Screw head punch
An improved punch to punch socket on the head of a screw that extends the service life of the punch and upgrades the quality of the screw by having a recess formed on one end of the body of the punch, a punching head protruding from the center of the recess, and multiple wings are respectively extended from the sides of the punching head at a level lower than that of the head of the punch to create traces to release punching pressure to avoid deformed socket or formation of stress concentration point at the corner of the socket.
(a) Technical Field of the Invention
The present invention is related to a punch for screw head, and more particularly, to one that extends service life of the punch and upgrades quality of the screw.
(b) Description of the Prior Art
A screw, though a small element among all hardware products, is a must for the assembly of various types of objects. To facilitate driving a screw, the on the surface of the head of the screw is usually provided with a socket either in flat, cross or square shape. To prevent the socket from restricting the use of the tool, e.g., a screwdriver, the socket is made in a shape combining two or more than two of the head shapes. In the formation of the socket, a punch is used to punch into the surface of the screw head when the screw is molded. Each punch is subject to more than two hundred rounds of punching the socket; therefore, a very high punching force is created in the punching process. Generally, in punching for the flat socket, the over concentration of stress at a certain point is less likely to happen giving longer service life of the punch and better quality of the processed socket. However, in the punching for comparatively complicated form of socket, e.g., cross, square, polygonal or their combinations, the concentration of stress at certain point occurs resulting in bouncing of punch force back to the punch or direct application of the force on the screw head during the punching process. Accordingly, the head of the punch is damaged in short time, the socket is deformed or cracks appear on the corner of the socket. A punch 1 of the prior art designated for punching a square socket as illustrated in the accompanying drawings is provided with a recess 12 on one end of the body and a punch head 13 formed at the center of the recess 12. The end of the punch head relates to a conic extending gradually from four corners toward its center so to punch against the head of a screw for a square socket. However, the structure of the punch 1 has served its purpose to punch for a square socket on the head of the screw, the over-concentrated stress results in that the damaged punch to cause extra cost of punching; that the square socket is deformed to cause the failure in a sound insertion between the head of the screw and the tool (e.g. a screwdriver) thus to affect the fastening; or that cracks appear on the four corners of the square socket to cause collapse when the square socket is driven by the screwdriver thus to prevent the fastening. No effective solution has been suggested for any of the flaws as described herein.
SUMMARY OF THE INVENTIONThe primary purpose of the present invention is to provide an improved structure of a punch for the head of a screw to extend the service life of the punch and upgrade the quality of the screw. To achieve the purpose, wings are provided on the sides of the punch head at a lever lower than that of the punch head so that when the punch is used to punch for a socket on the head of the screw, a flute slightly recessed will be formed on the sides of the socket to serve as a point for releasing the pressure incurred from the punching process, thus to prevent deformed socket or creation of stress concentration point on the corner of the socket.
The foregoing object and summary provide only a brief introduction to the present invention. To fully 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.
BRIEF DESCRIPTION OF THE DRAWINGS
The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
Referring to
When the punch head 23 is used punch against a screw head 3 for a square socket 31 as illustrated in
As illustrated in
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Claims
1. A punch for processing the socket on the surface of the head of a screw is comprised of a recess formed on one end of the body of the punch, a punching head protruding from the center of the recess; and multiple wings extending from the sides of the punching head at a level lower than that of the head of the punch.
Type: Application
Filed: Mar 24, 2004
Publication Date: Sep 29, 2005
Inventor: Kuo Lin (Kaohsiung Hsien)
Application Number: 10/807,127