Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication date
Publication of BE554715ApublicationCriticalpatent/BE554715A/xx
H04Q5/00—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange
H04Q5/02—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange with direct connection for all subscribers, i.e. party-line systems
H04Q5/14—Signalling by pulses
H04Q5/16—Signalling by pulses by predetermined number of pulses
C—CHEMISTRY; METALLURGY
C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
C11D1/02—Anionic compounds
C11D1/12—Sulfonic acids or sulfuric acid esters; Salts thereof
C11D1/22—Sulfonic acids or sulfuric acid esters; Salts thereof derived from aromatic compounds