Not applicable.
Not Applicable.
The present invention provides a cutting insert comprising a cutting edge wherein the cutting edge has a variable cutting edge height (or size) and strength along said cutting edge.
The present invention relates to a cutting insert comprising a cutting edge having a nose, and a depth of cut location, and wherein said depth of cut location is positioned opposite to said nose, and wherein said cutting edge has a first height, and wherein said depth of cut location of the cutting edge has a second height, and wherein the nose of the cutting edge that has a third height, and wherein the second height of the cutting edge of the depth of cut location is smaller than the third height of the cutting edge of the nose of the cutting insert. The present invention provides a cutting insert that has a higher K-factor at the cutting edge of the depth of cut location compared to the K-factor at the cutting edge of the nose of the cutting insert.
The background art discloses cutting inserts having cutting edges having a constant edge height. The background art further describes cutting inserts having cutting edges and chip dividing portions, and cutting inserts having top surfaces having octagonal shapes and edge portions that have wedge angles that change from a first angle at a first end of an edge portion to a different angle at a second end of the edge portion. The background art shows parallelogram-shaped cutting inserts having a main cutting edge that has a variable radial rake angle. The background art describes an indexable cutting insert for solid drills having four identical cutting edges wherein the height of the four cutting edges varies over the length of the respective cutting edges.
The background art does not address the need to have a cutting insert having a cutting edge in the area of the depth of cut location that has an increased K-factor to improve tool life while allowing for a standard edge preparation on the nose of the cutting insert. This invention addresses the above disadvantages of the background art.
A variable function edge preparation of a cutting insert is provided in this invention. In certain embodiments, a cutting insert comprising a cutting edge having a nose and a depth of cut location, wherein the cutting edge has a first end and a second end that is located opposite to the first end, and wherein the nose is located at the second end of the cutting edge, and wherein the depth of cut location is positioned opposite to the nose and extends in part away from the nose in the direction toward the first end of the cutting insert, and wherein the cutting edge has a first height, and wherein the depth of cut location has a cutting edge that has a second height, and wherein the nose has a cutting edge that has a third height, and wherein the second height of the cutting edge of the depth of cut location is smaller than the third height of the cutting edge of the nose of the cutting insert.
In certain embodiments of this invention, a cutting insert is provided having a base and at least one cutting edge positioned in juxtaposition to the base. The cutting edge has a first end and a second end that is located opposite to the first end and wherein the cutting edge has a length extending from the first end of the cutting edge to the second end of the cutting edge and wherein the cutting edge has a height measured from a plane of the base of the cutting insert and wherein the height of the cutting edge varies over the length of the cutting edge. The cutting edge has a nose located at the second end of the cutting insert and a depth of cut location located opposite to said nose and extending in part from the nose in the direction toward the first end of the cutting insert. The height of the cutting edge of the cutting insert at the depth of cut location is smaller than the height of the cutting edge located at the nose of the cutting insert. The present invention provides a cutting insert that has a higher K-factor at the cutting edge of the depth of cut location compared to the K-factor at the cutting edge of the nose of the cutting insert.
These and other embodiments of this invention shall be described in more detail herein and in the drawings that show certain embodiments of this invention.
While various embodiments of this invention are illustrated in the drawings, the particular embodiments shown should not be construed to limit the claims. Various modifications and changes may be made without departing from the scope of the invention.
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As used herein, the term “K-Factor” means the ratio of rake surface rounding to clearance surface rounding. In other words, “K-Factor” is the ratio between the rake edge rounding and the flank edge rounding, see
Cutting tool edge preparation is measured by size and shape. The rounding achieved on the rake and flank may be measured independently to fully define the hone shape. To describe the edge shape, K-Factor or “K” is commonly used.
The higher K-Factor at the depth of cut location will improve tool life, while allowing for a standard radius edge prep on the insert nose. The cutting insert of the present invention allows for standard honing brushes to be used in the manufacturing process of the variable functional edge of the present cutting insert without the need for special elliptical honing brushes or processing methods. Those persons of ordinary skill in the art will appreciate that the present invention's change of the cutting edge height of the cutting edge at the depth of cut location of the cutting insert compared to the height of the cutting edge of the nose of the cutting insert, combined with the use of a known in the art planar brush honing process creates an elliptical high K-factor hone in the depth of cut location (area) (see
Those persons of ordinary skill in the art appreciate that in some turning operations, a depth of cut notch may be formed on the cutting insert that leads to failure of the cutting insert. Changing the edge-preparation of the cutting insert involves changing the edge hone size and shape on the entire cutting edge of the cutting insert. It is difficult to achieve a significant, controllable differentiation in edge condition between the nose of the cutting insert and the depth of cut location. The present invention overcomes these difficulties and provides a cutting insert having a variable functional cutting edge that has a higher K-factor in the area of the depth of cut location compared to the K-factor of the cutting edge of the nose of the cutting insert.
As used herein, “including,” “containing” and like terms are understood in the context of this application to be synonymous with “comprising” and are therefore open-ended and do not exclude the presence of additional undescribed or unrecited elements, materials, phases or method steps. As used herein, “consisting of” is understood in the context of this application to exclude the presence of any unspecified element, material, phase or method step. As used herein, “consisting essentially of” is understood in the context of this application to include the specified elements, materials, phases, or method steps, where applicable, and to also include any unspecified elements, materials, phases, or method steps that do not materially affect the basic or novel characteristics of the invention.
For purposes of the description above, it is to be understood that the invention may assume various alternative variations and step sequences except where expressly specified to the contrary. Moreover, all numbers expressing, for example, quantities of ingredients used in the specification and claims, are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
It should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.
In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. In this application, the articles “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent.
Whereas particular embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.