Rotary tools or bits

Abstract

Cutter elements including pointed contact structures and elements, and rock tools or bits for carrying those elements, for chipping, cutting, and breaking non-ductile materials are disclosed. The cutter elements, the ends of which directly contact and cut through rock and other materials, have tapered contact structure ends which are flatter than those known to the prior art, obtaining increased durability. The contact elements which may be part of the contact structures are selected of materials having hardness and other characteristics in relation to those of the mounting structures, including the tapered and projecting portions, which also add durability and wear-resistance to the elements. Fixed, replaceable, and rotatable cutter elements are disclosed. Rock tools including bits are also disclosed for carrying the cutter elements, having sockets for threaded or rotatable cutter elements arranged in straight or curved rows on the head opposite the drill-string-engaging base of the tool. The tool also has radially-extending buttresses which help to protect the cutter elements from damage as the drill string and head is withdrawn from a bore.

I claim as my invention:  
     
         1 . A body for an earth-boring bit, the body comprising: 
 a head portion having an outer, bore-side surface, and    a plurality of sockets formed in and deployed about the surface thereof for receiving a corresponding plurality of cutter elements.    
     
     
         2 . A body for an earth-boring bit as defined in  claim 1 , wherein each socket is internally threaded.  
     
     
         3 . A body for an earth-boring bit as defined in  claim 1 , wherein the plurality of sockets are deployed generally in a plurality of rows.  
     
     
         4 . A body for an earth-boring bit as defined in  claim 3 , wherein each socket is internally threaded.  
     
     
         5 . A body for an earth-boring bit as defined in  claim 5 , wherein each socket is internally threaded.  
     
     
         6 . A body for an earth-boring bit as defined in  claim 1 , wherein the outward ends of the sockets are arranged in a generally round pattern about the central axis and at the periphery of the body.  
     
     
         7 . A body for an earth-boring bit as defined in  claim 3 , wherein a plurality of the rows are generally co-planar with the axis of the body.  
     
     
         8 . A body for an earth-boring bit as defined in  claim 3 , wherein at least one of the rows has a generally spiral arrangement with respect to the axis of the body.  
     
     
         9 . A body for an earth-boring bit as defined in  claim 1 , wherein the body is hollow and is formed with a fluid channel connecting an inner portion of the body to the outer surface.  
     
     
         10 . A body for an earth-boring bit as defined in  claim 3 , wherein at least three buttresses are deployed rearwardly from the ends of said rows of sockets.  
     
     
         11 . A body for an earth-boring bit, the body comprising 
 a base portion and a bore-side surface opposite the base, and    a plurality of sockets deployed in an array on the surface to receive a corresponding plurality of cutting elements to form a cutting surface, and wherein 
 at least one socket is angled backwards and to one side from a perpendicular to the surface of the body at the location of the socket, with respect to movement of the cutting element across a formation in a bore hole.  
   
     
     
         12 . A body for an earth-boring bit as defined in  claim 11 , wherein 
 the sum of a backward angle plus a sideward angle of an axis of the socket from a perpendicular to the surface of the body is less than 70 degrees.    
     
     
         13 . A body for an earth-boring bit as defined in  claim 11 , wherein 
 the sum of a backward angle plus a sideward angle of an axis of the socket from a perpendicular to the surface of the body is less than 50 degrees.    
     
     
         14 . An earth-boring bit comprising: 
 a rotatable body having a base and a bore-side surface opposite the base,    an engagement structure in the base of the body for the engagement of a rotating drill string, and    at least one generally pointed cutting element carried on the bore-side surface, and wherein, 
 at least a portion of the tapered structure is located in advance of the distal end point of said pointed contact structure in the direction of motion through an earth formation.  
   
     
     
         15 . An earth-boring bit as defined in  claim 14 , wherein at least one of said cutting elements is positioned at less than about 37 degrees from a perpendicular to the bore face at the position of the cutting element.  
     
     
         16 . An earth-boring bit as defined in  claim 14 , wherein at least three radially-extending buttresses are deployed on the bore-side surface and toward the base from the cutting elements.  
     
     
         17 . An earth-boring bit as defined in  claim 16 , wherein the cutting elements are arranged in a plurality of rows extending axially of the bit body, and each of the buttresses is located generally in line with one of said rows.  
     
     
         18 . An earth-boring bit as defined in  claim 14 , wherein at least one of said cutting elements is positioned at less than about 25 degrees from a perpendicular to the bore face at the position of the cutting element.  
     
     
         19 . An earth-boring bit as defined in  claim 18 , wherein at least three radially-extending buttresses are deployed on the bore-side surface and toward the base from the cutting elements.  
     
     
         20 . An earth-boring bit comprising: 
 a body having an outer surface, and    a plurality of tapered and generally pointed contact structures carried on the outer surface of the body, and wherein 
 at least one the contact structures is not rotatable about its own axis in the body surface.  
   
     
     
         21 . An earth-boring bit comprising: 
 a body having a central axis and a bore-side surface,    an engagement structure for engagement with the body along said axis of an elongated drill string, and    a plurality of generally pointed cutting elements arrayed about the bore-side surface of the body, wherein 
 at least four of the cutting elements are deployed in each of at least one row on said surface of the body.  
   
     
     
         22 . An earth-boring bit as defined in  claim 21 , wherein at least two of the rows are located substantially in one plane including the axis of the body.  
     
     
         23 . An earth-boring bit as defined in  claim 21 , wherein at least one of the rows is curved in at least two dimensions.  
     
     
         24 . An earth-boring bit comprising 
 a body having a bore-side surface, and    a plurality of generally pointed cutting elements carried on the body surface, and 
 wherein the tips of at least three cutting elements are carried on a circle that is normal to said axis to bear against the borehole side wall and to stabilize the bit therein during use.  
   
     
     
         25 . An earth-boring bit comprising: 
 a body with a base and a bore-side surface opposite the base,    an engagement structure in the base for the engagement of an elongated drill string,    a plurality of generally pointed replaceable cutting elements arrayed on the surface of the bit body, and wherein 
 said cutting elements are threadably engaged with the body.  
   
     
     
         26 . An earth-boring bit comprising a body and a plurality of generally pointed contact structures carried on the body, wherein 
 the number of pointed contact structures divided by the cross sectional area of the bore, in square inches, is greater than about 0.33.    
     
     
         27 . An earth-boring bit comprising a body and a plurality of generally pointed contact structures carried on the body, wherein 
 the number of pointed contact structures divided by the cross sectional area of the bore, in square inches, is greater than about 0.50.