Sewing machine having needle bar oscillating mechanism, needle bar interrupting mechanism and thread tension releasing mechanism

摘要

A sewing machine has a needle bar up/down moving mechanism, a needle bar oscillating mechanism, a needle bar interrupting mechanism, a thread tension adjusting mechanism, and a thread tension releasing mechanism. The sewing machine further includes a driving mechanism that transmits a driving force of an electric motor to the needle bar oscillating mechanism, the needle bar interrupting mechanism and the thread tension releasing mechanism. The driving mechanism comprises a first cam and a second cam which are driven by the electric motor. The first cam has an oscillating cam face that controls the needle bar oscillating mechanism and an interrupting cam face that controls the needle bar interrupting mechanism. The second cam has a releasing cam face that controls a thread tension releasing mechanism. Therefore, the needle bar oscillating mechanism, the needle bar interrupting mechanism and the thread tension releasing mechanism can be driven by a common electric motor.