JP5329657B2 - Rock drilling device, drill bit changing device and drill bit changing method - Google Patents

Description

Background of the Invention

  The present invention relates to a drill bit changing device, whereby a drill bit of a tool connected to a rock drill can be changed. The drill bit changer has a magazine in which the drill bit to be changed is stored. The exchange device further comprises a transfer device, whereby the drill bit is fed from the magazine to the drilling center and back.

  Furthermore, the present invention relates to a rock drilling apparatus equipped with such a drill bit exchanging apparatus and a method for exchanging a drill bit.

  The subject matter of the present invention is explained in more detail in the preamble of the independent claims of this application.

  In rock drilling, a rock drill is used with a tool connected to it, but the tool is rotated about its longitudinal axis and an impact pulse is sent to the rock drilled through the tool. Breaks and perforations are formed. The tool may have one or more drill bits and a replaceable drill bit connected to its outermost end. Typically, the tip of the drill bit is equipped with a plurality of bit buttons that penetrate the rock to be drilled. The drill bit, on the other hand, is so heavily loaded during drilling that it wears and sometimes gets damaged. Therefore, it is necessary to change drill bits from time to time to ensure drilling quality and efficiency. Manual drill bit replacement by the operator is difficult, slow and even dangerous for the worse. Accordingly, drill bit changers have been developed to mechanize the exchange of drill bits. However, current schemes do not fully satisfy user requirements.

  U.S. Pat. No. 4,065,845 discloses a drill bit changer that stores a drill bit in a space in the magazine, but the magazine limits the shape and dimensions of the drill bit. In addition, the changer is equipped with its own retainer with a hydraulic cylinder that presses the drill bit against the magazine. This causes an extra load on the magazine.

BRIEF DESCRIPTION OF THE INVENTION

  It is an object of the present invention to obtain a new and improved rock drilling device and drill bit changer. Another object is to provide a new and improved drill bit replacement method.

  In the rock drilling apparatus of the present invention, the drill bit exchanging device is disposed on the retainer fixed to the feed beam, and the drill bit is held by the retainer when the connecting screw portion of the drill bit is turned to open and close. It is characterized by being arranged.

  The exchange device according to the invention is characterized in that the drill bit is arranged in a standard retainer fixed to the feed beam.

  The method of the present invention uses a retainer fixed to the feed beam and having a fixed position in the longitudinal direction of the feed beam to hold the drill bit, and uses a drill bit changer provided on the retainer and having a magazine and a transfer device. It is characterized by handling drill bits.

  The idea of the invention is that the drill bit changer is not equipped with its own retainer, but the changer is arranged on the basic retainer of the rock drilling device, whereby the drill bit is held by a standard retainer. The basic retainer is fixed to the feed beam and its position is fixed in the longitudinal direction of the feed beam.

  The present invention provides the advantage that the drill bit changer does not have its own separate retainer and that a standard retainer can be used in the present invention. Therefore, the structure of the exchange device is simple and can be attached to a feed beam equipped with various retainers, and even to a feed beam equipped with an existing basic retainer. In addition, since the load is not generated by the operation of the retainer with respect to the magazine, the magazine can be made relatively light in structure.

  The concept of one embodiment is that the relative position of the longitudinal retainer and magazine of the feed beam is constant during operation of the rock drilling device. Furthermore, the transfer device is arranged to transfer the drill bit between the magazine and the drilling center in the transverse direction of the feed beam. The advantage of this embodiment is that the movement of the exchange device is simple. In addition, if the transfer device's transfer motion is in the transverse direction of the feed beam, the change device is when the tip of the feed beam is in contact with the rock, or in the vicinity of some other obstacle in front of the feed beam Sometimes it can be used.

  The concept of one embodiment is that the drill bit to be replaced is always placed at a predetermined axial position in the drilling center before the drill bit is gripped by the retainer. In this way, the position where the drill bit is gripped can be selected.

  The concept of one embodiment is that the retainer jaws grip the outer surface of the drill bit frame to be replaced at a predetermined distance from the working portion at the front of the drill bit. In this way, it is possible to ensure that the retainer does not damage the important tip of the drill bit in any state. In addition, gripping the frame portion ensures that the drill bit is straight between the jaws, which allows the drill rod and drill bit to be connected without difficulty.

  The concept of one embodiment is that the rock drilling device has at least one mechanical stop member against which the drill bit is arranged to be pressed before the drill bit is gripped by the retainer jaws. There is to be. The stop member may be provided at a predetermined axial distance from the jaws before the retainer jaws.

  The concept of one embodiment is that the stop member is a slide part. The stop member is arranged to move in the transverse direction of the drilling center by at least one actuator. The advantage of the slide is that its axial dimensions can be very small. In addition, the slide can be supported firmly.

  The concept of one embodiment is that the connecting hole in the drill bit is affected during transport and storage. As a result, the appearance and outer dimensions of the drill bit do not affect the handling device.

  The concept of one embodiment is that separate drill bit holders are disposed inside each drill bit during transport and storage. The drill bit holder is a kind of independent adapter for transport and storage and can be easily replaced. Further, the drill bit holder can be adjustable to fit various sized drill bits.

  The concept of one embodiment is that the drill bit holder has an arm and a gripping part at a part of the first end, and a gripping member of the transfer device can be connected to the gripping part. The drill bit holder can be easily attached to and detached from the magazine.

  The concept of an embodiment is that the drill bit holder has at least two support parts, which are arranged to support themselves with the connecting thread of the drill bit. The spacing between the support parts can be adjusted according to the size of the respective drill bit handled.

  The concept of one embodiment is to simultaneously store and handle at least two different drill bits with different outside dimensions or shapes by means of a drill bit changer. As a result, a wide variety of drill bits can be stored in the magazine even for special drilling situations.

  The concept of one embodiment is that the transfer device is arranged to transfer the drill bit using only linear motion.

  The concept of an embodiment is that the transfer device has at least one first transfer device for transferring the drill bit laterally from the magazine to the drilling center and back. The transfer device has at least one second transfer device for transferring the drill bit in the axial direction of the drilling center. At this time, the magazine and the retainer may be in various positions as viewed in the axial direction.

  The concept of one embodiment is that the magazine is placed in a coaxial position with the retainer so that the exchanged drill bit is transferred from the magazine to the retainer using only one linear movement of the transfer device. It is to arrange to do. At this time, the drill bit is fixed at a desired position in the jaw of the retainer and does not need to be arranged with movement in the direction of the drilling center portion with respect to the stop member. Instead, the drill bit to be removed from the drill rod is placed against the stop member by the feeder prior to being gripped by the jaws, and the drill bit is placed in the correct axial position for transfer. It is easy to measure an accurate and simple linear transfer movement between the magazine and the retainer. The transfer device may have a first transfer device and a second transfer device. The first transfer device may be for transverse transfer movements and the second transfer device may be arranged to move the pin-shaped drill bit holder into and out of the drill bit.

  The concept of one embodiment is that the magazine has a disk-like structure that can rotate about a rotation axis. The magazine may have a plurality of retaining holes for drill bit holders. The magazine may further have one exchange station, and each fixing hole may be directed to the exchange station.

  The concept of one embodiment is that the retainer has at least two jaws arranged to press the outer surface of the drill bit from both sides.

Several embodiments of the present invention will be described in further detail with reference to the accompanying drawings.
It is a schematic side view of a rock drilling rig having a drilling device equipped with a retainer and a drill bit exchanging device connected to the retainer. Or FIG. 2 is a schematic perspective view of a drill bit, and FIG. 2b also shows gripping of a hole in the drill bit. It is the schematic which looked at the retainer and the magazine connected to this from the front-end | tip part of a feed beam. It is the schematic which looked at the structure of the drill bit exchange apparatus and the stop apparatus from the front-end | tip of a feed beam. It is a schematic top view which shows the structure and operation | movement of a drill bit exchange apparatus in addition to a retainer. In these figures, some embodiments of the invention are simplified for clarity. In the drawings, similar parts are denoted by the same reference numerals.

Detailed Description of the Invention

  A rock drilling rig 1 shown in FIG. 1 has a movable carrier 2, and includes one or more drilling booms 3 on the movable carrier 2, and the drilling booms 3 have drilling devices 4 at their outermost ends. ing. The drilling device 4 comprises a feed beam 5, which supports a rock drill 6 that can be moved in the drilling direction A and in the reverse direction B by the feed device 7. In the figure, a broken line indicates a perforation line, that is, a perforation center portion C. The rock drill 6 may have an impact device 8 that applies an impact pulse to the tool 9 connected to the rock drill 6. Further, the rock drill 6 may have a rotating device 10 that rotates the tool 9 about its longitudinal axis. During drilling, the tool 9 is in the drilling center C and may comprise a drill rod 11 having a replaceable drill bit 12 at its outermost end. Furthermore, in drilling known as extension rod drilling, a plurality of drill rods 11 are connected in series to drill deep holes 13. When drilling the rock mass, the bit button of the drill bit 12 or the corresponding rock cutting part can be worn and damaged, so that the drill bit 12 is replaced during drilling. In addition, rock drilling and drilling quality can be improved with different special bits for different drilling situations and different drilling conditions. The drill bit 12 is typically connected to the drill rod 11 by a screw connection.

  At the distal end of the feed beam 5, that is, at the outermost end of the feed beam 5 when viewed in the drilling direction A, there is a retainer 14 having a jaw or a corresponding holding member. At least when the screw connection portion between the drill rod 11 and the drill bit 12 is opened and closed by the rotating device 10 of the rock drill 6, it can be held so as not to move. The retainer 14 is placed so that the held tool 9 is located at the drilling center C. The retainer 14 is typically used to hold the drill rod 11 when the drill rod 11 is replaced or continuously connected into one extension rod assembly. In the present invention, the retainer 14 is also used for replacing the drill bit 12. The basic retainer 14 is fixed to the feed beam 5 and forms part of the feed beam 5. Thus, the position of the retainer 14 on the feed beam 5 remains unchanged during operation of the drilling device. Such a structure of the retainer 14 can be robust and can simplify the movement required for its operation. The structure of the retainer 14 may be constructed in various ways.

  A drill bit exchanging device 15 is also disposed on the tip of the feed beam 5 so as to be connected to the retainer 14. The drill bit changer 15 has a magazine 16 in which a required number, typically 5 to 10 drill bits, can be stored. The magazine 16 may have a rotating disk shape, in which a space for storing the drill bit 12 is created. Alternatively, the magazine 16 may be a chain magazine or other suitable structure. The drill bit changer 15 may further comprise one or more stop members 17 that can mechanically stop the drill bit 12 at a predetermined axial position in the drilling center C. it can. The stop member 17 can be a slide, for example, and the slide can be pushed into the drilling center C from the front side of the retainer 14. Before the drill bit 12 is fixed by the retainer 14 for replacement. Still further, the drill bit changer 15 has one or more transfer devices 18 by which the drill bit 12 can be transferred from the magazine 16 to the retainer 14 or vice versa. However, the exchange device 15 does not have its own retainer. This is because the concept is to use the basic retainer 14 already on the feed beam 5.

  2a to 2c show various drill bits 12. As can be seen from these figures, the drill bit 12 is completely different externally. The drill bit 12 of FIG. 2a has a spiral groove 19 on the outer periphery of the frame portion 12a, whereas in the drill bit 12 of FIG. 2b, the frame portion 12a is a smooth cylinder. Further, in FIG. 2c, the frame portion 12a is provided with a shoulder 20 with a groove. Since the appearances of the various drill bits 12 can be quite different from each other, it is difficult to handle the drill bits 12 with their frame portions 2a, and it is required to create a free gripping portion or the like. On the other hand, it is necessary to avoid gripping the distal end portion or the mechanism portion 12b at the distal end of the drill bit 12. This is because it is the most important part of the drill bit and is equipped with a hard but fragile drill button 21. However, the drill bit 12 is handled by a suitable pin-shaped drill bit holder 22 that can be pushed into the hole 23 in the drill bit frame 12a, which is arranged to properly receive the connection of the drill rod 11. Can do. Since there is such each drill bit holder 22, even if the drill bit 12 is in the magazine 16 or is being transferred, it can be handled without fear of damaging the mechanism portion 12b. . It should be noted that the positioning of the drill bit 12 relative to the stop member 17 at the front of the retainer 14 is controlled and performed at a sufficiently slow movement speed. In addition, the load acting on the drill bit 12 is applied in the drilling direction A, ie in the same direction as during normal drilling. Therefore, the drill bit 12 and the steel button 21 are not damaged even if positioning is performed on a physical obstacle.

  FIG. 3 shows a very simplified structure and operation of the retainer 14 and the drill bit changer 15 arranged at the tip of the feed beam 5. The retainer 14 may have an arm 24 with a holding jaw 25 or equivalent. These arms 24 can be rotated relative to the rotary shaft 26 using an actuator 27 which can be, for example, a pressure medium cylinder. In the state of FIG. 3, the jaw 25 is in an open state, and the exchanged drill bit 12 is conveyed from the magazine 16 to the center of the drilling hole by the transfer device 18 and pressed against the mechanical stop member 17 of the stop device 28. Has been placed. Stop device 28 may include a pressure medium cylinder, or other suitable actuator, by which stop member 17 can be transported in the transverse direction D to and away from the drilling center. If the drill bit 12 to be replaced is at a predetermined axial position in the center of the drilling, the jaw 25 may be closed. The transfer device 18 can then be transferred away from the drilling center and the drill rod can be connected to the held drill bit.

  FIG. 3 also shows that the magazine 16 may be a disk or rotating device that can be rotated about a rotating shaft 29 to select the required drill bit 12. The magazine 16 may also be provided with a fixing point 30 such as a hole or the like, for example, where the drill bit holder 22 shown in FIGS. 2b and 5 may be arranged. FIG. 3 further shows that the exchange device 15 may be provided with its own frame 31 to support the magazine 16, the stop device 28 and the transfer device 18. Further, the exchange device 15 may be firmly fixed to the feed beam 5 with a rigid fastener.

  FIG. 4 shows another scheme, where the stop member 17 is a slide and the stop device 28 has a frame 32 with a control surface 33 that controls the movement of the slide in the transverse direction D to the center of the drilling. . Further, the actuator 34 of the stop device 28 may be a motor arranged to move the slide by a gear transmission, for example. The advantage of the slide-type stop device is that it takes a little space in the axial direction and is easy to arrange on the front side of the retainer 14.

  FIG. 5 shows another drill bit changer 15 disposed on the retainer 14. The exchange device 15 may have a transfer device 18 which is a kind of manipulator. The transfer device 18 may have a first transfer device 18a and a second transfer device 18b that are connected to each other by a fastening part 35. The first transfer device 18a is arranged so that the second transfer device 18b and the gripping member 36 connected thereto can be moved linearly in the transverse direction E, and the drill bit 12 is located between the magazine 16 and the jaw 25 of the retainer 14. So that it can be transported. The second transfer device 18b is arranged to move the drill bit holder 22 into and out of the hole 23 of the drill bit. The drill bit holder 22 is an elongated part, and the first end thereof may have a gripping portion 38, and the gripping member 36 of the transfer device 18 is attached to the gripping portion 38. The drill bit holder 22 is fixed to the magazine 16 by 38. Furthermore, the drill bit holder 22 may have one arm, in which two or more support parts 40a and 40b are arranged on the arm and the support parts are inside the hole 23 of the drill bit 12. It is dimensioned to support itself with the connecting screw portion 41. Further, the rearmost first support member 40a may include a shoulder 46, a flange, or the like that supports the drill bit 12 in the axial direction and supports the drill bit 12 in the axial direction. When the drill bit holder 22 is pushed into the hole 23 by the second transfer device 18b, the first support part 40a contacts the rear part of the drill bit 12 and is fixed, but is firmly connected to the arm 39. The support part 40b can be further advanced toward the tip of the drill bit 12. As a result, the support parts 40a and 40b are fixed at a fixed distance from each other, whereby the drill bit 12 is firmly supported by both sides of the hole 23. The spaced apart support parts 40a and 40b ensure that the drill bit 12 is kept straight. The bit holder 22 may have an adjustment member 45 such as an adjustment screw, and the adjustment member 45 can adjust the maximum distance in the direction H between the support components 40a and 40b. At the same time, the adjustment member 45 affects the spacing in the direction H between the gripping portion 38 and the first support component 40a. Since the drill bit 12 is supported by the shoulder 46 at the rear portion thereof, the tip end portion of the drill bit 12 having various lengths can be set at the same position in the magazine 16 by adjusting the drill bit holder 22. When the magazine is disposed in the axial direction in the retainer 14 and the tip of the drill bit 12 is disposed horizontally in the magazine 16, the transfer between the magazine 16 and the retainer 12 can be performed simply by the first transfer device 18a. This can be done by a lateral linear motion E.

  When the drill bit 12 is pressed between the jaws 25, the second transfer device 18b is used to pull the drill bit holder 22 backwards, i.e. in the reverse direction B, so that the support parts 40a, 40b are Touch each other and exit through hole 23. Next, the drill bit holder 22 is transferred away from the drilling center C by the first transfer device 18a, the drill rod 11 is connected to the drill bit 12, and then the stop member 17 and the jaw 25 are opened. Then normal drilling can be started. The drill bit holder 22 is removed from the drill bit 12 before being connected to the drill rod 11, so that the drill rod holder 22 is not involved in the actual tightening of the drill bit 12, but is an auxiliary instrument during transport and storage Work as. Therefore, the drill bit holder 22 is not connected to the tool during drilling.

  FIG. 5 shows that the jaws 25 of the retainer 14 can be arranged on the piston rod 42 of the pressure medium cylinder acting as the actuator 34, which can greatly simplify the structure of the retainer 14. The jaw 25 can move in the transverse direction J. The jaw 25 presses the frame 12a of the drill bit on both sides. The drill bit mechanism 12b does not receive the force generated by the retainer. When the drill bit 12 is gripped by the jaws 25 in the frame portion 12a, the drill bit 12 is more appropriately kept parallel to the drilling center portion C, thereby facilitating the connecting operation.

  FIG. 5 further shows that the drill rod 11 is transferred in the reverse direction B at the drilling center C during the exchange of the drill bit 12. A connecting portion 43 with a connecting screw portion 44 is provided at the tip of the drill rod 11, and the connecting screw portion 44 sends the drill rod 11 in the drilling direction and at the same time the drill rod 11 is rotated by the rotating device 10 of the rock drill 6. By rotating about its longitudinal axis, it can be connected to the internal thread of the drill bit 12 in the retainer 14. When the drill bit 12 connected to the drill rod 11 is removed, the stop member 17 is closed and the drill bit 12 is pressed against the stop member 17. In this way, the drill bit 12 is always correctly positioned with respect to the transfer device 18 and the retainer 14.

  It should be noted that the support parts 40a, 40b of the drill bit holder 22 are provided with means for gripping the hole 23 of the drill bit so that the drill bit 12 can be removed from the holder 22 even if the feed beam 5 is directed downward. It can be prevented from coming off. Support components 40a and 40b may include friction components such as retaining rings made of rubber or similar elastic material. Further, the drill bit holder 22 may include an expanding portion that expands under the influence of a pressure medium or mechanical motion and presses the inner surface of the hole 23 of the drill bit 12.

  It is also possible to position the drill bit 12 in the retainer 14 in some way other than by the stop device 28 shown in FIGS. For example, a sensor may be provided to monitor the axial position of the drill bit 12 in the drilling center C, thereby moving the drill bit 12 to the correct position based on data received from the sensor. However, the stopping of the drill bit for mechanical obstacles as described in FIGS. 3 to 5 is simple in construction, reliable and does not require precise control of the feeder 7.

  In some cases, the features described herein can be used by themselves regardless of other features. On the other hand, the features described in this application can be combined to provide various combinations as needed.

The drawings and the associated description are only intended to illustrate the concept of the invention. The invention may vary in detail within the scope of the claims.

Claims (15)

A feed beam,
And a rock drilling machine,
A feed equipment to move the rock drill machine drilling lateral leaps and to Gyakukata direction on the feed beam,
And Retail Na position when viewed from the longitudinal direction of at least the feed beam is secured in the fixed to the feed beam, a distal end portion of the feed beam,
Magazine storing Dorirubi' bets, and the Dorirubi' bets and a drill bit replacement equipment having a transfer equipment for transferring between the magazine and drilling center,
The drill bit replacement equipment is disposed at retail Na which is fixed to the feed beam,
The Dorirubi' DOO, in rock drilling apparatus is arranged such that the are in retail Na Accordingly retained when to open and close by turning the connecting screw portion between the Dorirubi' The reserve and Doriruro' de,
The relative position in the longitudinal direction of the feed beam of the retail Na and magazines are unchanged during operation of該削rock device,
The transfer equipment is the rock drilling apparatus characterized by being arranged to transfer the transverse direction of the beam feeding the Dorirubi' bets. The rock drilling device according to claim 1,
The retail Nah, rock drilling apparatus comprising at least two jaw over which is arranged to press the outer surface of the Dorirubi' bets. The rock drilling device according to claim 2 ,
The rock drilling device includes at least one openable and closable stop member, the drill bit being arranged to be pressed against the stop member before being gripped by the jaws of the retainer;
The rock drilling device according to claim 1, wherein the stop member is disposed at a predetermined axial distance from the jaw before the jaw of the retainer. The rock drilling device according to claim 3,
It said stop member is a rock drilling apparatus, characterized in that the slide part being arranged to move in the transverse Direction of the at least one actuator thus said perforations center. In rock drilling apparatus according to any one of 請 Motomeko 1 to 4,
The drill bit replacement equipment including said Dorirubi' separate drill bit Hol da plurality of possible support to the inner surface of the bets to be handled,
Each Dorirubi' metropolitan rock drilling apparatus, characterized in that during storage and transport are connectable to the drill bit Hol da. The rock drilling device according to claim 5,
Said drill bit Hol Da arm, and a gripping portion on the first end, the grip member of the transfer equipment with respect to the grip portion is connectable, the drill bit from the gripper Hol da is attachable possible easily detached for the magazine,
The arm is rock drilling apparatus, characterized in that it comprises at least two support portions article which is arranged to support itself on the inner coupling threaded portion of said Dorirubi' bets. In rock drilling apparatus according to any one of 請 Motomeko 1 to 6,
Drilling said transfer equipment is characterized in that it comprises at least one first transfer equipment to or return transferring said Dorirubi' bets to the magazine or al the drilling center by a linear motion transverse Direction apparatus. It can be placed on the feed beam of the rock drilling device,
A magazine for storing a plurality of Dorirubi' bets,
The Dorirubi' bets and a transfer equipment for transferring between the magazine and drilling center,
In the drill bit changer that is arranged in a standard retail na fixed to the feed beam,
The relative position in the longitudinal direction of the feed beam of the retail Na and magazines are immutable,
It said transfer equipment drill bit changer, characterized in that disposed to transfer in the transverse direction of the beam feeding the Dorirubi' bets. A method of exchanging a drill bit in a rock drilling device,
The rock drilling device includes a feed beam, a rock drill moved by the feed device on the feed beam, a rotating device belonging to the rock drill, a tool having at least one drill rod and a drill bit connected thereto. Including
Store multiple replaceable drill bits in the magazine,
The screw connection between the drill rod and the drill bit is removed by rotating the drill rod around its longitudinal axis at the drilling center by means of a rotating device,
Transport the removed drill bit from the center of the perforation into the magazine by a transfer device;
A new drill bit is taken out from the magazine by the transfer device and transferred to the center of the perforation,
Connecting the drill rod connecting screw portion to the new drill bit connecting screw portion by rotating the drill rod around the longitudinal axis at the drilling center portion by the rotating device;
When connecting or removing the drill rod with respect to the drill bit, hold the drill bit so as not to move in the center of the drilling hole,
Holding the drill bit using a retainer fixed to the feed beam and having a fixed position in the longitudinal direction of the feed beam;
A method comprising handling the drill bit using a drill bit changer disposed on the retainer and having the magazine and a transfer device, the method comprising:
Keeping the relative position in the longitudinal direction of the feed beam of the retainer and magazine unchanged,
A method of transporting a drill bit in the transverse direction of the feed beam between the magazine and a drilling center using a transverse movement of the transport device . The method of claim 9, wherein
Wherein placing the Dorirubi' bets before Accordingly gripping the retail Na, the predetermined axial position of always Dorirubi' bets to be the exchange the drilling center. The method of claim 10, wherein
Wherein said the Dorirubi' preparative be removed Oite the Doriruro' de whether we perforation center, pressed against the mechanical stop member having a position for determining the relative position of the retail Na and Dorirubi' bets. 12. A method according to any one of claims 9 to 11,
The Dorirubi' DOO taking mechanism or al a predetermined distance at the front, a method of the outer surface of the frame portion of Dorirubi' bets to be the exchange, characterized in that thus gripping the job over the retail Na. A method according to any of claims 9 to 12,
Wherein the during transport and storage is to arrange a separate drill bit Hol da inside the respective Dorirubi' bets. The method of claim 13, wherein
Wherein the supporting pins like the drill bit Hol Da to internal connection threads of the holes in the drill bit. A method according to any of claims 9 to 14,
How external size and shape differ by at least two different Dorirubi' bets the result stored in the drill bit exchange equipment to each other, wherein the handle.

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