Invention Grant
- Patent Title: Drum type, rotary, perpetual calendar
- Patent Title (中): 鼓式，旋转式，万年历
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Application No.: US68386746Application Date: 1946-07-16
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Publication No.: US2581810APublication Date: 1952-01-08
- Inventor: NICHOLS EDGAR B
- Applicant: NICHOLS EDGAR B
- Assignee: Edgar B Nichols
- Current Assignee: Edgar B Nichols
- Priority: US68386746 1946-07-16
- Main IPC: G09D3/06
- IPC: G09D3/06
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