Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B10/00—Drill bits
  • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
  • E21B10/58—Chisel-type inserts
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B10/00—Drill bits
  • E21B10/26—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B10/00—Drill bits
  • E21B10/36—Percussion drill bits
  • E21B10/38—Percussion drill bits characterised by conduits or nozzles for drilling fluids

Definitions

• the present invention relates generally to improvements in the art of rock drilling and; in particular, the present invention relates to an improved mining drill bit. Description of the Prior Art
• the mining drill bits disclosed in these patents are provided with some type of opening at the end of the drill bit which is disposed in communication with the hollow interior of the drill bit shaft for debris removal.
• bores are formed in the end of the drill bit on opposite sides of the cutter insert.
• the bores are of circular cross section and disposed at a predetermined angle with respect to the longitudinal cutting axis of the drill.
• the prior art drill bits require a number of cutting operations in order to form the finished product and are relatively expensive to manufacture.
• the present invention comprises a mining drill bit that has a circular body with a longitudinal bore extending in from one end while the other end defines the head of the drill bit and includes a pair of intersecting slots arranged diametrically transversely of the longitudinal axis of the body.
• One of the slots receives a cutting insert while the second slot, which is preferably disposed at an angle of about 20° to about 40° with respect to the first slot, provides a simple and efficient means of removing debris created as a result of the drilling operation. It is therefore an object of the present invention to provide a mining drill bit which obviates the disadvantages and objections of the prior art tools in that it is of a simple construction, inexpensive to manufacture and highly efficient in its use.
• FIG. 1 is an exploded, front elevational view of a mining drill bit constructed in accordance with the principles of the present invention
• FIG. 2 is a top elevational view of the mining drill bit as seen from line 2-2 in FIG. 1;
• FIG. 3 is a rear elevational view of the mining drill bit illustrated in FIG. 1 with the cutter insert removed for clarity; and ' FIG. 4 is a bottom elevational view of the mining drill bit as seen from line 4-4 of FIG. 3 and rotated 90°.
• FIGS. 5-8 are modifications of the drill bit of FIGS. 1-4 with corresponding views. DESCRIPTION OF THE PREFERRED EMBODIMENT
• the mining drill bit 10 is of a unitary - construction having a cylindrically shaped body 12 which in the example illustrated has a diameter of 1.25 inches and a longitudinal length of 2.2 inches.
• the lower or shank portion 14 of the cylindrical body 12 has a hexagonally shaped bore 16 that extends approximately 1.25 * inches into the interior of the body from the shank end 14 thereof.
• the bore 16 has a pair of longitudinally spaced undercuts 18 and 20 (FIG. 1), the purpose of which will be described hereinafter.
• the shank bore 16 is adapted to receive the tubular shaft 17 which rotatably drives the " mining drill bit 10.
• the mining drill bit 10 is secured to the tubular shaft 17 by means of a set screw or a clip (not shown) that extends through radial bore 22 (see FIGS. 3 and 4) and engages the tubular shaft 17 in the conventional manner.
• the head 24 of the mining drill bit 10 is slightly truncated and includes a first longitudinally transversely disposed slot 26 which is approximately .2 inches in width and extends the full diametrical width of the head 24.
• the slot 26 is approximately .56 inches in depth and is adapted to receive a cutting element or insert 28.
• the cutting element or insert 28 is conventional in its construction and is secured within the diametrical slot 26 in a suitable manner, such as by soldering, brazing or welding, so that the cutting element * 28 has a conventional impact portion extending above the head 24 of the mining drill bit 10.
• a copper or copper based alloy shim is utilized between insert 28 and slot 26.
• the mining drill bit 10 is further provided with a flushing opening, the placement and formation of the opening being extremely important in prolonging the life of the bit 10 and the cutting insert 28 carried thereby.
• a second diametrical slot 30 is formed in the head 24. As can best be seen in FIG.
• the slot 30 is approximately .25 inch wide, 1.00 inch deep and extends the full diametrical width of the cutting head 24 intersecting and passing through the cutting element slot 26 at an angle "A" between 32° and 38°, and preferably 35°.
• the slots 26 and 30 are simply formed by first cutting one diametrical slot in one pass over the head 24 of the bit 10 and then forming the second slot at the desired width and depth.
• This very simple construction and method of manufacture results in a drill bit which is substantially less expensive to manufacture than the prior art devices and provides excellent results in operation.
• debris and dust that is formed during the drilling operation will communicate with the tubular portion of the drive shaft 17 via the diametrical slot 30 and the interior of the bore of the shank bore 16.
• undercut or groove 18 is utilized to break metal chips of bit during broaching process. Bit 10 is held in place by retaining spring clip (not shown) fitting within groove 20.
• a vacuum may be applied to the opposite end of the drive shaft 17 to suck in through the transverse slot 30 and the shank bore 16 the dust-laden air and the like, thereby cleaning the drill hole at the cutter insert which results in a longer life for the insert and the mining drill bit 10.
• angle of the first and second slots range from about 20° to about 40" preferrably about 30° to about 40°.
• FIGS. 5-8 are modifications in the drill bit of
• FIGS. 1-4 with comparable views. It has been found that for ease of manufacturing the slots can be opened at the periphery 50, 50' of the drill bit as best shown in FIG. 6. This is best shown by comparing FIGS. 2 and 6.
• Another alternative to joining the body 12 to drill shaft 17 would be to threadingly engage the shaft by having female threads in the interior of the bit body 12.
• Another modification of the invention would be to have a 5/16" (0.79 cm) opening for the slot 30 for a 1"

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=24219495

Family Applications (1)

Country Status (8)

Cited By (9)

Citations (6)

• 1984
  • 1984-11-26 ZA ZA849207A patent/ZA849207B/xx unknown
  • 1984-11-28 KR KR1019840007447A patent/KR850004138A/ko not_active Application Discontinuation
  • 1984-11-29 EP EP85900342A patent/EP0163727A1/en not_active Withdrawn
  • 1984-11-29 AU AU37431/85A patent/AU3743185A/en not_active Abandoned
  • 1984-11-29 CA CA000468971A patent/CA1240311A/en not_active Expired
  • 1984-11-29 PL PL25063184A patent/PL250631A1/xx unknown
  • 1984-11-29 IT IT23810/84A patent/IT1178643B/it active
  • 1984-11-29 WO PCT/US1984/001949 patent/WO1985002442A1/en unknown

Patent Citations (6)

Also Published As

Similar Documents

Legal Events