Abstract: A self-releasing and self-locking string locking mechanism for adjusting a string includes a fixed seat mounted on a stringed instrument, a worm shaft, a worm gear, a rotating shaft and a sleeve. The worm shaft drives and rotates the worm gear, and is installed on the fixed seat. The rotating shaft, pivotally connected on the fixed seat and secured on the worm gear, includes a self-releasing thread having a pitch thread between 1.25 mm and 1.6 mm and applied with a lubricant, and a locking pin. The sleeve is for the locking pin to be inserted therein, and internally includes an inner thread corresponding to the self-releasing thread and a lower surface for the locking pin to abut against. The sleeve is further provided with a through opening for the string to pass through near the lower surface.

Abstract: A turning peg structure equipped with changeable faceplate to drive a winding shaft assembly of a string instrument to adjust the tightness of a string. The turning peg structure includes a bracket, at least one first faceplate, at least one second faceplate and a linking rod. The bracket includes a plate and a passage embedded in and run through the plate. The plate includes a first side and a second side opposite to the first side. The first faceplate includes a first connecting portion connected to the first side of the bracket. The second faceplate includes a second connecting portion connected to the second side of the bracket. The linking rod has one end located in the passage and another end engaged with the winding shaft assembly. Through the bracket, the turning peg structure does not lose string adjustment function due to damage thereof.

Abstract: A string adjustment apparatus includes an outer shell, an adjustment stem member, a winding shaft member and a base. The outer shell includes a housing recess and a recess opening. The adjustment stem member includes a stem and a turning peg. The winding shaft member includes a shaft, a worm gear portion and a string hole portion. The base includes a plate corresponding to the recess opening and a first tube extended from the plate towards a direction remote from the outer shell. The worm gear portion and the stem are located in the housing recess and coupled with each other. The shaft runs through the first tube to make the string hole portion to pass through the first tube and also make the plate to cover the recess opening. Thus, a simpler structure is formed to make assembly easier.

Abstract: A string tension adjustment structure includes a dock, a winding axle longitudinally coupling with the dock that has an upper end fastened to a worm gear held in the dock and a lower end to wind a string, and a transverse rotary knob running through the dock that has a worm at one end to engage with the worm gear. The dock has a pair of insertion troughs to hold a U-shaped elastic reed. The elastic reed has a pair of clipping blades each has a notch at the top portion to clip an indented neck formed on the worm to anchor the rotary knob on the dock. The structure is simpler and fabrication and assembly are easier.