发明名称 Clip-on compass
摘要 The invention is in the field of compass course following and comprises a means and method of mounting a compass directly on a map with a North-South reference line and following a course on the map directly once the compass needle is aligned with North. In all references to the direction "North" throughout this document magnetic North only shall apply.
申请公布号 US4404752(A) 申请公布日期 1983.09.20
申请号 US19810270083 申请日期 1981.06.03
申请人 HANNA, JOHN W. 发明人 HANNA, JOHN W.
分类号 G01C17/18;(IPC1-7):G01C17/04 主分类号 G01C17/18
代理机构 代理人
主权项
地址