发明名称 |
VERKTYG FOR RULLNING AV EN SKRUVGENGA |
摘要 |
A thread-forming screw has a point or lead thread portion having a relatively steep entry angle with respect to the screw axis. Adjacent to the point thread is a tapered thread portion of about two to three pitches in axial length. This tapered thread has a shallow entry angle defined by the taper of the maximum diameter of the thread toward the point. This shallow entry angle may be approximately 5 DEG to 8 DEG or equal to about three times the helix angle of the tapered thread. This configuration of the tapered thread results in a balanced action of thread formation and axial in-feed of the screw, resulting in a lower end pressure to initiate the thread-forming in a workpiece. A roll-threading die is contoured to provide ridges and valleys to effect the tapered thread portion. |
申请公布号 |
SE450468(B) |
申请公布日期 |
1987.06.29 |
申请号 |
SE19830005142 |
申请日期 |
1983.09.23 |
申请人 |
RESEARCH ENGINEERING & MANUFACTURING INC |
发明人 |
H G * MUENCHINGER |
分类号 |
B21H3/06;B21H3/02;B21H3/10;F16B25/00;F16B25/04;(IPC1-7):B21H3/06 |
主分类号 |
B21H3/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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