| 摘要 |
A sewing machine is equipped with an automatic control assembly for the needle bight and/or the feed dog. The control assembly comprises a control cam block having a plurality of juxtaposed cam track portions to be operatively connected, through a contact mechanism, to the sewing machine needle or to a device for setting the feed dog. The contact mechanism comprises a contact finger which can be set by a handwheel, and a cam track connected to the handwheel, against one of the various cam track portions. The handwheel is mounted on a shaft carrying the control cam block, while the cam track connected to the handwheel forms a ring surrounding the control cam block. The contact finger directly engages the cam track, so that a control assembly of small overall length and having a small number of parts is obtained. To make straight seams, the contact finger can be displaced through the cam track into a position laterally of the control cam block, in which a contact member connected to the finger engages against stepped abutment surfaces of one of a set of switch cams which are also part of the handwheel.
|
