Indexable cutting inserts and methods for producing the same

Abstract

A method of making a cutting insert includes: (i) forming a blank having a substrate and superhard material, the substrate having more than 4 pockets, the superhard material disposed within the pockets; (ii) removing cutting tips from the blank by cutting the blank along cutting lines; (iii) providing a cutting insert body having a plurality of cavities for receiving a corresponding number of cutting tips; (iv) inserting a cutting tip into each of the plurality of cavities; and (v) brazing the cutting tips to the cutting insert body. A related cutting insert includes: a cutting insert body having a plurality of cavities formed therein; a plurality of cutting tips, each of the plurality of cutting tips disposed in a respective cavity, the cutting tips having a geometry that provides a mechanical retention or lock when inserted into the cavities of the cutting insert body, said geometry including a generally trapezoidal anchor portion with its base substantially flat and spaced away form the cutting edge of the body, the cutting tips further being brazed in the cutting insert body.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 10 / 918,391, filed Aug. 16, 2004 (Attorney Docket No. 024445-308).FIELD OF THE INVENTION [0002] The present invention relates to cutting inserts having cutting edges formed from a superhard abrasive material, and methods of making the same. BACKGROUND OF THE INVENTION [0003] In the description of the background of the present invention that follows, reference is made to certain structures and methods, however, such references should not necessarily be construed as an admission that these structures and methods qualify as prior art under the applicable statutory provisions. Applicants reserve the right to demonstrate that any of the referenced subject matter does not constitute prior art with regard to the present invention. [0004] Indexable cutting inserts typically have a polygonal shape with a superhard material disposed generally at the corners. ...

AI Technical Summary

Benefits of technology

[0013] The present invention provides devices and methods that address the above-mentioned problems, and others.

Problems solved by technology

However, several problems are associated with such techniques.

The braze joint connecting the cutting tips to the body of the cutting insert creates an inherent weak point in the structure.

This is particularly true due to the high temperatures that tend to exist during use of such cutting inserts, these high temperatures being in close proximity to the braze joint.

Another problem posed by such techniques is that the extent of superhard material presented to the workpiece and available for wear is limited, thus limiting the useful operating period for that particular cutting edge.

Such techniques also present certain difficulties.

The process by which the superhard material is bonded to the blank or substrate is difficult and costly.

In this regard, the cost of the superhard and substrate raw materials are relatively minor when compared with the costs associated with the process cycle necessary to join them.

However, customers of such cutting inserts seem to strongly favor cutting inserts having relatively few cutting corners, which are more costly to make on a per unit basis using this technique.

Another disadvantage associated with this second technique is that if a single pocket of superhard material is defective, the entire insert cannot be sold and may have to be scrapped.

Yet another disadvantage or inefficiency is that only a single cutting insert is produced from each costly and difficult process cycle.

Images