United States Patent 2629981
Inventors:
Raphael, Melik-minassiantz
Publication Date:
03/03/1953
Assignee:
Raphael, Melik-minassiantz
Other Classes:
968/359, 368/285, 224/164, 63/29.100
International Classes:
G04B37/14
Foreign References:
| CH70941A | | | | |
| CH138954A | | | | |
| CH170503A | | | | |
| CH179155A | | | | |
| CH185202A | | | | |
| CH214435A | | | | |
| AU112154B | | | | |