| 摘要 |
<p>1,096,274. Sewing machines. LIGHT'S LONDON Ltd. March 5, 1965 [March 9, 1964; July 30, 1964], No. 9939/64 and 30203/64. Heading D1G. Apparatus for securing together plies of material along a predetermined path comprises a tool, a work-holder rigid with a template and releasably secured to a carriage movable in a plane transverse to the tool in two directions mutually at right angles, first and second ram means for moving the carriage in a respective direction, a fixed guide element engagable with the template whereby operation of the ram means constrains the carriage to move along the predetermined path, and fluid pressure supply means, the rate of flow of fluid to the ram means being controlled by the forces exerted on the ram means due to engagement of the template with the guide element. As shown, a work-holder 134 is formed with two pattern slots 234, each defining the edge of a shirt collar and engagable by bosses on the respective presser feet 18 of two synchronously-driven sewing machines 2 and 4, and work-holder 134 is secured to a universallymounted carriage driven by rams 100 and 124, whereby, during operation, the slots 234 are traversed by said bosses. The work-holder comprises a lower sheet 230 and an upper transparent sheet 232 interconnected by a fabric hinge 244'. End bosses 246 and intermediate bosses 250 on sheet 230 project through aligned recesses in sheet 232. The pattern slot in sheet 232 is the width of the boss on presser foot 18, and is aligned with a narrower, needle-passing slot in sheet 230. Work pieces placed between the sheets are held by fabric discs (238), Fig. 10, on sheet 232 entering recesses (240) in fabric sheets (242) on sheet 230, and by fabric discs (244) on sheet 232 engaging sheet 230. The work-holder, supported by a table top 6, abuts a bar 140 comprised in the carriage, and is formed with a central notch engaging a lug on bar 140. A rod 142, journalled on bar 140, carries fingers 146 biased by a spring 150 against blocks 148 on sheet 232. The fingers 146 may be raised by a handle 144 for releasing the work-holder. Bar 140 is connected by a pair of U-shaped rods 136 to a bar 122 slidable in an angle bar 118 parallel to the length of the work-holder. Bar 118 is secured to three spaced-apart bars 110 slidable in respective fixed angle bars 112 disposed at right angles to bar 118. A doubleacting fixed hydraulic ram 100 has a through piston rod secured at its respective ends to the centre bar 110 and to bar 118 for moving the carriage front to rear and vice versa. A doubleacting hydraulic ram 124, carried by bar 118, has its piston rod secured to bar 122 for moving the carriage left to right and vice versa. Each ram is controlled by a slide valve spring biased to one end position for directing pressure fluid to one end of the ram, and movable to the other end position by an energised solenoid for reversing the ram. Pressure fluid is supplied by a pump 152 driven by crank means 158. The output of the pump is controlled by a needle valve for varying the stitch length. The rams are by-passed by a normally-closed valve which is opened when a bellows-operated microswitch is actuated by excess fluid pressure. Said microswitch is also closable manually to permit of manual operation of the carriage. The machines 2, 4 support an instrument panel and are interconnected by a shaft 30 coupled to the machine main shafts via respective gear boxes 36. A pulley 28, journalled on shaft 30 and driven via a belt 26 from an electric motor, is rigid with a boss 46 formed with splines 48 slidably supporting a driving clutch element 50. A driven element 52, rigid with shaft 30, is magnetised on energisation of a coil 58 to attract element 50. A brake element 72, slidable on splines 76 rigid with shaft 30, is attracted to a fixed 'brake element 82 on energisation of a coil 80. A solenoid 22 is energised to lift the presser bar 20 against spring bias via a flexible cable 24. With the carriage in its rearmost position, a fixed two-way limit switch 310, is actuated by an abutment 312 on a sliding bar 110 to deenergise the clutch coil 58 and to energise the brake coil 80. A two way switch 336 may then be actuated for energising the solenoids 22 for lifting the presser feet 18 and opening a pair of switches in series with the clutch coil 58. A bottom thread cutter is acutated, simultaneously with the raising of the presser feet, by solenoids connected in parallel with the solenoids 22. To initiate operation with the carriage in its leftmost and rearmost position, a switch 382 is actuated for selecting right hand movement, switch 336 is actuated for lowering the presser feet, and a starting switch 374 is momentarily actuated for de-energising the brake coil 80 and energising the clutch coil 58. Upon actuation of the limit switch 310, permanent disconnection and connection respectively of the brake and clutch coils is effected. For sewing the collar edge pattern, the only longitudinal movement required is from left to right. The carriage must move forwardly for sewing the right hand side of the collar and also at the left hand end of the collar front, and must move rearwardly at the right hand end of the collar front and at the left hand side of the collar. To effect said rearward movements of the carriage, an actuator 262, carried on a bar 263 rigid with the presser bar 20 of machine 4, is arranged to engage respective cam bars 258 and 256 provided on the upper sheet 232 of the work-holder at positions respectively parallel to the right hand end of the collar front and to the left hand side of the collar, for actuating a microswitch, via a flexible cable, to energise the solenoid controlling the reversal of ram 100. A second actuator 260 is provided on bar 263 for actuating a microswitch controlling the operation of ram 124. and appropriate cam bars may be provided for engaging actuator 260 for reversing the side to side movement of the carriage in accordance with pattern requirements. Actuation of limit switch 310 at the end of the stitching serves to connect the clutch coil 58 through a variable resistor 350 effect slow running until a cam 84 on shaft 30 acuates a microswitch to de-energise clutch coil 58 and to energise brake coil 80 to stop the machines with the needles raised. The apparatus is provided with means to enable back stitching to be effected at each end of the seam. For this purpose the limit switch 310 is arranged to be initially engaged, but not actuated, by the moving abutment 312 when the needles are about 3/4 inch from the ends of the slots 234, a further moving abutment 536 acuates a microswitch 512 when the needles reach the ends of the slots for energising a relay to reverse the action of the rams, and limit switch 310 is actuated by abutment 312, on the return movement of the latter, to stop the machine. The apparatus may comprise more than two machines operated from shaft 30, or it may comprise only one machine. Various warning lamps are provided. A neon lamp 450 is lit when the pressure fluid by-pass valve is open. Red lamps 460, 466 light when the work-holder is detached from the carriage, and green lamps 470, 476 light when the workholder is attached. Red lamps 462, 464 light when the presser feet are raised, and green lamps 472, 474 light when the presser feet are lowered. The starting switch 374 is permanently lit. The switch 382, selecting carriage movement to the right, is lit when the carriage is at the left hand end of its travel and the brake is applied. A switch 374, selecting carriage movement to the left, is lit when the carriage is at the right hand end of its travel and the brake is applied.</p> |
