Patent GB-950568-A (GB)
Title: An overedge stitching machine
IPC: D05B1/20
Filed: 1962-03-30
Abstract: 950,568. Sewing. VIRGINIO RIMOLDI & C. S.p.A. March 30,1962 [April 6, 1961], No. 12422/62. Heading D1G. In a sewing machine adapted to trim the edges of workpieces and to secure the latter together by a two- or three-thread overedge seam and a parallel line of two-thread chain stitching, and comprising a longitudinal driving shaft located under the work-supporting plate, and a needle bar carrying two needles, movement of the chain stitch looper parallel to the axis of said shaft is derived from an arm carrying the overedge stitch under looper, and movement of the chain stitch looper transverse to said shaft is derived from an eccentric carried by the latter adjacent its end beneath the work-supporting plate. Multi-needle machines, stitch-forming. Figs. 1,2,3,4. A shaft 22 is oscillated through 60 degrees, via a connecting rod 21, from a main shaft 17. A crank-pin 23 on shaft 22 is pivoted to a bar 24. One end of the latter is pivoted at 25 to an arm 26 pivoted about a fixed pin 26a, and the other end is pivoted at 27 to a member 28 slidable on a fixed bar 29. Pin 23 is arranged to oscillate 30 degrees on each side of the line which passes through the pivots 23,25,27 perpendicularly to the path of pivot 27. The axis of shaft 22 lies midway between the path of pivot 27 and a parallel line passing through pivot 26a. The distance between pivot 23 and the axis of shaft 22 is 1/6th of the distance between the path of pivot 27 and the parallel line passing through pivot 26a. It is stated that this arrangement produces substantially rectilinear movement of the slide 28, maximum lateral displacement of the latter for a stroke of 25 mm. not exceeding 2 microns. Slide 28 carries needles 30 and 31. Needle 30 cooperates with looper 40 and 49 to produce overedge stitching. Needle 31 co-operates with a looper 50 to produce two-thread chain stitching. Looper 40 is carried by an arm 39 rigid with a pivoted shaft 38 carrying an arm 37 coupled by a connecting rod 36 to a crank-pin on shaft 17 for oscillating arm 39. Looper 49 is carried by a bar 45 slidable in a sleeve 46 pivoted about a fixed axis normal to the axis of bar 45. The latter is pivoted to an arm 44 rigid with a pivoted shaft 43 which also carries an arm 42 coupled by a connecting rod 41 to a crank-pin on shaft 17, whereby bar 45 reciprocates in sleeve 46 and the latter oscillates. Looper 50 is carried by an arm 51 rigid with a pivoted and axially slidable shaft 52: Arm 51 is coupled by a link 58 to arm 39 for oscillation with the latter. A pivoted shaft 66 carries at one end a forked arm 63 engaging abutments on shaft 52, and at the other end an arm 68 coupled by a connecting rod 70 to an eccentric on shaft 17, whereby shaft 52 is reciprocated for imparting needle-avoiding movements to looper 50. Thread passes to looper 50 via a pair of guides 78, 79 situated on opposite sides of a vertically-adjustable horizontal plate 77, the thread being held against plate 77 by a slotted leaf spring 80. A cam 78 on shaft 17 passes through the slots to act upon the thread between the guides 78,79. Work feeding. Figs. 2, 3, 4, 10,11. An eccentric 100, mounted loosely on shaft 17, has a lateral projection 101 adjustably slidable in a sleeve 72 rigid with shaft 17, for permitting variation in the eccentricity of eccentric 100. The latter is coupled by a connecting rod 73 to an arm 104 rigid with a pivoted shaft 105. An arm 126 rigid with the latter, is connected by a link 125 to a feed bar 120 carrying a feed dog 129. An arcuate arm 106, rigid with shaft 105, carries a slidable member 107 which is connected by a link 108 to a feed bar 119 carrying a feed dog 128, and is also connected by a link 109 to an arm 110 rigid with a pivoted shaft 111. A lever 74 carried by the latter can be secured in adjusted angular position by a knob 113 to fix the stroke of feed bar 119. Alternatively, lever 74 may be moved to vary the stroke of feed bar 119 during operation of the machine. Feed lift movement is imparted to the feed bars 119,120 by an eccentric 121 on shaft 17. The feed bars, at their ends remote from the feed dogs, are slidably mounted on a pivoted block 122. Work holding. Fig. 11. A presser foot 13 is carried by a presser bar 12 pivoted at its other end by a vertical pin 133 to a lug 134 rigid with a horizontal pin 135 pivoted in the machine frame. An arm 137, rigid with pin 135, lies within a recess in bar 12. A rod 14 is biased downwardly by a spring 15 to engage a roller 14a with a notch 12b in bar 12. The latter may be raised via an arm 136 rigid with pin 135, stress on which is relieved the inter-action of arm 137 with bar 12. A rod 139, biased downwardly by a spring 140, has a flange 138 underlying a lug 14b on rod 14. Rod 139 may be raised by a lever 141 to release roller 14a from bar 12, when the latter may be swung outwardly about pin 133. Frames, lubricating, work trimming. Figs. 2, 3, 4,14. The upper casing 1 of the machine is supported by an oil seal gasket 2 carried by a lower casing 3 containing a lubricant pump driven by a pulley 4 via the belt which drives the handwheel on the main shaft 17. The upper part of casing 1 is closed by a transparent cover 5 having a domed portion 5A which protudes through an opening formed in an outer cover 6. A connecting rod 32 couples a crank-pin on shaft 17 to an arm 33 on a pivoted shaft 34 which carries a worktrimming blade 35. The latter co-operates with a fixed blade located in a notch 146 formed in the needle plate 16. The trimmings pass down a channel 147 bounded by a rib 148 on a cover 149 providing lateral access to the lower part of casing 1. Cover 149 is hinged at its lower edge about a pin 150 and is fixed to the closed position by a spring 152.