Patent ID: 8919268

Claim:
A sewing machine needle bar changing device, comprising: a cylindrical needle bar case having longitudinal slide ways, a pivoting section, and a plurality of spaced needle bar holes on a portion of the needle bar case so as to be circumferentially arrayed, each of the needle bar holes having on at least one side thereof at least one of the longitudinal slide ways which communicates the needle bar hole with an external space; a cylindrical needle bar case holder being located at one side of the cylindrical needle bar case and having a control guide way formed thereon, the control guide way having a longitudinal opening, and facing towards each of the longitudinal slide ways; a plurality of needle bars being received in the needle bar holes in a one-to-one correspondence and each carrying a needle, the needle bars in the needle bar holes being engaged with the longitudinal slide ways and the control guide way at a same time so as to both prevent the needle bars from rotating in the needle bar holes, and limit axial motion of the needle bars except a first needle bar of the needle bars that is moved to align with the longitudinal opening; a needle bar guide member being engaged with the first needle bar that is moved to align with the longitudinal opening, the needle bar guide member being connected to and brought by a crank link on a sewing machine to move upward and downward; and a driving mechanism connected to the pivoting section for driving the cylindrical needle bar case to display by rotating and providing a locating function, so as to change positions of the needle bar holes relative to the needle bar guide member, so that a selected one needle bar hole of the needle bar holes is selectively rotated to a sewing position, at which the needle bar in the selected one needle bar hole is in line with the longitudinal opening and the needle bar guide member, the needle bar in the selected one needle bar hole that is selected and rotated to the sewing position can be brought by the needle bar guide member to axially move upward and downward synchronously with the needle bar guide member, while all other needle bars of the needle bars that are not located at the sewing position are restricted by the control guide way from axially moving upward and downward.