BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a conventional screw screwing into the object.
FIG. 2 is a schematic diagram showing the first preferred embodiment of the present invention;
FIG. 3 is a schematic diagram showing the second preferred embodiment of the present invention;
FIG. 4 is a cross section diagram of the first preferred embodiment screwed into an object;
FIG. 5 is a cross section diagram of the third preferred embodiment screwed into an object; and
FIG. 6 is a schematic view showing that the fourth preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, the first preferred embodiment of the present invention comprises a head 31, a shank 32 which connected to the head 31, and a first thread section 33 spirally connected to the shank 32 along with the shank axial line “α”; wherein the head 31 is defined with recesses for the screwdriver to screw. Moreover, the recesses are sorts of Phillip, slotted, and many different kinds of shape according to the user's need, so as to fit in with different kinds of screwdriver. Besides, the distal end of the shank 32 forms a cone-shaped tip portion 320 and the cone-shaped tip portion 320 forms a drill point 321; furthermore, wherein the first thread section 33 has a first thread segment 331 and a second thread segment 332 spirally defined on the shank 32 and the cone-shaped tip portion 320. Each thread of first thread segment 331 forms a thread peak 333 thereon. Furthermore, the outer diameter of the thread at second thread segment 332 is shorter than the outer diameter of the first thread segment 331; meanwhile, the second thread segment 332 can depend on the user's needs to extend upwardly from the drill point 321 or from a non-drill point part (referring to FIG. 3), and here is an example of the second thread segment 332 extending upwardly from the drill point 321. Besides, the thread of the second thread segment 332 forms a plane-surface 334 thereon, and the plane-surface 334 is converged toward the thread peak 333 of the first thread segment 331.
Referring to FIG. 4, a screwing torque is applied on the head 31 while screwing, therefore to tug the second thread segment 332 sharper cutting the object 4. Moreover, the object 4 is a mixture material made by wood scrap, rubber, and adhesive, and further to illustrate with a high-pressure formed object. The plane surface 334 of the second thread segment 332 drills into the object 4 to enlarge the screwing channel. Since the channel is enlarged, the first thread segment 331 can enter the object 4 efficiently with the enlarged channel to lower the screwing torque. Furthermore, after the second thread segment 332 drills into the object 4, the cutting debris can be eliminated from the space between the enlarged channel and the first thread segment 331, therefore to avoid crack in the work piece, to enhance the screwing speed, and to lower the screwing torque during operation. Since the cutting debris is eliminated from the space between the enlarged channel and the first thread segment 331, the left debris can be filled into the channel and can achieve the fastening effect.
Referring to FIG. 5, the third preferred embodiment of the present invention, same as the explanation in the first embodiment, comprises a head 31, a shank 32 connected to the head 31, and a first thread section 33 spirally connected to the shank 32 along with the axial line “α”; in particular, thereon the shank 32 between the head 31 and the first thread section 33 is defined with a second thread section 34 which is deposed in reverse direction to the first thread section 33. Besides, the start point 341 of the second thread section 34 is engaged with the end point 335 of first thread section 33. In screwing the screw, by means of the second thread section 34 is disposed in the reverse direction, and the start point 341 of the second thread section 34 is engaged with the end point 335 of the first thread section 33, the cutting debris can be removed efficiently. Further, the second thread section 34 fills in the space with part of the cutting debris, so as to enhance the fastening effect. Consequently, the first thread 33 and the second thread section 34 subdue to each other so as to avoid the screw being loosen.
Referring to FIG. 6, the fourth preferred embodiment of the present invention comprises a head 31, a shank 32 connected to the head 31, and a first thread section 33 spirally connected on the shank 32 along with the shank axial line “α”. In particular, said shank 32 and the first thread section 33 are formed of a triangular shape. Beside, there between the first thread section 33 and the head 31 is defined with a smooth section 35; further, the cone-shaped tip portion 320 forms a auxiliary third thread section 36 extending upwardly among each thread of the second thread segment 332, and the auxiliary third thread section 36 is formed of triangular shape. Moreover, Due to the shank 32, the first thread section 33 and the auxiliary third thread 36 forming a triangular shape, the contacting area with the object 4 is reduced and the friction torque from the screwing operation is lower; therefore to enhance the anti-loosen effect by screwing the auxiliary third thread section 36 and to avoid the cladding material which platting on said shank falling off. In addition, the cladding material on the screw 3 is efficient at anti-rust and isolation.
To sum up with above description, the present invention provides a plane-surface defined on the thread connecting to the cone-shaped tip portion, so as to drill into the object 4 to enlarge the screwing channel. It benefits at lowering screw torque and enhancing better effects on fastening. Finally, accompanying with the shank and the threads formed of triangular shape, the friction force between the screw and the object can be lower, and therefore to enhance the anti-rust and isolation effect.
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
Patent Application
20080095594
