Patent GB-881763-A (GB)
Title: Automatic sewing machine
IPC: D05B3/06
Filed: 1958-11-20
Abstract: 881,763. Sewing machines. SINGER MANUFACTURING CO. Nov. 20, 1958 [Nov. 25, 1957], No. 37382/58. Class 112 [Also in Group XVI] Automatic sewing apparatus comprises a sewing machine adapted on being started to operate through a predetermined sewing cycle and then to stop automatically, work-feeding mechanism adapted to advance a workpiece from a loading position to a sewing position, manuallyactuated means adapted to initiate operation of the feeding mechanism, and means adapted, on completion of a feeding cycle with the feeding mechanism in loading position and with a workpiece presented for sewing, to initiate operation of a sewing cycle. As shown, the apparatus comprises a button-hole sewing machine and a button sewing machine, both of conventional form, mounted in head to head relationship upon a table and adapted to operate simultaneously to form a buttonhole in and to sew a button upon respective ends of a shirt cuff. The shirt cuffs are fed to the machines in respective workholders fastened at intervals to an endless driving chain. A buttonhole machine 33 is mounted on a table top 5 supported by legs 7, 8, 9, 10 rising from front and rear channel members 2 and 3, and is driven by a belt 40 from a motor 38, the machine and the motor being carried by a plate 39 adapted to be moved, to adjust the machine longitudinally, by means of a screwed rod 35 and handwheel 37. The work clamp 42 of the machine is raised by a lever 44 actuated via a rod 45 from a solenoid 46. The starting lever 49 of the machine is actuated via a spring 50 from a solenoid 51. A safety switch 54 is adapted to be opened by an interlock 52 between the levers 42 and 49 to prevent the raising of the work clamp while the machine is operating. A button sewing machine 55 is mounted on a table top 6 supported by legs 20, 21, 22, 23 rising from the channel members 2, 3, and is driven by a belt 59 from a motor 56. A button-feeder 66 of known design, mounted on table top 6, is driven via a belt from a motor 67 and has a movable arm 68 adapted to place a button in the jaws of the button clamp 61 of the machine 55. Cycling of the button-feeder is started by a solenoid 77 connected to the button-feeder by a rod 79. The button-feeder actuates the starting lever 64 of machine 55 via rods 65, 71 and a lever 69, and also the button clamp lifting lever 62 via rods 63, 74 and a lever 72. The latter is adapted to close a delay switch 75 when the button clamp is lowered. Motor 56 also drives a shaft 110 via a belt 114, and shaft 110 is connected via a belt 108 and slipping clutch 107 to a shaft 87. The latter is normally held stationary by the engagement of a nose 122 on a spring-biased lever 119 with a notch 117 and shoulder 118 on a cam disc 116 fixed to shaft 87. Energisation of a solenoid 123 serves to rock lever 119 to close a switch 125 and to release disc 116, whereby shaft 87 rotates once and is stopped by the re-engagement of nose 122 with notch 117. A sprocket 84 fixed to shaft 87 engages an endless chain 81 which passes over two idle sprockets 82, 83 to form a horizontal upper run. Attached to chain 81 at intervals are work-holding trays 80, the arrangement being such that when shaft 87 is stationary, one tray is at a loading station B at one end of the upper run of chain 81, a second tray is in the stitching position A, and a third tray is in a discharging position at the other end of the upper run. One rotation of shaft 87 serves to move the tray from position A to the discharging position, to move the tray from position B to position A, and to bring a fresh tray to position B. Each tray has raised leading and trailing edges 94 and 95, and a cut-out portion 98 in which the work clamp 42 engages the workpiece held on the tray. The lefthand end of the workpiece passes under a guide 97 which positions and forces downwardly said end as it moves under the work clamp 61. A finger 99, pivoted to the leading edge 94 and spring-biased upwardly, has a contact piece 101 that is engaged by a stationary arm 102 and forced downwards, whereby finger 99 holds down the leading edge of the workpiece as it is moved under the work clamp 42. The completed workpiece on reaching the rear end of the upper run of chain 81 is thrown from the tray 80 on to the sloping lower flange 161 of an L-shaped work-receiving member 160, the upper flange 162 of which is fixed to a pivoted shaft 159, the workpiece sliding on flange 161 under a fixed guard 163 to abut a fixed wall 132 A crank arm 166 fixed to shaft 159 is connected by a link 167 to a lever 168 carrying a follower roller 170 which is biased by a spring 173 into engagement with a cam 171 on shaft 87. In the stationary position of the latter, roller 170 adjoins a radial cam surface 172, whereby, immediately shaft 87 begins to rotate, roller 170 engages surface 172 and flange 161 is thereby swung rapidly upwards to deposit the workpiece carried thereon upon a stack S of completed workpieces resting on a platform 144. Member 160 then returns to its original position in which flange 162 abuts a cushion 175. A flange depending from platform 144 is releasably secured to an endless chain 136 which passes over an upper idler sprocket 137 and a lower driven sprocket 138. The latter is carried by a shaft 140 coupled by a one-way clutch 153 to a crank arm 154 connected by a link 155 to a crank pin 156 radially adjustable on a disc 158 fixed to shaft 87. The eccentricity of pin 156 is so adjusted that one revolution of shaft 87 serves to lower platform 144 by a distance equal to the thickness of a workpiece. A source P1 of electricity supplies motors 38 and 56 via leads 184 and 185 respectively. A further source P2 supplies motor 67 via leads 186 and the control system via leads 187, 188. To initiate operation a starting switch 127 is momentarily closed by manipulating a contact piece 128. Solenoid 123 is thereby energized to swing lever 119 for releasing shaft 87 and for closing switch 125. The latter serves to energize solenoid 46 for raising the work clamp 42 and to energize a solenoid 195 to actuate a double-throw switch 196 for charging a condenser 200 via a rectifier 198 and a resistance 199. Rotation of shaft 87 serves to transfer a work piece from receiving-flange 161 to platform 144 and to move the latter a step downwards, and also to transfer a tray 80 from the loading position B to the sewing position A, and the tray from position A to the position in which it tips the completed workpiece on to flange 161. When shaft 87 is stopped after one revolution by nose 122, the opening of switch 125 serves to de-energize solenoid 46 for lowering work clamp 42 and to de-energize solenoid 195 for actuating switch 196 whereby condenser 200 discharges through a solenoid 202 to close a switch 204. The latter serves to energize solenoid 77, via an optionally used cut-out switch 129, to initiate the cycling of the button positioner 66. The latter subsequently lowers the button clamp 61 via rod 74 and lever 72 and starts machine 62 via rod 71 and lever 69. Actuation of lever 72 serves to close delay-switch 75 to energize solenoid 51 for starting motor 33, which thereby starts after the button clamp has been lowered.