Patent Publication Number: US-6341823-B1

Title: Rotatable cutting tool with notched radial fins

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates to the field of earth and mining working equipment and specifically to a earth and mining penetrator bit which is configured to penetrate hardened earth, rock and mining materials. 
     2. Description of the Related Art 
     Penetrator bits are attached to the chain excavation lines, and/or rotatable drum equipment for excavation of rock, highly compressed earth and mining materials. Conventional penetrator bits are manufactured from hardenable alloy steel and/or tungsten carbide, and are configured for use in penetrating and removing rock and material of the like from an excavation and mining site. The upper end of a conventional penetrator bit defines a conical configuration, a penetrator tip being carried by the distal end thereof. At the lower end of the bit is provided a means for removably attaching it to a holder carried on an implement of earth and mining working equipment such as cutting chain equipment, a rotatable drum, or the like. After repeated use, it is well-known that the penetrator tip wears away and the bit must be replaced due to wear by grinding of rock waste materials generated during boring, drilling, trenching and mining. When penetrating into and removing particularly hard earth or rocks from a bore hole or ditch, the number of bit replacements can be excessive. 
     In the field of rotary trenching, earth moving construction equipment, and mining, replaceable penetrator bits with carbide tips are utilized. Typically, a penetrator bit holder is welded to a chain attachment or rotatable drum device utilized for trenching, drilling, boring in rock and mining. The penetrator bit holder is configured to retain a penetrator bit therein. When the tip of the penetrator bit is worn down, the bit is removed from the bit holder and replaced with a new penetrator bit. 
     It is an object of this invention to provide a penetrator bit specifically designed to penetrate hard rock during trenching, drilling, boring and mining operations. 
     It is another object of the present invention to extend the life of penetrator bits attached to a mining, trenching, drilling, or boring implement of earth working equipment. 
     It is another object of the present invention to provide a tip insert for a penetrator bit which is configured to maximize penetration into hard rock, drilling, boring, mining or trenching operations, while removing rock waste or other materials from the bore hole or trench. 
     BRIEF SUMMARY OF THE INVENTION 
     Other objects and advantages will be accomplished by the present invention which is a rotatable cutting tool configured to maximize penetration into hard rock, coal, and/or any other material during trenching, drilling, mining or boring operations. The rotatable cutting tool of the present invention includes a body which defines an upper bit end and a lower shank end. The upper bit end defines a bit insert opening configured to detachably accept a penetrator bit tip. The lower shank end is configured to be securable to a penetrator holder that is welded to an implement of earth working equipment such as the chain excavator or a rotatable drum, or the like. A flange, or pocket protector, is defined between the upper and lower ends in order to provide protection for the bit penetrator lower end and a holder in which it is received by minimizing rock and earth fines from contacting and building up between the holder and bit penetrator. Further, the flange acts as a load bearing surface between the bit penetrator and the holder, thereby protecting the lower end of the bit penetrator and the face and bore of the holder. 
     A plurality of fins are defined between the flange and the upper end in order strengthen the integrity of the bit penetrator. The fins allow for a reduced diameter upper end, as compared to the lower end, in order to enhance the cutting of the bit penetrator. In order to allow for a more fluid flow of material from the tip of the bit penetrator and out of the area being excavated, each fin defines a notched portion along the terminal edge thereof. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The above mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which: 
     FIG. 1 is a perspective view of a blank for manufacturing a rotatable cutting tool constructed in accordance with several features of the present invention; 
     FIG. 2 is a perspective view of the rotatable cutting tool of the present invention; 
     FIG. 3 is a side elevation view of the rotatable cutting tool of the present invention; and 
     FIG. 4 is an elevation view of the rotatable cutting tool, in section taken at  4 — 4  of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A rotatable cutting tool for earth displacement equipment incorporating various features of the present invention is illustrated generally at  10  in the figures. The rotatable cutting tool for earth displacement equipment, or cutting tool  10 , is designed to penetrate rock and hardened earth more efficiently with a tungsten carbide insert, or insert  20 , while extending the life of the insert  20 . The insert  20  is insertable into the cutting tool  10 , which is attachable to trenching equipment, mining equipment or earth working equipment such as a chain excavator or a rotatable drum or hammer equipment, or the like. In one embodiment, the cutting tool  10  is designed to receive an insert  20  of a configuration to penetrate rock in hardened strata. 
     The cutting tool  10  of the present invention can be formed by hot or cold forming, casting or machining. In the preferred embodiment, the cutting tool body  12  is fabricated from steel and the insert  20  is fabricated from tungsten carbide. However, it will be understood that other materials of manufacture may be used to accomplish similar results, depending upon the particular use thereof. The cutting tool  10  defines a body  12  including an upper end  14  and a lower end  16 . A flange  18  is defined between the upper and lower ends  14 , 16 . The flange  18  serves as a pocket protector as will be described below. 
     A plurality of fins  28  are defined between the flange  18  and the upper end  14  in order strengthen the integrity of the cutting tool  10 . The fins  28  allow for a reduced diameter upper end  14 , as compared to the diameter of the lower end  16 , in order to enhance the cutting of the cutting tool  10 . The fins  28  further serve to reduce the vibration of the cutting tool  10  and therefore tend the life thereof. The terminal edge  32  of each fin  28  extends from a point inside the perimeter of the flange  18  to approximately the distal end of the upper end  14 . In the preferred embodiment, as illustrated, the terminal edge  32  does not reach the perimeter of the flange  18 . The slope of the terminal edge  32  of the fin  28  is determined largely in part by the diameter of the flange  18 , the distance from the perimeter of the mange  18  that the fin  28  terminates, and the length and diameter of the upper end  14 . The terminal edge  32  defines a curved surface in the illustrated embodiment. In order to allow for a more fluid flow of material from the tip of the cutting tool  10  and out of and away from the area being excavated, each fin  28  defines a notched portion  30  along the terminal edge  32  thereof. In the illustrated embodiment, the notched portion  30  is defined at an approximate midpoint of the terminal edge  32  of the fin  28 . The notched portion  30  also provides a shear point at which the cutting tool  10  is permitted to fail in conditions where the equipment might otherwise sustain damage. This is especially beneficial on smaller machines which are designed to withstand smaller loads, thus allowing the same cutting tool  10  to be used on both large and small equipment. 
     The lower end  16  of the body  12  defines a shank configured to be received within a holder (not shown). The holder is securable by conventional means such as welding to an implement of earth working equipment. To this extent, the holder defines a through opening configured to loosely receive the lower end  16  of the body  12  in order to allow free rotation of the cutting tool  10  therein. 
     The flange  18  provides protection for the bit penetrator lower end  16  and the holder in which it is received by minimizing rock and earth fines from contacting and building up between the holder and cutting tool  10 . Further, the flange  18  acts as a load bearing surface between the cutting tool  10  and the holder, thereby protecting the lower end  16  of the cutting tool  10  and the face and through opening or bore of the holder. In order to enhance the flow of material from the tip of the cutting tool  10 , a curved surface  24  is defined from the extent of the flange  18  to the side wall of the upper end  14 , thus eliminating a corner otherwise formed by the flange  18  and the upper end  14 . 
     Illustrated in FIG. 1 is a cutting tool  10  of the present invention as formed in a conventional manufacturing process. Illustrated in FIG. 2 is a finished cutting tool  10  of the present invention. In order to achieve the cutting tool  10  of the latter figure, after molding the body  12  as shown, the upper end  14  is modified to define an insert receptor  22 , for receiving an insert  20 , as most clearly illustrated in FIG.  4 . The insert receptor  22  is configured to receive and retain an insert  20  of a selected diameter. The distal end of the upper end  14  is also modified to define a chamfered surface  26  from approximately the insert receptor  22  to approximately the terminal edge of the fins  28 . 
     The insert  20  is secured within the receptor  22  by conventional means such as brazing or welding. The insert  20  defines a conical configuration on its distal end, or tip  21 . In the preferred embodiment, the insert  20  is fabricated from tungsten carbide or diamond material. It will be understood, although not illustrated, that the insert  20  may be releasably received within the receptor  22  for removal and replacement thereof. 
     The lower end  16  is also modified to define a radial receptor  17  for receiving a retainer clip (not shown). The radial receptor  17  is disposed a distance from the flange  18  slightly greater than the length of the holder through opening so as not to prevent free rotation of the cutting tool  10 . The retainer clip is configured to be closely received within the radial receptor  17  when the bit penetrator lower end  16  is received within the holder through opening. The retainer clip is further configured to define an outer diameter greater than the diameter of the holder through opening, thus serving to prevent extraction of the cutting tool  10  from the holder. It will be understood that other means for removably securing the cutting tool  10  within the holder to allow free rotation of the cutting tool  10  may be incorporated with similar results. For example, a band may be placed on the lower end  16  and received in a recess defined by the holder through opening may be used to retain the cutting tool  10  in the holder. 
     From the foregoing description, it will be recognized by those skilled in the art that a rotatable cutting tool for earth working equipment offering advantages over the prior art has been provided. Specifically, the cutting tool is designed to penetrate hard rock in hardened strata, and to extend the life of a penetrator bit insert. Further, the cutting tool is configured to receive a penetrator bit insert formed from tungsten carbide or diamond materials. The cutting tool flange provides protection for the lower shank end and the holder in which it is received by minimizing rock and earth fines from contacting and building up between the holder and bit penetrator. Further, the flange acts as a load bearing surface between the bit penetrator and the holder, thereby protecting the lower end of the bit penetrator and the face of the holder. The flange thereby reduces the likelihood of breakage of the cutting tool lower end. 
     While a preferred embodiment has been shown and described, it will be understood that it is not intended to limit the disclosure, but rather it is intended to cover all modifications and alternate methods falling within the spirit and the scope of the invention as defined in the appended claims.