| 摘要 |
<p>An electric door comprises a positive and reverse motor, a band brake and three control buttons for raising, descending and intermediate position respectively, wherein three limit switches are provided, with an intermediate limit switch (SQ2) being disposed between an upper end switch (SQ1) and a lower end switch (SQ3). The electric door can be operated to reach a half-opened position by only pressing the control button for intermediate position one time.</p> |
