping threaded fastener, the method of making same and the rolling dies therefor wherein said fastener is adapted for assembly with a member in which a standard internal thread is formed by the fastener and in which a zero running torque or controlled prevailing torque is established between said fastener and member. A plurality of thread forming lobes are disposed on an otherwise standard, substantially fully formed thread on the tapered work entering end, wherein predetermined lobes on said tapered end proximate the shank portion are rolled such that their ultimate projection is within the envelope of the imaginary projection of the convolution of the shank thread toward the tip of said fastener. The method of making said fastener includes rolling a substantially continuous thread from said shank portion throughout said tapered work entering portion and simultaneously forming spaced apart thread forming lobes superimposed upon said thread in said work entering portion, then subsequently rerolling said threaded shank portion and said predetermined lobes on the work entering portion to the cylindrical thread convolution of said shank portion, as projected. The dies for rolling said fastener include a first, and second rolling dies, said dies having a fastener entrance end and a fastener exit end, and disposed intermediate said ends thread forming surfaces including a plurality of parallel thread crest forming grooves and thread root forming ridges having a shank forming flat portion being bounded along one edge by an upwardly inclined tip forming surface, said first rolling die being the primary rolling die and having a shank and tip forming section including a lobe forming section wherein a plurality of regularly spaced lobe forming pockets are disposed in said thread forming grooves and ridges in said tip forming surface, a reroll support section wherein said thread forming surfaces match said shank forming flat portion and a release section, said reroll support section of a predetermined rolling length so as to reroll a predetermined number of said thread forming lobes, and a said second rolling die having shank and tip forming sections, and a reroll section so disposed as to reroll a predetermined number of said thread forming lobes.

Abstract translation: 自攻螺纹紧固件，其制造方法及其制造方法，其中所述紧固件适于与由紧固件形成标准内螺纹的构件组装，其中建立零运行扭矩或受控的主要扭矩 在所述紧固件和构件之间。 在锥形工件进入端的另外标准的基本上完全成形的螺纹上设有多个螺纹形成凸角，其中在所述锥形部分附近的所述锥形端部上的预定凸角被卷起，使得它们的最终突出部位在所述假想投影的外壳内 的柄螺纹朝向所述紧固件的尖端的卷曲。 制造所述紧固件的方法包括在所述锥形加工进入部分中从所述柄部部分滚动基本上连续的螺纹，并且同时形成在所述工件进入部分中叠加在所述螺纹上的间隔开的螺纹形成凸角，然后随后重新滚动所述螺纹柄部分和所述预定 如所投射的，工件进入部分的叶片突出到所述柄部分的圆柱形螺纹卷积。