Patent GB-1035375-A (GB)
Title: Semi-automatic sewing machines
Inventor: SMIRNOV NICKOLAI TROFIMOUICH
IPC: D05B29/06
Filed: 1964-07-08
Abstract: 1,035,375. Sewing machines. SHVEINAJA FABRIKA NO. 9, UPRAVLENIJA SHVEINOI PROMYSHLENNOSTI MOSGORSOVNARKHOZA. July 8, 1964, No. 28107/64. Heading D1G. A sewing machine adapted for sewing padding to a garment comprises a sewing head driven along guide members, a table for supporting the garment, a platform for supporting the padding, presser feet engaging the padding and being carried by levers releasably held in the lowered position against spring bias, a feed wheel set at an angle to the stitching line and driven at a peripheral speed greater than the movement of the sewing head, and shears for cutting the sewing threads at the end of the stitching. A stand comprises end wall 4, 5 supporting the ends of guide rods 1, 2 and a lock 48. A sewing head 8 is supported by means of rollers on the rods 1, 2, and is driven therealong in one direction or the other by the alternative engagement of driven pinions, carried by head 8, with rack 48. The machine serves to sew padding, biased by separate and adjacent presser feet 106 against a fined platform 101, to a garment biased by a bar 165 against a table 157. Six presser feet each 200 mm. long are used. It is stated that the plurality of side by side presser feet enables a curved seam to be sewn in a straight line initially. Driving. The main shaft 22, Fig. 2 (not shown), of the sewing head 8 is driven by a motor 34 via a belt 38 movable from a loose pulley 37 to a fast pulley 36 by a fork rigid with a frame 41, Fig. 8 (not shown), pivoted at 172, when frame 41 is locked by actuation of a handle 46, rigid therewith, against the bias of a spring 43. Frame 41 is held in the operative position by the engagement of a lug 99 thereon with a notch in a lever 94 pivoted at 95 and biased against lug 99 by a spring 98. Manual actuation of lever 94 serves to disengage the latter from lug 99. In normal operation the drive is automatically started and stopped at the beginning and end respectively of the operative leftward movement of sewing head 8. For this purpose a roller 87, Fig. 5 (not shown), slidably carried on a rod 86 rigid with frame 41, co-operates with an abutment 93 adjustably fixable in the right hand end of bar 1, to shift frame 41 to the operative position. At the end of the operative movement of the sewing head, a tongue 97, Fig. 8, on lever 94 engages an abutment 100 adjustably fixable in the left hand end of bar 1 to disengage lever 94 from lug 99. A treadle 174 is connected by a linkage to a switch 180 for starting and stopping motor 34. Feeding. A gear box 50, Fig. 14 (not shown), carries a plate 56 pivoted intermediately on a shaft 63. Plate 56 carries end pins 55 and 62 journalling respective gears 54 and 61 driven in opposite directions from motor 34, Fig. 2, via a belt 71, the speed of gear 61 being three times that of gear 54. A lever 65, Fig. 12 (not shown), pivoted at 66 to gear box 50, is biased by a spring 64 towards plate 56 and is formed with a tooth a normally engaged in the central one of three notches in plate 56 to hold gears 54 and 61 disengaged from rack 48. Pin 55 is connected by a link 78, Fig. 5, to a pivoted handle 49, the arrangement being such that when handle 49 is swung in one direction, plate 56, Fig. 12, is swung clockwise to engage gear 54 with rack 48 and tooth a with the upper notch. Machine head 8 then moves operatively leftwards. Handle 49 may also be swung in the opposite direction to engage gear 61 with rack 48 and tooth a with the lower notch, for moving the machine head rightwards. The machine is arranged for automatic reversal of the machine head at the end of the operative movement. To this end a lever 79, Fig. 12, pivoted intermediately at 80 to lever 65, is formed at one end with a tooth b and is pivoted at its other end to a rod 81 which projects outwardly from the machine head frame. At the end of the operative movement, a lug 82 rigid with handle A9 engages and compresses a spring-biased plunger 83 mounted in the end wall 4. Rod 81 simultaneously engages wall 4, whereby lever 79 is turned clockwise to engage tooth b with a notch in plate 56, when lever 79 co-operates with a pin 84 on lever 65 to disengage tooth a from plate 56, tooth b also becoming disengaged. Expansion of plunger 83 then serves to turn handle 49 for engaging gear 61 with rack 48. At the end of the return movement, gear 61 engages a non- toothed part 93 of the rack bar. A feeding wheel 124 is also provided, set at an angle of 20 degrees to the line of stitching and carried at the free end of a pivoted arm 130, Fig. 5, biased upwardly by a spring 128. When frame 41 is moved to the operative position, a roller 200 thereon swings a pivoted member 134 to engage a leaf spring 136 with arm 130 for lowering wheel 124. A cord fixed at its ends to the end walls 4, 5 passes around pulleys 131 on the sewing head and around a pulley rigid with wheel 124 and having a diameter 30 per cent less than that of wheel 124. The needle bar 12, Fig. 2, is mounted in a frame 14 pivoted about a vertical axis on pins 15, 15. A follower roller, adjustably carried by frame 14, co-operates with a cam 21 on shaft 22 for oscillating the needle bar in the direction of work feed, the amplitude of oscillation being half a stitch length. Thread tension release. A rod 171, Fig. 8, rigid with frame 41 passes slidably through a guide 173, the arrangement being such that when frame 41 is moved to the operative position, the wedge-shaped free end of rod 171 moves between the discs of the thread tension 170 to relieve the thread tension. Threads cutting. An arm 142, Fig. 8, rigid with a brush 141 pivoted on a pin 140, carries at its free end a pair of shears blades 143, the movable blade being biased to the closed position by a spring 144. Arm 142 is normally biased against an abutment 146 by a spring 152. At the end of the leftward operative movement of the sewing head, a roller 148 carried by a rod 147, rigid with brush 141, engages an abutment 151, carried by end wall 4, to swing arm 142. The movable blade is thereby first opened then closed, to sever the upper and lower threads, by co-operation of a cam member 145, rigid with the movable blade, with a pivoted member 149 resting on an abutment 150. Work holding. A pair of arms 154, pivoted to the stand and biased towards the serving head by springs 159, is rigid with a table top 157 and with a trough 158 beneath the latter. The garment contained in trough 158 has an edge position supported on table top 157 and held thereon by a bar 165 which is pivoted at its ends to table top 157 and is biased thereagainst by a spring 166 acting through a linkage 167, 168, Fig. 2. The padding is supported by a fixed platform 101 and its edge is held thereon by a plurality of presser feet 106. Each of the latter is carried by a curved arm 105, Fig. 10 (not shown), pivoted at 103 to platform 101 and biased upwardly by a spring 109 supported by a vertical plate 102 rigid with platform 101. An eccentric sheave 111, pivoted on plate 102, is rigid with a handle 112, and a strap 116 on sheave 111 is rigid with a bar 114. The arrangement is such that lowering of handle 112 serves to move bar 114 into engagement with a vertical plate 115 on arm 105 for depressing the latter. A bell crank lever 118, Fig. 4 (not shown), pivoted to plate 115, has a horizontal arm disposed beneath rod 114 and a hook-ended vertical arm. A hook-ended arm 122, pivoted on the serving head, rides over the vertical arms of the bell crank levers 118 during the operative leftward movement of the serving head, but turns the bell crank levers 118 in succession during the return rightward movement of the serving head to release the rods 114 from the plates 115. A handle 123, rigid with arm 122, may serve to raise the latter from engagement with the bell crank levers 118.