HOOK FOR LOCKSTITCH SEWING MACHINE COMPRISING AT LEAST ONE TENSION SPRING TO CREATE A STABLE TENSION OF THE BOBBIN THREAD

摘要

Hook (11, 12, 13, 14) for a lockstitch sewing machine, or parts of the hook such as the support element of the tension spring (in particular the basket or the bobbin case) or the tension spring itself, including a tension spring (80, 90, 100, 110, 120) that includes a bending towards the outside (with respect to the support element on which it is mounted and with respect to the main bending radius of the tension spring) of the tension spring's extremity designed to press on the bobbin thread, so that the pressure point (P) on the bobbin thread is the point of tangency between the bending radius (R) of the bending of the tension spring's extremity and the support element of the tension spring, so as to generate a stable tension of the bobbin thread.

主权项

1. Hook (11, 12, 13, 14) for lockstitch sewing machine, comprising a tension spring (80, 90, 100, 110, 120) bent with a main bending radius towards the inside of its support means on which it is mounted, in particular the bobbin case (8) or the basket (6) of the hook, and a bobbin (4) on which is wound the bobbin thread, wherein said tension spring comprises a bending towards the outside, with respect to the support means on which it is mounted and with respect to said main bending radius of the tension spring, of the extremity of the tension spring designed to press on the bobbin thread, so that the point of pressure (P) on said bobbin thread is the point of tangency between the radius (R) of said bending towards the outside of the extremity of the tension spring and said support means of the tension spring, so as to generate a stable tension of the bobbin thread.