Patent ID: 8939097
Filing Date: 2015-01-27
Classification: D05B

Abstract:
1. A threading device for a sewing machine lower looper that passes a looper thread through a looper eye of the lower looper on the underside of a needle plate, comprising: a first moving member with a threading member fixed to one end thereof, with the threading member having a hook part that can be inserted into the looper eye of the lower looper; a second moving member that is connected to the first moving member in such a manner as to be able to move in a direction opposite to that in which the first moving member moves, with an operating member being connected thereto on the same side as the hook part; and a lock lever having, in a lower part thereof, a convex part that engages with a groove of a groove cam attached to a main shaft and, in an upper part thereof, a protruding part that comes into contact with the operating member, wherein when the convex part of the lock lever engages with the groove, the operating member and the protruding part of the lock lever are separated from each other, which prevents movement of the second moving member from being restricted.