Screw with spiral triangular threads

Details Screw with spiral triangular threads Screw with spiral triangular threads

1999-12-01

2001-07-03

Saether, Flemming (Department: 3627)

Expanded, threaded, driven, headed, tool-deformed, or locked-thr

Externally threaded fastener element, e.g., bolt, screw, etc.

Thread or shank structure

C411S387400, C411S310000

Reexamination Certificate

active

06254327

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is related to an improvement in the structure of a screw and in particular to one which can be easily turned into a piece hard wood.
2. Description of the Prior Art
The conventional screw consists essentially of a solid cylinder, usually of metal, around which a thread winds spirally, either clockwise or counterclockwise. However, it is difficult to turn the screw into an object if it is made of hard wood. Hence, an improved screw (see
FIG. 1
) has been designed to obviate this drawback. As shown, the screw includes a shank
1
formed with spiral circular threads
11
at the upper portion thereof. The spiral circular threads
11
at the lower portion of the shank
1
are provided with a plurality of teeth
12
for facilitating the tuning of the screw into the wood. Nevertheless, although the teeth
12
enables the screw to turn into a piece of hard wood, it still requires a lot of effort to turn the screw thereby often making one feel utterly exhausted in order to fasten pieces of hard wood.
Therefore, it is an object of the present invention to provide an improvement in the structure of a screw which can obviate and mitigate the above-mentioned drawbacks.
SUMMARY OF THE INVENTION
This invention is related to an improvement in the structure of a screw.
According to a preferred embodiment of the present invention, a screw comprising a shank having an upper portion formed with spiral circular threads and a lower portion formed with spiral triangular threads, each of said spiral triangular threads having three sharp edges and three pointed tips, said pointed tips of said spiral triangular threads being located at different positions.
It is the primary object of the present invention to provide an improved screw which can be easily turned into a piece of hard wood.
It is another object of the present invention to provide an improved screw which is simple in construction.
It is a further object of the present invention to provide an improved screw which is inexpensive to manufacture.
The foregoing objects and summary provide only a brief introduction to the present invention. To filly appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.


REFERENCES:
patent: 3918345 (1975-11-01), Phipard
patent: 4637767 (1987-01-01), Yaotani
patent: 5044855 (1991-09-01), Fukibayashi
patent: 5772374 (1998-06-01), Ode
patent: 957675 (1964-05-01), None
patent: 2040769 (1980-09-01), None

Affiliated with

Also associated with

Rating

Screw with spiral triangular threads does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Screw with spiral triangular threads, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Screw with spiral triangular threads will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2453604