Patent search ap:("SASKATCHEWAN POTASH") AND inv:"NUTT JOHN G" Page 1

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发明授权
Machine and method for mining underground deposits 失效
Title translation: 矿井采矿机及方法

公开(公告)号：US2754101A

公开(公告)日：1956-07-10

申请号：US7177449

申请日：1949-01-21

Applicant: SASKATCHEWAN POTASH

Inventor： NUTT JOHN G , HAWORTH RUSSELL G

IPC: E21C27/24 , E21D9/13

CPC classification number: E21C27/24 , E21D9/13

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