| 摘要 |
1,021,286. Sewing machines. LOUIS HAND Inc. Aug. 17, 1964, No. 33496/64. Heading DIG. A sewing machine comprises an electricallyheated thread-cutting member which is located forwardly of the sewing needle, is movable between positions respectively above and below the horizontally-extending path of work feed and is normally biased to its upper position, suction means located adjacent said path and cutting member, and means actuated by the advance of a work piece past a predetermined point for urging the cutting member to its lower position and for releasing the cutting member for return to its upper position upon passage of the work piece past said predetermined point. An L-shaped throat plate 12 is flush with the work-supporting plate 13 and is secured to a plate 22 which is secured to the undersurface of plate 13. An aperture 16 is defined by one edge 14 of the throat plate and the adjacent edge of plate 13. The presser foot 18 has secured to one edge an arm 20 which is flush with the undersurface of the presser foot and which is disposed above the aperture 16. An arm 30 is pivoted to a flange 26 on plate 22 and comprises an upper conducting bar 32 separated by insulation 34 from a lower conducting bar 33. Bars 32, 33 are connected together at one end by a U-shaped resistance element 40 disposed in the line of stitching but normally positioned above the work-supporting surface. A member 49, pivoted at 48 to a flange or plate 22, is disposed in aperture 16 between edge 14 and arm 20, and, has a forked end 50 which embraces arm 30. When the leading edge of a work piece is fed beneath the presser foot 18 by the dogs 17 to engage the member 49, the latter is pivoted to depress the heated element 40 below the work-supporting surface. When the trailing end of the work piece releases member 49, element 40 rises to sever the thread chain adjacent said trailing end. The continuing thread chain then passes into a suction duct 51 and is severed adjacent the leading edge of the succeeding work piece when the latter engages member 49. |
