Patent GB-615742-A (GB)
Title: Improvements in or relating to mechanisms for producing auxiliary movements in textile machines
IPC: D03D51/00
Filed: 1946-01-17
Abstract: 615,742. Looms. SULZER FRERES SOC. ANON. Jan. 17, 1946, Nos. 1635 and 1636. Convention dates, Jan. 20, 1945, and March 5, 1945. [Classes 142(i) and 142(ii)] [Also in Group XXIV] Mechanism for bringing a loom into a suitable condition for remedying defective weaving includes a pair of clutches, of which the first is engaged for weaving and the second for removing a defect; the clutches have a common operating member (92, Fig. 6 or 77, Fig. 10) which is moved in one direction to disengage the first clutch and then in the opposite direction to engage the second clutch. The first clutch is of the type disclosed in Specification 606,732, which, on being disengaged, is prevented by a blocking member from re-engaging until one half of the clutch has rotated a definite amount relative to the other half. In the loom described, two such mechanisms are provided: one is controlled by a warp stop motion to close the shed for repair of a broken warp thread; the other may be controlled manually or by a weft stop motion to open the previous shed for removal of a broken pick, the let-off and take-up motions being also reversed. Driving arrangement.-When weaving, the main shaft 11 (Fig. 6) is driven by an electric motor through a friction clutch (not shown); when the warp or weft stop motion acts, the clutch is disengaged and a brake applied. The shedding mechanism 22 and a shaft 20 which actuates the let-off and take-up motions are driven from the shaft 11 through a clutch 12, 13 and a chain wheel 14. The motor also drives, through shafts 53, 50 a bevel gear 49 having clutch elements on both sides; the gear 49 rotates continuously in the opposite direction to the shaft 20, and provides the auxiliary drive for removing defects. Warp stop motion; closing shed (Fig. 10).-Reverse operation of the shedding mechanism 22 to the closed shed position, or from the closed to the open shed position, is effected by a chain drive, of which the chain wheel 64 is fixed to a hollow shaft 61 loose on the shaft 20. Clutch rings 56, 68 are splined to the hollow shaft and are coupled together by toggle links 75, 76 of such length that the clutch rings cannot engage their complementary clutch rings 54, 69 simultaneously. Normally, the clutch ring 68 is in engagement with the ring 69 which is secured to the loom framework and thus cannot rotate. When a warp thread breaks, a circuit is closed through the corresponding dropper (not shown), a switch 98, and a solenoid 101, which thereupon turns a stop motion shaft 59 to the position shown to stop the main drive of the weaving mechanism. The solenoid also swings a pawl 107 into the path of an oscillating lever 109, which pushes a rod 77 to break the toggle 75, 76, thereby disengaging the clutch 68, 69, whereupon a blocking member 70 prevents its reengagement. Disengagement of the clutch moves a rod 97 which breaks the circuit at the switch 98, thereby allowing a spring 108 to move the pawl 107 clear of the oscillating lever, and allowing a spring 80 to straighten the toggle; as the clutch 68, 69 cannot re-engage, the clutch ring 56 engages the clutch ring 54 on the gear 49, whereby the shedding mechanism 22 is turned backward to close the shed. At the end of one revolution, the blocking member 70 allows the clutch 68, 69 to re-engage under the action of a spring 71, the clutch 54, 56 being simultaneously disengaged by the toggle links. After repairing the broken warp thread, the weaver depresses a pedal 78, thereby initiating another cycle similar to that described to open the shed; weaving can then be restarted by means of a manual control.. Manual control of reverse shedding (Fig. 6).-Turning a handle 95 (with weaving stopped) moves a rod 92 to the right, thus turning a lever 85 clockwise and a lever 82 anti-clockwise to disengage the clutch 12, 13, thereby uncoupling the shedding mechanism 22 from the normal drive shaft 11. A blocking member 16 drops between the clutch rings 12, 13, consequently (upon release of the handle 95) a spring 115 acting on the rod 92 turns the lever 85 about the point 84, thereby moving a rod 88 to the left to engage the clutch ring 57 with the auxiliary drive gear 49; the shedding mechanism 22 is thus driven backwards by the shaft 20 to open the previous shed. The clutch ring 13 is also rotated (by the chain drive) and, when it has made one revolution, the blocking member 16 permits a spring 15 to re-engage the clutch 12, 13, the clutch 55, 57 being simultaneously disengaged by the linkage 82, 85, 88. Automatic control of reverse shedding (Fig. 6) can be initiated by a weft detector 48 closing a switch 116 when weft is absent from the shed, thus energising a solenoid 120 which turns the stop motion shaft 59 (to stop the weaving operations) and brings a pawl 127, carried by the rod 92, into the path of an oscillating lever 129; the rod 92 is thereby moved to the right, whereupon the operations described in the preceding paragraph occur. Upon disengagement of the clutch 12, 13 a rod 86 breaks the circuit at a switch 119, so that the solenoid releases the pawl 127 and a spring 128 moves it clear of the oscillating lever 129, allowing the spring 115 to return the rod 92 to the left. Restarting of the weaving mechanism by manual operation of the stop motion shaft 59 whilst an auxiliary drive is in operation is prevented by the end of the rod 86 (Fig. 6) or of the rod 97 (Fig. 10) butting against an arm 87 on the shaft 59. Warp let-off and tensioning; fabric takeup (Fig. 1).-The shaft 20 drives a vertical shaft 27 through a friction clutch 25 controlled by a tension roller 32 loaded by a spring 45. The take-up motion is driven from the other end of the shaft 20. When the auxiliary drive is used to open the shed for repairing a broken warp yarn, the let-off and take-up are unaffected; but when the shedding mechanism is reversed for unpicking weft, the shaft 20, driven in reverse as described above, lets back the fabric and takes back the warp.