Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21C—MINING OR QUARRYING
  • E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
  • E21C35/18—Mining picks; Holders therefor
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21C—MINING OR QUARRYING
  • E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
  • E21C35/18—Mining picks; Holders therefor
  • E21C35/19—Means for fixing picks or holders
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21C—MINING OR QUARRYING
  • E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
  • E21C35/18—Mining picks; Holders therefor
  • E21C35/19—Means for fixing picks or holders
  • E21C35/191—Means for fixing picks or holders for fixing holders
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21C—MINING OR QUARRYING
  • E21C35/00—Details of, or accessories for, machines for slitting or completely freeing the mineral from the seam, not provided for in groups E21C25/00 - E21C33/00, E21C37/00 or E21C39/00
  • E21C35/18—Mining picks; Holders therefor
  • E21C35/19—Means for fixing picks or holders
  • E21C35/193—Means for fixing picks or holders using bolts as main fixing elements

Definitions

• the invention relates to a bit arrangement for cutting bits of a rotating tool carrier, such as e.g. a cutting head or a cutting roller, in which the chisel tips are arranged so as to be prematurely inclined in the circumferential and rotational directions of the tool carrier, and the chisel is tiltably mounted while overcoming a spring force.
• a rotating tool carrier such as e.g. a cutting head or a cutting roller
• the spherical joint socket defines the position of the swivel axis of the chisel, this swivel axis being behind the engagement of the chisel in the rock with respect to the position of the chisel tip relative to the face in the direction of rotation.
• EP-Bl-0 200 037 shows and describes a pivotable holder of a cutting bit, in which the bit can be pivoted about a pivot axis between stops in a receiving bore of the bit holder carrying the pivot axis.
• the chisel holder is located after an initial pivoting of the chisel receiving component to such a stop, and is thus rigidly supported.
• the pivotability of the component receiving the chisel serves to actuate a valve, the actuation of the valve taking place against the force of a spring which, in turn, is intended to lift the component receiving the chisel from the valve tappet after exiting the rock.
• reaction forces are not supported by such a spring, the pivot axis being internal in the embodiment selected in EP-B1-0 200 037. is half the radial projection of the chisel tip on the tool carrier. The chisel is pivoted into the rock during active intervention so that it cannot detach itself from the rock contact.
• the invention now aims to provide a chisel arrangement of the type mentioned at the outset, with which it is possible above all that the chisel can move away from the rock when it engages in the rock to be cut.
• the task according to the invention consists essentially in the fact that the tilting axis of the chisel in the circumferential or rotational direction of the chisel is arranged on the tool carrier's rotation axis before the normal projection of the chisel tip onto the axis of rotation of the tool carrier and that the chisel is in the engagement position against a spring is supported tiltable.
• the tilt axis is arranged at a distance ahead on the tool carrier, which lies in front of the line connecting the cutting axis to the bit tip, creates the possibility of safely detaching from the rock contact, it being further essential that the bit engages in the Rock and thus is tiltably supported in the engagement position against a spring.
• the chisel should thus be able to be tilted further against the force of a spring in the engagement position, in order in this way to improve the balance of forces and to intercept occurring force peaks.
• the design according to the invention is so made that the chisel holder is fixed to a one-armed pivot lever, the end of which faces away from the pivot axis is pressed against a spring element.
• the pressing of the end of the pivot lever facing away from the pivot axis against a spring element is of essential importance in the operating position for the absorption of the forces on the chisel engagement.
• the swivel lever should be pressed against the spring element under a defined pretension and it therefore corresponds to a preferred development of the chisel arrangement according to the invention that the pressing force of the swivel lever against the spring element is adjustable. One just closing a valve after removing The spring force assuring the chisel is in no way suitable for absorbing such reaction forces.
• Secure support and particularly good power absorption can be achieved in that the longitudinal axis of the pivot lever is articulated at an acute angle of less than 35 °, in particular less than 25 °, to the tangent to the tool carrier in the region of the pivot axis, such an arrangement of the pivot lever the corresponding leverage ensures, which is advantageous for a secure resilient support of the dynamic passive forces.
• the spring element must also be resilient in the engagement position and must therefore be able to absorb high reaction forces.
• the design is therefore advantageously made such that the spring element is formed by a leaf spring or a leaf spring assembly, the longer axis of which is fixed approximately parallel to the pivot axis of the pivot lever on the tool carrier, as a result of which high spring forces and thus high force peaks can be absorbed in a small space.
• a particularly good introduction of force to absorb the cutting forces can be achieved in that the distance (a) of the swivel axis from the normal projection of the chisel tip onto the chisel holder is at least one third, preferably at least half, of the normal distance of the swivel axis from the face or the cutting track plane of the Chisel.
• Such a design allows the desired pivoting against the force of a spring with effective absorption of the cutting forces, for which purpose the design is advantageously made such that the distance of the contact point or contact center of the pivot lever on the spring element from the pivot axis is greater than the distance (a) the swivel axis from the normal projection of the chisel tip onto the chisel holder.
• the cutting forces are introduced into the spring element via a correspondingly long lever arm, so that they are small and stiff Feathers that can be found.
• the reaction forces are introduced into the spring at a greater distance than the distance between the line of action of the passive forces and the swivel axis.
• a particularly simple adjustability of the desired spring preload for the effective support of the forces mentioned can be achieved in that the pivot lever is pressed against the spring element by a clamping bolt passing through the pivot lever between the pivot axis and the contact point.
• the articulation geometry of the chisel arrangement is advantageously chosen according to the invention in such a way that the resilient support of the pivot lever in the operating position of the chisel is selected so that the cutting forces which become effective are reduced.
• FIG. 1 shows a side view of a pivotable chisel holder on the tool carrier and
• FIG. 2 shows a top view of the arrangement according to FIG. 1.
• FIG. 1 shows a cutting chisel 1 which is received in a chisel holder 2.
• the chisel can be received in the chisel holder 2 in a conventional manner and in particular in a manner rotatable about the chisel axis 3 in order to minimize wear.
• the cutting reaction force is indicated by arrow 4, which is the direction of the resulting one.
• This resulting cutting reaction force is composed of a passive force, the vector of which is 5 and a circumferential force of which the vector is indicated by 6.
• the line of action of the passive force, which is directed toward the center of the rotational movement of the tool carrier 7, is designated by 8, the axis of rotation of the tool carrier 7 being indicated by 9.
• the chisel holder 2 is mounted on a one-armed pivot lever 10 so that it can pivot about the pivot axis 11, the pivot axis 11 being arranged in a bearing component 12 which is connected to the tool carrier 7.
• the pivoting of the pivot lever 10 about the pivot axis 11 takes place against a spring element 13 which is designed as a leaf spring and is likewise fixed on the tool carrier 7 in a corresponding spring holder 14.
• the bias of the pivot lever 10 against the spring element 13 is adjusted accordingly by means of a bolt 15 and nuts 16.
• the distance a of the pivot axis from the line of action of the cutting normal force of the cutting reaction forces is chosen so that the bit 1 and the bit holder 2 can move against the spring element 13 during operation and force peaks can be compensated in this way.
• the free end of the pivot lever 10 rests on the spring element 13 and is pressed against this spring element 13 under prestress.
• the forces are introduced into the spring element 13 at a greater distance from the pivot axis 11 than the distance a between the line of action of the cutting normal force and the pivot axis.
• the lever arm length over which the reaction forces are derived in the spring element 13 is indicated with b.
• the pivot axis 11 is furthermore at a distance c from the cutting track, the desired reduction in the force peaks being obtained by a suitable choice of these three distances.
• Fig. 2 it can be seen that the longitudinal axis 17 of the leaf spring 13 is arranged substantially parallel to the pivot axis 11 on the tool holder schematically indicated by 7.
• the tool holder itself forms part of the circumference of a cutting head or a cutting roller and is naturally idealized in the representations according to FIGS. 1 and 2.
• the kinematics of the articulation is such that the longitudinal axis 18 of the pivoting lever 10 with the tangent to the tool carrier 7 has an acute angle ⁇ of approximately 20 °, in FIG. 1 one to this tangent parallel line is entered.

Landscapes

• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• Percussive Tools And Related Accessories (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Drilling And Exploitation, And Mining Machines And Methods (AREA)
• Turning (AREA)
• Earth Drilling (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=3506551

Family Applications (1)

Country Status (6)

Families Citing this family (1)

Family Cites Families (5)

• 1997
  • 1997-06-25 AT AT0109897A patent/AT408017B/de not_active IP Right Cessation
• 1998
  • 1998-06-18 ZA ZA985311A patent/ZA985311B/xx unknown
  • 1998-06-22 WO PCT/AT1998/000156 patent/WO1999000580A1/fr not_active Ceased
  • 1998-06-22 AU AU78976/98A patent/AU7897698A/en not_active Abandoned
  • 1998-06-22 DE DE59803023T patent/DE59803023D1/de not_active Expired - Lifetime
  • 1998-06-22 AT AT98929115T patent/ATE213051T1/de not_active IP Right Cessation
  • 1998-06-22 EP EP98929115A patent/EP0991848B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

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