Abstract: There is described a device for unwindng thread by means of which the bobbin can easily rotate about the pin when a pull is exerted on the thread, but which stops the bobbin very rapidly when said pull on the thread stops, in such a way that the thread is thus no more unwound. The cross-section of the pin when considered at a right angle to the lenthwise direction thereof and the inner cross-section of the bobbin sleeve, also as considered at a right angle to the lengthwise direction thereof, at least where the sleeve and the pin engage one another, are so selected as to make possible a sidewise movement of the bobbin relating to the pin and at least where the sleeve and the pin engage one another, the one cross-section is circular while the other cross-section has a shape which is substantially different from a circular shape.

Abstract: The rotary hook of a sewing machine is provided with a beak portion which extends substantially tangentially outwardly away from the circumferential wall of the rotary hook to capture the needle thread loop at new point radially outwardly of the rotary hook thereby allowing for a shorter needle stroke so that the tip of the needle does not penetrate into the bobbin supporting basket.