Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a novel screw for mounting
on an electrical apparatus, such as a plug, by which elec-
trical wires can be easily connected with the inner end of
prongs of the electrical plug to form a good electrical
connection without peeling off a partial of insulated skin
of the electrical wires.
Conventionally, wires which are used to connect with
an electrical apparatus, such as a plug, are firstly peeled
off one end of its insulated skin wrapped around a conductive
metal core so as to make the metal core able to contact
electrically with the apparatus. The peeling of the skin is
troublesome and needs a special hand tool such as a nipper
or a knife. Furthermore, the conductive metal core is
easily cut off during the peeling operation. Further dis-
advantages associated with the prior art will be discussedhereinafter in connection with the drawings.
In accordance with the present invention, there
is provided a novel screw, which can be mounted on the
conventional electrical apparatus, comprising a threaded main
body having an insulating layer provided at the head thereo~,
and a socket located at its lo~er end; a detachable pene-
trating device having a plurality of pointed teeth, and a
through~hole located preferably at its central portion, and
a connecting rod for inserting through the hole of the pene-
trating device into the socket of the main body so as tomount the penetrating device on the main body rotatably.
According to this invention, the penetrating device provides
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a relatively large contacting area when it penetrates into the
insulated skin and contacts with the metal core of the elec~
trical wire by turning the main body.
After the penetrating device penetrates and contacts
S with the electrical wire, the screw of the invention is
preferably connected electrically with the known electrical
apparatus.
Accordingly, a main object of the present invention
is to provide a novel screw, which is provided with a
plurality of pointed teeth, adapted to mount on a known plug
so as to make the plug connecting wires easily without
peeling off the skin of the wires.
It is another object of the present invention to
provide a screw having a relatively large conductive area
when it penetrates into the skin of and contacts with the
metal core of the wire.
These and other objects of the present invention
will become more apparent from the following description of
embodiments of the invention with reference to the accompany-
ing drawings, in which:
FIG. 1 is an exploded erspective view o~ an
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electrical plug disclosed in ~.O.C-.~ ~ No. 5030, published
March 1974 to Chuan Cheng;
FIG. 2 is a sectional view of a known electrical plug;
FIG. 3 is a sectional view of a known electrical
terminal board;
FIG. 4 is a sectional view of another conventional
electrical terminal board;
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FIG. S is a sectional view of an emhodiment of the
invention;
FIG. 6 is a perspective with partial exploded view
of the embodiment shown in Fig. 5;
FIG. 7 is a partial enlarged perspective with exploded
view of the main body as shown in Figs. 5 and ~; and
FIG. 8 is a sectional view of another embodiment
of the invention showing how it is screwed into an electrical
plate. ~ ~ c~f.,~
Referring to the drawings in greater detail, .~o~.e~
Pat. No. 5030, published March 1974 to Chuan Cheng, discloses
a safety plug as shown in Fig. 1 in which the inner end of
two prongs 20 are provided with an outward pointed teeth edge
21 for penetrating into the insulated skin of an electrical
wire, which is placed between the pointed teeth edge and a
screw 22, and for contacting with the metal core of the wire,
when the electrical wire is pressed tightly by turning the screw.
Although the-safety plug provides an advantage of not
needing the skin to be peeled off of the wire, it still cannot
fulfill the requirements of good contact because of the small
con~acting area between the pointed teeth edge and the metal
core of the wire.
~ Figs. 2 to 4 show respectively different kinds of
;~ conventlonal apparatus such as a terminal board or a plug.
To connect them to the electrical source, one end of the skin
of the wires has to be peeled off firstly. Conseqently,
it is still desired to provide an improved device, by which
the skin of the wires need not bé peeled off to connect
with an electrical apparatus, in -the art.
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DETAILED DESC~IPTION OF T~IE PP,EFERPED EMBODI~qENTS
Referring now to Figs. 5 to 7 there is shown
preferred embodiment of the present invention in which
a screw consisting of a threaded cylindrical main body
50) a connecting rod 52, and a detachable penetrating
device 53. On the upper end of the main body 50 there
is provided with an insulating layer 51 so as to avoid
to occur any shortage during using of the screw. At
the lower end of the main body 50 has a socket 54 (as
~0 best shown in Fig. 7) which is used to receive tightly
a part of the connecting rod 52. The penetrating
device 53 is in the form of a cylindrical cap, and has
a plurality of pointed teeth 56 surrounded on its
circular lower end, and an opening 55 provided at the
- 15 center of its top surface. One end of the connecting
rod 52 is provided with a head 57 whose diameter is
larger than that of the opening 55. However, the
diameter of the shank of the connecting rod 57 is
smaller than that of the opening 55 so that the
penetrating device 53 can be mounted slidably on the
threaded main body 50 by inserting a part o~ the shank
of the connecting rod 52 into the socket 54 of the main
body 50.
Fig. 8 shows another preierred embodiment of
25 lJ the invention in which the diameter of the cylindrical
penetrating device 80 is larger than that of the main
body 81. At central portion of the underside of the`
main-body is provided with a protrusion 82 having a
socket therein for receiving -the whole shank of the
conDecting rod ~3. The diameter of the opening g4
provided at -the top surface of the penetrating device
80 is smaller than -that o~ -the head of the connecting
rod 83 but is l.arger than that of the protrusion B2.
Thus, in using -the screw -the main body 81 is firstly
screwed into the object, and then, the penetrating
device 80 is mounted slidably on the protrusion 82 by
inserting the shank of the connecting rod 85 through
the opening of the penetrating device 80 into the
~0 socket of the main body.
In operation, while the penetrating de~ice
contacts initially to the insulated skin of the electrical
wire by turning the main body, it will not rotate with
the main ~ody but instead moved downwards against the
underside of -the main body to penetrate the insulated
skin of.the electrical wire.
It is to be understood that various modifications ,
may be made therein, and it is intended to cover in the
appended claims all such modifications as fall within
the true spirit and scope of the invention.
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