| 摘要 |
<p>PROBLEM TO BE SOLVED: To make intermittent oscillating movement possible by providing a spring which, when an engaging member engaged with the projecting part of the disc member only within the required range is disengaged, restores the engaging member to its initial position, the disc member being eccentric with respect to a drive shaft. SOLUTION: A disc member 15 has a projecting part 15a formed on its outer peripheral surface, and a cup-shaped member 16 is provided with an engaging member 17 which projects inward radially. A drive shaft 12 and a driven shaft 10 are provided in such a way as to be eccentric with respect to each other. When the disc member 15 is rotated by the drive shaft 12, the inner end 17a of the engaging member 17 is engaged with and disengaged from the projecting part 15a of the disc member 15, converting rotation of the drive shaft 12 in one direction into the intermittent oscillating movement of the driven shaft 10. One end of a power spring 18 is secured to the boss part of the cup-shaped member 16, and when the drive shaft 12 side of the inner end 17a is disengaged from the projecting part 15a, the cup-shaped member 16, i.e., the driven shaft 10, is returned in its original direction by the resiliency of the power spring 18. With a brush surface pressed against teeth along the direction of alignment of the teeth, the toothbrush oscillates intermittently through a predetermined angle, thus allowing ideal toothbrushing.</p> |
