GB2321029A

GB2321029A - Metal shears

Info

Publication number: GB2321029A
Application number: GB9700450A
Authority: GB
Inventors: Jong-Shing Chang
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-01-08
Filing date: 1997-01-10
Publication date: 1998-07-15
Also published as: FR2758489A3; GB9700450D0; CA2194635A1; DE29700906U1

Abstract

Metal shears comprise two handles, two toggles, two jaws 16, and two clamping and cutting members 18. The jaws have two opposed recesses 70 which are provided respectively with a first load surface 72 having a first resisting surface 74 and a second resisting surface 76. The clamping and cutting members comprise a plurality of second load surfaces 82 capable of making contact with the first load surface 72 and having a plurality of cutting blades 84. 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 52 which presses against the clamping and cutting member to facilitate the change in the cutting operation of the metal shears.

Description

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 lever 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 consuming to replace the jaws with precision.

SUMMARY OF THE INVENTION It is therefore the primary objective of the present invention to provide 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 making 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.

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 33 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.

DETAILED 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 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 construction and have a triangular 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 second load surfaces 82 and the cutting blades 84.

As illustrated in FIG. 4, the second resisting surface 76 is provided 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.

Claims

WHAT IS CLAIMED IS:

1. A metal shears comprising: two handles; two toggles fastened respectively at one end thereof with said handles such that said toggles are fastened pivotally with a first pivoting member; two jaws fastened respectively with another ends of said toggles by a second pivoting member such that said jaws are fastened pivotally and respectively at a midsegment thereof with a connection member, said two jaws provided with two opposed recesses having a first load surface, a first resisting surface located at one end of said first load surface such that said first resisting surface is perpendicular to said first load surface, and a second resisting surface located at another end of said first load surface such that said second resisting surface is perpendicular to said first load surface; two clamping and cutting members having a plurality of cutting blades and a plurality of second load surfaces capable of making contact with said first load surface; and two resisting members fastened with said jaws such that said resisting members urge said clamping and cutting members.

2. The metal shears as defined in claim 1, wherein said resisting members are screws having one end extending into said recesses.

3. The metal shears as defined in claim 2, wherein said clamping and cutting members are provided respectively at a center of one end thereof with a recessed portion for said screws to extend into said recesses.

4. The metal shears as defined in claim 1, wherein said second resisting surface is provided with a locating element; and wherein said clamping and cutting members are provided respectively at a center of one end thereof with a recessed portion for receiving said locating element.

5. The metal shears as defined in claim 4, wherein said second resisting surface is provided with a hole; and wherein said locating element is a steel ball having a diameter greater than a depth of said hole.

6. The metal shears as defined in claim 1, wherein said resisting member is a screw fastened with one of said jaws such that said screw penetrates said first resisting surface; and wherein said second resisting surface is provided with a locating element coaxial with said screw.

7. The metal shears as defined in claim 1, wherein said connection member is composed of two plates holding said jaws such that said clamping and cutting members and said recesses are partially held between said two plates.

8. The metal shears as defined in claim 7, wherein said clamping and cutting members have a length smaller than a length of said recesses.

9. The metal shears as defined in claim 1, wherein said second load surfaces and said cutting blades of said clamping and cutting member are odd in number.

10. A metal shears substantially as hereinbefore described with reference to the accompanying drawings.