| 摘要 |
PURPOSE:To obtain an accurate car speed by preventing the chattering of a content point by vibration, by providing a groove having magnets provided to both sides thereof to the outer periphery of a rotor so as to extend along the rotary direction of said rotor and arranging a lead switch in said groove. CONSTITUTION:A groove 6 is formed to the outer periphery of a rotor 5 and magnets 7 are fixed to the outer peripheral part of said rotor 5 at mutually opposed positions while a lead switch 3 having a contact point 4 is provided so as to be positioned in the groove 6. When the rotor 5 is rotated, the magnets 7 are rotated and the contact point 4 of the lead switch 3 is turned ON and OFF. A car speed is detected from the intermittent signal of said lead switch 3. By this constitution, the change in a magnetic field acted on the lead switch 3 is reduced even if vibration is applied and the stable intermittent signal can be obtained. Therefore, an accurate car speed can be detected. |
