Kerf machine

KERF MACHINE (EN: coal cutter; DE: Schrammaschine; FR: haveuse; ES: rozadora de carbon; RU: врубовая машина) is the mining machine, which is purposed for the creation of the kerf (slot) within the massif of the useful minerals (coal, petroleum shale, salt, coquina, tuff, and so on) with the purpose of the facilitation of its subsequent excavation. This machine can work under the conditions of the flat, inclined, and steep seams.

The first kerf machine has been produced within the United Kingdom during the 1852; the working tool of the machine in the form of the disk with the cutters was brought into the rotational motion by two workers. During the middle of the 50-ies of the 19th century, there have emerged within the United Kingdom the kerf machines of the rod type, initially with the pneumatic mover, and later with the electric mover. During the 1864, there has been produced the kerf machine of the chain type with the bar. The kerf machines of the disk, rod, and percussive types have been displaced during the 30-ies of the 20th century by the machines with the bars of the chain type, which have been equipped with the cutters. The production of the fatherland kerf machines has been organized for the first time at the Gorlovka industrial plant during the 1927. Within the USSR, during the 1928, there worked at the underground coal mines 549 kerf machines, during the 1950, there worked 4815 machines (the maximal quantity), and during the 1976, there worked 163 machines.

The structure of the kerf machines comprises the executive tool (bar, rod), the transmission, the mechanism for the advancing (for the movement), and the electric or pneumatic motor. The types of the executive tool, of the mechanism for the advancing, of the type of the energy, which is consumed, and of the method for the regulation of the rate of the advancing, form the basis for the classification of the kerf machines. The major types of the kerf machines are: with the transversal bar, with the longitudinal bar, with the rotational bar, and universal.

The modern kerf machine ("Ural-33") has the hydraulic mechanism for the advancing, which permits to perform (with the help of the mineral oil pump and hydraulic motor) the stepless regulation of the speed of the advancing from 0 to 8 metres per minute. The kerf machines may be used both during the preparatory works, and during the clearing works, in case of the multi-operational technology of the excavation, which is including the following operations: the creation of the kerf, the drilling of the blastholes, the blasting breaking and the loosening of the useful minerals, the bulk loading of these minerals onto the stope conveyor or into the minecarts. The usage of the combined mining cutting-loading machines has limited the field of the usage of the kerf machines. On the basis of the kerf machines of the bar type, there have been created the bulk loading machines, the bulk loading kerf machines, and the first designs of the combined cutting-loading machines for the extraction of the coal. The characteristics of the fatherland kerf machines are listed within the Table.

(Table) The characteristics of the fatherland kerf machines
The name of the machine The length of the bar, metres The speed of the advancing, metres per minute The power of the motor during the prolonged periods (hour), kilowatts The year of the creation
DL (from the Donetsk city, lightweight)* - - 2.2(7) 1928
DT (from the Donetsk city, heavyweight) 1.45-2.22 0.53-1.36; 12 8(25) 1928
DTK (from the Donetsk city, heavyweight, of the rope type) 1.65-2.22 0.53-1.36; 14 8(25) 1932
BSH-1 (of the bar type, for the drifts, on the spacing strut and carriage) 1.8 - 5.6(15) 1934
SHVK-48 (for the drifts, for the kerfs, from the Donetsk city, on the spacing strut and carriage) 2.4 0.33; 3.33 14(35) 1935
GTK-3 (from the Gorlovka city, heavyweight, of the rope type) 1.6-2 0.58; 6.6 8(25) 1935
LVSH-2 (lightweight, for the kerfs, for the drifts, on the slab) 1.4  0.33; 3.33 7(18) 1936
SV-3 (from the Stahanov city, for the kerfs, with the curved bar) 2.05 0.75; 10.6 8(30) 1936
VTU (for the kerfs, heavyweight, universal, with the rotational bar) 2.84 0.87; 16.8 15(35) 1937
GVU (from the Gorlovka city, for the kerfs, universal, with the rotational bar) 2.88 0.73; 14.05 21(41.5) 1938
KMP-2 (from the Kopeysk city, powerful, with the pulsating advancing) 1.6-2.8 0-0.86; 8.6 15(47) 1945
MV-60 (powerful, for the kerfs) 2-2.8 0.27-1.08; 14.5 28.5(60) 1946
GTK-35 1.6-2.2 0.2-0.8; 12 14(35) 1949
KMP-3 2 0-1.4; 8.6 22(50) 1951
"Ural-33" 1.6-2 0.75; 10.6 33(80) 1960
*The executive tool is the percussive-rotational rod with the drilling crown.