| 摘要 |
A fastener including a chisel point that pre-bores a hole in a work piece to prevent damage to the work piece as the fastener advances. The fastener can include a head, a shaft and a chisel brake point formed at an end of the shaft. The chisel brake point can include first and second opposing inclined surfaces disposed at an angle of about 800 to about 1500 relative to one another. A thread can begin adjacent the chisel brake point and form an extension of an inclined surface and/or a chisel edge. The chisel brake point can scrape material from a work piece while pre-boring a hole. The material can be transferred to the thread, and subsequently fed up the thread, out of the pre-bored hole. The chisel brake point can also selectively retard advancement of the fastener into the work piece. Methods of installing the fastener also are provided. 10 22 24 24 4554j 20 Fig.1 100 10 22 24 4049 5 45 2826 30 5225 20 Fig.32 2826 30 1054 Fig 4ig Fi.3 104-Fig.7 9Fig.8 5 Fig.9 1035 59 109 107 0 '10 10%d --Fig.10 |
