Tape or film cassette play counter and lock - prevents use after completion of predetermined number of plays and has cam acting on toothed blocking wheel on counter-plate

On a backplate (28) of the appts., a locking wheel (17) is partially toothed and operated by a cam (2), a swinging beam (25) and a feeler mechanism (11-14). A locking stop (19) and a rearming lug (22) are provided on the untoothed portion of the locking wheel (17). A tube (26) allows access for a key or pin through an opening (27) for setting the rearming lug (22) against a head (23). The locking wheel (17) may be combined with a toothed counting wheel (7) which counts the operations of the cassette and displays the number in a window. The appts. can be incorporated in a system for determining a number of plays, after which the reeling of tape or film is prevented by such a counter. LE DISPOSITIF COMPREND, DANS UNE CONTREPLAQUE 28, UNE ROUE DE COMPTAGE 7 QUI EST PARTIELLEMENT CRANTEE EN 18 ET QUI EST ACTIONNEE PAR UNE CAME 2, UN BALANCIER 25 ET UN MOYEN FAISANT OFFICE DE PALPEUR 11, 12, 13, 14; SUR LA PARTIE NON CRANTEE DE LA ROUE 17 SONT DISPOSEES UNE BUTEE DE BLOCAGE 19, UNE BUTEE DE REARMEMENT 22 A LAQUELLE ON ACCEDE PAR UN TUBE 26 OUVERT EN 27 ET QUE L'ON MANOEUVRE JUSQU'A UN TETON DE REARMEMENT 23; LA ROUE DE BLOCAGE 17 PEUT ETRE COMBINEE AVEC UNE ROUE DE COMPTAGE 7.L'INVENTION S'APPLIQUE AUX CASSETTES A RUBANS OU FILMS SUPPORTS DE SONS, IMAGES OU AUTRES SIGNAUX.