U.S. patent application number 11/398692 was filed with the patent office on 2006-10-12 for punch.
Invention is credited to Chao Wei Lin.
Application Number | 20060229133 11/398692 |
Document ID | / |
Family ID | 37081881 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060229133 |
Kind Code |
A1 |
Lin; Chao Wei |
October 12, 2006 |
Punch
Abstract
The present invention generally relates to a punch, and more
particularly to the improvement of a bit portion of a punch for
forging a screw. A drive recess of the screw head includes four
symmetrical arc-shaped grooves and a square groove formed at the
center of the arc-shaped grooves. Also, the bit portion of the
punch is used for forging the screw, and includes four symmetrical
arc-shaped protrusions and a square protrusion formed at the center
of the arc-shaped protrusions. Thus, the types of slot, cross,
cross-square combination, square and double-cross of the drive bit
of the conventional screw driver bit can be adapted to insert into
and engage with the drive recess. Particularly, when the screw
driver bit having arc-shaped drive bit is simultaneously used, it
is easy to control the screw during locking and to generate larger
driving torque, thereby achieving the object of practical utility
and economizing effort.
Inventors: |
Lin; Chao Wei; (Kwanmiao,
TW) |
Correspondence
Address: |
LOWE HAUPTMAN BERNER, LLP
1700 DIAGONAL ROAD
SUITE 300
ALEXANDRIA
VA
22314
US
|
Family ID: |
37081881 |
Appl. No.: |
11/398692 |
Filed: |
April 6, 2006 |
Current U.S.
Class: |
470/63 |
Current CPC
Class: |
B25B 15/005
20130101 |
Class at
Publication: |
470/063 |
International
Class: |
B21K 1/56 20060101
B21K001/56 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 6, 2005 |
TW |
094110796 |
Claims
1. A punch for forging a head of a screw, wherein the screw head is
provided with a drive recess including four symmetrical arc-shaped
grooves and a square groove formed at a center of the arc-shaped
grooves, characterized in that: the punch has a bit portion
corresponding to the drive recess of the head of the screw and
comprising four symmetrical arc-shaped protrusions and a square
protrusion formed at a center of the arc-shaped protrusions.
2. The punch as claimed in claim 1, wherein the arc-shaped groove
is a part of circle-shaped groove.
3. The punch as claimed in claim 2, wherein the arc-shaped groove
has an arc span which is at least more than a half circle.
4. The punch as claimed in claim 3, wherein the arc span is
three-fourth of circle.
5. The punch as claimed in claim 1, wherein the arc-shaped groove
is a part of oval-shaped groove.
Description
[0001] This application claims the priority benefit of Taiwan
Patent Application Serial Number 094110796, filed Apr. 6, 2005, the
full disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a punch, and more
particularly to a punch for forming a drive recess of a screw head,
thereby generating larger driving torque.
[0004] 2. Description of the Related Art
[0005] Currently, conventional screws or bolts include many types
of head, such as pan head, conical head, annular head, countersink
head, oval head, truss head, etc., which can be adapted to drive
recesses such as slot drive recess (A), cross (Phillips) drive
recess (B), cross-square combination drive recess (C), square drive
recess (D) and double-cross (Pozi) drive recess (E) as respectively
shown in FIGS. 1, 2, 3, 4 and 5. However, hand tools which match
with the above-mentioned drive recesses (A), (B), (C), (D) and (E)
includes a screw driver bit having drive bits which are limited to
only the types of slot, cross, cross-square combination, square and
double-cross, etc. Thus, the application of the screw driver bits
is restricted, such that currently other screw driver bits cannot
insert into the above-mentioned drive recesses, and the screw
cannot generate larger diving torque.
[0006] Furthermore, according to the requirement of engagement
between the drive recess and the screw driver bit, the screw driver
bit must engage with the drive recess quickly, and simultaneously
the loose engagement (the drive bit wobbles excessively within the
drive recess) shouldn't be large after the screw driver bit is
engaged with the drive recess. If the loose engagement is large,
the drive recess and the drive bit of the screw driver bit will be
damaged when a power-driven tool suddenly turns to generate large
torque, because the engagement between the drive recess and the
screw driver bit is not tight, such that the loose engagement is
large and then the drive bit slips out of the drive recess.
[0007] Accordingly, in order to solve the above-mentioned problem
and to improve above-mentioned screw, mold and screw driver bit,
Taiwan Patent Publication Number 382306, entitled "Screw, Mold and
Screw Driver bit" and commonly assigned to the assignee of the
present application, discloses a drive recess of screw head
including four symmetrical fan-shaped grooves and a square groove
formed at the center of the fan-shaped grooves. A bit portion of a
mold for forging the screw and a drive bit of a screw driver bit
for matching with the screw, correspondingly include four
symmetrical fan-shaped protrusions and a square protrusion formed
at the center of the fan-shaped protrusions. However, it is not
easy to form four fan-shaped grooves, but is easy to damage the
mold so as to substantially increase the cost.
[0008] Accordingly, there still exists a need for a punch capable
of solving the above-mentioned problem.
SUMMARY OF THE INVENTION
[0009] In order to tightly engage a screw driver bit with a drive
recess, fan-shaped grooves of the drive recess of the screw head
can be replaced with arc-shaped grooves. Also, if the angle between
arc-shaped protrusions and square protrusion of the screw driver
bit is small and the arc-shaped protrusions and square protrusion
of the screw is nearly parallel to central line of the screw, the
loose engagement (the drive bit wobbles excessively within the
drive recess) can be substantially decreased and the driving torque
can be comparatively increased, when compared with Taiwan Patent
Publication Number 382306. Furthermore, preferably, the arc-shaped
groove can have an arc span which is at least more than a half
circle. Thus, the drive recess of the screw head of the present
invention includes four symmetrical arc-shaped grooves and a square
groove formed at the center of the arc-shaped grooves, wherein
preferably the arc-shaped groove can have an arc span which is at
least more than a half circle. A bit portion of a punch (mold) for
forging the screw and a drive bit of a screw driver bit for
matching with the screw, correspondingly include four symmetrical
arc-shaped protrusions and a square protrusion formed at the center
of the arc-shaped protrusions.
[0010] Accordingly, it is an object of the present invention to
provide a drive recess of head of screws or bolts not only applied
to a variety of types of drive bit of the screw driver bit and but
also matched with the structure of the screw driver bit of a hand
tool result therefrom, whereby the screw can generate larger diving
torque of engagement, and the drive bit of the screw driver bit can
much tightly engage with the drive recess, because the drive recess
includes four symmetrical arc-shaped grooves and a square groove
formed at the center of the arc-shaped grooves.
[0011] It is another object of the present invention to provide a
punch of a screw forging device resulted from the drive recess of
the screw for forging the screw head, wherein a bit portion of the
punch is corresponding to the drive recess of the screw head and
includes four symmetrical arc-shaped protrusions and a square
protrusion formed at the center of the arc-shaped protrusions.
[0012] It is a further object of the present invention to provide a
structure of a screw driver bit of a hand tool resulted from the
drive recess of the screw, wherein a drive bit of the screw driver
bit is corresponding to the drive recess of the screw head and
includes four symmetrical arc-shaped protrusions and a square
protrusion formed at the center of the arc-shaped protrusions.
[0013] The foregoing, as well as additional objects, features and
advantages of the invention will be more readily apparent from the
following detailed description, which proceeds with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a top view of a slot drive recess of a first
conventional screw;
[0015] FIG. 2 is a top view of a cross drive recess of a second
conventional screw;
[0016] FIG. 3 is a top view of a cross-square drive recess of a
third conventional screw;
[0017] FIG. 4 is a top view of a square drive recess of a fourth
conventional screw;
[0018] FIG. 5 is a top view of a double-cross drive recess of a
fifth conventional screw;
[0019] FIG. 6 is a top view of a screw according to an embodiment
of the present invention;
[0020] FIG. 7 is a cross-sectional view along A-A' line of FIG.
6;
[0021] FIG. 8 is a partial perspective view of a screw of the
present invention;
[0022] FIG. 9 is a side elevational view of a screw of the present
invention;
[0023] FIG. 10 is a side elevational view of a punch according to
an embodiment of the present invention;
[0024] FIG. 11 is a side elevational view of a screw driver bit
according to an embodiment of the present invention; and
[0025] FIG. 12 is a cross-sectional view along B-B' line of FIG.
11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Referring to FIGS. 6 and 7, they depict a screw according to
an embodiment of the present invention. The screw includes a screw
head 1, a shank 2 and a male-thread 3. The screw head 1 can be pan
head, conical head, circular head, annular head, countersink head,
oval head, truss head, etc. The screw head 1 is provided with a
drive recess 4, wherein the drive recess 4 includes four
symmetrical arc-shaped grooves 40 and a square groove 41 formed at
the center of the arc-shaped grooves 40, in order to match with a
wide variety of shapes of drive bit of screw driver bit. Also, the
arc-shaped groove 40 can be a part of circle-shaped groove or
oval-shaped groove. The arc-shaped groove 40 can have an arc span
which is at least more than a half circle (e.g. the arc span is
three-fourth of circle, shown in FIGS. 6 and 8). Furthermore, an
included angle .alpha. between groove wall of the arc-shaped groove
40 and central line of the screw is between 0 and 45 degrees, shown
in FIG. 9. Likewise, an included angle .alpha. between groove wall
of the square groove 41 and central line of the screw is between 0
and 45 degrees.
[0027] Referring to FIG. 10, it depicts a punch 5 according to an
embodiment of the present invention. The punch 5 can be a
male-punch of a forging device for forming the drive recess 4 of
the screw head 1 of the present invention. A bit portion of the
punch 5 is corresponding to the drive recess 4 of the screw head 1
and includes four symmetrical arc-shaped protrusions 50 and a
square protrusion 51 formed at the center of the arc-shaped
protrusions 50, thereby forging the drive recess 4 of the screw
head 1.
[0028] Referring to FIGS. 11 and 12, they depict a screw driver bit
7 according to an embodiment of the present invention. The screw
driver bit 7 can tightly engage with the screw of the present
invention. A drive bit of the screw driver bit 7 is corresponding
to the drive recess 4 of the screw head 1 and includes four
symmetrical arc-shaped protrusions 70 and a square protrusion 71
formed at the center of the arc-shaped protrusions 70, thereby
applying to the drive recess 4 of the screw head 1 of the
screw.
[0029] Likewise, the arc-shaped protrusions 50, 70 of the punch 5
and the screw driver bit 7 can have an arc span which is at least
more than a half circle (e.g. the arc span is three-fourth of
circle, shown in figure).
[0030] As described above, when the screw is requested to be
engaged by larger driving torque, the types of slot, cross,
cross-square combination, square and double-cross of the drive bit
of the conventional screw driver bit and the screw driver bit 7 of
the present invention can be used to and fully engage with the
drive recess 4 of the screw. Thus, the loose engagement (the drive
bit wobbles excessively within the drive recess) can be
substantially decreased, and the driving torque of engagement can
be substantially increased and transferred to a body of the screw,
thereby economizing effort to drive the screw and controlling the
screw to be locked, and further increasing the locking effect and
efficiency of screw. Compared with the driving torque of engagement
resulted from the conventional drive recesses shown in FIGS. 1, 2,
3, 4 and 5, the driving torque of the present invention can be
increased to be at least more than 30% and transferred to the body
of the screw by experiment. Accordingly, the present invention
really has inventive step.
[0031] Although the invention has been explained in relation to its
preferred embodiment, it is not used to limit the invention. It is
to be understood that many other possible modifications and
variations can be made by those skilled in the art without
departing from the spirit and scope of the invention as hereinafter
claimed.
* * * * *