Bar-type stone-cutting machine

BAR-TYPE STONE-CUTTING MACHINE (EN: jib rock-cutting machine; DE: Steinschneidmaschine; FR: brise-roche à bras; ES: roza-dora de brazo para roca; RU: баровая машина камнерезная) is the extracting machine with the working implement in the form of the bar for the cutting of the blocks or monoliths from the massif.

The bar-type stone-cutting machine:Bar-type stone-cutting machine

  1. the driven pulley;
  2. the working implement (bar);
  3. the chain;
  4. the feeding mechanism;
  5. the drive of the feeding mechanism;
  6. the base frame;
  7. the rails;
  8. the console crane;
  9. the leading sprocket;
  10. the console of the bar.

They are used for the monolithic rocks with the angle of dip of the layers not more than 15 degrees. There is laid within the bar-type stone-cutting machine the design principle of the coal-extracting cutting machines. They have started to use the bar-type stone-cutting machine for the first time for the cutting of the blocks of stone since the 20-ies of the 20th century within the USSR, Germany, France.

They distinguish according to the purpose and field of usage the machines for the extraction of the wall (with the coefficient of strength of up to 5) and facing (with the coefficient of strength of up to 9) stones; according to the character of the work the before-bench and above-bench machines; and also the machines, which are working within the open pits and underground workings. According to the quantity of the working implements, they distinguish the single-bar and multiple-bar bar-type stone-cutting machines. Most bar-type stone-cutting machines are universal, they can perform all types of cuts (saw-cuts), which are necessary for the separation of the block from the massif. There have acquired the widest distribution the single-bar stone-cutting machines for the extraction of the facing stone at the open pit mining works. The bar-type stone-cutting machine (Figure) comprises the base frame, onto which there are installed the working implement and the feeding mechanism with independent drives, sometimes there is mounted the console crane.

The working implement of the bar-type stone-cutting machine, namely, the guiding bar, is the flat elongated structure (the ratio of the length to width is approximately 6:1), along the periphery of which within the guides there is moving the endless chain, which is armored with the hard-alloy cutters; the motion drive is of the chain type with the electric or hydraulic motor. The bar-type stone-cutting machine moves on the rails along the stope during the process of the stone-cutting. See within the table the technical characteristics for the most distributed models of the bar-type stone-cutting machines.

During the usage of the bar-type stone-cutting machine, they commonly use the room-and-pillar system of development. Initially, they cut the bench with the transverse saw-cuts into the long columns, and then, with the longitudinal saw-cuts (horizontal under-cutting and vertical cutting), they separate the block from the stope along the entire width of the place.

(Table) The major technical data of the bar-type machines for the extraction of the facing stone
Indicators The model of the machine, company, country
KMX-2, "Mineral-komplekt" (Bulgaria) ST-VH, "Korfmann" (West Germany) ST-320, "Korfmann" (West Germany)

HR-70 VK, "F. Perie"(France)

"SEFAMA", "VAMO" (France)
The depth of the cut, millimetres 2000 2000 3200 3300 1850
The width of the cut, millimetres 40 40 40 40 28
The speed of the cutting chain, metres per second 0.6-1.25 0.3-1.4 0.6-1.25 1-3 1-3
The speed of the working feed, centimetres per minute 0.65-25 2-15 0.65-25 1-10 3-25
The established power, kilowatts 42.2 25.2 39.2 30 11.1
The mass of the machine, tonnes 4.9 2.6 4.5 - 0.75
The operational performance, square metres of the saw-cut per shift for the white marble 35 40 45 40 30

The advantage of the bar-type stone-cutting machine in comparison with the other types of the stone-cutting machines is the increased coefficient of utilization of the length of the working tool (up to 85%) with its relatively small thickness. There is ensured the performance of the deep saw-cuts, and thus the extraction of the blocks with significant size, but with small losses of the raw materials within the saw-cuts. There is intensified the process of separation of the blocks from the massif, there are increasing the height of the extracting benches, the tempo of the deepening of the open pits, the coefficient of the filling of the working space of the stone-cutting machine tools. The usage of the bar-type stone-cutting machine instead of the stone-cutting machines with circular cutters permits to decrease the losses onto the performance of the saw-cuts. The ways for the perfecting of the bar-type stone-cutting machine are the increasing of the service life and reliability of the working implement, which is achieved by the usage of the diamonds and superhard materials, by the replacement of the chain by the flexible carrying element, and so on.