DEVICES USED FOR IN SITU MEASUREMENTS OF COAL-CUTTING FORCE

Kings College Wedge Tester.-This device measures the cutting force and displacement. It does not easily permit spaced grooves.

Figure 1.-Kings College wedge tester.

Czech. ZP-1 Hydraulic Linear Cutter.-The ratio of cutting force to depth of cut is used as the cuttability index.

Figure 2.-Czech. ZP-1 hydraulic linear cutter.

Polish Haremza Spring-Loaded Linear Cutter.-Knowing the spring constant and the measured cut length achieved by the available spring force, the work required to cut coal is calculated. This is considered to be a measure of coal cuttability.

Figure 3.-Polish Haremza spring-loaded linear cutter.

Russian Lubimov Borehole Tester.-The ratio of the pull force to the volume of coal cut is the measure of the available spring force, the work required to cut coal is calculated. This is considered to be a measure cuttability for this tester.

Figure 4.-Russian Lubimov borehole tester.

Polish Komag Rotary Cutter.-The ratio of the mean force to the mean depth of cut is used in conjunction with the lateral breakout angle of the coal for a measure of cuttability.

Figure 5.-Polish Komag rotary cutter.

Russian Przenasny Pryzrzad PR-5 Borehole Tester.-The ratio of the pull force to the cut is the measure of cuttability of this tester.

Figure 6.-Russian Przenasny Pryzrzad PR-5 borehole tester.

Russian Przyrzad SDM-1 Hole-Expander Drill.-The force resisting the hole-expanding drilling operation is cuttability index.

Figure 7.-Russian Przyrzad SDM-1 hole-expander drill.

May,2005