CA1095890A - Rock drill with hard metal drilling head - Google Patents
Rock drill with hard metal drilling headInfo
- Publication number
- CA1095890A CA1095890A CA320,831A CA320831A CA1095890A CA 1095890 A CA1095890 A CA 1095890A CA 320831 A CA320831 A CA 320831A CA 1095890 A CA1095890 A CA 1095890A
- Authority
- CA
- Canada
- Prior art keywords
- drill
- shank
- rock drill
- rock
- drill according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000011435 rock Substances 0.000 title claims abstract description 43
- 238000005553 drilling Methods 0.000 title claims abstract description 24
- 239000002184 metal Substances 0.000 title claims abstract description 19
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 19
- 238000005520 cutting process Methods 0.000 claims abstract description 38
- 239000007787 solid Substances 0.000 claims abstract description 8
- 230000008901 benefit Effects 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 238000000227 grinding Methods 0.000 description 4
- 239000004566 building material Substances 0.000 description 2
- 239000004567 concrete Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000002787 reinforcement Effects 0.000 description 2
- 230000036346 tooth eruption Effects 0.000 description 2
- 230000001154 acute effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 239000011150 reinforced concrete Substances 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
Landscapes
- Processing Of Stones Or Stones Resemblance Materials (AREA)
- Drilling Tools (AREA)
- Earth Drilling (AREA)
Abstract
ABSTRACT
A rock drill for rotary blow drilling with a drilling head arrang-ed at the free end of the drill shaft, which at least partially consists of hard metal. The drilling head, the end face of which is of circular disc or ring shape, comprises a formed piece of solid hard metal. Cutting bodies machined out of the end face of this piece of hard metal have the shape of pyramids or truncated pyramids and taper with increasing distance from the drill shank.
A rock drill for rotary blow drilling with a drilling head arrang-ed at the free end of the drill shaft, which at least partially consists of hard metal. The drilling head, the end face of which is of circular disc or ring shape, comprises a formed piece of solid hard metal. Cutting bodies machined out of the end face of this piece of hard metal have the shape of pyramids or truncated pyramids and taper with increasing distance from the drill shank.
Description
~9~8~
The present invention relates to a rock drill for rotary blow drilling with a drill head located at the free end of the drill shank and at least partially consisting of hard metal.
Known rock drills of this type have hard metal plates extending diametrically inserted into the drill crown, the hard metal plates being ground roof-shaped along their longitudinal edge forming the end face of the drill crown. With these rock drills a separate centering drill is provided for centering the drill in the hole to be bored. In addition to two cutting edge drill crowns, cross bits are also known in which at the end face of the drill crown a total of four hard metal cutting edges are uniformly distributed over the end face and arranged in a cross shaped manner. However, experience has shown that with these known rock drills, a high driving power is required to obtain rapid progress of the drilling operation.
It is, therefore, an object of the present invention so to improve a rock drill of the above mentioned type that an increased drilling output can be obtained for the same amount of driving energy.
The invention provides a rock drill for rotary blow drilling comprising a chucking shank having a free end on which is located a drill shank having a drill head with an end face formed with cutting bodies shaped as pyramids arranged in a grid pattern, said drill head comprising a flat solid hard metal piece fastened to the end face of the drill shank, at least one B
conveying spiral being provided on the casing of the drill shank. Expediently, the pyramid shaped cutting bodies have acute angles of about from 50-90. In the end face, the cutting bodies form a grid pattern which -la-advantageously is designed eccentrically with regard to the drill axis. As a result thereof, the many small abrasive teeth are given the effect of an unequal tooth pitch. The advantage of this design, in addition to the above mentioned increased drilling output, is a considerably improved round-ness of the drilled bore and the capability to cut through the iron rein-forcement in reinforced concrete. Both advantages are particularly impor-tant in connection with the employment of plugs which are to be inserted into the finished drilled hole.
With a preferred embodiment of a rock drill according to the in-vention for a drill of diameter of more than 15 mm and a length-diameter ratio of more than 10:1, it is provided that the drill head is designed as annular solid hard metal tubular body the annular end face of which is ~;1 provided with the pyramid shaped cutting bodies in wa~r shaped arrangement Advantageously, in view of the grinding operation during which the cutting bodies are machined out of solid material, the cutting bodies are arranged uniformly with regard to each other in rows which extend eccentrically with regard to the drilling axis.
According to a further preferred feature of the invention, with a rock drill set forth above for increasing the drilling output it is also possible, to arrange a plurality of pyramidal cutting bodies distributed over the circumferential surface of the drill head. The rock drill accord-ing to the invention is provided for use in rotary blow machines and in drifters or stopers.
The objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing in which:
Figure 1 represents a first embodiment of a rock drill accor~;ng to the invention as seen from the side.
Figure 2 represents a view of the end face of the rock drill according to Figure 1.
Figure 3 is a longitudinal section through the rock drill of Fig-ure 1.
Figure 4 illustrates the portion encircled by a dot-dash circle X of Figure 1 but on an enlarged scale.
Figure 5 shows a portion located within the dot-dash circle Y of Figure 2 but on an enlarged scale.
Figure 6 shows a modification of the end face shown in Figure 2 of the drill of Figure 1.
Figure 7 is a side view of a second embodiment of a rock drill according to the invention.
Figure 8 shows the end face of the drill of Figure 70 Referring now to the drawings in detail, the rock drill illus-trated in Figures 1-5 is intended for rotary blow drilling for carrying out deep drilling in masonary or concrete, which drills have a diameter of more than 15 mm and a length-diameter ratio of greater than 10:1. The drill has a chucking shank 1 for connection in a rotary blow drill and in drifters or stopers. The drill shank 2 is, as shown in Figure 3 tubular and has its circumferential surface provided with a conveying spiral with a pitch angle of about 10 . The drill shank 2 at its free end face is fi,rmly connected to a solid hard metal cutting ring by hard solderingO The cutting ring 4 1~95~
has its end face (shown in Figure 2) provided with cutting bodies 5 designed as pyramids or truncated pyramids, these cutting bodies 5 being formed by grinding. The cutting bodies 5 as shown in Figure 4 are provided with tip angles ~ of from 40-90. The base lines 6 which are formed by grinding out the pyramidal cut-ting bodies 5 and which define square-shaped base surfaces of the cutting bodies, intersect at an angle ~. These cutting bodies are spaced at a distance a which determines the spacing of the grid pattern which is formed by the cutting bodies 5 and amounts to about 1-6 mm, preferably about from 3-4 mm. As is furthermore shown in Figure 2, the base lines 6 closest to the axis of rota-tion 7 of the drill are spaced therefrom, by a distance _ which determines the eccentricity of the grid pattern relative to the axis of rotation 7. Due to this eccentric arrangement of the grid pattern relative to the axis of rotation 7, the effect of an unequal tooth pitch is obtained even although all cutting bodies 5 are of equal size and accordingly are uniformly distributed over the end face of the drill crown.
The advantage of the design of the solid hard metal cutting ring 4 is seen in the fact that the illustrated drill, in contrast to the heretofore known drill crowns, requires no spec-ial centering drill but by means of longitudinal chisel blows of the driving machine (not shown), it is necessary only to drive a few millimeters deep, whereupon the rotary blow of the driving machine can be directly turned on. The drilling output of the rock drill according to the invention over heretofore known rock ~ -4-lO9S8~
drills, due to the rock diminution occurring at the end face only of said annular drill head is higher by about 30%
because with a progressing drill operation, 1~3 -4a-- 1~39S890 a drilling core remains standing just slightly less than the inner diameter d of the drill shank 20 Removal of the drill core from the drill shank is no problem whatsoever because upon separating the drill shank from the shank chucking part of the machine, the drill core can be removed toward the rear. In this connection, it is important that the clear pipe diameter within the region of the chucking shank is maintained.
The conveying spiral 3 designed in the form of a thread suffices for the drilling dust transport as has been proved by practical tests.
Additional withdrawal of the drilling dust is not necessary and it would appear from tests carried out so far, does not result in any material improvement in the drilling output.
With the illustrated embodiment, the connection between the drill shank and the chucking shank is established by the conveying spiral 3 which serves directly as a threaded connector, and after completion of drilling operations will permit the drill shank 2 to be separated from the chucking shank 1 merely by unscrewingO As shown in Figures 1 and 3, the conveying spiral 3 has only a small groove depth 8. In view of this small groove depth 8 of the conveying spiral, the axial radiation surfaces which are responsible for sound transmission with the longitudinal oscillation of the drill during the drilling process are very smallO Comparative noise measur-ing of a standard helical drill and a rock drill according to the invention shows a reduction in noise by from 10-15 dB.
This advantage of the reduced sound emission is due not only to the reduction in the radiation surfaces but is also due to the damping of high frequency bending vibrations which is made possible by the geometrically 5~
favorable cross section of the drill shank 2. A further material advantage of the drill consists in the possibility that in addition to the known building materials such as masonry and concrete, also additional wire re-inforcements embedded in the building material and having diameters up to 10mm can be cut through. This is achieved by the configuration of the cut-ting bodies in the hard metal cutting ring 4 because these cutting bodies due to their great number and uneven arrangement act like milling cuttersO
With a rock drill having its end face modified as shown in Fig-ure 6, the pyramidal cutting bodies have diamond-shaped bases. The base lines 6 defining the bases of the pyramidal cutting bodies 5 intersect each other at an angle ~ of 45 . Independently of the square or diamond shaped design of the base surface of the pyramidal cutting bodies 5, both embodi-ments provide that on the circumferential surface of the drill head 4 there are also numerous cutting teeth 9 machined out of the drill head, said cut-ting teeth 9 having a triangular cross section. With both embodiments of the drill head the solid hard metal cutting ring 4 is expediently, axially relieved on its inner diameter and/or outer diameter d by an angle ~ (see Figure 3) which may amount from 1-10 .
With both embodiments of the rock drills illustrated in Figures
The present invention relates to a rock drill for rotary blow drilling with a drill head located at the free end of the drill shank and at least partially consisting of hard metal.
Known rock drills of this type have hard metal plates extending diametrically inserted into the drill crown, the hard metal plates being ground roof-shaped along their longitudinal edge forming the end face of the drill crown. With these rock drills a separate centering drill is provided for centering the drill in the hole to be bored. In addition to two cutting edge drill crowns, cross bits are also known in which at the end face of the drill crown a total of four hard metal cutting edges are uniformly distributed over the end face and arranged in a cross shaped manner. However, experience has shown that with these known rock drills, a high driving power is required to obtain rapid progress of the drilling operation.
It is, therefore, an object of the present invention so to improve a rock drill of the above mentioned type that an increased drilling output can be obtained for the same amount of driving energy.
The invention provides a rock drill for rotary blow drilling comprising a chucking shank having a free end on which is located a drill shank having a drill head with an end face formed with cutting bodies shaped as pyramids arranged in a grid pattern, said drill head comprising a flat solid hard metal piece fastened to the end face of the drill shank, at least one B
conveying spiral being provided on the casing of the drill shank. Expediently, the pyramid shaped cutting bodies have acute angles of about from 50-90. In the end face, the cutting bodies form a grid pattern which -la-advantageously is designed eccentrically with regard to the drill axis. As a result thereof, the many small abrasive teeth are given the effect of an unequal tooth pitch. The advantage of this design, in addition to the above mentioned increased drilling output, is a considerably improved round-ness of the drilled bore and the capability to cut through the iron rein-forcement in reinforced concrete. Both advantages are particularly impor-tant in connection with the employment of plugs which are to be inserted into the finished drilled hole.
With a preferred embodiment of a rock drill according to the in-vention for a drill of diameter of more than 15 mm and a length-diameter ratio of more than 10:1, it is provided that the drill head is designed as annular solid hard metal tubular body the annular end face of which is ~;1 provided with the pyramid shaped cutting bodies in wa~r shaped arrangement Advantageously, in view of the grinding operation during which the cutting bodies are machined out of solid material, the cutting bodies are arranged uniformly with regard to each other in rows which extend eccentrically with regard to the drilling axis.
According to a further preferred feature of the invention, with a rock drill set forth above for increasing the drilling output it is also possible, to arrange a plurality of pyramidal cutting bodies distributed over the circumferential surface of the drill head. The rock drill accord-ing to the invention is provided for use in rotary blow machines and in drifters or stopers.
The objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing in which:
Figure 1 represents a first embodiment of a rock drill accor~;ng to the invention as seen from the side.
Figure 2 represents a view of the end face of the rock drill according to Figure 1.
Figure 3 is a longitudinal section through the rock drill of Fig-ure 1.
Figure 4 illustrates the portion encircled by a dot-dash circle X of Figure 1 but on an enlarged scale.
Figure 5 shows a portion located within the dot-dash circle Y of Figure 2 but on an enlarged scale.
Figure 6 shows a modification of the end face shown in Figure 2 of the drill of Figure 1.
Figure 7 is a side view of a second embodiment of a rock drill according to the invention.
Figure 8 shows the end face of the drill of Figure 70 Referring now to the drawings in detail, the rock drill illus-trated in Figures 1-5 is intended for rotary blow drilling for carrying out deep drilling in masonary or concrete, which drills have a diameter of more than 15 mm and a length-diameter ratio of greater than 10:1. The drill has a chucking shank 1 for connection in a rotary blow drill and in drifters or stopers. The drill shank 2 is, as shown in Figure 3 tubular and has its circumferential surface provided with a conveying spiral with a pitch angle of about 10 . The drill shank 2 at its free end face is fi,rmly connected to a solid hard metal cutting ring by hard solderingO The cutting ring 4 1~95~
has its end face (shown in Figure 2) provided with cutting bodies 5 designed as pyramids or truncated pyramids, these cutting bodies 5 being formed by grinding. The cutting bodies 5 as shown in Figure 4 are provided with tip angles ~ of from 40-90. The base lines 6 which are formed by grinding out the pyramidal cut-ting bodies 5 and which define square-shaped base surfaces of the cutting bodies, intersect at an angle ~. These cutting bodies are spaced at a distance a which determines the spacing of the grid pattern which is formed by the cutting bodies 5 and amounts to about 1-6 mm, preferably about from 3-4 mm. As is furthermore shown in Figure 2, the base lines 6 closest to the axis of rota-tion 7 of the drill are spaced therefrom, by a distance _ which determines the eccentricity of the grid pattern relative to the axis of rotation 7. Due to this eccentric arrangement of the grid pattern relative to the axis of rotation 7, the effect of an unequal tooth pitch is obtained even although all cutting bodies 5 are of equal size and accordingly are uniformly distributed over the end face of the drill crown.
The advantage of the design of the solid hard metal cutting ring 4 is seen in the fact that the illustrated drill, in contrast to the heretofore known drill crowns, requires no spec-ial centering drill but by means of longitudinal chisel blows of the driving machine (not shown), it is necessary only to drive a few millimeters deep, whereupon the rotary blow of the driving machine can be directly turned on. The drilling output of the rock drill according to the invention over heretofore known rock ~ -4-lO9S8~
drills, due to the rock diminution occurring at the end face only of said annular drill head is higher by about 30%
because with a progressing drill operation, 1~3 -4a-- 1~39S890 a drilling core remains standing just slightly less than the inner diameter d of the drill shank 20 Removal of the drill core from the drill shank is no problem whatsoever because upon separating the drill shank from the shank chucking part of the machine, the drill core can be removed toward the rear. In this connection, it is important that the clear pipe diameter within the region of the chucking shank is maintained.
The conveying spiral 3 designed in the form of a thread suffices for the drilling dust transport as has been proved by practical tests.
Additional withdrawal of the drilling dust is not necessary and it would appear from tests carried out so far, does not result in any material improvement in the drilling output.
With the illustrated embodiment, the connection between the drill shank and the chucking shank is established by the conveying spiral 3 which serves directly as a threaded connector, and after completion of drilling operations will permit the drill shank 2 to be separated from the chucking shank 1 merely by unscrewingO As shown in Figures 1 and 3, the conveying spiral 3 has only a small groove depth 8. In view of this small groove depth 8 of the conveying spiral, the axial radiation surfaces which are responsible for sound transmission with the longitudinal oscillation of the drill during the drilling process are very smallO Comparative noise measur-ing of a standard helical drill and a rock drill according to the invention shows a reduction in noise by from 10-15 dB.
This advantage of the reduced sound emission is due not only to the reduction in the radiation surfaces but is also due to the damping of high frequency bending vibrations which is made possible by the geometrically 5~
favorable cross section of the drill shank 2. A further material advantage of the drill consists in the possibility that in addition to the known building materials such as masonry and concrete, also additional wire re-inforcements embedded in the building material and having diameters up to 10mm can be cut through. This is achieved by the configuration of the cut-ting bodies in the hard metal cutting ring 4 because these cutting bodies due to their great number and uneven arrangement act like milling cuttersO
With a rock drill having its end face modified as shown in Fig-ure 6, the pyramidal cutting bodies have diamond-shaped bases. The base lines 6 defining the bases of the pyramidal cutting bodies 5 intersect each other at an angle ~ of 45 . Independently of the square or diamond shaped design of the base surface of the pyramidal cutting bodies 5, both embodi-ments provide that on the circumferential surface of the drill head 4 there are also numerous cutting teeth 9 machined out of the drill head, said cut-ting teeth 9 having a triangular cross section. With both embodiments of the drill head the solid hard metal cutting ring 4 is expediently, axially relieved on its inner diameter and/or outer diameter d by an angle ~ (see Figure 3) which may amount from 1-10 .
With both embodiments of the rock drills illustrated in Figures
2 and 6, the cutting ring width b may amount to from 1.1 to 2.0 times the ~}7il p~
B wall thickness W. The above mentioned eccentricity e of the rlstor fiold relative to the axis of rotation 7 of the drill expediently amounts to from Oo1 to 0.9 of the raster spacing a preferably about equal e=005 x a.
The rock drill illustrated as a further embodiment in Figures 7 and 8 is preferably employed for making drill holes of less than 20mm 1t~95~9~
outer diameter, and has a drill shank 12 which is integral with a slightly conical chuck shank 11. The drill shank 12 may be designed as a single or double thread helix. A drilling head 14 which when seen in top view is circular disc shaped and is soldered onto the free end face of the shank.
This drilling head 14 is designed as solid metal full circular disc and at its end face free carries numerous pyramidal cutting bodies 15 machined by grinding from the hard metal disc and which respectively have square shaped base surfaces.
The important advantage of this tool becomes particularly evident when employing the tool for dowel art and is that the prepared drilling hole has a considerably improved roundness, and that in addition it is possible without difficulty to cut through iron reinforcement having a thickness of up to lOmmO
It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawing but also comprises any modifications within the scope of the appended claimsO
B wall thickness W. The above mentioned eccentricity e of the rlstor fiold relative to the axis of rotation 7 of the drill expediently amounts to from Oo1 to 0.9 of the raster spacing a preferably about equal e=005 x a.
The rock drill illustrated as a further embodiment in Figures 7 and 8 is preferably employed for making drill holes of less than 20mm 1t~95~9~
outer diameter, and has a drill shank 12 which is integral with a slightly conical chuck shank 11. The drill shank 12 may be designed as a single or double thread helix. A drilling head 14 which when seen in top view is circular disc shaped and is soldered onto the free end face of the shank.
This drilling head 14 is designed as solid metal full circular disc and at its end face free carries numerous pyramidal cutting bodies 15 machined by grinding from the hard metal disc and which respectively have square shaped base surfaces.
The important advantage of this tool becomes particularly evident when employing the tool for dowel art and is that the prepared drilling hole has a considerably improved roundness, and that in addition it is possible without difficulty to cut through iron reinforcement having a thickness of up to lOmmO
It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawing but also comprises any modifications within the scope of the appended claimsO
Claims (20)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A rock drill for rotary blow drilling comprising a chucking shank having a free end on which is located a drill shank having a drill head with an end face formed with cutting bodies shaped as pyramids arranged in a grid pattern, said drill head comprising a flat solid hard metal piece fastened to the end face of the drill shank, at least one conveying spiral being provided on the casing of the drill shank.
2. A rock drill according to claim 1, in which said cutting bodies have a tip angle of from 50° to 90°.
3. A rock drill according to claim 1 in which the base surface, of said pyramidal cutting bodies are diamond-shaped.
4. A rock drill according to claim 3 wherein said base surfaces have minor angles of 45°.
5. A rock drill according to claim 1, in which adjacent pyramidal cutting bodies have a grid spacing therebetween amounting to from 1 to 6 mm.
6. A rock drill according to claim 5, in which grid pattern formed by said cutting bodies is symmetrical with respect to the axis of rotation of said drill.
7. A rock drill according to claim 5, in which the grid pattern of said cutting bodies is arranged eccentrically with regard to the axis of rotation of said drill, the eccentricity amounting to from 0.1 to 0.9 times the grid spacing.
8. A rock drill according to claim 5, in which the grid pattern of said cutting bodies is arranged eccentrically with regard to the axis of rotation of said drill, the eccentricity amounting to substantially 0.5.
9. A rock drill according to claim 1, in which said drill shank is tubular.
10. A rock drill according to claim 1, 2 or 3 in which said drill head is in the form of an annular disc.
11. A rock drill according to claim 10, in which the ratio of the wall thickness of said drill shank to the outer diameter of said drill shank amounts to from 1:5 to 1:10.
12. A rock drill according to claim 1, in which said con-veying spiral is in the form of a rectangular screw thread.
13. A rock drill according to claim 12, in which the conveying spiral has a pitch of about 10 mm.
14. A rock drill according to claim 12, in which the conveyor spiral provides a threaded connection between said drill shank with said chucking shank.
15. A rock drill according to claim 14, in which the drill shank is provided with a through-bore is detachably con-nected to said chucking shank.
16. A rock drill according to claim 1, in which said drill head is annular and has a radial width of from 1.1 to 2 times the wall thickness of said drill shank.
17. A rock drill according to claim 16, in which the width of said annular drill head amounts to from 1 to 2 times the grid spacing.
18. A rock drill according to claim 16 or 17 in which said annular drill head has an inner mantle and an outer mantle, and in which at least one of said mantles is axially relief ground by an angle .alpha. of from 1 to 10 .
19. A rock drill according to claim 1, 2 or 3 in which the circumferential surface of said drill head is provided with pyramidal cutting bodies machined out of the hard metal of said drill head.
20. A rock drill according to claim 1, 2 or 3 in which said hard metal drill head is hard soldered to said drill shank.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA320,831A CA1095890A (en) | 1979-02-05 | 1979-02-05 | Rock drill with hard metal drilling head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA320,831A CA1095890A (en) | 1979-02-05 | 1979-02-05 | Rock drill with hard metal drilling head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1095890A true CA1095890A (en) | 1981-02-17 |
Family
ID=4113456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA320,831A Expired CA1095890A (en) | 1979-02-05 | 1979-02-05 | Rock drill with hard metal drilling head |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1095890A (en) |
-
1979
- 1979-02-05 CA CA320,831A patent/CA1095890A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4202420A (en) | Rock drill with hard metal drilling head | |
| JPH086865Y2 (en) | Drill for rock drill | |
| US4951761A (en) | Rock drill | |
| KR100694578B1 (en) | Milling tool and its manufacturing process | |
| US4189266A (en) | Rotary drill bit for hand-held power drills | |
| US5553682A (en) | Rock drill | |
| US4645389A (en) | Multiple-tooth drill bit | |
| US4667755A (en) | Drill bit having hollow cylindrical body and a plurality of PCD cutting elements | |
| US7137462B2 (en) | Drill bit | |
| EP0468515B1 (en) | Excavation tool | |
| US4106578A (en) | Percussion drill bit | |
| US6675917B2 (en) | Twist drill bit for rock drilling | |
| US3400617A (en) | Drill bit tip | |
| EP1275457B1 (en) | Drill bit | |
| US6032750A (en) | Drilling tool having a drill bit with primary and secondary cutting edges | |
| CA1095890A (en) | Rock drill with hard metal drilling head | |
| US6571890B2 (en) | Twist drill | |
| KR20030038531A (en) | Indexable drill and cutting inserts therefor | |
| SU1778264A1 (en) | Impregnated drilling bit | |
| US2876995A (en) | Percussion drills | |
| SU1620588A1 (en) | Bit for rotary drilling | |
| US3534971A (en) | Boring tool | |
| EP0350526B1 (en) | Non-core drill | |
| JP3122080B2 (en) | Drill bit | |
| SU1668620A1 (en) | Rotary drilling bit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |