| 1. | New electric leakage protection device of electric coal drill
一种新型的煤电钻漏电保护装置 |
| 2. | Problems and countermeasures of electric coal drill comprehensive device
煤电钻综合装置的问题及对策 |
| 3. | Flameproof hand - held electric coal drill
隔爆型手持式煤电钻 |
| 4. | Flame - proof rapid interruption geb for underground coal drills
煤矿用隔爆型快速断电煤电钻综合保护装置 |
| 5. | Diamond core bit for coal drilling
煤田钻探金刚石取心钻头 |
| 6. | Development of comprehensive protective device of electric coal drill motor
煤电钻电动机综合保护装置的研制 |
