Audible Indication Patents (Class 340/384.1)
- Rotary actuator (Class 340/392.2)
- Plural armatures (Class 340/393.1)
- Battery operated (Class 340/393.2)
- Pushbutton (Class 340/393.3)
- Including timer (Class 340/393.4)
- Volume control (Class 340/392.3)
- Alternating current (Class 340/401.1)
- Nonelectrical driving means (e.g., spring or weight) (Class 340/398.1)
- Tubular sound producer (e.g., signal chimes) (Class 340/392.4)
- Resonator (e.g., signal chimes) (Class 340/392.5)
- Suspended (e.g., locomotive bell) (Class 340/395.1)
- Armature support (Class 340/397.1)
- Interrupter (Class 340/397.3)
- Polarized (Class 340/397.5)
- Housing or mounting (Class 340/396.1)