Rototrol Trademarks

ROTOTROL
VALVE MEANS FOR USE WITH SWIMMING AND BATHING POOLS
Expired  ·  March 17, 1966  ·  72241284  · 
ROTOTROL
ROTATING REGULATORS FOR CONTROLLING THE EXCITATION OF ELECTRIC GENERATORS
Expired  ·  October 10, 1942  ·  71456135  ·