| 摘要 |
PURPOSE:To attain to enhance a printing speed by effectively and rapidly suppressing rebound, by attracting the flight hammer driven by a piezoelectric element by a permanent magnet. CONSTITUTION:In a printing hammer for a dot impact type printer, when a flight hammer 13 is contacted with the force transmitting member 15 connected to the leading end of a piezoelectric element 11, the magnetic flux generated from a permanent magnet 18 passes through a first yoke 16, the flight hammer 13 and a second yoke 17 to be returned to the permanent magnet 18 as shown by an arrow B. Therefore, attraction force acts on the flight hammer 13. Because the flight hammer 13 flies out forwardly during printing operation, the magnetic flux generated from the permanent magnet 18 reaches the second yoke 17 through the first yoke 16 and does not pass through the flight hammer 13 and, therefore, almost no attraction force 13 acts on the flight hammer 13. Because large attraction force acts only when the flight hammer 13 is contacted with the force transmitting member 15 as mentioned above, rebound can be rapidly suppressed without almost exerting adverse effect on printing operation. |
