The utility model belongs to the technical field of sewing machines, and particularly relates to a cutter mechanism for a
sewing machine, which comprises a casing, an upper shaft arranged in the casing, a cutter component mounted at the head of the front end of the casing, a mounting seat arranged on the side of the front end of the casing, a cutter shaft arranged in the mounting seat, and a cutter
crank I mounted on the periphery of one end of the cutter shaft. The other end of the first cutter
crank is connected with the upper shaft through an eccentric connecting rod, the periphery of the other end of the cutter shaft is provided with a second cutter
crank, the other end of the second cutter crank is connected with a first connecting rod, the other end of the first connecting rod is connected with a second connecting rod, and the other end of the second connecting rod is provided with a
clutch piece so as to be connected with or separated from the cutter
assembly. In the actual working process, the cutter shaft is driven to move through the upper shaft, then the cutter
assembly is driven to move up and down through the first connecting rod and the second connecting rod, the cloth
cutting action is achieved, the mechanism is simple in design, the number of parts is small, and cost is reduced.