| 摘要 |
<p>The generator includes a permanent magnet and a concentric stationary coil, mounted for relative axial translation. The permanent magnet and the coil have rest positions in which two poles, directed radially of the magnet, are aligned with two flanges on a stationary core member which supports the coil. The rest position of the magnet is determined by its magnetic field and by the contour of the core. A cooperating cam element and a cam follower element are connected respectively to the magnet and to the coil, and follow their axial movements. One of the cam elements is rotated by the rotation of the meter, through a drive gearing including two elements constructed to provide for a substantial backlash. As the meter turns, the cam and follower cause relative axial movement between the magnet and the magnet core, away from their rest positions, being driven slowly by the meter. The backlash between the gearing elements is taken up at this time by the driving force acting through the cam and follower. Substantially no current is induced in the coil at this time. When the cam follower reaches the end of a helical riser on the cam, the follower drops off the riser of the cam and into a recess on the follower so that the magnet is restored to its rest position, with a slight amount of over-travel. During this rapid return, a sharp pulse of electrical current is produced in the coil and is delivered to appropriate pulse counting mechanism located remotely from the meter. The backlash in the gearing is freed at this time, so that there is no frictional engagement between the cam and follower during this rapid return.</p> |
