Description
Class G08B : SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
Subclass 5/20: Visible signalling systems, e.g. personal calling systems, remote indication of seats occupied (display of time signals G04B 19/00, G04C 17/00, G04C 19/00, G04G 9/00; for display of alphanumeric information G09F; flags, banners G09F) using hydraulic transmission; using pneumatic transmission with indicator element moving rectilinearly with reset means necessitating a separate operation to return the indicator element