Note: Descriptions are shown in the official language in which they were submitted.
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METAL SHEARS
FIELD OF THE INVENTION
The present invention relates generally to a metal cutting device,
and more particularly to a metal shears.
BACKGROUND OF THE INVENTION
The conventional metal shears is capable of severing the bolts and
the strong metal wires, and is generally composed of two jaws, two
toggles, and two handles. The jaws are fastened pivotally with both ends
of a connection member and are provided with two opposed cutting
edges. The toggles are fastened with the jaws to bring about a lever
action in conjunction with the connection member. The handles are
fastened with the toggles for extending the le~er of force.
Such a conventional metal shears as described above is defective
in design In that the jaws and the cutting edges are made integrally, and
that the entire jaws must be replaced even if only the cutting edges are
damaged. The jaws are rather expensive. In addition, it is rather time-
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consuming to replace the jaws with precision.
SUMMARY OF THE INVENTION
It is therefore the primary objective of the present invention toprovide a metal shears with the cutting blades which can be replaced
economically.
It is another objective of the present invention to provide a metal
shears with jaws independent of the cutting blades.
It is still another objective of the present invention to provide a
metal shears with the cutting blades capable of various cutting functions.
In keeping with the principle of the present invention, the
foregoing objectives of the present invention are attained by a metal
shears, which comprises two handles two toggles, two jaws and two
clamping and cutting members. The jaws have two opposed recesses
which are provided respectively with a first load surface having a first
resisting surface and a second resisting surface. The clamping and
cutting members comprise a plurality of second load surfaces capable of
m~kin~; contact with the first load surface and having a plurality of
cutting blades. The clamping and cutting members have a length equal to
the distance between the first and the second resisting surfaces. The jaws
are provided respectively with a resisting member which presses against
the clamping and cutting member to facilitate the change in the cutting
operation of the metal shears.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a front elevational view of a metal shears of a first
preferred embodiment of the present invention.
FIG. 2 shows an exploded view of jaws of the metal shears of the
first preferred embodiment of the present invention.
FIG. 3 shows a sectional view taken along the direction of a line 3-
3 as shown in FIG. 1.
FIG. 4 shows a sectional view similar to the one as shown in FIG.
3 according to a second preferred embodiment of the present invention.
DETAII,l~,~ DESCRIPTION OF THE INVENTION
As shown in FIGS. 1-3, a metal shears 10 embodied in the present
invention comprises two handles 12, two toggles 14, two jaws 16 and
two clamping and cutting members 18.
The toggles 14 are fastened pivotally with a first pivoting member
40 such that the toggles 14 are fastened respectively at one end thereof
with the handles 12. One of the two toggles 14 has a groove 42 serving
to divide the toggle 14 into two portions opposite to each other, and
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further has a first screw 44 and a second screw 46. The inner wall of one
side of the groove 42 is urged by the first screw 44. In the meantime, the
second screw 46 is engaged with one of the toggles 14. As a result, the
first screw 44 and the second screw 46 can be adjusted in position in
relation to the toggle 14 so as to enable the user of the metal shears to
change the width of one end of the groove 42, thereby enabling the user
to adjust the relative position of the two jaws.
The jaws 16 are fastened pivotally with the second pivoting
member 60 such that the jaws 16 are fastened pivotally and respectively
at one end thereof with the toggles 14, and that the jaws 16 are fastened
pivotally and respectively with the connection member 66, which is
composed of two plates having appropriate length and width.
The jaws 16 are provided with two opposed recesses 70, each of
which has a first load surface 72, a first resisting surface 74 and a second
resisting surface 76. The first and the second resisting surfaces 74 and 76
are located at both ends of the first load surface 72 such that they are
perpendicular to the first load surface 72. The first resisting surface 74 is
provided with a threaded through hole 50 which is engaged with a
resisting member 52. The second resisting surface 76 is provided with a
cavity 54 for receiving a locating ball 56 of a steel material. The locating
ball 56 has a diameter greater than the depth of the cavity 54. As a result,
the locating ball 56 is partially received in the cavity 54. The recess 70
has an axis 58. The threaded through hole 50 of the first resisting surface
74 and the cavity 54 of the second resisting surface 76 are aligned with
the axis 58.
The clamping and cutting members 18 are columnar in
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construction and have a kiangular cross section. Each of the clamping
and cutting members 18 has three second load planar structures 82, and
three prismatic cutting blades 84 arranged at an interval of 120 degrees
between the second load planar structures 82. Each clamping and cutting
member 18 is provided respectively at the centers of both upper and
lower ends thereof with a recessed portion 80 dimensioned to receive the
portion of the resisting member 52, which remains outside the first
resisting surface 74, or the portion of the locating ball 56, which remains
outside the second resisting surface 76. As a result, each clamping and
cutting member 18 is held securely in the recess 70. The connection
member is composed of two plates holding the jaws such that the
recesses and the clamping and cutting members are partially held
between the two plates.
The distance dl between the second load surface 82 and the
recessed portion 80 is equal to the distance d2 between the axis 58 and
the first load surface 72. As a result, the first load surface 72 and the
second load surface 82 are in an intimate contact when the clamping and
cutting members 18 are retained securely in the recesses 70, thereby
enabling the clamping and cutting members 18 to withstand a great
pressure, without being deformed by the pressure exerting thereon.
The clamping and cutting members 18 have a length smaller than
the length of the recesses 70, as shown in FIG. 4. The clamping and
cutting members 18 may have a tetragonal or pentagonal cross section.
Preferably, the metal shears of the present invention comprises an odd
number of second load surfaces 82 and the cutting blades 84.
As illustrated in FIG. 4, the second resisting surface 76 is provided
s
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with a hole 78 for receiving the locating ball 56 and a spring 77. The
clamping and cutting members 18 have a length equal to the length of
the recesses 70.
