| 摘要 |
<p>To lower the sewing machine (1) threader (11) for the threading operation, the threader (11) is constructed for connection with the needle shaft carrier decoupled from the needle shaft. The threader can be transferred between a position of use and a parking position in the lower side (13) of the upper arm (7) and vice versa. Additional lifting movements of the threader are caused by the motor operating the mechanism driving the pressure foot. To couple the needle (17) shaft (21) carrier to the threader, a swinging lever is articulated to the threading device and driven by the pressure foot drive mechanism. To coupling with the lever, the pressure mechanism is constructed for additional downward movement. The lever is constructed to clip onto a pin on the needle shaft carrier. To regulate thread tension, the drive motor is connected to a carrier disc. The disc has two directions of rotation (-, +). In the first (-) it is connected to the thread brake. In the second (+) it is connected to a thread deflection lever, which moves it between resting- and deflected positions. The thread deflection lever is swung by a tooth segment on the carrier disc between the drive motor and the thread brake. This tooth engages the thread deflection lever, when the carrier disc is turned in the second direction (+).</p> |
