Patent GB-677821-A (GB)
Title: Improvements in or relating to textile machines
IPC: D05C5/04
Filed: 1949-12-05
Abstract: 677,821. Sewing-machines. ELECTROTEXT CORPORATION. Dec. 5, 1949 [Dec. 7, 1948], No. 31151/49. Class 112. Embroidery machines.-The operation of the machine is controlled by means employing a perforated tape and electrical means for translating the various combinations of perforations into the required operations in the machine, such as positioning the work-frame and selecting the needle or needles to be actuated in each stitching cycle. A number of machines can thus be controlled from a central apparatus by plug and socket or other connections each of which carries all the necessary circuits for the relevant machine, and each machine may be selectively connected to any one of several sets of central control apparatus, each producing a different design. In a machine embodying the invention, several needles and corresponding shuttles are connected by solenoid-controlled means, one or more at a time, to operating bars reciprocated by cams which are given one revolution at a time through solenoid-controlled clutch from a continuously-running shaft; they may remain connected at the end of an operating cycle if required for use in the succeeding cycle. The work-frame, guided by rollers on spring-biassed arms and vertically balanced by weights on cords running over pulleys, receives its vertical and horizontal movements through spring-engaged half-nuts engaging vertical and horizontal leadscrews driven through clutches and gearing from continuously-rotating motor-driven shafts; each clutch and gearing unit comprises a pair of equal and oppositely-rotating driving gears connectible through a solenoid-controlled one-revolution clutch with corresponding driven gears meshing with a single gear from which rotation of the lead-screw is derived through a solenoidcontrolled gear-box giving two ratios, one preferably twice the other, so that the lead-screw may be given a double or single shift in either direction, the combination of vertical and horizontal movements in different amounts and directions giving a choice of sixteen possible directions of movement of the work-frame. The various solenoids controlling the movement of the frame and the operation of the needles and shuttles are energised selectively from a perforated-tape transmitter through a constantlyrotating distributor which in each rotation produces the positioning of the work-frame according to one code and the selection and putting into or out of operation of the needles and shuttles according to the succeeding code; desired needle changes may require more than one selecting cycle without movement of the workframe or operation of the needle mechanism. Hand switches may be provided to connect the needles for selection and operation in groups and for inserting suitable resistances in the circuits according to the changes in the number of solenoids connected. Limit switches actuated when the work-frame reaches its extreme positions may light indicating lamps or may open the appropriate circuits controlling the movement of the frame. Stitch-forming devices.-The needle-bars 287, Fig. 6, are arranged in a horizontal rank, each having on its lower side a rack for engagement. with a pinion on a shaft 281 and a recess 322 for engagement by a pin 321 on the pinion ; the rear or needle end of each needle-bar carries a pivoted work-engaging device 325 slidable thereon against a spring as the needle is advanced through the work 292 on the rear face of the frame 69 The needle thread is supplied from a spool 309, and is wound round a feed-wheel 303 actuated by ratchet gear by spring-biassed arm 307 engaged by the front end of the needle-bar, the thread passing from the wheel 303 through an eye in the arm 307 and thence to the needle. The shaft 271 is geared to a rack 278 reciprocated by a cam 232 on the shaft 226, which is given one revolution in each cycle. Each needlebar is normally held by a solenoid-operated latch 297 in a position in which its rack teeth are clear of the pinion, and is spring-biassed towards its operative position. When a needle is to be actuated, its latch solenoid and a solenoid putting into operation the shaft 226 are energised, and as the bar 228 is lifted by the cam 232 the needle-bar is moved to the left by a spring until its teeth engage the pinion on the shaft 281 for positive operation. On the return of the bar 278 the needle-bar is retracted, being finally moved clear of the pinion into the latching position by the pin 321 if a solenoid-operated bar 268 has been positioned so that a notch therein receives a pin 267 on the bar 278; normally, however, the bar 268 is positioned so that it prevents the full descent of the bar 278. and the needle-bar remains connected to the shaft 281 for actuation in successive cycles. The shuttles 398 are reciprocated in paths slightly inclined to the vertical by carriers'linked to individual bars which are selectively connected to a shaft 364 in the same way as the needle-bars to the shaft 281 ; the shaft 364 is actuated by a rackbar 358 connected to a bar 347 which is operated by a cam 231 on the shaft 226 and which may be prevented from making its full upward movement by a latch 367 engaging the cam-follower lever 342, this latch (which corresponds to the bar 268) being retracted by a solenoid when a shuttle is not required to operate in the next cycle. Thread-cutters and thread-end holders.-The needle and shuttle threads are cut on the final movement of the needle-bar and shuttle-carrier to their inoperative positions. The needlethread cutter comprises a blade fixed on the work-engaging member 325, which is tilted upwardly by engagement with a fixed cam 339 to cut the thread when the needle-bar moves out of engagement with its operating pinion. The member 325 carries a pair of small discs spring- pressed together to receive the thread before it is cut and to hold the cut end. The shuttle thread is cut by a sliding member 413 with a hole which is normally in line with the needle hole in the plate 411 but is moved out of line, to shear the thread, by a lever operated by a cam on the shuttle-carrier when the bar actuating the latter is moved clear of its operating pinion.