Screw with waved thread
A screw with wave thread including a head, a shank extending therefrom, and a thread spirally disposed on the shank; in particular, the thread has respective first and second threaded sections. Each thread unit of the second threaded section defines a continuous wave-shaped directrix around the shank for a base. A plurality of thread segments are formed on each thread unit of the second threaded section, and each of which has an upper flank as well as a lower flank extended from the shank and disposed along the wave shape directrix to form into a wavy arrangement around shank, thereby disposing more peaks converged by the upper flank and the lower flank for increasing the drilling capability.
1. A screw with waved thread comprising:
a head;
a shank connecting to said head with a drilling member formed opposite to the said head; and
a thread spiraling on said shank and having a first threaded section disposed near said head and a second threaded section disposed immediately following said first threaded section; wherein, each of said first and said second threaded sections including thread units, on each of which plurality of interlaced thread segments are disposed; each said thread segment having an upper flank and a lower flank both extending from said shank and a peak converged by said upper flank and said lower flank; a continuous wave-shaped directrix being defined around said shank as a base line for said second threaded section standing thereupon, and said peaks on said thread unit of said second threaded section being disposed in a wave shape of said directrix; said upper flanks and said lower flanks on said thread unit of said second threaded section being disposed in a wavy arrangement along said wave-shaped directrix.
2. The screw as claimed in claim 1 , wherein, the space between any two adjacent peaks on each said thread unit of said second threaded section is not a constant.
3. The screw as claimed in claim 1 , wherein, said directrix includes two sides, an upper side and a lower side, and at least two said adjacent peaks in a group are disposed on either side thereof.
4. The screw as claimed in claim 1 , wherein, each of said peaks serves as a drilling interface.
5. The screw as claimed in claim 4 , wherein, said drilling interface is inclined with said wave-shaped directrix by an included angle.
6. The screw as claimed in claim 1 , wherein, each of said peaks adopts a drilling facet for cutting object.
7. The screw as claimed in claim 1 , wherein, a power receiving face is formed on a side of said peak.
8. The screw as claimed in claim 1 , wherein, a plurality of wave-shaped thread units are disposed between said first threaded section and said head.
9. The screw as claimed in claim 1 , wherein, said shank forms a polygonal shape.
10. The screw as claimed in claim 1 , wherein, any of said threaded sections forms a polygonal shape.