Ua hoʻokomoʻia ka pahu pahu lima lima lima e ka ingersoll-randco. I ka makahiki 1912. E like me keʻano mana, ua maheleʻia iʻehā mau māheleʻehā: pneumatic, hydraulic, ka uila a me ke kala a me ke kala kūloko ʻO Pneumatics ka mea nui loa. He kūpono nā Drill Rock Rock i lalo no ka laweʻana i lalo i lalo a iʻole nā lua kīwī nui. ʻO ka Drill Diameterʻo 19 ~ 42mm, a me ka hohonu hohonu o ka hohonu loa he 5m,ʻoi aku ka liʻiliʻi ma lalo o 2.5m. Hoʻohana pinepineʻia nā Drills Pneumatic Hand-By Rock Drills i kahi ikaika o 15 ~ 45J, kahi hopena o ka mahina he 27,7N
POST manawa: Mar-31-2021
