| 摘要 |
PURPOSE:To manufacture an electromagnetic type sound body having dust and water-proof construction with small size and thin thickness, by crowning the diaphragm plate of the electromagnetic type sound body at the external circumference of yoke and providing a water-proof member between the crown and watch case. CONSTITUTION:The crown 1a of a sound diaphragm plate 1 made of magnetic material is crowned on the external circumference 15 of a sound body yoke 3. An O ring is provided at the external circumference of the crown 1a for dust and water- proof, and it is fitted by using a nail 20 to the watch case 19. |
