Mushroom-compaction and asymmetric-thread impact-drivable screw
OwnerW. C. Litzingerinventor
Life of this patent
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Abstract
An asymmetric thread impact drivable screw and clip for use with a power impact device for penetrating wood fibers while minimizing cut fibers. The screw includes an impact head and a conical shaped tip having a ballistic insertion angle at the ends of a shank. The shank defines asymmetrical threads with an insertion flank having a long side at a slide angle peaking at a crest supported by a catch flank positioned at a grip angle. Varying tool accepting recess are taught for the head along with multiple thread sections. A mushroom compaction thread section is also taught.
Claims12
An asymmetric thread impact drivable screw apparatus for use with a impact device, the apparatus comprising:
- an impact head;
- a conical shaped tip having a single constant ballistic insertion angle between twenty three degrees and thirty three degrees along the entire length of the conical shaped tip;
- a shank defining an axis, the shank having a shank diameter,
- the shank having a first end connected to the impact head and a second end connected to the conical shaped tip,
- the shank defining a spiral of asymmetrical threads with an insertion flank peaking at a crest with the crest supported by a catch flank, the conical shaped tip extending to the crest defining a thread diameter larger than the shank diameter, the threads having a pitch distance and a thread diameter, the thread diameter being approximately twice the pitch distance;
- the insertion flank protruding from the shank at slide angle;
- and
- the catch flank protruding from the shank at a grip angle of approximately forty degrees.
Dependencies are inferred from the claim text.