| 摘要 |
994, 569. Sewing machines. SINGER CO. May 11,1964 [May 14, 1963], No. 19503/64. Heading D1G. In a lockstitch sewing machine in which a bobbin, journalled in a rotary looptaker, is adapted to be rotated, for being wound in situ, by a member movable into and out of engagement with the bobbin, said member is connected to a lever which is spring-biased for moving said member to the disengaged position and is connected to a push rod protruding through an aperture in the machine casing and being biased by spring means against the side of said aperture, the push rod being provided with latch means adapted, on depression of the push rod, to engage releasably with the machine casing. A rotary looptaker body 40, carried by a hollow shaft 25 and driven by gears 22 from a bed shaft 24, journals a bobbin 42 adapted to be rotated by a member 43 in order to be wound in situ. Member 43 is rigid with a shaft 44 which is journalled in shaft 25 and carries at its lower end a pin 47. If shaft 44 is shifted upwardly, pin 47 enters a recess 48 in the gear 22 rigid with shaft 25, and pin 49 on member 43 enters a recess in body 40. A lever 60, pivoted intermediately at 61, carries at one end a leaf spring 62 embracing the lower end of shaft 44 between collars 46 and 64 thereon. A spring75 biases lever 60 counter-clockwise to engage the cushioned upper end 77 of a pin 76 on lever 60 with the machine bed 11, and to shift shaft 44 to its lowermost and inoperative position. The other end of lever 60 is connected by a leaf spring 66 to the lower end of a rod 65 which projects upwardly through a bush 69 in bed 11, and which is biased against bush 69 by spring 66. The junction between rod 65 and a push button 68 at the upper end thereof is constituted by a shoulder 70. If the presser bar 14 is raised to lift the presser foot 81, and downward pressure is applied to push button 68, shoulder 70 is engaged with the under surface 71 of bush 69 to lock rod 65 in the depressed position and shaft 44 in the raised and bobbin-driving position. Lateral pressure then applied to button 68 serves to release rod 65 and thereby to return shaft 44 to the inoperative position. A lever 85 co-operates with a block 83 rigid with presser bar 14 to raise the latter. A cable 90 is attached at one end by a screw 91 to block 83. The other end of cable 90, after passing through a fixed guide 92, is attached to one arm 93 of a lever 94 pivoted intermediately at 95 to the machine frame. The arrangement is such that when lever 85 is actuated to raise the presser bar, the needle thread tension is released, and the end 96 of the other arm of lever 94 is moved clear of rod 65. If the presser bar is lowered while the bobbin is being driven, end 96 engages bar 65 transversely to release shoulder 70 from surface 71. End 96 then enters a notch 100 in rod 65 to prevent depression of the latter when the presser bar is lowered. Driving. A motor 26, mounted in the machine standard 12, drives the arm shaft 17 via a worm 27 and worm wheel 28. |
