A guide to the electrical patents granted ... as described in the Official gazette grouped in the classes and subclasses of the Manual of classification of the United States Patent Office.Electrical, including communications and radiant energy. C1. 179: Sub. 1 the center channel loudspeaker normally being audible within the said area wherein sounds from the right and left channel loudspeakers are also audible. ... first voltage also located in said central station, signalling means located in said central station, a manual switch located in said remote station and operable to complete a firstanbsp;...
|Title||:||The National Catalog of Patents|