Mining machine with core breakers

Details Mining machine with core breakers Mining machine with core breakers

1999-11-03

2001-11-13

Bagnell, David (Department: 3673)

Mining or in situ disintegration of hard material

Hard material disintegrating machines

Vertical cutter tooth orbit

C299S079100, C299S101000, C299S085100

Reexamination Certificate

active

06315365

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a driving or mining machine comprising cutter rolls or drums rotatably mounted on a cantilever arm pivotable in the vertical direction, in which bearings and/or gears are arranged in the axial direction of the cutter rolls or drums between parts of the rolls or drums, which bearings and/or gears are connected with the cantilever arm or the actuating means provided in the cantilever arm.
2. Prior Art
With roll cutter machines of the initially defined kind, the mine face, as a rule, is worked by initially moving the cutter roll or drum in the direction towards the mine face and into the mine face, whereupon the mine face is worked by vertically pivoting the cantilever arm carrying the cutter rolls. Due to the mounting and the transmission of the rotary drive onto the rolls, a material rib will each be left between neighboring roll parts or drums by such a driving or mining machine, which in most cases is referred to as a core. If there is sufficiently crumbly material, it is usually possible to break up the cores left in the region of the mine face by moving the cutting tools further in the direction towards the mine face. With tougher rocks, the removal of such cores is cumbersome and not readily feasible without additional measures. Such a material core, as a rule, is left, in particular, in the region of the roof and consequently will hamper headway timbering, impeding the perfect attachment of covering plates and the perfect arrangement of roof elements.
In order to remove or break up such cores, so-called core breakers have already been proposed, which were stationarily arranged on a support. Such a configuration may be taken, for instance, from U.S. Pat. No. 3,279,856, in which a U-shaped support carries a circumferential continuous splitter edge mounted to the gear case in the region of the core.
Alternatively, it has already been suggested to arrange, in the region of the core, bits which are more or less difficult to pivot, such arrangements being characterized by relatively high structural expenses and the fact that the subsequent equipment of cutter rolls with such devices is not readily feasible.
In addition to a continuous splitter edge extending in the circumferential direction as proposed in U.S. Pat. No. 3,279,856, it has, moreover, already been proposed to arrange a plurality of individual bits and, in particular, replaceable parallel shank bits on a support fixed to the cantilever arm in the region of the core. Such a configuration may be taken, for instance, from U.S. Pat. No. 4,669,786. Due to the use of parallel shank cutters and the fact that such cutters were arranged at a radial distance from the axis of rotation of the rolls substantially smaller than the radial distance from the actual cutter bits of the rolls or drums, a core likewise would remain in such configurations at least in the region of the roof, the further disintegration of which core was not readily feasible. Further, U.S. Pat. No. 4,253,705 proposed an obliquely extending breaking edge in the region of the core, via which the core forming on the mine face was to be broken by lateral pressure.
SUMMARY OF THE INVENTION
The invention aims at providing a simple device easy to retrofit, by which primarily the core remaining in the region of the roof can be reliably cut and broken. After all, the breaking away of cores left in the mine face is to be facilitated, too. To solve this object, the configuration according to the invention essentially consists in that at least one stationary cutter bit is arranged on the cantilever arm in the region of the bearings and/or gears between neighboring parts of the rolls or drums in a plane through which the axis of the cantilever arm passes, and that the cutter bit has at least two cutting edges, a first cutting edge being provided substantially tangential to the enveloping curve of the rotating bits in the direction of the axis of the cantilever arm and a second cutting edge being provided so as to enclose an angle with the first cutting edge. By arranging on the upper side of the cantilever arm in a substantially radial direction at least one bit having at least two cutting edges, whose external cutting edge is located substantially tangential to the enveloping curve of the rotating bits, it is feasible during penetration, i.e., while moving the cutter rolls into the mine face, to appropriately disintegrate the core left on the roof, to which end said bit comprises at least two cutting edges. As the cantilever arm carrying the cutter rolls is advanced, both the front edge adjacent the mine face and the bit edge located radially outwards and substantially tangential to the enveloping curve of the bits are entering into operation such that the core left on the roof can be reliably cut and broken. Since that bit is a stationary cutter bit, it may be fixed to the gear case or to the cantilever arm in a simple manner.
Advantageously, the configuration is devised such that the cutting edge in the direction of the axis of the cantilever arm is longer than the width of the bit transverse to the length of the cutting edge.
In order to ensure that at least the core remaining in the region of the roof can be reliably cut and broken, the configuration advantageously is devised such that the second cutting edge encloses an angle of 90°±45° with the first cutting edge.
Between such bits positioned in a substantially diametrically opposite relationship on a larger circumference, further bits may be arranged in the circumferential direction, which are to facilitate the breaking of cores left in the region of the mine face. To this end, the configuration advantageously is devised such that two substantially diametrically opposite bits are arranged on a larger circumference than further stationary bits facing the mine face, between parts of the rolls or drums, wherein said further bits arranged on a smaller radius preferably are arranged so as to be distributed over a central angle &agr; of 90°&agr;<150°. The further bits arranged between the cutter bits for the roof or floor may readily be arranged on a smaller radius, since slender cores remaining in the region of the mine face may be broken away with little effort during further advance. In this respect, the configuration in a particularly simple manner may be devised in that the further bits are designed as parallel shank bits. The use of different types of bits for different partial regions of the peripheries of the core has proved to be of particular advantage, enabling to take into account to an optimum degree the different regions over which the cutter drums enter into operation. Particularly preferred is an embodiment in which wedge-shaped bits are arranged adjacent the bits comprising two cutting edges, the externally arranged cutting edges of which wedge-shaped bits are located on a smaller diameter than the bits having two cutting edges. Such wedge-shaped bits are provided for cutting in the transitional region between the roof and the mine face, wherein these bits may be arranged within the track of the externally arranged bits having at least two cutting edges or also offset relative to that track. Only in the central region, which relates to a central angle of about ±45° relative to the axis of the cantilever arm, may circular bits or parallel shank bits be employed in an advantageous manner, since in those cases the axial pressure exerted on the remaining cores in the form of a lumped load allows for an optimum disintegration performance and the simple breaking away of cores left in the region of the mine face.
In a particularly simple manner, the arrangement may be devised such that the bits are fixed to a gear lid or a stationary support connected with the gear lid.


REFERENCES:
patent: 2808253 (1957-10-01), Miller
patent: 3010709 (1961-11-01), Bentley et al.
patent: 3279856 (1966-10-01), Silks
patent: 3290099 (1966-12-01), Lundquist
patent: 4253705 (1981-03-01), LeBegue
patent: 4391472 (1983-07-01), Krekele

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