Rotary hook for sewing machines

Abstract

A bobbin which is housed in a bobbin case holder is held, as it is elastically pressed by a peripheral wall of a bobbin case. Passing through a gap which is created between an outermost portion of a flange of the bobbin which is disposed on an open end side of the bobbin case holder and an inner peripheral surface of the peripheral wall of the bobbin case and between the flange of the bobbin which is disposed on the open end side of the bobbin case holder and the inner surface of an end wall of the bobbin case, a bobbin thread which is wound around the bobbin is led outside through the bobbin thread leading hole which is formed in the end wall of the bobbin case. When the bobbin thread is led out as sewing is started, since the bobbin is held as it is elastically pressed by the peripheral wall of the bobbin case within the bobbin case holder, tension force of the bobbin thread prevents the bobbin from getting displaced within the bobbin case holder in an axial line direction, and hence, an inconvenience that the tension force of the bobbin thread varies is avoided, nonuniform fastening of the thread does not result, and the quality of sewing is improved.

Dependencies are inferred from the claim text.