Patent SE-304670-B (SE)
Inventor: SAGI Z
IPC: D05B81/00
Filed: 1968-03-06
Abstract: 1,165,102. Sewing machines. SINGER CO. 4 March, 1968 [7 March, 1967], No. 10305/68. Heading D1G. A zig zag sewing machine in which the lateral movements of the needle bar are controlled by programme means is provided with means, under control of the programme means, for interrupting the endwise reciprocation of the needle bar at predetermined intervals for producing skip stitching, and means for selectively rendering the needle bar interrupting means non-responsive to the programme means. The needle bar 20, carrying a needle 21, is releasably coupled to means 104 actuated by a crank 106 on the arm shaft 54. The needle bar is slidable in an arm 22 pivoted on a fixed vertical pin 24 and pivoted to one end of a pitman 26. A spring 32 acts on the latter to bias a plate 28, pivoted at 30 to the other end of pitman 26, against a pair of cam followers 42, 44 interposed between plate 28 and a stack 46 of pattern cams rigid with a shaft 48 driven via gearing 50, 52 from shaft 54. Pitman 26 is connected to a handle 58, manipulation of which serves to shift pin 30 either opposite one or the other of the cam followers or between the latter. Follower 42 is pivoted and axially slidable on a vertical pin 60. A blade 66 passes through a slot in the hub of follower 42 into engagement with a selected one of a series of notches 64 formed in pin 60 in correspondence with the cams of stack 46. Blade 66 is rigid with a crank 78 on a shaft 76 journalled and axially slidable in the machine frame and provided with a handle 84. pressure on the latter shafts shaft 76 axially against the bias of a spring 86 to disengage blade 66 from pin 60 and to engage crank 78 with an arm 80 rigid with follower 42 for disengaging the latter from stack 46. Turning of handle 84 then serves to align blade 66 with a selected notch 64. Cam 44 is pivoted on a vertical pin 62 formed with notches 70 selectively engageable by a blade 72 rigid with an arm 94 on a bracket 88 pivoted and axially slidable on shaft 76 and provided with a handle 92. Pressure on the latter shifts bracket 88 axially against a -spring 100 to disengage blade 72 from pin 62 and to engage an extension 96 of arm 94 with an arm 98 rigid with follower 44 to disengage the latter from stack 46. Turning of handle 92 then serves to align blade 72 with a selected notch 70. The coupling means 104 comprises a pair of vertical flanges 108 interconnected by a horizontal pin 110 apertured vertically to receive a sleeve 112 secured thereto by a screw 114. A plate 118, secured to sleeve 112, is formed with a horizontal slot 122. A coupling lever 124, pivoted to plate 118, is biased by a spring 128 to pass through slot 122 and an aligned slot (132) in sleeve 112 into engagement with a notch (116) formed in the needle bar 20 slidable axially in sleeve 112 and plate 118. An arm 134 is pivoted at its lower end on a fixed pin 136 and is pivoted at its upper end to one end of a slidable bar 138, the other end of which is formed with a slot 150 engaged by a pin 148 rigid with a lever 142 pivoted at its inner end on a fixed pin 144 and selectively engageable with notches 146, 147 formed in the machine frame. When lever 142 engages notch 147, arm 134 is pivoted out of the range of movement of lever 124 and normal zig zag stitching is effected. When lever 142 engages notch 146, arm 134 is so positioned as to be engaged by lever 124 during the right hand swing of needle bar 20. The arrangement is such that lever 124 moving upwards in sliding engagement with arm 134 is pivoted progressively away from needle bar 20, and disengages from notch (116) when the needle bar is near the top of its stroke, whereby no stitch is produced during the right hand swing to produce skip stitching. The needle bar is halted in its position of disengagement by a friction arm 156 pivotally mounted on the presser bar 157 and slidable on a fixed rod 153 against the bias of a compresssion spring 161. For skip stitching, the follower 44 is arranged to co-operate with a special cam 158.