Thread hooking device for a hemming device of a sewing machine

A thread hooking device for a hemming device of a sewing machine, comprising a swing arm with one end connected to and moved by a drive shaft, and at another end of the swing arm being provided a first hook which is provided at one end thereof with a thread hole for the passage of a thread, an elongated thread groove being formed on a surface of the hook portion and having one end connected to the thread hole, the thread hooking device being characterized in that:

• in the middle of the first hook is formed a guide portion with a first end and a second end, a thread hooking member is slidably mounted on the guide portion and located at the second end of the guide portion, at one end of the thread hooking member is formed a thread hooking portion, the thread is inserted into the thread groove via the thread hooking portion and then extends out of the thread hole;
• the thread guiding member moves from the second end of the guide portion to the first end of the guide portion, when the thread hooking is aligned to the first end of the guide portion, the thread is inserted through the thread hole, moving the thread hooking member to the second end of the guide portion makes the thread insert in the thread groove
• a stop portion is formed at a lower portion of the first end of the guide portion, at the first end of the guide portion is formed a protrusion with an inclined bottom, the lateral wall is provided with an extension portion located corresponding to the lower portion of the first end of the guide portion and a push portion located corresponding to the guide portion, beside the push portion is a stop member which has one end fixed to the lateral wall, and another push end, the thread hooking member is located at the second end of the guide portion to provide an elastic force in such a manner that the push end is pushed against the inclined bottom, and the extension portion is stopped from moving back by the stop portion.