Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02616478 2007-12-28
FASTENER WITH REMOVABLE ELEMENT
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fastener, in particular to
a screw with removable element.
2. Description of the Related Art
A conventional screw 1 for screwing into metal objects is shown
in Fig. 1 and generally includes a head 11, a shank 12 connecting
thereto, a plurality of threads 13 defined around the shank 12,
and a tip section 14 formed at a distal end of the shank 12. While
screwing, the screw 1 is driven into the metal objects (not shown)
by the tip section 14 and threads 13 to bore through it and further
drill therein. When the screw 1 is in use of screwing roofing objects,
users used to climb on the roof and use a tool (not shown) for rotating
the head 11 and drilled into the objects. However, the screw 1 may
be facilely screwed in but hardly taken out of the surface of objects,
namely users often need to climb on the roof and repeat the above
operation for repairing the objects or loosening and tightening
the screw, which makes burden and damages users in time of operation.
Referring to Fig. 2, a screw 2 made for improving the above
shortcomings includes a shank 21 and a tip section 22. The shank
21 fabricated of a stainless steel comprises a plurality of threads
211 spirally arranged thereon, a head 212 disposed at one end thereof,
and a polygonal recess 213 at the other end. A tip section 22 made
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of another kind of harden metal respectively forms a tip portion
221 and an insertion 222 at two ends thereof, and the insertion
222 fits with the polygonal recess 213. While using, the screw 2
has the same operation as the screw 1 and here it is omitted;
particularly, the tip section 22 can be removed from the shank 21
and repeatedly used after securing the objects to the roof, and
users simply put a tool (not shown) into the recess 213 to directly
tighten or loosen the screw 2 without climbing on the roof very
often.
As seen in Fig. 3, in practical, the insertion 222 is initially
put into the recess 213, and the tip section 22 bores a hole 31
through the metal objects 3; nevertheless, the threads 221 with
its outer diameter may not directly enter into the hole 31 and further
make the screw 2 interfered between the shank 21 and the tip section
22, which result of the screw 2 unable to be substantially drilled
into the objects 3 or be broken under the forced screwing although
being successfully drilled therein.
SUMMARY OF THE INVENTION
Therefore, the present invention intends to provide a screw
with removable element which is conducive to substantially drive
the screw into metal objects and increase the convenience of using.
The present invention relates to a screw comprising a shank
and a tip section, wherein the shank includes a first threaded section
consisting of threaded sections with different diameters, and an
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insertion of the tip section has a coincident shape with a recess
defined on the end face of the shank. In use, the tip portion initially
bores through the metal objects, and the first threaded section
is smoothlydriven and drilled into the hole from the threaded section
with a smaller outer diameter toward the threaded section with a
larger outer diameter, thereby assisting the screw to be firmly
fixed therein and preventing from damaging threads thereof under
a forced screwing. Further, the insertion can be removed away and
a wrench is used instead to loosen or tighten the screw if necessary
and increase the convenience of using.
The advantages of the present invention over the known prior
arts will become more apparent to those of ordinary skilled in the
art by reading the following descriptions with the relating
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view showing a conventional screw;
Fig. 2 is a perspective view showing another conventional screw;
Fig. 3 is a schematic view showing the screw of Fig. 2 drilled into
the metal objects;
Fig. 4 is a perspective view showing a first preferred embodiment
of the present invention;
Fig. 5 is a schematic view showing that a wrench is put into the
recess while the tip section is removed away;
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Fig. 6 is a perspective view showing a second preferred embodiment
of the present invention;
Fig. 7 is an elevation view showing a third preferred embodiment
of the present invention;
Fig. 8 is an elevation view showing a fourth preferred embodiment
of the present invention; and
Fig. 9 is a schematic view showing the screw of Fig. 7 drilled into
the metal objects.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 4, a fastener ( for instance of a screw 4)
of a first preferred embodiment comprises a shank 41 and a tip
section42; the shank 41 made of a kind of inetal material, for instance
of a stainless steel, comprises a shank body 411, a first threaded
section 412 extending around the shank body 411, a head 413 disposed
at one end of the shank body 411, and an end face 414 disposed at
the other end thereof, opposite to the head 413; wherein the first
threaded section 412 includes an upper threaded section 412a located
adjacent to the head 413 and a lower threaded section 412b located
adjacent to the end face 414; an outer diameter "Dla" of the upper
threaded section 412a is greater than an outer diameter "Dib" of
the lower threaded section 412b. Further the end face 414 has a
recess 415 defined on the surface thereof, and the recess 415 formed
in a polygonal contour, e.g. a hexagonal shape, is applied to the
preferred embodiments.
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Still further, the tip section 42 made of another kind of harden
metal material includes a tip body 421, a tip portion 422 disposed
at one end thereof, and an insertion 423 extending axially from
the other end thereof for being removably inserted into the recess
415. The insertion 423 can also have a polygonal configuration and
here a hexagonal pillar is adopted so that the insertion 423
accurately fits with the recess 415.
Referring to Fig. 4 and 5, in operation, the screw 4 is adopted
to use in screwing roofing panels, for instance of screwing metal
objects S. Before screwing, the insertion 423 is initially put into
the recess 415, and then the tip portion 422 is drilled into the
objects 5 by rotating the head 413 and bores a hole 51 through it.
When the tip section 42 is entirely drilled therein, the shank body
411 is further driven along the hole 51 into the objects 5 by the
lower threaded section 412b with the smaller outer diameter "Dlb"
to prevent the screw 4 from being directly interfered or blocked
between the shank body 411 and the tip body 421 in time of screwing
and the upper threaded section 412a with the larger outer diameter
"Dla" to impel the shank 41 firmly fixed into the objects 5.
Subsequently, the tip section 42 can be alternatively removed from
the recess 415 for a repeated use if necessary, and the recess 415
would perform in another use, namely users can work inside the house
and exert a wrench 6 to insert into the recess 415 either for loosening
or tightening the screw 4 from the objects S. In this manner, the
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screw 4 is freely adjusted according to user's demand without
climbing on the roof and thus increasing the convenience.
Further referring to Fig. 6, a screw 4 of a second preferred
embodiment still comprises the similar elements, and the operations
and the effects are the same as the first embodiment. Differentially,
the tip section 42 further provides with a second threaded section
424 disposed between the tip portion 422 and the insertion 423,
and the threaded sections 412a- 412b- 424 have the same pitches.
Further referring to Fig. 7 and 8, an outer diameter "Dla" of the
upper threaded section 412a is greater than an outer diameter "D2"
of the second threaded section 424 and an outer diameter "Dlb" of
the lower threaded section 412b, and the outer diameter "D2" can
be larger (shown in Fig. 7) or be smaller (shown in Fig. 8) than
the outer diameter "Dlb". Here it is adopted in the Fig. 9 that
the outer diameter "Dla" is greater than "D2" and further "D2" is
greater than "Dlb".
Referring to Fig. 9, the tip portion 422 initially bores through
the metal objects 5, and the second threaded section 424 assists
to form a bigger hole 51 so that the lower threaded section 412b
can also be gradually driven into the objects 5 along the hole 51
without being interrupted. While drilling from the lower threaded
section 412b toward the upper threaded section 412a, the upper
threaded section 412a is secured into the objects 5 to result of
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the screw 4 being firmly fixed therein and thus increasing the
screwing stability.
To sum up, the present invention takes advantage of the shank
having a first threaded section with different outer diameters and
the tip section which may also include a second threaded section
spiraling thereon. In use, the shank can be smoothly driven into
the objects along the screwing hole by the above threaded sections,
so that the screw is substantially and entirely drilled into the
objects without breaking the first threaded section and retains
a good screwing stability. After screwing, a wrench can be used
instead of the tip section to insert into the recess for loosing
or tightening the screw, thereby increasing the convenience of
using.
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.
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