US 2612348 A
Description (OCR text may contain errors)
Sept. 30, 1952 CATALLO DIAMOND SET CORE BIT Filed Sept. 14, 1949 4 LIII Patented Sept. 30, 1952 DIAMOND SET CORE BIT Leo Catallo, Detroit, Mich., assignor to Wheel Trueing Tool Company, Detroit, Mich., a corporation of Delaware Application September 14,1949, Serial No. 115,618
1 Claim. (01. 255 -42) This invention relates to a core bit andmore particularly to a diamond set core bit for drilling oil wells. I
As is customary in drilling operations, a drilling annular body I I, formed of metal or of a metallic inner'and outer surfaces I2 and I3 are substanfluid, or drilling mud as it is called, is pumped 5 tially cylindrical and are relieved at their ends, down through the hollow drilling head assembly as at I5 and IE, to form annular shoulders that to flow outwardly over the workin face of the lie inlongitudinally spaced planes. Said shouldrill bit and upwardly in the hole or well. In ders l5 and 16 have functional purposes in conthe case of diamond set bits, surges in the fluid nection with the other elements of the drilling pressure at the bottom of the hole will often cause head assembly with which the core bit [0 is to be bumping of the working end of the bit against associated in the setting up of the drilling equipthe bottom of the hole with consequent damage ment. The convex end surface I4 smoothly joins to the diamonds by being broken against hard the inner and outer cylindrical surfaces I 2 and formations. Such surging may be due to pump l3 but with a curve of lesser radius to form the surges or to faulty pump circulation, but bump- 5 inner contour [1 than the radius of the curve ing may also be caused by the provision of Water ming the outer contour l8. courses in the working face of the bit of insufiih Surfaces 4 and I3 constitute the workvcient volume to accommodate the Volume of ing face of the core bit and, for this purpose, are culating fluid that must escape from the inside set with abrasive particles, or diamonds, indicated of the t to t t i if balanced flow is to be 20 at i9. The diamonds H! are individually set in maintained. If an out-of-balance condition obthe mold usedin making the core bit l0, and are tains, sufficient pressure may build up to lift the arranged n predetermined P s and With bit up off the bottom of the hole, with the result v rying lengths of the diamonds pro rudin from that when this excess pressure is relieved sudh fac f the y, r in W ch the demy, the eight of t drilling equipment may diamonds are set. For instance, the diamonds force the bit down against the bottom of the hole l9 over the end surface [4 protrude rather subwith a striking blow that may break the diamonds stantiaily f m the Surface in Which y are set, in the working face of the bit. but the diamonds, indicated at I9a. along .the Ihave now found that by a proper construcouter cylindrical surface I3 gradually become tion and design of a diamond set core bit and flush :with the surface down toward the lower with a novel arrangement of water courses, the d, or shoulder I 6 of said surface, tendency of excess-fluid pressure to build up and he Working face of the core bit is provided relieve itself in the manner described is largely With a plurality of symmetrically arranged radiminimized or even eliminated entirely. This reating grooves 20, which serve as water courses for sult is accomplished in accordance withthe prine ow of drilling fluid from the interior of the ciples of my invention I by providing auxiliary drilling assembly radially aCI'OSS e Working face water grooves in a novel and effective arrangef he core bit and upwardly along the outer ment with respect to the working face of thecore surface Is. Said main water grooves 20 lie in bit and the positioning of the diamonds, or other planes P g through the axis of the core bit abrasive particles, set therein. 40 and divide the Working f ce of the core bit into It is therefore an important object of this in sector-shaped portions indicated at S. The main vention to provide a diamond set core bit of novel grooves 20 are segmentally circular in cross section and improved construction and design in the use d are of substantially uniform cross section of. which there is less tendency of thediamonds roughout their lengt t m a g n the inbecoming ke by percussiv impact against Side at the shoulder 55, asat 20a, and at the hard drilling formations. outside at the shoulder I6, as at 2017. In addi- *(Dther and further important objects of this tion to the main water grooves, there are the invention 111 be v arent from the disclosures usual junk grooves 2!, of which four are shown in the specification and the accompanying ,drawequi-sp about t periphery f the core bit. ings v The junk grooves are for facilitating theescape Asshown on the drawings: 0f junkiron that may be found in the hole, pro- Figure 1 is a bottom plan view of a diamond vided the junkiron is in small enough particle set core bit embodying the principles of my insize. In order to prevent damage to the diamonds vention. of the core bit, allforeign objects should be kept Figure 2 is a sectional view taken substantially o fthe 11018, Or should be removed before along the broken linen-11 of Figure 1. Starting the diamond d g operation.
on the drawings; My observations as to the operation of dia- The reference numeral 10 ndicates generally mond set core bits provided with water courses a diamond set core bit embodying the principles arranged as are the water courses 20 in the ac of my invention. Said core bit I0 comprises an companying drawings have led me to the con-v lieved ends lying in axially spaced planes, abrasive particles set in said working face and extending in rows diverging outwardly over said, convex end surface and in generally parallel rows extending axially along said inner and outer surfaces, the abrasive particles in said outer surface lying substantially flush therewith but those in said end surface protruding substantially therefrom. said surfaces being provided with main water courses lying in planes through the axis of said body and extending transversely of said body across'all of said surfaces to the relieved inner and outer ends and dividing said end SUI- face into sector-shaped portions, said end and outer surfaces being provided with auxiliary water grooves intermediate said water courses and beginning near the middle of said sector- -shaped portions and extending therefrom along I said end surface and said outer surfaces to the relieved end of said outer surface.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS OTHER REFERENCES Diamonds, by Carroll Deely, World Oil, Oct. 1947, pages 87-90.