71545475
Dec 26, 1947
Nov 14, 1950
SURGICAL DRAINAGE PUMPS EACH HAVING A WORKING CHAMBER LINED WITH AN ELECTRICAL RESISTANCE FILAMENT ALTERNATELY ENERGIZED AND DE-ENERGIZED TO EFFECT EXPANSION AND CONTRACTION OF THE GAS THEREIN AND VALVED TO PROVIDE AN UNIDIRECTIONAL FLOW OF THE GAS THERETHROUGH
Medical, Beauty & Agricultural