Rotary shuttle for sewing machine

A rotary shuttle for a sewing machine comprising:

• a hook body (10) having a lower part to which a drive shaft is rotatably coupled;
• a lower thread base (20) that is coupled to an inner circumference of the hook body (10) to rotate in a direction opposite to the hook body (10) when the drive shaft rotates and includes a concave groove (21) recessed in a downward direction on an upper part of a main wall, and a lower thread case (30) surrounding upper and lateral parts of a lower thread (A) that is inserted into the lower thread base (20) to expose an upper part thereof,
• wherein:
• the lower thread case (30) includes a protrusion (31) that protrudes to be inserted into the concave groove (21) by spring elastic force, a hook (32) having one end coupled to a hook coupling hole (31a) formed in the protrusion (31) and moving the protrusion (31) in an inward direction when a remaining end is lifted, a case body (33) that includes a protrusion inlet (33a) formed on an upper part thereof to allow opposite lateral parts of the protrusion (31) to be inserted thereinto and to be supported by spring elastic force and is shaped like a cylinder with an opened lower surface to insert the lower thread (A) thereinto, and a bobbin shell (34) coupled to one side of an outer circumference of the case body (33) and including a lower thread hanger (34a) bent inward at one end to guide the lower thread (A) when the lower thread (A) is pulled out;
• and
• the protrusion inlet (33a) includes a lower thread concave groove (33a′) formed in one end thereof to be positioned inward to guide the lower thread (A) when the lower thread (A) is pulled out.