Patent ID: 6810824
Filing Date: 2004-11-02
Classification: D05B

Abstract:
A sewing or embroidery machine (1) with a hook (15) driveable by a drive motor and with a lower thread bobbin (17) rotatably mounted therein for receiving a lower thread supply, the bobbin having a hollow cylindrical arbor and annular flanges (21, 22) set on the arbor ends, of which at least one of the flanges (21) having perforations (19) therethrough, or provided with non-reflecting markings, a light source (35), which emits a light ray beam of conical shape, and two photosensors (43â€², 43â€³) for receiving the light rays (37) emitted from the light source (35) at two spaced-apart locations, and a calculating and control unit (45) for processing signals supplied by the photosensors (43â€², 43â€³), wherein the light source (35) and the two photosensors (43â€², 43â€³) are arranged axially spaced in front of the flange (21) with the perforations (19) or markings (19â€²); and the light rays (37) are directed at an acute angle onto a front surface (39) of the flange (21).