| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved thread used in a spinal fixation system. <P>SOLUTION: A reverse angled threadform with anti-splay clearance includes inner and outer helical threads, each with respective leading stab flanks and trailing load flanks, the load flanks mutually engaging when an inner member with the inner threads is advanced into an outer member with the outer threads. The inner load flanks form acute angles with a helical axis, while the outer load flanks form obtuse angles with the helical axis. A clearance is formed between the stab flanks of the inner and outer threads. On threadforms with root and crest other than angular peaks, such as cylindrical root and crest surfaces, the anti-splay clearance is also formed between the mutually facing root and crest surfaces of the inner and outer threads. The load flanks may be parallel, outwardly diverging, or outwardly converging. <P>COPYRIGHT: (C)2013,JPO&INPIT |
