Polycrystalline diamond percussion drill bits using low thrust and torque and incorporating PCD chisel type inserts, or combination of PCD chisel type inserts with PCD conical inserts, for application with small diameter drill bits

Abstract

A polycrystalline diamond drill bit for percussion drilling, in small hole high silica ground. The bit is made having a bit body, and a series of inserts locating in the bit body, and the bits are made using a double chisel design, or a modified double chisel design. The inserts are either chiseled shaped inserts, or the inserts are a combination of chisel shaped inserts and conical inserts, and are set into the bit body at very specific angles, in order to attain slicing of the earth when percussion drilling is performed. The inserts have specific lengths to cut clearance for the bit body. The cutting angle and the radius of the tip of each insert in addition to the diameter of the inserts, provide for use of a machine thrust pressure and machine torque pressure at low ranges when the PCD bits are used in percussion drilling.

I claim: 
     
         1 . A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a center axis and a cutting face, the cutting face having a frontal face, and a beveled face extending outwardly radially therefrom, the body and the cutting face being integrally formed;
 said drill bit formed of a double chisel design or modified double chisel design configuration;   said drill bit capable of operating at a machine torque pressure of less than 20 Bar, and a machine thrust pressure of less than 20 Bar;   said frontal face and said beveled face having a series of openings provided therein, and inserts being pressed fitted within said openings in preparation for usage of the drill bit in said percussion drilling operation, each of said inserts having a tip comprising a polycrystalline diamond coating;   select of said inserts being of a conical design, and others of said inserts being of a chisel design;   the chisel design inserts being arranged at an angle between about 0° to about 45° within the drill bit to provide for a plowing or slicing action of the drill bits when cutting of the earth during a percussion drilling operation;   said drill bit body having a gauged diameter of between about 1⅜ inches to 8 inches in diameter; and   each insert having a gripping portion of a diameter between about 0.300″ to 0.520″, each insert having a grip length of between about 0.300″ and 0.600″, and each tip of each insert having a length of between about 0.200″ to 0.360″ in their location within the percussion drill bit in preparation for a drilling operation.   
     
     
         2 . The percussion drill bit of  claim 1  wherein said chisel inserts are arranged at approximately 15° off the perpendicular to the arc of rotation of the drill bit during its usage in percussion drilling. 
     
     
         3 . The percussion drill bit of  claim 1  wherein said inserts are arranged at approximately 30° off of the perpendicular to the arc of rotation of the drill bit during the performance of a drilling. 
     
     
         4 . The percussion drill bit of  claim 1  wherein the drill bit operating range for machine torque pressure is between about 8 to 15 Bar, and the machine thrust pressure setting for drill bit operation is set between about 12 and 20 Bar during a drilling operation. 
     
     
         5 . The percussion drill bit of  claim 4  wherein the drill bit operation for optimal percussion drilling provides a machine torque pressure setting at 12 Bar, and the machine thrust pressure setting at 15 Bar. 
     
     
         6 . The percussion drill bit of  claim 1  wherein the drill bit is formed of a double chisel design, and the bit body has a gauge diameter between about 1¼″ to 2¼″. 
     
     
         7 . The percussion drill bit of  claim 1  wherein said drill bit is formed of a modified double chisel design, and said drill bit body has a gauge diameter of between about 2½″ to 3½″. 
     
     
         8 . The percussion drill bit of  claim 6  wherein the drill bit of double chisel design comprises four PCD inserts provided upon the beveled face, and two PCD inserts fitted within the frontal face. 
     
     
         9 . The percussion drill bit of  claim 6  wherein the drill bit of double chisel design comprises four PCD inserts provided upon the beveled face, and at least one PCD insert fitted within the frontal face. 
     
     
         10 . The percussion drill bit of  claim 7  wherein said drill bits of a modified double chisel design comprising between four to six PCD inserts mounted in the beveled face, and from two to four PCD inserts mounted within the frontal face. 
     
     
         11 . The percussion drill bit of  claim 8  wherein the first and second sets of PCD inserts each comprising at least three PCD inserts. 
     
     
         12 . The percussion drill bit of  claim 10  wherein the first and second sets of PCD inserts each comprise at least four PCD inserts. 
     
     
         13 . The percussion drill bit of  claim 1  wherein the polycrystalline diamond coating of each tip of each conical and chisel insert is 0.010-0.030″ thick. 
     
     
         14 . The percussion drill bit of  claim 19  wherein the radius of the center axis of the drill bit for each PCD insert provided within the frontal face is as set forth in the following chart. 
       
         
           
                 
                 
                 
               
                     
                 
                   Drill Bit Size 
                   No of face Inserts 
                   Distance from C/L 
                 
                     
                 
                     
                 
                 
                 
                 
               
                   1¼″-1⅝″ 
                   1 
                   ⅛″ 
                 
                   1¾ 
                   2 
                    3/16″- 5/16″ 
                 
                   2″ 
                   2 
                   ⅜″- 7/16″ 
                 
                   2¼ 
                   2 
                   ⅜″- 7/16″ 
                 
                   2½ 
                   3 
                   ⅜″- 7/16″-½″ 
                 
                   3.0 
                   4 
                   ⅜″-½″- 13/16″-1.0″ 
                 
                   3½ 
                 
                     
                 
             
                
                
                
               
               
                
               
            
             
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         15 . The percussion drill bit of  claim 1  wherein each insert provided within the drill bit body having dimensions within ranges as set forth as follows: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Range Claimed for Inserts 
                   Range Dimensions 
                 
                     
                     
                 
                     
                   OAL of Insert 
                   .500″-.650″ 
                 
                     
                   Diameter of Insert 
                   .3000″-.4200″ 
                 
                     
                   Tip Length 
                   .200″-.260″ 
                 
                     
                   Tip Angle 
                   15.00°-35.00° 
                 
                     
                   Tip Radius 
                   .100″ R-.145″ R 
                 
                     
                   Grip Length 
                   .290″-.420″ 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         16 . The percussion drill bit of  claim 1  wherein each insert provided within the drill bit body having dimensions within ranges as set forth as follows: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Range Claimed for Inserts 
                   Range Dimensions 
                 
                     
                     
                 
                     
                   OAL of Insert 
                   .600″-.785″ 
                 
                     
                   Diameter of Insert 
                   .3900″-.4900″ 
                 
                     
                   Tip Length 
                   .250″-.350″ 
                 
                     
                   Tip Angle 
                   15.00°-35.00° 
                 
                     
                   Tip Radius 
                   .120″ R-.155″ R 
                 
                     
                   Grip Length 
                   .300″-.450″ 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         17 . The percussion drill bit of  claim 1  wherein each insert provided within the drill bit body having dimensions within the ranges as set forth as follows: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Range Claimed for Inserts 
                   Range Dimensions 
                 
                     
                     
                 
                     
                   OAL of Insert 
                   .625″-.785″ 
                 
                     
                   Diameter of Insert 
                   .4800″-.5200″ 
                 
                     
                   Tip Length 
                   .260″-.335″ 
                 
                     
                   Tip Angle 
                   25.00°-40.00° 
                 
                     
                   Tip Radius 
                   .135″ R-.170″ R 
                 
                     
                   Grip Length 
                   .330″-.500″ 
                 
                     
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         18 . The percussion drill bit of  claim 1  wherein each PCD chisel insert provided within the drill bit body having dimensions within the ranges as set forth as follows: 
       
         
           
                 
               
                     
                 
                   Preferred Ranges Claimed for PCD Chisel Inserts 
                 
                     
                 
                     
                 
                 
                 
                 
               
                     
                   PCD Insert Diameter range  
                   .300″ to .750″ 
                 
                     
                   PCD Insert grip length 
                   .300″ to .600″ 
                 
                     
                   PCD Insert tip length 
                   .250″ to .360″ 
                 
                     
                   PCD Tip radius on Chisel Inserts 
                    .04″ to .135″ 
                 
                     
                   PCD Tip length in a range of 
                   .225″ to .375″ 
                 
                     
                   PCD Coating thickness on Tip of inserts 
                   .010″ to .035″ 
                 
                     
                     
                 
             
                
                
                
               
               
                
               
            
             
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         19 . A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a cutting face, the body and the cutting face being integrally formed;
 the drill bit formed of a double chisel design or modified double chisel design configuration;   said drill bit capable of operating at a machine torque pressure of less than 20 Bar, and a machine thrust pressure of less than 20 Bar;   said frontal face of the drill bit having a series of openings provided therein, and PCD inserts being pressed fitted within said openings in preparation for usage of the drill bit in said drilling operation, there being at least two PCD inserts provided within the frontal face of the drill bit;   each of said PCD inserts having a tip comprising a polycrystalline diamond coating;   said inserts being arranged at a cutting angle of between about 0 to 45° off of the arc of rotation of the drill bit during performance of a drilling operation;   each PCD insert provided in the cutting face of the drill bit positioned at a select radius from the center axis of said bit body;   said drill bit body having a gauged diameter between about 1¼″ to 3½″;   each of the inserts being of a polycrystalline chisel design; and   each insert having a gripping portion of a diameter between about 0.300″ to 0.520″, each insert having a grip length of between about 0.290″ and 0.550″, and each tip of each insert having a length of between about 0.200″ and 0.320″, and a conical surface at the tip of its formed chisel for each insert.   
     
     
         20 . The percussion drill bit of  claim 19  wherein the frontal face of the percussion drill bit is contoured into an outer beveled design, each beveled portion extending outwardly from the center of the drill bit, and having at least one chisel insert provided therein. 
     
     
         21 . A percussion drill bit, said drill bit formed having a body, the body capable of being secured with a drill shaft in preparation for a percussion drilling operation, the body having a center axis and a cutting face, said cutting face having a front face and a beveled face outwardly of the frontal face, the body and the cutting face being integrally formed;
 said drill bit having a series of PCD inserts provided upon its frontal face, select of said PCD inserts being of a chisel design, and said PCD inserts having a tip, and the tip having a coating of polycrystalline diamond;   said drill bit capable of operating at a machine torque pressure of 20 Bar or less, and a machine thrust pressure of 20 Bar or less;   said chisel design inserts being arranged at a angle between about 0° to about 45° within the drill bit to provide for one of a plowing or slicing action of the drill bit when cutting of the earth during a percussion drilling operation;   said drill bit body having a diameter between about 1⅜ inches to 8 inches in diameter; and   said percussion drill bit provided for drilling into hard rock and high silica ground during performance of a percussion drilling operation.   
     
     
         22 . The percussion drill bit of  claim 21 , wherein all of said inserts are of a PCD chisel design. 
     
     
         23 . The percussion drill bit of  claim 21 , wherein select of said inserts are of a PCD conical design. 
     
     
         24 . The percussion drill bit of  claim 21 , wherein the inserts provided upon the frontal face of the drill bit function to drill the pilot hole within the earth during a percussion drilling operation, and the inserts provided upon the outer beveled portion of the drill bit are provided for furnishing a reaming of the drilled hole during performance of a percussion drilling operation, and wherein said inserts provided upon front face of the bit extending more forwardly than the inserts provided upon the beveled portion of the drill bit. 
     
     
         25 . The percussion drill bit of  claim 21 , wherein said PCD chisel inserts have the following range of dimensions: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   PCD Insert diameter range  
                   .300″ to .750″ 
                 
                     
                   PCD Insert grip length 
                   .300″ to .600″ 
                 
                     
                   PCD Insert tip length 
                   .250″ to .360″ 
                 
                     
                   PCD Tip radius on Chisel Inserts 
                    .04″ to .135″ 
                 
                     
                   PCD Tip length in a range of 
                   .225″ to .375″ 
                 
                     
                   PCD Coating thickness on Tip of inserts 
                   .010″ to .035″ 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
         and said chisel inserts provided for one of plowing and slicing of the earth during the performance of a percussion drilling operation. 
       
     
     
         26 . The percussion drill bit of  claim 21 , wherein the PCD conical inserts have the following range of dimensions: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   PCD Insert diameter range  
                   .300″ to .750″ 
                 
                     
                   PCD Insert grip length 
                   .300″ to .600″ 
                 
                     
                   PCD Insert tip length 
                   .250″ to .360″ 
                 
                     
                   PCD Tip radius on Conical Inserts 
                   .115″ to .170″ 
                 
                     
                   PCD Tip length in a range of 
                   .225″ to .400″ 
                 
                     
                   PCD Coating thickness on Tip of inserts 
                   .010″ to .035″ 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         27 . The percussion drill bit of  claim 21 , wherein the drill bits perform at low machine thrust pressures of 1.0 Bar to 20 Bar, and low machine torque pressures of 8 Bar to 20 Bar, and are used in combination with PCD chisel inserts and PCD conical inserts installed into the drill bit to maximize its percussion drilling performance. 
     
     
         28 . The percussion drill bit of  claim 21 , wherein each drill bit at its smallest size is in the size range of approximately 1 and ⅜ inches to 1 and ⅝ inches in diameter. 
     
     
         29 . The percussion drill bit of  claim 21 , wherein select of said PCD chisel inserts are linear aligned upon the cutting face of the drill bit, and other of said PCD inserts being linearly aligned at an offset angle from the linear alignment for the first set of chisel inserts when installed in the percussion drill bit.