Casing Block

Abstract

A preset recessed casing block for retaining a cutter bit is provided that can be mass-produced and easily installed in the casing of a core barrel. The block has a size and shape that provides for quick and easy insertion and welding into a casing. The block has a cavity that receives and retains a cutter bit while allowing for the removal or extraction of the cutter bit when the bit becomes worn or broken. Because the block is manufactured to fit inside the casing, wear on the block is minimized and it's lifetime extended. The cavity in the block and the shape of the block itself may have different, preset angles and pitches, to allow for the same size block to be placed in a variety of locations around the casing, thereby enabling the manufacturer to produce a variable, raking pattern of the cutter bits for improved annulus cutting.

1 . A device for retaining a cutter bit in a casing comprising: a bottom, four sides, a top, and a cutter bit retaining section, where the bottom and the four sides are capable of fitting into a cavity of a casing. 
     
     
         2 . The device of  claim 1 , wherein one of the four sides comprises an opening through which a bottom of a shaft portion of a cutter bit can be accessed, wherein this opening is a terminal cavity. 
     
     
         3 . The device of  claim 1 , where the four sides are of equal length, thereby making a square. 
     
     
         4 . The device of  claim 1 , where the four sides have two sides of one length and two sides of another length, thereby making a rectangle. 
     
     
         5 . The device of  claim 1 , wherein the device further comprises four beveled edges, where there is a beveled edge between each of the four sides, and where the beveled edges allow for welding material to be inserted in between the device and the casing. 
     
     
         6 . The device of  claim 1 , further comprising a trailing support edge, where the trailing support edge is a raised section proximate to the cutter bit retaining section. 
     
     
         7 . The device of  claim 1 , where the device further comprises a terminal cavity, where the terminal cavity is proximate to the cutter bit retaining section, wherein the cutter bit retaining section comprises a first retaining portion and a second retaining portion, and wherein the terminal cavity has an opening. 
     
     
         8 . The device of  claim 7 , wherein the cutter bit retaining section is shaped to mate with a shank section of a cutter bit. 
     
     
         9 . The device of  claim 7 , wherein the first retaining portion and second retaining portion each have a diameter, where the diameter of the first retaining portion is greater than the diameter of the second retaining portion. 
     
     
         10 . The device of  claim 1 , wherein the cutter bit retaining section is manufactured in a low pitch. 
     
     
         11 . The device of  claim 1 , wherein the cutter bit retaining section is manufactured in a high pitch. 
     
     
         12 . The device of  claim 1 , wherein the cutter bit retaining section is manufactured in a medium pitch. 
     
     
         13 . The device of  claim 1 , wherein the device is manufactured for an inside position on a casing. 
     
     
         14 . The device of  claim 1 , wherein the device is manufactured for a middle position on a casing. 
     
     
         15 . The device of  claim 1 , wherein the device is manufactured for an outside position on a casing. 
     
     
         16 . The device of  claim 1 , wherein the bottom of the device comprises a flat base portion and two angled base portions, whereby the flat base portion and angled base portions enable the same device to be used for an inside position, middle position, or outside position in a casing. 
     
     
         17 . The device of  claim 1 , additionally comprising a terminal cavity, wherein the terminal cavity is accessible though one of the four sides. 
     
     
         18 . The device of  claim 17 , wherein a cutter bit can be removed from the device through the use of a wedge shaped tool. 
     
     
         19 . The device of  claim 1 , wherein the cutter bit retaining section is designed to accommodate a rotating cutter bit. 
     
     
         20 . The device of  claim 1 , wherein the cutter bit retaining section is designed to accommodate a non-rotating cutter bit.