METHOD AND APPARATUS FOR A CUTTING TOOL
A method of making a cutting tool comprises providing a lever with a jaw having a cutting edge and a body arranged such that the cutting edge is offset from the body; providing a rotary cutting tool with an edge profile that may be complex and/or non-planar to form a complementary edge profile geometry on the cutting edge by moving the edge profile geometry of the rotary cutting tool along the length of the cutting edge.
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This application claims benefit of priority under 35 U.S.C. §119(e) to the filing date of to U.S. Provisional Application No. 61/328,505, as filed on Apr. 27, 2010, which is incorporated herein by reference in its entirety.
BACKGROUNDThe most common process for forming a cutting edge on a diagonal pliers is by first machining the tool when the metal is in a “soft” state using an end mill or similar cutter. One problem with this process is that it limits the geometry on the cutting edge to simple angular shapes that are limited to flat planar surfaces. The process may also lead to variations in the finished product because each cutting edge is formed by two independent machining steps determined by the depth or trajectory of each cut. Because of these variations, the process may further require hand finishing of the hardened cutting edges to bring the edges into proper final alignment. CNC machining of the cutting edges is an alternative to standard machining, but can be costly and/or slow in a production setting. CNC is also limited to only cutting the edges in the soft state of the pliers.
SUMMARY OF THE INVENTIONA method of making a cutting tool comprises providing a lever with a jaw having a cutting edge and a body arranged such that the cutting edge is offset from the body; providing a rotary cutting tool with an edge profile that may be planar and/or non-planar to form a complementary edge profile geometry on the cutting edge by moving the edge profile geometry of the rotary cutting tool along the length of the cutting edge.
Another method of making a cutting tool comprises providing a lever with a jaw having a cutting edge that may comprise complex, planar and/or non-planar shapes and a body arranged such that the cutting edge is offset from the body; providing a rotary cutting tool with a first edge profile and a second edge profile; and forming a first portion of complementary edge profile geometry on the cutting edge by moving the first edge profile of the rotary cutting tool along the length of a first side of the cutting edge and forming a second portion of complementary edge profile geometry on the cutting edge by moving the second edge profile of the rotary cutting tool along the length of a second side of the cutting edge.
The step of forming may be done when the cutting edge is in a soft state or when the cutting edge is in a hardened metal. The lever arm of the tool may be fixtured in a predetermined position. The rotary cutting tool may be fed in a straight path along the cutting edge. The rotary cutting tool may traverse the entire cutting edge. The rotary cutting tool may traverse the cutting edge without contacting the body. A plurality of levers each having a cutting edge may be fixtured such that all of the cutting edges are aligned and the rotary cutting tool is moved along a linear path along the cutting edges. The rotary cutting tool may be a grinding wheel or a form cutter.
A grinding or machining technique is used to create the finished geometry on the cutting edge of a tool. Grinding can be done with the pliers in either in a soft state or on hardened metal such as after induction hardening or other hardening operation. Machining is typically performed before hardening with the edge being hardened after the machining operation. The grinding operation is performed using a rotary grinding wheel that uses abrasion to remove material to form the edge. The machining operation is performed using a rotary form cutter having sharp cutting edges that cut the material to form the edge. As used herein the term “rotary cutting tool” means both a grinding wheel and a form cutter and the term “rotary cutting operation” means both an abrasive grinding operation and a form milling operation.
One lever arm of the tool is fixtured in a predetermined position before it is assembled to the other lever arm of the tool. A rotary cutting tool is fed in a straight path along the cutting edge so that the geometry of the rotary cutting tool forms the shape of the tool's cutting edge. This is advantageous because a variety of different and complex shapes may be provided to create specialized edge shapes such as parabolic, hollow ground, or compound forms that are not obtainable using known techniques and that may be used for cutting materials of differing hardness and diameter.
Referring to
The rotary cutting tool 32, 132 is moved along the length of edge 18 such that the rotary cutting tool 32, 132 forms the shape of the edge 18 but does not interfere with the rest of the tool. The rotary cutting tool 32, 132 is arranged such that the rotational axis a-a of the rotary cutting tool 32, 132 is normal to the cutting plane of the edge.
This method can be used on any cutting tool where the rotary cutting tool 32, 132 is able to traverse the cutting edge without interfering with or contacting the remainder of the tool. Referring to
To use the grinding method of the invention on both jaws of the tool, both jaws may be designed with the cutting edge being offset outside of the width of the body of the lever.
Another benefit of using rotary cutting tool 32, 132 as described herein is that multiple levers can be fixtured in alignment such that one rotary cutting tool 32, 132 can follow a linear path along the aligned cutting edges of multiple tools. Referring to
Referring to
To form the cutting edge 18 a rotary cutting tool as described above is provided. A first cutting profile P1 is disposed along one side of the rotary cutting tool and the rotary cutting tool is aligned such that the rotary cutting tool is passed over the cutting edge 18 in a linear path, as previously described, with the first cutting profile P1 forming one half of the cutting edge as shown in
While embodiments of the invention are disclosed herein, various changes and modifications can be made without departing from the spirit and scope of the invention as set forth in the claims. One of ordinary skill in the art will recognize that the invention has other applications in other environments. Many embodiments are possible. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described above.
Claims
1. A method of making a cutting tool comprising:
- providing a lever comprising a jaw having a cutting edge and a body arranged such that the cutting edge is offset from the body;
- providing a rotary cutting tool with an edge profile geometry;
- forming a complementary edge profile geometry on the cutting edge by moving the edge profile geometry of the rotary cutting tool along the length of the cutting edge.
2. The method of claim 1 wherein the step of forming is done when the cutting edge is in a soft state.
3. The method of claim 1 wherein the step of forming is done when the cutting edge is in a hardened metal.
4. The method of claim 1 wherein the lever arm of the tool is fixtured in a predetermined position.
5. The method of claim 1 where the rotary cutting tool is fed in a straight path along the cutting edge.
6. The method of claim 1 where the rotary cutting tool traverses the entire cutting edge.
7. The method of claim 1 where the rotary cutting tool traverses the cutting edge without contacting the body.
8. The method of claim 1 further comprising providing a plurality of levers each having a cutting edge, fixturing the plurality of levers such that each cutting edge of the plurality of levers are aligned, moving the rotary cutting tool along a linear path along the cutting edges.
9. The method of claim 1 wherein the rotary cutting tool is a grinding wheel.
10. The method of claim 1 wherein the rotary cutting tool is a form cutter.
12. A method of making a cutting tool comprising:
- providing a lever comprising a jaw having a cutting edge and a body arranged such that the cutting edge is offset from the body;
- providing a rotary cutting tool with a first edge profile and a second edge profile;
- forming a first portion of complementary edge profile geometry on the cutting edge by moving the first edge profile of the rotary cutting tool along the length of a first side of the cutting edge and forming a second portion of complementary edge profile geometry on the cutting edge by moving the second edge profile of the rotary cutting tool along the length of a second side of the cutting edge.
13. The method of claim 12 wherein the step of forming is done when the cutting edge is in a soft state.
14. The method of claim 12 wherein the step of forming is done when the cutting edge is in a hardened metal.
15. The method of claim 12 wherein the lever arm of the tool is fixtured in a predetermined position.
16. The method of claim 12 where the rotary cutting tool is fed in a straight path along the cutting edge.
17. The method of claim 12 where the rotary cutting tool traverses the entire cutting edge.
18. The method of claim 12 where the rotary cutting tool traverses the cutting edge without contacting the body.
19. The method of claim 12 further comprising providing a plurality of levers each having a cutting edge, fixturing the plurality of levers such that each cutting edge of the plurality of levers are aligned, moving the rotary cutting tool along a linear path along the cutting edges.
20. The method of claim 1 wherein the rotary cutting tool is a grinding wheel or a form cutter.
Type: Application
Filed: Apr 19, 2011
Publication Date: Oct 27, 2011
Applicant: IRWIN INDUSTRIAL TOOL COMPANY (Huntersville, NC)
Inventors: Thomas M. Chervenak (Stanley, NC), David P. Engvall (Stanley, NC), Mark B. Latronico (Charlotte, NC)
Application Number: 13/089,744
International Classification: B21K 21/00 (20060101);