29. PROCEDURE FOR SELECTING RIPPER POINT 29.1 PROCEDURE FOR SELECTING RIPPER POINT 5-6 Install standard point B No (Less than 70%) (Only type of Yes point is worn) Dose rock have high Is wear fast ? Install point E quartz contents ? Excessive generation Yes (Over 70%) of heat at point (Whole point is worn evenly) No Yes Yes Are thermal Do impact force Install point Install point F D cracks produced ? cause breakage ? No No Does it penetrate ? Does impact Does it penetrate ? Install (Can it be used force cause (Can it be used standard to end ?) breakage ?
to end ?) point B Yes No No Yes No ,.../ Soft Hard Basalt, andesite, granite, chest ‡ Proportion of quartz is not so high (40% – 70%) ‡ Rock is not in layers or seams, so heat is generated at point, point wear rapidly, ripping is difficult Point G ‡ Symmetrical shape ‡ Red ‡ Short 195-78-71390 Point F ‡ Non-symmetrical shape ‡ Red ‡ Short 195-78-71330 Point E ‡ Non-symmetrical shape ‡ Red ‡ Long 195-78-71350 ,/ Soft Medium Sandstone ‡ Proportion of quartz is high (70% – 95%), point wears rapidly Point D Non-symmetrical ‡ shape ‡ Yellow ‡ Long 195-78-71340 ,.../ Soft Hard All type of general rock — Point C ‡ Symmetrical shape ‡ Yellow ‡ Short 195-78-71370 Point B Non-symmetrical ‡ shape ‡ Yellow ‡ Short 195-78-71320 Shale, limestone ‡ Little quartz, little wear ‡ Deposited in layers, so ripping is easy Point A Non-symmetrical ‡ shape ‡ Yellow ‡ Short 195-78-71420 1 Procedure 2 Procedure Check wear 3 Procedure Check for cracks or breakage 4 Procedure Check penetration Hardness Type of rock Features Features Shape Part No.
Typical rock Suitable point