Patent GB-952023-A (GB)
Title: Work stacking mechanism for sewing machines
IPC: D05B41/00
Filed: 1962-08-13
Abstract: 952,023. Conveyers for sewing machines; stacking. SINGER CO. Aug. 13, 1962 [Aug. 24, 1961], No. 31016/62. Headings B8A and B8C. [Also in Division D1] A sewing machine is provided with workstacking means comprising a work support which receives workpieces from the sewing machine and has a plurality of spaced parallel slots, work-carrying means arranged to rise through the slots to pick up a workpiece, to move the workpiece on to a stack and to retract from the slots, and means for engaging the workpiece to hold the latter against movement during retraction of the work-carrying means. A sewing machine 3 is mounted on a table top 1 which is supported by a stand 2 and has an extension formed with an end recess 9. A bar 11, fixed across the inner end of the recess, carries a series of spaced-apart, substantially horizontal fingers 10. On completion of a workpiece the thread chain is severed by a knife 12, and the workpiece is transferred by a swinging foot 28 to the fingers 10. Further fingers 113 then rise through the fingers 10 and transfer the workpiece to a plate 57, on which the workpiece is held by fixed rods 72 and movable fingers 124 while the fingers 113 retreat. Plate 57 is arranged to move downwards each time a workpiece is stacked thereon. A frame 15, fixed to table top 1, carries a motor 16 driving a rotary crank arm 19. The latter is pivoted to an intermediate point on a bar 20, one end of which is slidable in sleeves 22 rigid with a pin 21 pivoted in frame 15. To the other end of bar 20 is pivoted at spaced-apart points a pair of bars 23, 24 which are also pivoted to a bar 25, a spring 26 connected between bars 23, 24 biasing a stop member 27, carried by bar 20, against bar 20. Foot 28 is pivoted to the lower end of bar 25, and a bar 30 rigid with and depending from the latter is connected by a pivotal link 31 to an auxiliary foot 32. In the normal and stationary position of crank 19, a lug 34 rigid therewith engages a crank 44 on a pivoted shaft 45 having a trip finger 46 which opens a normally-closed switch 47 (not shown) to de-energize motor 16. On completion of a workpiece, a treadle 33 is momentarily depressed to close a switch for energizing motor 16. Arm 19 then rotates clockwise, and continues to rotate as lug 34 frees crank 44 to enable switch 47 to close. Auxiliary foot 32 first engages the completed workpiece in the vicinity of sewing machine 3, and on further rotation of arm 19 moves rearwardly adjacent foot 28 to tension the thread chain. Lug 34 then engages a crank 35 on a pivoted shaft 36 carrying a trip finger 37 which momentarily closes a switch 38 to actuate the solenoid-operated knife 12. In the course of continued rotation of arm 19, during which foot 28 transfers the workpiece to the fingers 10, lug 34 engages a crank 40 on a pivoted shaft carrying # trip finger which momentarily closes a switch 43 (not shown) to energize a motor 97, adapted to actuate the fingers 113 for moving the workpiece from fingers 10 to plate 57. Fixed to the table top 1 on opposite sides of the opening 9 are respective bars 48 and 49. Depending from the latter at the outer ends are bars 50, and at the inner ends bars 51. Bars 50 and 51 are connected together at their lower ends by bars 52 which support a plate 53. Bar 49 and a bar 52 are connected together by a vertical channel bar 55. Bar 48 and the other bar 52 are connected together by a vertical angle bar 56. The plate 57 carries rollers 59 engaging the channel bar 55, and a roller 61 engaging a flange of bar 56. Plate 57 is connected to endless chains 62 carried at their upper ends by sprockets 63 on a shaft 64, and at their lower ends by sprockets 65 on a shaft 66, the latter being connected via gears 68 and 69 to a motor 67. Holes 70 formed in plate 53 are vertically aligned with holes 71 formed in plate 57. Rods 72 fixed in holes 70 at the inner end of plate 53 pass loosely through the corresponding holes 71. Similar rods 136 are provided at the outer end of plate 53. The substantially horizontal fingers 113, which are vertically aligned with the spaces between the fingers 10, are rigid with a horizontal bar 112 pivoted at the upper post of a movable frame 77. The weight of fingers 113 pivots bar 112 to engage an arm 117 thereon with a stop 118, whereby a trip finger 115, rigid with bar 112, is disengaged from a normally-open switch 116 carried by frame 77 to de-energize motor 77. A fixed bar 84 is formed with a horizontal channel 83 engaged by a pair of rollers 82 carried by a member 78, and the latter is formed with a vertical channel 80 engaged by a pair of rollers 79 carried by frame 77. A pair of fixed plates 87 are each formed with an inwardly-facing guide channel comprising an upper horizontal run 90, a lower horizontal run 91, a descending run 92 and an ascending run constituted by a member 93 pivoted at 95 to the respective plate 87. The channels are engaged by respective rollers 89 carried by the frame 77. The shaft 99 of motor 97 carries a crank arm 100 coupled by a connecting rod 104 to frame 77. When the latter is stationary, and at the inner end of the guide channels, a lug 105 rigid with crank 100 engages a crank 106 on a pivoted shaft 107 carrying a trip finger 109 which opens a switch 110 to deenergize motor 97. When switch 43 is closed to start motor 97, lug 105 frees crank 106, allowing switch 110 to close for continued running of motor 97. Frame 77 then moves outwardly, and the rollers 89 move into the upper runs 90, whereby the fingers 113 ascend through the fingers 10 to pick up the workpiece from the latter and to transfer it to a position above plate 57, the workpiece being engaged by stops 114 provided on the fingers 113. During the return movement of frame 77 the fingers 113 initially descend into engagement with plate 57 or the workpieces stacked thereon, the workpiece carried by the fingers 113 being retained on plate 57 by the rods 72 while the fingers retract. Engagement of fingers 113 with plate 57 or a workpiece thereon causes pivoting of bar 112 to close switch 116 momentarily, whereby motor 67 operates to lower plate 57 a short distance. Near the end of their return movement the rollers 89 displace the pivoted members 93, frame 77 being stopped at the end of the return movement when lug 105 re-engages crank 106. The fingers 124 are carried by a pivoted bar 125 carrying a crank arm 127 adjustably connected by a pivotal link 128 to one end of a lever 129, the other end of which is connected by a pivotal link 132 to a bar 133 slidable in a vertical slot 134 and biased upwardly by a spring 121. A pair of vertical bars 119, rigid with bar 133 and slidable in fixed sleeves 120, have horizontal extensions 122 which are positioned, when the rollers 89 are in the lower runs 91, immediately below rollers 123 (not shown) carried by the frame 77. The arrangement is thereby such that the descent of frame 77 is cushioned by spring 121 when the accompanying depression of the bars 119 stresses the latter, while the fingers 124 pivot downwardly to engage the workpiece transferred to plate 57 during the first half of the return movement of frame 77, the free ends of the extensions 122 being downwardly inclined to free the bars 119 thereafter.