Patent ID: 7802692

Claim:
A fastening device, comprising: a first component member including a plurality of threads of a female screw formed on an inner peripheral wall of said first component member and each of said threads of the first component member having a same predetermined lead angle; and a second component member having an open end portion and including a plurality of threads of a male screw formed on an outer peripheral wall of said open end portion so as to engage with the threads of said first component member, at least two of the threads of said second component member disposed on said second component member and extending along their length at a first lead angle relative to the open end of said second component member and at least another one of the threads of said second component member disposed on said second component member and extending along its entire length at a second lead angle relative to the open end of said second component member and disposed between two of the threads of the second component member disposed at the first lead angle, the first and second lead angles being different and the first lead angle being the same as the predetermined lead angle of the threads of the first component member, said first and second component members being formed of an elastic material, wherein when said first and second component members are moved closer from a first relative position to a second relative position, one of the threads of the female screw initially slides against a thread of the male screw having the second lead angle to result in the first and second component members engaging each other, and when said threads of the first and second component members engage, said threads are elastically deformed by each other by moving said threads at a distance, and said first and second component members are fixed in the second position while maintaining their engaged relationship by the frictional engagement of the threads differing in said lead angle.