| 摘要 |
PURPOSE:To prevent the damage of the supporting and holding part of an elastic body against the pressing of the elastic body by making a system in which a recessed spherical face receives a fulcrum spherical body when a pushing operational part on the upper face of a key top member is pressed and the fulcrum spherical body held by the elastic body is prevented from moving. CONSTITUTION:When either one of pushing operational parts 2a,...2a formed up and down and right and left on the upper of a key top member 2 is pushed, the key top member 2 is pushed down against the elastic force of the skirt part 51b which holds a short column head part of a movable supporting part 51 of an elastic body 5 in the pushed side. Consequently, a recessed spherical face 22 of the key top member moves closer to a fulcrum spherical body 3 and is brought into contact with a projected spherical face in the upper part of the fulcrum spherical body 3. The slanting movement of the member 2 is carried out in the side toward which the spherical body 3 contact-slides on the projected spherical face. Then, while the recessed spherical face 22 is brought into contact with the spherical body 3 and the spherical body 3 works as a fulcrum, the member 2 slantingly moves further and a contact point pushing part 21 pushes down the movable supporting part 51 further and brings the movable contact point part 51a just under the part 51 into contact with an electrode 4a on a substrate and shuts a circuit. When the member 2 is released from being pushed, the member 2 returns to the original position due to the restoring force of the elastic body 5. |
