Drilling apparatus

#This invention relates to drilling apparatus, and more particularly relates to a novel and improved drilling apparatus with fluid delivery bores for directing fluids from a drill string into drill bits, reaming tools and the like. The invention is adaptable for use with liquids and gaseous materials but is particularly useful in connection with liquids to be used in subsurface formations.

#I have previously devised drill bit assemblies as well as reaming devices which are broadly characterized by having a rotary drill bit mounted at the lower end of a conventional drill string and cutter blades pivotally mounted on the drill bit. In high speed earth boring operations to be carried out with fluid assist, the cutter blades are equipped with fluid discharge nozzles which communicate with fluid delivery hoses extending downwardly through the drill string into direct connection with the fluid discharge passages in each of the cutter blades. Although the hoses prevent leakage between the drill string and blades, they are quite bulky, are subject to wear or blow out under repeated use and impose limitations on the ability to mount the cutter blades for free pivotal movement from a vertical to horizontal position at the end of the drill string. Accordingly, there is a need for a fluid delivery system which eliminates the need for fluid delivery hoses and can achieve direct delivery of fluid through bores formed out of the thickness of the blade support body. Still further, and in association with the improved fluid delivery system, is to provide for a novel and improved ball joint between the blade support body and cutter blades which does not interfere with fluid delivery and results in an improved installation, operation, versatility and reliability in use of the blades in downhole operations.

#Representative patents are U.S. Pat. Nos. 2,203,998 to D. J. O'Grady, 2,814,463 to A. W. Kammerer, Jr., 3,196,961 to A. W. Kammerer, 3,552,509 to C. C. Brown, 3,554,304 to H. D. Link et al, 3,656,564 to C. C. Brown, 3,684,041 to A. W. Kammerer et al, 5,271,472 to R. E. Leturno, 5,385,205 to C. D. Hailey and 5,494,121 to A. L. Nackerud.

#FIG. 1 is a front elevational view of a preferred form of blade support body for a drill bit with the blades shown at rest;

#FIG. 1A is a bottom plan view of the apparatus shown in FIG. 1;

#FIG. 2 is a side elevational view of the preferred form of invention shown in FIG. 1;

#Referring in more detail to the drawings, there is shown by way of illustrative example in FIGS. 1 to 4 a drill bit assembly 10 which is comprised of a sub 12 in the form of a hollow cylindrical blade support body 13 having an upper threaded end 14 and a lower bifurcated pivotal end 16. A pair of cutter blades 17 and 18 are each made up of an elongated blade arm 20 tapering into a rounded pivotal end 22 having a transverse bore 23, 23′ for pivotal connection to the lower pivotal ends 16 of the blade support body 13. Each blade arm 20 is of generally semi-circular configuration having flat, confronting surface portions 19. Thus the blades 17 and 18 are supported for pivotal movement between a first position extending substantially in a lengthwise direction when at rest and a transverse or mutually perpendicular direction when in operation as illustrated in FIGS. 1 and 4, respectively. The pivotal ends 16 are in the form of ears or extensions of the hollow cylindrical body 13 so as to be arcuate in cross-section.

#Each of the blades 17 and 18 has a generally concave surface portion tapering into the pivotal end 22, and the pivotal ends 22 are of a thickness such that when mounted on the pivot shaft 24 will clear the pivotal end 16 so that the blade arms are free to swing freely into and away from the mutual perpendicular positions shown in FIG. 4.

#Each of the blade arms 20 includes radially offset larger and smaller semi-circular body portions 30 and 32, the larger portion 32 extending along the inner radial surface of the arm 20 adjacent to the pivotal end 22. The smaller portion 30 is of approximately the same length as the larger portion 32 and terminates in an outer squared distal end 34 of the arm. In the smaller surface portion 30, a series of first cutter disks 36 are mounted for rotation about individual roller shafts 37 which are fixed in recesses in the undersurface of each of the blade arms 20 and at uniform, axially spaced intervals along the undersurface of each arm adjacent to the flat surfaces 19. As best seen from FIG. 1, the axis of rotation for each disk is such as to correspond to the radius of curvature which that disk follows. In other words, the shaft 37 for that disk is perpendicular to the radius of curvature at that point on the undersurface of the arm 20. The individual disks 36 are of a hardened material, such as, tungsten carbide material and have tapered surfaces which terminate in a common cutting edge 38.