Abstract:
A cutting insert for use on a tool body includes a first member formed in a predetermined shape and a second member formed separate from the first member in a second predetermined shape and coupled to the first member. At least one of the first member or the second member comprise a number of cutting portions adapted to perform cutting operations on a workpiece.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 13/362,131 entitled “Modular Cutting Insert and Method of Making Same” filed Jan. 31, 2012, the entire disclosure of which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates generally to cutting inserts for use with cutting tools and, more particularly, to cutting inserts formed from more than one component. The invention further relates to a method for making such cutting inserts. 
         [0004]    2. Background Information 
         [0005]    Rotary cutting tools, such as, for example, without limitation, drills, reamers, or endmills are commonly formed wholly from hardened tool steels, from hardened tool steels coated with a secondary, hardened material, or formed from hardened tool steels provided with replaceable cutting inserts formed from other hardened materials such as, for example, ceramic, cemented carbide, and cermet. The use of such replaceable cutting inserts generally is more cost-effective in comparison to tools formed wholly from hardened materials as the use of replaceable cutting inserts allows for a particular tool body to be reused for an extended period of time as only the inserts need to be replaced in order to essentially have a new cutting tool. However, the materials from which such replaceable inserts are formed is generally quite high which generally also makes the cost of such replaceable inserts quite high. Thus the cost of such inserts may cancel out the potential cost savings of such tools in small volume operations. 
         [0006]    There is, therefore, a need for improved cutting inserts and methods of forming the same. 
       SUMMARY OF THE INVENTION 
       [0007]    Deficiencies in the prior art are addressed by embodiments of the invention which are directed to an improved cutting insert and a method of making an improved cutting insert. 
         [0008]    As one aspect of the invention, a cutting insert for use on a tool body is provided. The cutting insert comprises a first member formed in a predetermined shape and a second member formed separate from the first member in a second predetermined shape and coupled to the first member, wherein one of the first member or the second member comprise a number of cutting portions adapted to perform cutting operations on a workpiece. 
         [0009]    The first member may be formed from a first material and the second member may be formed from a second material different from the first material. 
         [0010]    The first member may be formed from a first material and the second member may be formed from the first material. 
         [0011]    The first member may comprise a first mating portion, the second member may comprise a second mating portion in engagement with and coupled to the first mating portion, and at least one of the first mating portion and the second mating portion may comprise a first number of recessed portions formed therein. 
         [0012]    Each recessed portion of the first number of recessed portions may form a portion of a sealed chamber within the cutting insert. 
         [0013]    The other one of the first mating portion and the second mating portion may comprise a second number of recessed portions formed therein. 
         [0014]    Each recessed portion of the first number of recessed portions and each recessed portion of the second number of recessed portions may be disposed in the respective mating portions in a manner such that each recessed portion of the first number of recessed portions is generally aligned with a corresponding recessed portion of the second number of recessed portions. 
         [0015]    Each recessed portion of the first number of recessed portions and each recessed portion of the second number of recessed portions may form a number of sealed chambers within the cutting insert. 
         [0016]    Each recessed portion of the first number of recessed portions and each recessed portion of the second number of recessed portions may be disposed in the respective mating portions in a manner such that each recessed portion of the first number of recessed portions is generally not aligned with a corresponding recessed portion of the second number of recessed portions. 
         [0017]    The first member may comprise a number of first locating features, the second member may comprises a number of second locating features, and the number of first locating features and the number of second locating features may cooperatively engage each other in a manner that aligns the first member and the second member in a predetermined manner. 
         [0018]    The first member may comprise a first aperture, the second member may comprise a second aperture, and the first aperture and the second aperture may be generally aligned and structured to receive a mechanism for coupling the cutting insert to the tool body. 
         [0019]    As another aspect of the invention a cutting insert for use on a tool body is provided. The cutting insert comprises a body portion including a portion having a number of cutting regions and a number of sealed chambers disposed within the body portion. 
         [0020]    The body portion may comprise a plurality of separately pre-formed members permanently coupled together to form the body portion. 
         [0021]    As yet another aspect of the invention, a method of forming a cutting insert is provided. The method comprises forming a first member in a first predetermined shape, the first member including a number of cutting portions, each cutting portion adapted to perform cutting operations on a workpiece; forming a second member in a second predetermined shape; and coupling the first member and the second member together to form a single cutting insert. 
         [0022]    At least one of forming a first member and forming a second member may comprise forming via a pressing or injection molding process. 
         [0023]    Coupling the first member and the second member together may comprise sintering the first member and the second member to form a single member. 
         [0024]    Forming a first member may comprise forming a number of first locating features on the first member, forming a second member may comprise forming a number of second locating features on the second member, and coupling the first member and the second member together to form a single cutting insert may comprise cooperatively engaging the number of first locating features with the number of second locating features. 
         [0025]    At least one of forming a first member in a first predetermined shape and forming a second member in a second predetermined shape may comprise forming a number of recesses in the respective member, and coupling the first member and the second member together to form a single cutting insert may comprise forming a number of sealed chambers formed in-part by the number of recesses. 
         [0026]    Forming a first member in a first predetermined shape may comprise forming the first member from a powdered tungsten carbide material and forming the second member in a second predetermined shape may comprise forming the second member at least in-part from powdered tungsten carbide material scrapped from formation of the first member. 
         [0027]    These and other objects, features, and characteristics of the present invention, as well as the functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which: 
           [0029]      FIG. 1  is an isometric view of a cutting insert in accordance with an example embodiment of the present invention; 
           [0030]      FIG. 2  is an exploded isometric view of the cutting insert of  FIG. 1 ; 
           [0031]      FIG. 3  is a side view of the top member of the cutting insert of  FIGS. 1 and 2 ; 
           [0032]      FIG. 4  is a bottom view of the top member of the cutting insert of  FIGS. 1 and 2 ; 
           [0033]      FIG. 5  is an isometric view of the top member of the cutting insert of  FIGS. 1 and 2  showing the bottom portion of the top member; 
           [0034]      FIG. 6  is top view of the bottom member of the cutting insert of  FIGS. 1 and 2 ; 
           [0035]      FIG. 7  is a side view of the bottom member of the cutting insert of  FIGS. 1 and 2 ; 
           [0036]      FIG. 8  is an isometric view of the bottom member of the cutting insert of  FIGS. 1 and 2  showing the top portion of the bottom member; 
           [0037]      FIG. 9  is a view of the top and bottom portions of the cutting insert of  FIGS. 1 and 2  in alignment prior to being coupled; 
           [0038]      FIG. 10  is a cross-sectional view of the cutting insert of  FIGS. 1 and 2  taken along line A-A of  FIG. 1 ; and 
           [0039]      FIG. 11  is a cross-sectional view of the cutting insert of  FIGS. 1 and 2  taken along line B-B of  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0040]    Directional phrases used herein, such as, for example, left, right, front, back, top, bottom and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein. Identical parts are provided with the same reference number in all drawings. 
         [0041]    As used herein, the term “number” shall be used to refer to any non-zero quantity (i.e. one or any quantity greater than one). 
         [0042]      FIGS. 1 and 2  depict an example cutting insert  10  in accordance with a non-limiting embodiment of the present invention, for use with a tool body (not shown) in conducting rotary cutting operations on a workpiece (not shown) when the tool body to which cutting insert  10  is coupled is rotated about a central longitudinal axis. As common with conventional cutting inserts, cutting insert  10  includes a base portion  12  and a top portion  14  bounded by a number of cutting regions  16 , each cutting region  16  having a geometry suitable for performing cutting operations on a workpiece. While four cutting regions  16  are shown in the exemplary embodiment, it is to be appreciated that one or more of the quantity, shape, size or other attribute may be varied without varying from the scope of the present invention. 
         [0043]    Cutting insert  10  may also include an aperture  17  for receiving a coupling mechanism, such as a retaining or clamping screw (not shown) for coupling cutting insert  10  to a tool body. It is to be appreciated that the present invention contemplates any suitable coupling means may be employed to couple cutting insert  10  to a tool body, hence one or more of the size, shape, or location of aperture  17  may be varied without varying from the scope of the present invention. Additionally cutting insert  10  may be formed without aperture  17  without varying from the scope of the present invention. 
         [0044]    As shown in the exploded view of  FIG. 2 , cutting insert  10  is formed from a first member  18  and a second member  20  which are initially separately formed in desired predetermined shapes such as by, for example, without limitation, pressing or injection molding. Once formed, first member  18  and second member  20  are then coupled together to form cutting insert  10 . In other embodiments, one of the first or second members may be sintered prior to coupling with the other member, which may then be green formed around the already sintered member. Such sintering of one member is generally preferable in embodiments when the materials from which the two members are separately formed have very different sintering temperatures. 
         [0045]    Although the exemplary embodiment described in detail herein is formed from two members, it is to be appreciated that that the present invention contemplates that more than two members may also be used to form a cutting insert. As an example, without limitation, a double-sided cutting insert (e.g., one two members cutting portions) formed in accordance with the present invention may be formed having a third member disposed between members having cutting portions. 
         [0046]    In an exemplary embodiment, first member  18  was formed from a tungsten carbide material (WC-10% Co) having a hardness of 91 HRA, and second member  20  was formed from scrapped carbide powder, thus reducing the amount of waste material, and thus the overall cost of producing such inserts. However, it is to be appreciated that first and second members  18  and  20  may be formed from other suitable materials without varying from the scope of the present invention. 
         [0047]    In the exemplary embodiment shown in  FIG. 1 , first member  18  and second member  20  are brought together and then permanently coupled via a sintering process. It is to be appreciated, however, that other coupling processes may be employed without varying from the scope of the present invention. 
         [0048]    Having thus described the overall layout of cutting insert  10 , further details of first member  18  will now be described in conjunction with  FIGS. 3-5  which show side, bottom, and lower isometric views, respectively, of first member  18 . 
         [0049]    First member  18  includes top portion  14  which, as previously discussed, includes a number of cutting regions  16 . First member  18  further includes a first mating portion  22  disposed opposite top portion  14 . In the exemplary embodiment depicted, first mating portion includes a locating feature  24  embodied as a projecting portion extending from first mating portion. As will be discussed in greater detail below, when first member  18  and second member  20  are brought together, locating feature  24  cooperatively engages a portion of second member  20  in a manner that generally aligns first member  18  and second member  20  in a predetermined manner. It is to be appreciated that locating feature  24  depicted in the FIGS. is provided for example purposes only and that one or more of the size, shape, height or quantity of such locating feature  24  may be varied without varying from the scope of the present invention. Although generally desirable, first member  18  may also be formed without any locating feature(s). 
         [0050]    Continuing to refer to the exemplary embodiment of  FIGS. 4 and 5 , first mating portion  22  may also include a number of recessed portions  26  formed therein which generally extend from first mating portion  22  toward top portion  14 . The benefit of such recessed portions  26  will be discussed further below. Although four generally circular recessed portions  26  are shown in the exemplary embodiment depicted, it is to be appreciated that one or more of the size, shape, depth or quantity of such recessed portions  26  may be varied without varying from the scope of the present invention. It is also to be appreciated that first member  18  may also be formed without any recessed portions  26  without varying from the scope of the present invention. 
         [0051]    Referring to  FIGS. 6-8 , which depict top, side and isometric views, respectively, of second member  20 , second member  20  includes a second mating portion  28  disposed opposite base portion  12 . In the exemplary embodiment depicted, second mating portion  28  includes a locating feature  30  in the form of a central circular groove portion which is sized and positioned to cooperatively engage the corresponding locating feature  24  (i.e., the projecting portion) of first mating portion  22  of first member  18  in a manner that aligns first member  18  and second member  20  in a predetermined manner when first mating portion  22  and second mating portion  28  are brought together in a manner as shown by the arrow in  FIG. 9 . It is to be appreciated that like locating feature  24  of first member  18 , one or more of the size, shape, height, or quantity of locating feature  30  of second member  20  may be varied to coincide with locating feature  24  without varying from the scope of the present invention. Also, although generally desirable, second member  20  may also be formed without any locating features. 
         [0052]    Continuing to refer to  FIGS. 6 and 8 , second mating portion  28  may also include a second number of recessed portions  32  formed therein which generally extend from second mating portion  28  toward base portion  12 . The benefit of such recessed portions will be discussed further below. Although four generally circular recessed portions  32  are shown in the exemplary embodiment depicted, it is to be appreciated that one or more of the size, shape, depth or quantity of such recessed portions  32  may be varied without varying from the scope of the present invention. It is also to be appreciated that second member  20  may also be formed without any recessed portions  32  without varying from the scope of the present invention. 
         [0053]    Having thus described the components of cutting inserts and optional features thereof, features of the finished cutting insert  10  and benefits thereof will now be discussed in reference to  FIGS. 9-11 . 
         [0054]      FIG. 9  shows the basic alignment of first member  18  and second member  20  in forming cutting insert  10 . Alignment of first member  18  and second member  20  is simplified by the inclusion of first and second locating features  24  and  30  which cooperatively engage each other in a manner that generally aligns first and second members  18  and  20 . The cross-sectional view of  FIG. 10  generally shows such cooperative engagement and alignment. 
         [0055]    As shown in the cross-sectional view of  FIG. 11 , each of the first number of recessed portions  26  and each of the second number of recessed portions  32  may align in such a manner so as to form a number of sealed chambers  40  within cutting insert  10 . It is to be appreciated that recessed portions  26  and  32  may also be misaligned or not aligned whatsoever without varying from the scope of the present invention. 
         [0056]    By selectively providing such sealed chambers  40  within cutting insert  10 , less material is required to produce cutting insert  10  as compared to a cutting insert with similar exterior dimensions. By requiring less material, the material cost of such an insert having interior chambers or voids is lessened in comparison to solid inserts of comparable size. By carefully placing such chambers in areas of low internal stress, overall strength and durability of the cutting insert is not compromised. Additionally, by making such chambers sealed, the risk of potential entrapment of cutting materials or fluids is of no concern. 
         [0057]    In addition to the benefits of being able to reduce the amount of material needed to form a particular insert, it is to be appreciated that the present invention also provides the benefit of being able to reduce the amount of hardened material needed to produce a particular insert by allowing the portion of the insert spaced away from the cutting surfaces or edges (e.g., second member  20 ) to be formed from a different, less expensive material. Such arrangement using different material for different portions may be used without any internal chambers or with internal chambers to maximize potential material cost savings. 
         [0058]    In addition to the embodiments described herein, it is to be appreciated that the concepts described herein may also be used to form modular inserts having non-sealed passages formed therein. Such non-sealed passages may be used to provide coolant fluid or cooling gases to one or more of the number of cutting edges provided on an insert. 
         [0059]    While specific embodiments of the invention have been described in detail herein, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.