| Patents for E21B 10 - Drill bits (19,464) |
|---|
| 05/07/1991 | US5013927 Object location apparatus |
| 05/07/1991 | US5013191 Cast-in-place piling method and apparatus |
| 05/07/1991 | US5012876 Rotary drill bit providing separation of liquid from gas |
| 05/07/1991 | US5012863 Pipe milling tool blade and method of dressing same |
| 05/07/1991 | US5012701 Method of making a threaded retainer ring for a roller cutter on a drill bit |
| 05/01/1991 | CN2076153U Variable-bore borer with multiple variable diameter valve |
| 05/01/1991 | CN2076152U Pilot bit |
| 04/30/1991 | US5011515 Composite polycrystalline diamond compact with improved impact resistance |
| 04/30/1991 | US5011514 Hard particles with metal coating as matrix; high strength cutting tools |
| 04/30/1991 | US5011509 Polycrystalline diamond layer bonded to substrate |
| 04/30/1991 | US5010967 Milling apparatus with replaceable blades |
| 04/30/1991 | US5010955 Casing mill and method |
| 04/30/1991 | US5010789 Method of making imbalanced compensated drill bit |
| 04/24/1991 | CN1050836A Extra hard rock inserting diamond tool making method |
| 04/23/1991 | US5009519 Sealing assembly for relatively movable members |
| 04/23/1991 | US5009274 Laterally adjustable drilling tool |
| 04/23/1991 | US5009271 Drill assembly |
| 04/23/1991 | CA1283402C Drill bit assembly |
| 04/18/1991 | DE3933867A1 Drilling crown for drilling tube - has teeth welded at equal intervals around its leading edge perimeter and is then welded to tube |
| 04/17/1991 | EP0422435A2 Diamond compacts for rock drilling and machining |
| 04/16/1991 | US5007493 Drill bit having improved cutting element retention system |
| 04/16/1991 | US5007207 Abrasive product |
| 04/16/1991 | CA2001180A1 Post hole digger |
| 04/13/1991 | CA2021607A1 Diamond compacts for rock drilling and machining |
| 04/09/1991 | US5005989 Roller bit |
| 04/09/1991 | CA1282687C Enhanced diameter clean-out tool and method |
| 04/04/1991 | WO1991004393A1 Device for fixing disk cutter to tunnel excavator |
| 04/03/1991 | EP0420262A2 Rotary drag bit including multi-element cutting structure |
| 04/03/1991 | EP0419913A1 Cutting member and drill bit for earth boring having diamond cutting surface |
| 04/02/1991 | US5004057 Drill bit with improved steerability |
| 04/02/1991 | US5004056 Percussion-rotary drilling tool |
| 03/30/1991 | CA2026498A1 Self-renewing multi-element cutting structure for rotary drag bit |
| 03/27/1991 | EP0418706A1 Earth boring bit for soft to hard formations |
| 03/27/1991 | CN2073929U Cold-adhered new type mono-line bit |
| 03/26/1991 | US5002435 Device for making cast-in-situ piles using a continuous hollow auger |
| 03/26/1991 | US5002139 Drilling tool |
| 03/26/1991 | CA1282054C Disc cutters for rock working machines |
| 03/23/1991 | CA2025933A1 Drill bit having diamond film cutting surface |
| 03/20/1991 | CN1050075A Well reamer |
| 03/20/1991 | CN1012089B Cutter assembly for rotary boring of earth |
| 03/19/1991 | US5000273 Low melting point copper-manganese-zinc alloy for infiltration binder in matrix body rock drill bits |
| 03/13/1991 | CN1049892A Manufacturing process of secondary moulding electroplated diamond bit |
| 03/13/1991 | CN1011995B Hard alloy cutter bit |
| 03/07/1991 | WO1991002884A1 Rotatable cutting tool |
| 03/07/1991 | WO1991002882A1 An excavating tooth for an earth auger |
| 03/06/1991 | EP0415519A1 Dual seal system for rotary drill bit |
| 03/06/1991 | EP0414751A1 Bit assembly utilizing carbide insert. |
| 03/06/1991 | CN2072588U Hard alloy involute cambered surface tooth type bot pick head |
| 03/06/1991 | CN1049698A Impulse-rotary drilling bits |
| 03/05/1991 | US4997049 Tool insert |
| 02/28/1991 | DE3927625A1 Deep well diamond boring head - with high-speed central drill bit and slow-speed outer drill bit driven by moineau motor |
| 02/27/1991 | CN1011808B Pocketed stud for polycrystalline diamond cutting blanks |
| 02/26/1991 | US4995887 Cutting elements for rotary drill bits |
| 02/26/1991 | CA1280797C Diamond bearing and manufacture thereof |
| 02/26/1991 | CA1280633C Milling tool |
| 02/20/1991 | CN1049392A Diamond composition material and drill bit made of it |
| 02/19/1991 | US4993505 Stress relieving by leaching cobalt from tungsten carbide; purification; strengthening the cutter |
| 02/19/1991 | US4993503 Horizontal boring apparatus and method |
| 02/19/1991 | CA1280405C Mounting means for cutting elements in drag type rotary drill bit |
| 02/13/1991 | EP0412174A1 Production of bore holes in a given direction |
| 02/12/1991 | US4991671 Means for mounting a roller cutter on a drill bit |
| 02/12/1991 | US4991670 Rotary drill bit for use in drilling holes in subsurface earth formations |
| 02/06/1991 | EP0411831A1 Cutting element for rotary drill bit with multilayer cutting surface |
| 02/06/1991 | CN2070813U Division detachable in hole drill bit for stud wheel |
| 02/06/1991 | CN2070812U Uncontinuous offset edge alloy rock drill bit with one blade |
| 02/06/1991 | CN2070811U Hole efflux nozzle on drill bit |
| 02/06/1991 | CN2070810U Locking device of roller bit |
| 02/05/1991 | US4989680 Drill bit having improved hydraulic action for directing drilling fluid |
| 02/05/1991 | US4989578 Method for forming diamond cutting elements for a diamond drill bit |
| 02/05/1991 | CA1279866C Drill bit with covered ring nozzle retainer |
| 02/05/1991 | CA1279865C Percussive tool with high pressure fluid jet |
| 01/31/1991 | DE3924271A1 Drill bit with spiral thread - produces holes of greater dia. than drill chuck |
| 01/29/1991 | US4987800 Cutter elements for rotary drill bits |
| 01/23/1991 | EP0409446A1 Tool actuator |
| 01/23/1991 | EP0409387A1 Drill bit having improved hydraulic action for directing drilling fluid |
| 01/23/1991 | CN1011322B Erosion resistant rock drill bit |
| 01/23/1991 | CN1011321B Method of large diameter boring and drill head for directional enlarging |
| 01/22/1991 | US4986375 Device for facilitating drill bit retrieval |
| 01/22/1991 | US4986373 Post hole digger |
| 01/22/1991 | US4986368 Planting apparatus |
| 01/19/1991 | CA2019460A1 Rotary drill bits |
| 01/16/1991 | EP0408379A1 Improvements in drills |
| 01/15/1991 | US4984944 Drill bit blade for masonry and rock drill |
| 01/15/1991 | US4984643 Anti-balling earth boring bit |
| 01/15/1991 | US4984642 Composite tool comprising a polycrystalline diamond active part |
| 01/15/1991 | US4984488 Method of securing cutting elements on cutting tool blade |
| 01/12/1991 | CA2020781A1 Steerable earth boring device |
| 01/10/1991 | DE3920392A1 Verfahren zum abbau und zur foerderung einer unter wasser lagernden bodenschicht und vorrichtung zur durchfuehrung des verfahrens A method for degrading and foerderung a ground layer overlying underwater and apparatus for performing the method |
| 01/09/1991 | EP0406492A1 Method and apparatus for directional drilling using sonic energy |
| 01/08/1991 | US4982802 Method for stabilizing a rotary drill string and drill bit |
| 01/02/1991 | EP0406195A1 Tunnel boring machine |
| 01/02/1991 | CN2068578U Medium tooth ball drill |
| 01/02/1991 | CN2068577U Drill hole wall axial initial cut solid bot pick |
| 01/01/1991 | US4981328 Rotatable tool having a carbide insert with bumps |
| 01/01/1991 | US4981184 Diamond drag bit for soft formations |
| 01/01/1991 | US4981183 Apparatus for taking core samples |
| 01/01/1991 | US4981182 Sealed rotary blast hole drill bit utilizing air pressure for seal protection |
| 12/31/1990 | CA2020042A1 Tunnel boring machine |
| 12/26/1990 | CN2068143U Drill hole wall axial initial cut shank head |
| 12/20/1990 | DE3919894A1 Rotary boring device for concentric enlargement of boreholes - used for bored piles, in loose or cohesive soils |