.~ Percussion-type sound producer (e.g., signal chimes or bells) {15}
397.5
.~.~ Polarized
DEFINITION
Classification: 340/397.5
Polarized:
(under subclass 392.1) Subject matter wherein the striking means is electromagnetically operated and comprises a permanent magnet operatively causing the reciprocating of the armature.
(1) Note. This subclass includes, for example, a permanent magnet for magnetizing the armature, thereby creating permanent magnetic flux in the air gaps between the ends of the armature and the cores; current sent through the coils, produces a flux which adds to or subtracts from the permanent magnetic flux in the air gaps causing the armature to attract or repulse from two poles of the coils thereby causing the movement of the armature to reciprocate the striking mechanism; successive reversal of current in the coil terminal changes the direction of magnetism in the air gaps and thereby causing the armature to move up and down.
