| 摘要 |
PROBLEM TO BE SOLVED: To smoothly and reliability form loop sewing seams in a sewing machine which forms the loop sewing seams with a plurality of needles respectively having a needle thread and a looper having a looper thread. SOLUTION: The loop sewing machine is provided with: the plurality of needles which are vertically moved by penetrating the needle hole of a needle board and which have the needle thread; the looper having the looper thread which is reciprocatively moved in a direction crossing with a cloth feeding direction in the lower part of the needle board; a guide hole which is provided in the needle board which guides the loop formed by the needle thread and the looper thread in cooperation between the needle and the looper to a rear part in the cloth feeding direction; and a main feed dog which is disposed to be rear from the guide hole in the cloth feeding direction and which feeds the loop in the cloth feeding direction. In the loop sewing machine, an upper end edge in the rear part of the guide hole in the cloth feeding direction has a planar shape which is crossed with the cloth feeding direction and which changes in the right part as it gradually approaches the needle. Besides, the thread guide surface in which chamfering is formed in the upper end edge is provided, which chamfering gradually becomes shallower as it approaches the upper surface of the needle board from the left part to the right part.
|
