1
Edward M Galle, Anton F Zahradnik: Compensator for earth boring bits. Hughes Tool Company, Robert A Felsman, March 1, 1988: US04727942 (93 worldwide citation)

In an earth boring bit of the type having a rotatable cone secured to a bearing shaft, an improved pressure compensating and relief system. A flexible diaphragm has an enlarge peripheral portion in an o-ring configuration sealingly secured in a compensator cavity to form a mud region and a lubricant ...


2
Robert J Costo Jr, James L Overstreet, Anton F Zahradnik, James L Duggan, Russel S Smith, Mark E Morris: Steel body drill bits with tailored hardfacing structural elements. Baker Hughes Incorporated, TraskBritt, November 25, 2003: US06651756 (70 worldwide citation)

Hardfacing is deposited on a PDC-equipped steel body rotary drag bit and forms substantially protruding structural elements, such as wear knots or chip breakers. Hardfacing may also be applied to features such as gage pads, wherein at least two different hardfacing compositions are utilized and spec ...


3
Anton F Zahradnik, Terry J Koltermann, Don Q Nguyen, Aaron J Dick, Eric Sullivan, Scott Shiqiang Shu: Bearing insert sleeve for roller cone bit. Baker Hughes Incorporated, Bracewell & Giuliani, June 17, 2008: US07387177 (49 worldwide citation)

An earth boring bit has a bearing pin with a sleeve mounted on it. The sleeve is fixed against rotation but able to float relative to the bearing pin. A cone fits over and forms a bearing surface with the sleeve. The sleeve and bearing pin are configured to have a clearance between them that has a f ...


4
Steven R Radford, Scott Shiquiang Shu, Anton F Zahradnik, J Lindley Baugh: Expandable reamers for earth boring applications. Baker Hughes Incorporated, TraskBritt, March 8, 2011: US07900717 (45 worldwide citation)

An expandable reamer apparatus for drilling a subterranean formation includes a tubular body, one or more blades, each blade positionally coupled to a sloped track of the tubular body, a push sleeve and a drilling fluid flow path extending through an inner bore of the tubular body for conducting dri ...


5
Anton F Zahradnik, Don Q Nguyen, Ronny D McCormick, Terry J Koltermann, Michael Joseph Veasey: Seal insert ring for roller cone bits. Baker Hughes Incorporated, Bracewell & Giuliani, July 1, 2008: US07392862 (39 worldwide citation)

An earth boring bit has a bit body with a depending bearing pin. An insert ring is mounted on the bearing pin. The insert ring has an inner diameter greater than an outer diameter of the bearing pin, defining a clearance between the insert ring and the bearing pin to allow the insert ring to float r ...


6
Anton F Zahradnik: Floating seal for earth boring bit. Hughes Tool Company, Robert A Felsman, James E Bradley, January 31, 1984: US04428687 (38 worldwide citation)

An earth boring bit has a bearing seal that floats to accommodate angular and axial movement of the cutter with respect to the shaft. The seal is located in an annular groove formed in the shaft. A supporting ring is located in the groove. The supporting ring has an inner diameter larger than the in ...


7
Anton F Zahradnik, Rudolf Carl Pessier, Don Q Nguyen, Michael Steven Damschen, Karlos B Cepeda, Tim King Marvel, Matt Meiners: Hybrid drill bit and method of drilling. Baker Hughes Incorporated, Locke Lord Bissell & Liddell, December 7, 2010: US07845435 (28 worldwide citation)

A hybrid drill bit having both roller cones and fixed blades is disclosed, and a method of drilling. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elem ...


8
Anton F Zahradnik, Eric C Sullivan, Chih Lin, Terry J Koltermann, Scott R Schmidt: Earth-boring bit with improved bearing seal. Baker Hughes Incorporated, James E Bradley, Felsman Bradley Vaden Gunter & Dillon, February 22, 2000: US06026917 (25 worldwide citation)

An earth-boring bit has a bit body and at least one bearing shaft depending inwardly and downwardly from the bit body. The bearing shaft has a base where it joins the bit body. At least one cutter is mounted for rotation on the bearing shaft and has radial and axial surfaces that cooperate with the ...


9
George E Dolezal, Douglas J Clinkscales, Anton F Zahradnik, Turlach P Boylan: Mechanical lock to prevent seal ring rotation. Baker Hughes Incorporated, Robert A Felsman, March 22, 1994: US05295549 (23 worldwide citation)

An earth boring bit of the type having at least one rotatable cutter on a bearing shaft, a hydrostatic pressure compensator to balance the pressure of the lubricant with the pressure of the drilling fluid in the borehole, a metal face seal assembly of the type that enables movement of the seal to co ...


10
Anton F Zahradnik: Earth-boring bit having an improved hard-faced tooth structure. Baker Hughes Incorporated, Robert A Felsman, Mark D Perdue, October 4, 1994: US05351771 (20 worldwide citation)

An earth-boring bit has a bit body and at least one cutter rotatably secured to the bit body. The cutter has a plurality of teeth formed integrally thereon and arranged in circumferential rows. Each of the teeth includes an outer end, an outer end, a pair of flanks and a crest substantially transver ...