| 摘要 |
315,883. Etablissements E. Jaeger, (Assignees of Planiol, J. H.). July 20, 1928, [Convention date]. Electric and magnetic speed indicators.-Comprises a construction of electric speedometer and drive therefor. A resistance 1 is wound on a ring and is fed at two opposite points 2, 3 by a source of direct current 4. Brushes 5, 6, 7 on the shaft 8, the speed of which is to be measured, pass over the resistance 1 and the multiphase currents pass to a receiver comprising an asynchronous motor. The multiphase currents from the brushes 5, 6, 7 are sent in windings 9 only one of which is shown. These windings have a core 10 and the magnetic flux closes through a part 11. In the air gap between the parts 10, 11 is arranged a metal bell 12 mounted to rotate about an axis 13, 15 against the influence of a torsion spring 16. The amount of rotation of the bell corresponds to the speed of the shaft 8 and is indicated by a pointer 17. Means are described for compensating for variation in potential of the battery 4. The shaft 8 may drive the distance counter through a worm and cam switch device electrically, or the counter may be actuated by a metal element rotating in the air gap of the receiver and subjected to a braking torque proportional to the speed as in known power meters. |
