Producing Acoustic Time Signals By Electrical Means (for Mechanical Clocks Or Watches Subclasses 225 And 243) [g04c 21/00] Patents (Class 968/580)

Cross-Reference Art Collections

Constructional details (subclasses 582 and 588 take precedence) (sound- producing devices in general g10k, e.g., 1/00) [g04c 21/02] (Class 968/581)

Indicating the time of the day (acoustic indication of time subclass 217) [g04c 21/04] (Class 968/582)

By striking mechanism [G04C 21/06] (Class 968/583)
By electro-acoustic time means [G04C 21/12] (Class 968/586)

Producing the signals at adjustable fixed times [g04c 21/16] (Class 968/588)

By mechanically unlocking an electromechanical vibrator, e.g., actuated by the leakage flux of the electric driving means, etc. [G04C 21/18] (Class 968/589)
By closing a contact to ring an electromechanical alarm [G04C 21/20] (Class 968/591)
By closing a contact to put into action electro-acoustic means, e.g., awakening by music, etc. [G04C 21/28] (Class 968/596)
With provision for a number of operations at different times, e.g., ringing the bells in a school, etc. [G04C 21/30] (Class 968/597)
Devices on watches or similar portable timepieces [G04C 21/34] (Class 968/602)
Signal-repeating devices [G04C 21/36] (Class 968/603)
Adjusting the duration of signals [G04C 21/38] (Class 968/604)

There are no patents to show for this class.