United States Patent 2796691
Inventors:
William, Norris
Publication Date:
06/25/1957
Assignee:
CROWN CONTROLS COMPANY INC
Other Classes:
42/106, 473/583, 473/578, 42/99
International Classes:
F42B6/04; F42B12/36; F42B6/00; F42B12/02
Foreign References:
| NO27349A | | | | |
| IT411731B | | | | |
| FR910493A | | | | |