The novel scheme can solve the problem that speed for adjusting jaw opening is too slow for the prior-art pipetongs.
新方案能够解决传统管钳调节钳口的开口量时速度过慢的弊端。
2
Lead and backup tong-men should not stand between the two pipetongs while the driller is making up or breaking out pipe or collars.
当司钻正在上卸钻杆和钻铤时，内外钳工不要站在两个大钳之间。
3
The utility model has the advantages that reversing work does not need to be carried out by manpower with pipetongs, the operators have no danger and the human casualty accidents can not occur.