sewing machine

摘要

A sewing machine (100) comprising: a looper (132) which links an upper thread (T, T ') and a lower thread (Td, Td') together by engaging the thread through a needle eye (131a, 131a ') of a sewing needle ( 131, 131 ') catches the upper thread (T, T'); a thread lever (133) which has a small hole (113a) through which the upper thread (T, T ') is guided and which holds the upper thread (T, T ') lifts from a sewing material (Ob, Ob'), which is an object to be sewn, by lifting the small hole (113a) from a lower turning point to an upper turning point; a central foot (135, 135 '), which prevents the sewing material (Ob, Ob') from being lifted; a drive source (136) which drives the central foot (135, 135 '); a transport unit (P1) which transports the sewing material (Ob, Ob'); anda tension monitoring unit (1A3c) which monitors an upper thread tension on the basis of a force exerted by the upper thread (T, T ') on the central foot (135, 135') by the central foot (135, 135 ') during transport of the sewing material (Ob, Ob ') is brought into contact with the upper thread (T, T') by the transport unit (P1).