Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B3/00—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools
  • B24B3/24—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of drills
  • B24B3/33—Sharpening cutting edges, e.g. of tools; Accessories therefor, e.g. for holding the tools of drills of drills for stone
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
  • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
  • B24D5/06—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental
  • B24D5/066—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental with segments mounted axially one against the other

Definitions

• the present invention relates to a grinding appliance for grinding of button drill bits which comprise a drilling head with a plurality of buttons, and a method for manufacturing such a grinding appliance.
• a button drill bit intended for rock drilling comprises usually a plurality of buttons which are made of, for example, hard metal and are embedded in a drilling head which is made of a relatively softer material, e.g. steel.
• Each button usually has a cylinder-like portion partly embedded in the steel, a cupola-shaped end profile shape protruding from the steel.
• the end profile shape of the button may be of various shapes, e.g. semi- ballistic, as depicted in the drawings in this specification, hemispherical or semi- cylindrical or some other desired shape.
• Such a button is often made of a hard metal, usually a material comprising tungsten carbide grains combined with a binding phase which comprises cobalt or material with similar characteristics.
• Swedish patent specification SE434356 refers to a grinding facility for grinding of drill bits.
• the grinding facility comprises a grinding appliance comprising an abrasive wheel fastened to a powered spindle, and a rotatable table with a holder for the button drill bit.
• a spindle is a machine part which, via a shaft, transmits a rotary motion to a tool, in this case the abrasive wheel, fastened in the shaft.
• the abrasive wheel has running round it a profile groove corresponding to an intended end profile for the button drill bit.
• the end profile is obtained by rotating the tool about the geometric axis of symmetry of the button.
• the abrasive wheel is also fastened in such a way that it can grind a button to its original shape in conjunction with the button drill bit being held firmly on the rotating table.
• Such an abrasive wheel for grinding of button drill bits with the object of restoring a worn button to its original shape is known from European patent EP397955.
• the abrasive wheel according to that patent takes the form of a pulley with a groove situated between two flanks, with the shape which the drilling button originally had and which is to be recreated by the abrasive wheel.
• the groove on the abrasive wheel is provided with a grinding agent, usually a diamond facing, intended to be able to grind away the hard metal which the drilling button is made of.
• a grinding appliance according to Swedish patent SE458425 is used.
• the grinding appliance according to that patent takes the form of a disc-shaped abrasive wheel provided with an abrasive facing of boron nitride adapted to grinding the steel material of the drilling head.
• Using such an abrasive wheel for grinding the button of the drill bit makes it possible for the shape of the button to be restored, thereby greatly lengthening the service life of the drill bit. In normal use, a drill bit can be reground about 8-10 times.
• a problem is that if a boron nitride facing intended for grinding the steel of the drilling head comes unintendedly into contact with a hard metal button, the abrasive facing is very quickly destroyed and the abrasive wheel has to be scrapped.
• the boron nitride facing used as the abrasive medium for grinding the drilling head e.g. cubic boron nitride (c-Bn)
• c-Bn cubic boron nitride
• a first object of the invention is to propose a grinding appliance of the kind indicated in the introduction which solves the above problem, and a method for manufacturing such a grinding appliance.
• the solution is a grinding appliance which has the characterising features of claim 1.
• Such a grinding appliance for grinding a button drill bit which has a drilling head provided with a plurality of buttons comprises a first element provided with a first abrasive facing comprising diamonds of a first average grain size as the abrasive medium adapted to grinding a button to an intended end profile shape, and at least one second element adapted to grinding the drilling head, at least one section of the second element being provided with a second abrasive facing comprising diamonds of a second average grain size adapted to grinding the material of the drilling head.
• a grinding appliance in such a way that it comprises a plurality of separate but mutually assembled parts made of different materials makes it possible for each part of the abrasive wheel to have a function of its own, i.e. for each part to be adapted to grinding different portions of the drill bit. This makes it possible for each part to be adapted according to the material, e.g. hard metal or steel, which is ground by the various parts of the grinding appliance. It is also possible to change the parts separately if they become worn at different rates.
• an abrasive facing which comprises coarser diamond grains on the abrasive wheel's flanks adapted to grinding the material of the drill bit causes the abrasive facing to last for more grinding operations than is the case with an abrasive facing which comprises finer diamond grains, since the coarser abrasive facing will grind away larger material fragments, thereby making the grinding process quicker.
• a further advantage is that the second element adapted to grinding the drilling head is diamond-faced, since diamond grains are more durable than, for example, boron nitride, making it possible for the second element not to become worn prematurely if the grinding appliance inadvertently comes into contact with the hard metal of the button, thus allowing for careless handling.
• the average grain size for the diamonds in the second abrasive facing is preferably different from that in the first abrasive facing, since the respective abrasive facings are thereby adapted to grinding materials which have different characteristics.
• the diamonds in the second abrasive facing have an average grain size within the range 210-500 ⁇ m, corresponding to US mesh 70/80 - 35/40. In a preferred embodiment, the diamonds in the second abrasive facing have an average grain size of 250-354 ⁇ m, corresponding to US mesh 60/70 - 45/50.
• the diamond grain size of the abrasive medium determines the amount of material which can be removed with a certain amount of abrasive media.
• the material of the drilling head is softer than that of the drilling button.
• the material of the drilling head is ground by the second abrasive facing.
• the material of the drilling head is, for example, steel or a material with characteristics similar to steel, e.g.
• the diamonds in the first abrasive facing have an average grain size within the range 37-320 ⁇ m, corresponding to US mesh 400/500 - 45/60. In another embodiment according to the invention, the diamonds in the first abrasive facing have an average grain size within the range 37-229 ⁇ m, corresponding to US mesh 400/500 - 60/80.
• the size of the diamond grains is less significant as regards grinding speed and wear resistance when grinding the button made of, for example, hard metal than when grinding the drill bit made of, for example, steel.
• diamond abrasive grains which are too large may cause deep scratches in hard metal, which may lead to the hard metal cracking during the grinding process. Smaller diamond grains limit surface roughness and result in small depth of scratches, thereby increasing the durability, and allowing more regrindings, of the button.
• the average grain size for the diamonds in the second abrasive facing is larger than the average grain size in the first abrasive facing.
• the first element is a first separate component
• the second element is a second separate component
• these components are connected for joint rotation so that a complete profile groove with an intended end profile shape is formed.
• the grinding appliance is an abrasive wheel and the first element has running round it a concave profile groove corresponding to the intended end profile shape, and the second element is a concentric circular flank, a concentrically circular side portion.
• the elements with the profile groove and the flank are connected for joint rotation so that a complete profile groove with an intended end profile shape is formed.
• the circular profile groove is provided with the first abrasive facing intended for grinding the button.
• the concentric circular flank is provided with the second abrasive facing intended for grinding the drilling head.
• the abrasive wheel is with advantage mounted on a spindle in a grinding facility.
• the profile groove has a shape such that a button with a convex shape corresponding to the through-section of a substantially spherical zone of a trapezoid can be ground.
• the grinding appliance comprises a third separate element connected for joint rotation with the first element and opposite to the second element, which third element is provided with a third abrasive facing comprising diamonds as the abrasive medium adapted to grinding the drilling head.
• the third element is a second concentric circular flank.
• the abrasive wheel comprises a middle portion made of one material and separate flanks made of another material. The grinding appliance is thus specially adapted to grinding a soft material, e.g. steel or a material with similar characteristics to steel, with the flanks of the abrasive wheel while at the same time the hard metal button is ground by the middle portion, the waist of the abrasive wheel.
• the first element is an inner portion of a grinding cup and the second element is an adjacent firmly connected outer portion of the grinding cup intended to grind the drilling head.
• the inner portion of the grinding cup is provided with the first abrasive facing intended to grind the button to an intended end profile shape.
• the second element of the adjacent firmly connected outer portion of the grinding cup is provided with the second abrasive facing adapted to grinding the drilling head.
• At least one of the abrasive facings comprises diamonds with protrusions.
• the diamonds with protrusions have preferably only one layer of diamonds so that a thin abrasive layer with a well-controlled surface profile can be applied.
• the diamonds with protrusions will grind steel or a material with characteristics similar to steel quicker, without the abrasive wheel being destroyed, than if boron nitride is used as the abrasive facing, resulting in more efficient grinding.
• at least one of the abrasive facings comprises matrix diamonds. An advantage of matrix diamonds is that the diamonds will be in two or more layers, so the layer can be made thicker.
• Another object of the invention is to propose a grinding facility for grinding of button drill bits which have a drilling head with a plurality of buttons, comprising a grinding appliance according to any one of claims 1-13.
• a third object of the invention is to propose a method for manufacturing a grinding appliance of the kind indicated in the introduction which solves the above problem.
• the solution is a method which has the characterising features of claim 15.
• Such a method for manufacturing a grinding appliance for grinding of button drill bits which comprise a drilling head with a plurality of buttons comprises: providing a first element of the grinding appliance with an abrasive facing comprising diamonds as the abrasive medium of a first average grain size adapted to grinding a button to an intended profile shape, providing at least one section of a second element of the grinding appliance with an abrasive facing comprising diamonds as the abrasive medium,
• the average grain size for the diamonds in the second abrasive facing being of a different average grain size adapted to grinding the drilling head.
• the method further comprises:
• a fourth object of the invention is the use of a grinding appliance according to claims 1- 13 for grinding of buttons of a button drill bit which comprises a drill bit with a plurality of buttons.
• Figure 1 depicts a side view of a grinding facility intended for grinding of drill bits
• Figure 2 A depicts a through-section of an abrasive wheel according to the invention
• Figure 2B depicts an exploded diagram of a through-section of the abrasive wheel in Figure 2A
• Figure 2C depicts a side view of the abrasive wheel in Figure 2A
• Figure 2D depicts a perspective view of the abrasive wheel in Figure 2A
• Figure 3 depicts another through-section of an abrasive wheel according to the invention
• Figure 4 depicts further through-section of an abrasive wheel according to the invention
• Figure 5 depicts a through-section of a grinding cup according to the invention
• Figure 6 depicts a detail of a through-section of an abrasive facing intended for a grinding appliance according to the invention
• Figure 7 depicts a further detail of a through-section of an abrasive facing intended for a grinding appliance according to the invention.
• Figure 8 depicts a method according to the invention for manufacturing a grinding appliance according to the invention. Description of embodiment examples The following description refers to both the method and the device.
• Figure 1 depicts a grinding facility intended to grind buttons of a button drill bit with a grinding appliance according to the invention.
• the grinding facility is in this case intended to be mounted on a drilling rig and includes a supporting frame 1 intended to be fastened in the drilling rig, not depicted in the drawing.
• the supporting frame 1 has an upper arm 2 running outwards which supports a grinding machine 3 via a supporting structure 4 which is movable in the horizontal plane.
• the grinding machine 3 can be raised and lowered in the supporting structure, i.e. it is adapted to pivoting to and fro in the vertical plane.
• the supporting frame 1 also comprises a fastening means 5 situated below the grinding machine 3.
• the fastening means 5 is adapted to firmly holding a drill bit 6.
• the drill bit 6 can easily be fitted into and locked in the fastening means 5 by means of a locking handle 7.
• the drill bit comprises a number of buttons 8, the size and positioning of which on the bit 6 may vary.
• the grinding machine 3 comprises also a grinding unit 9 which includes a motor unit 10 and a spindle 1 1 which is driven by the motor.
• the grinding unit 9 is thus also adapted to pivoting to and fro about a vertical axis which coincides with the geometric axis of symmetry of the button 8.
• a grinding appliance in this case an abrasive wheel 12, is supported at the end of the spindle 1 1.
• the abrasive wheel 12 is adapted to grinding the buttons of the drill bit.
• the grinding unit 9 is so arranged that the spindle 1 1 will slope somewhat relative to the horizontal plane, so that the abrasive wheel 12 rotates about the spindle.
• the grinding unit is supported by a supporting means 13 on the grinding facility and can be pivoted about a substantially vertical axis 14 by means of a pivot cylinder 15.
• the geometric axis about which the grinding unit 9 moves forwards and rearwards is a generally vertical axis which coincides with the geometric centre of the button 8 when the grinding machine 3 is adjusted relative to the button drill bit.
• FIG. 1A depicts a grinding appliance 20 for grinding a button 8A of a button drill bit 6A. In this case the grinding appliance is an abrasive wheel 20.
• the grinding appliance comprises a first element 22 and the second element 24 which are connected to one another for joint rotation with respect to the axis of rotation of the spindle so that a complete profile groove with an intended end profile shape is formed.
• the first element 22 is a first separate component and the second element 24 is a second separate component.
• the first element 22 has running round it a profile groove in the form of a concave surface corresponding to an end profile shape 26 intended for the button 8A.
• the profile groove thus forms a waist round the first element 22.
• the waist is limited to the cap-shaped end profile shape of the hard metal button.
• the first element 22 is thus adapted to grinding the button 8A to, for example, a spherical or fully ballistic end profile shape.
• the grinding appliance also comprises a second element 24 which is a concentric circular flank situated at one of the planar outsides of the grinding appliance.
• the flank has running round it an outer portion with a substantially arcuate cross- section adapted to grinding the drilling head 28 round the button 8A.
• the grinding appliance further comprises a third separate element 29 connected for joint rotation with the first element and opposite to the second element.
• the third element 29 is a second concentric circular flank.
• the first element is provided with, running round it, an outer layer 30 with an abrasive facing comprising diamonds as the abrasive medium.
• the abrasive facing 31 of the second element is depicted in the same Figure 2A in a first embodiment illustrated on the second element 24.
• the second element 24 is provided with, running round it, an outer layer with an abrasive facing 31 comprising diamonds as the abrasive medium.
• the abrasive facing is applied on the circular outer portion 32 with a substantially arcuate cross-section.
• Figure 2A depicts a further embodiment on the third element 29, the second flank.
• the third element 29 is a component which is homogeneously made of the second abrasive facing 32 so that the whole flank comprises the abrasive medium. It should be noted that both flanks in the two embodiments illustrated in Figure 2A may have an abrasive facing of the same kind.
• the hatched portions which follow the waist 30 and the flanks 31, 32 in Figure 2A show where the diamond facing is applied on the first element 22 and the second element 24 respectively.
• the average grain size for the diamonds in the first abrasive facing 30 is adapted to grinding of hard metal.
• the average grain size for the diamonds in the second and third abrasive facings is of an average grain size adapted to grinding the drill bit.
• the diamonds are, for example, fastened in a layer which is nickel-based or chrome-based or a mixture of these materials or some other material with similar characteristics, so that the layer is softer than hard metal but nevertheless retains its shape and tolerates impacts.
• the grinding appliance in Figure 2A is firmly clamped to a grinding facility, not depicted, by a screw 33 and a nut 34. They may also be joined together by, for example, adhesive bonding or welding or by bolts, not here depicted, or by other similar fastening devices.
• FEPA Federal Communications Commission
• ANSI indicates a US mesh size
• FEPA indicates a DIN size
• the diamonds have in the first abrasive facing an average grain size within the range of 37-320 ⁇ m, corresponding to US mesh 400/500 - 45/60.
• the average grain size for the diamonds in the second abrasive facing is adapted to grinding of drilling steel.
• the diamonds in the second abrasive facing have an average grain size within the range 210-500 ⁇ m, corresponding to US mesh 70/80 - 35/40. In another embodiment, the diamonds in the second abrasive facing have an average grain size of 250-354 ⁇ m, corresponding to US mesh 60/70 - 45/50.
• the average grain size for the diamonds in the second abrasive facing is adapted to grinding the drill bit, so it is preferable that the average grain size for the diamonds in the second abrasive facing be larger than the average grain size in the first abrasive facing.
• Figure 2B depicts an exploded diagram of a through-section of the drawing in Figure 2A. It shows the separate elements of the grinding appliance before they are joined together.
• the first element 22 is a first separate component
• the second element 24 is a second separate component
• the third element 29 is a third separate component.
• the second element 24 is a first concentric circular flank.
• the third element 29 is a second concentric circular flank.
• the first element 22 has running round it a concave profile groove 26 corresponding to an end profile shape intended for the button 8A.
• the second element 24 is a concentric circular flank and is adapted to being joined together with the first element 22, the respective end portions 22A, 24A being adapted in size to one another so that the continuous end profile shape 26 is formed.
• the third element 29 is adapted to being joined together with the first element 22, the respective end portions 22B, 29B being adapted in size to one another so that the continuous end profile shape 26 is formed.
• the second element 24 has in this embodiment a smaller outside diameter than the largest diameter of the first element 22.
• the third element 29 has a larger outside diameter than the largest diameter of the first element 22.
• the grinding appliance is adapted to being angled during the grinding of a button so that the device, not depicted, fastening the grinding appliance to the grinding facility will be clear of the other buttons in the button drill bit.
• the second element 24 and the third element 29 may also be equal in size, not depicted.
• Figure 2C depicts a side view of the abrasive wheel in Figure 2A. It shows the second element 24 as a concentric circular flank. The outer layer 31 with abrasive facing comprising diamonds is applied to the concentrically outermost portion of the flank.
• Figure 2D depicts a perspective view of the abrasive wheel in Figure 2A.
• the grinding appliance 20 comprises the first element 22, the second element 24 and the third element 29 connected for joint rotation with respect to the spindle's axis of rotation A.
• the first element 22 has running round it a profile groove 26 in the form of a concave surface corresponding to an end profile shape intended for the button 8A.
• the first element 22 is provided with, running round it, an outer layer 30 with a first abrasive facing comprising diamonds adapted to grinding of hard metal buttons.
• the second element 24 and the third element 29 are provided with, running round them, an outer layer with a second abrasive facing 31 and a third abrasive facing 32 comprising diamonds with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel, as the abrasive medium.
• FIG 3 depicts a further embodiment of a grinding appliance for grinding a button 8B of a button drill bit 6 comprising a drilling head 6B with a plurality of buttons, hi this case the grinding appliance is an abrasive wheel 40.
• the grinding appliance comprises a first element 41 and a second element 42 adapted to being joined together for joint rotation with one another with respect to the spindle's axis of rotation C so that a complete profile groove with an intended end profile shape 43 is formed.
• the first element 41 is a first separate component and the second element 42 is a second separate component.
• the first element 41 has running round it a concave profile groove with an end profile shape 43 corresponding to an end profile shape intended for the button 8B.
• the first element 41 is thus adapted to grinding the button 8B to, for example, a spherical or fully ballistic end profile shape.
• the second element 42 of the grinding appliance is a concentric circular flank.
• the flank has running round it in this embodiment an outer concentric ring homogeneously made of the abrasive facing adapted to grinding the drilling head, and an inner concentric ring 44 adapted to being fastened to the grinding facility.
• the outer ring has a substantially convex cross-section adapted to grinding the drilling head 28 round the button 8B.
• the flank may also have an outer circular shaped portion of a ring made of abrasive media and with a substantially convex cross-section.
• the flank may also have an inner ring of other than concentric shape adapted to being fastened to the grinding facility.
• the profile groove 43 on the first element 41 is provided with a first abrasive facing 46 comprising diamonds with an average grain size adapted to grinding of hard metal, as the abrasive medium.
• the second element 42 is provided with a second abrasive facing 48 comprising diamonds as the abrasive medium with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel.
• this abrasive wheel also has an undepicted embodiment in which the second element 42 is homogeneously made of the abrasive medium 48 comprising diamonds as the abrasive medium with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel.
• Figure 4 depicts another embodiment of a grinding appliance for grinding a button drill bit 6C comprising a drilling head with a plurality of buttons 8C.
• the grinding appliance is a half abrasive wheel 50.
• the grinding appliance comprises a first element 52 and a second element 54 adapted to being joined together for joint rotation with one another with respect to the spindle's axis of rotation D so that a complete profile groove is formed.
• the first element 52 is a first separate component and the second element 54 is a second separate component.
• the first element 52 has running round it a profile groove 53 corresponding to a half end profile shape intended for the button 8C.
• the grinding appliance also comprises a second element 54 which is a concentric flank with a parabolic shape.
• the first element 52 is thus adapted to grinding the button 8C to, for example, a spherical or fully ballistic end profile shape while at the same time the second element 54 is adapted to grinding the drilling head 6C round the button 8C.
• the flank has running round it an outer convex portion with a substantially arcuate cross- section adapted to grinding the drilling head 28 round the button 8C.
• the first element 52 is provided with an abrasive facing comprising diamonds with an average grain size adapted to grinding the button 8C.
• the second element 54 is provided with an abrasive facing comprising diamonds with an average grain size adapted to grinding the drilling head 6G.
• the profile groove on the first element 52 is thus provided with a first abrasive facing 56 comprising diamonds as the abrasive medium with an average grain size adapted to grinding of hard metal.
• the second element 53 is thus provided with an abrasive medium which is a second abrasive facing 58 comprising diamonds with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel.
• this abrasive wheel also has a undepicted embodiment in which the second element 54, the flank, is homogeneously made of the abrasive medium 48 comprising diamonds with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel.
• Figure 5 depicts a further grinding appliance, in this case a grinding cup 60, for grinding a button 8D of a button drill bit 6D.
• the first element 62 is a grinding cup filled with an abrasive facing comprising diamonds as the abrasive medium.
• the second element 64 is an outer portion applied round part of the grinding cup 62.
• the profile groove on the first element 62 is filled with an abrasive medium with a first abrasive facing 66 comprising diamonds with an average grain size adapted to grinding of hard metal.
• the second element 64 is provided with a second abrasive facing 68 comprising diamonds as the abrasive medium with an average grain size adapted to grinding a soft material, e.g. steel or a material with characteristics similar to steel.
• the second abrasive facing may also comprise boron nitride, silicon carbide, aluminium oxide, titanium carbide and titanium nitride, or similar material.
• the grinding cup 60 or the button 8D is rotated during grinding or both the grinding cup and the button are rotated.
• FIG. 6 depicts a detail of an abrasive facing 70 intended for a grinding appliance as described above.
• the abrasive facing 70 comprises an abrasive medium with a single layer of diamonds 72A, 72B, 72C, 72D , 72E, 72F fastened in a layer which is nickel- based or chrome-based or a mixture of these or some other material with similar characteristics, such that the layer is softer than hard metal but nevertheless retains its shape and tolerates impacts.
• the diamonds in this abrasive facing have a protrusion, which means that one portion of each diamond is fastened in the layer and the other portion protrudes.
• This abrasive facing is applied preferably on the first element for grinding the hard metal of the button.
• This abrasive facing may also be applied on the second and third elements for grinding the layer of a soft material, e.g. steel or a material with characteristics similar to steel.
• Figure 7 depicts a further detail of an abrasive facing 80 intended for a grinding appliance as described above.
• the abrasive facing 80 comprises an abrasive medium with diamonds 82A, 82B, 82C, 82D, 82E, 82F, fastened in this case in a nickel-based layer. Some other material with similar characteristics may also be used.
• the diamonds in this abrasive facing comprise matrix diamonds.
• the matrix diamonds are situated in two or more layers in the abrasive facing so that a layer of diamonds may be ground away and uncover a new layer of diamonds.
• This abrasive facing is applied preferably on the second and third elements for grinding the drilling head made of, for example, steel.
• Figure 8 depicts a method for manufacturing a grinding appliance 90 for grinding of button drill bits which comprise a drilling head with a plurality of buttons.
• the method comprises: a) providing a first element of the grinding appliance with an abrasive facing comprising diamonds as the abrasive medium of a first average grain size adapted to grinding a button to an intended profile shape (92), b) providing at least one section of a second element of the grinding appliance with an abrasive facing comprising diamonds as the abrasive medium of a second average grain size adapted to grinding a drilling head (94), c) joining the first element and the second element together for joint rotation so that a complete profile groove is formed (96).

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Polishing Bodies And Polishing Tools (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40526445

Family Applications (1)

Country Status (5)

Cited By (1)

Citations (6)

• 2007
  • 2007-10-03 SE SE0702215A patent/SE531596C2/sv unknown
• 2008
  • 2008-10-02 AU AU2008307767A patent/AU2008307767B2/en active Active
  • 2008-10-02 EP EP08835712A patent/EP2205396A4/en not_active Withdrawn
  • 2008-10-02 WO PCT/SE2008/000538 patent/WO2009045142A1/en active Application Filing
  • 2008-10-02 CA CA2701017A patent/CA2701017C/en active Active

Patent Citations (6)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events