Pulling string apparatus of stringing machine

A pulling string apparatus of a stringing machine comprising a string gripper, a sensor, a drive element, a transmission mechanism and a control circuit;

• the sensor is connected with the string gripper to detect the pull force of the string gripper, then the detected pull force value is transferred to the control circuit;
• the control circuit compares the detected pull force value with a pre-set value, and control the rotation of the drive element according to the comparison result;
• the transmission mechanism comprises a mounting base, a sliding block, a transmission rack and a drive gear;
• wherein the drive gear is connected to an output shaft of the drive element and is engaged with the transmission rack, the sliding block is arranged on the transmission rack and is connected with the sensor;
• the mounting base is configured with guide rods, wherein the sliding block is slidably mounted on the guide rods;
• when the sensor and the string gripper are driven forward by the sliding block under the act of the transmission rack engaged with the drive gear, the racket string will be tensioned;
• when the sensor and the string gripper are driven backward by the sliding block under the act of the transmission rack engaged with the drive gear, the racket string will be loosened.