| 摘要 |
<p>372,078. Control of motors. POOCK, O. M., 1517, E. 3rd Street, Dayton, Ohio, U.S.A.-(Assignee of Powell, W. C. ; 1702, Huffman Avenue, Dayton, Ohio, U.S.A.) April 21, 1931, No. 11799. Convention date, June 11, 1930. [Class 38 (iii).] Continuous reversals.-A motor driving a gear polishing-machine as described in Specification 375,475 is started by momentary closure of push-button 34, thereby causing closure of electromagnetic switch 20 to complete the forward circuit of the motor, the switch being maintained closed over contacts 33. At the end of a given forward rotation, a limit switch 31 is automatically moved by the motor with a snap-action to engage contact 26. This causes opening of switch 20 and closure of switcht 21 to complete the backward circuit of the motor. At the end of the backward rota. tion, the switch is moved to re-engage contact 25. This causes switch 21 to open, but switch 20 does not reclose until button 34 is again closed, so the motor comes to rest.</p> |
