| 摘要 |
The sewing machine has a differential work transport, consisting of a lower main feed and lower and upper auxiliary feeds, with the step sizes of the auxiliary feeds being adjustable, from a step size substantially in accordance with the step size of the main feed, against spring bias. The step sizes are adjusted by respective setting devices having associated setting members connected, through a lever drive, to a common actuating device. The lever drive interconnecting the setting members of the setting devices for the lower and upper auxiliary feeds is operable to vary the step sizes of the lower and upper auxiliary feeds so that one of said lower and upper auxiliary feeds increases as the other of said lower and upper auxiliary feeds decreases. The transmission ratio of the lever drive is adjustable, and the lever drive includes a driver connection operative in one direction only.
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