Patent GB-120313-A (GB)
Title: Improvements in Means for Finding and Securing the Free Ends of Filling Wound upon Bobbins, Cops or like Filling Carriers in Automatic Weft Replenishing Looms or other Textile Machines.
IPC: D03D45/50
Filed: 1918-02-06
Abstract: 120,313. British Northrop Loom Co., (Northrop Loom Co.). Feb. 6, 1918. Shuttles, changing bobbins in, automatically; bobbins, finding and holding detached the free ends of yarn on.-In apparatus for finding and securing .the free ends of yarn wound upon bobbins &c. in looms and other textile machines, the bases of the bobbins are gripped by jaws, and a rotatable member, such as a hollow drum, is moved longitudinally over the yarn mass and simultaneously rotated against the action of a spring, which rotates the member at the end of this movement to cause one or more end-finding devices in the member to pick up and grip the free end of the yarn which is unwound from the bobbin during the return longitudinal movement of the member. Thus, in an automatic self-replenishing loom of the Northrop type, the base of each bobbin is secured to the end disk 7, Fig. 3, of the magazine by a fixed jaw 8 and a movable jaw 9 pressed towards the jaw 8 by springs 10 on bolts 11 passing through a flange 12. The tips of the bobbins are supported at the top of the magazine by a ledge 15, Fig. 1, on a fixed disk 14, which is cut away at its lower part to allow the end finding and gripping device to move over the bobbins. This device comprises a hollow drum rotatable within a sheath 36 secured to a cross-head 21, which is slidably mounted on rods 18, 19. The drum has a number of plungers 26, Fig. 8, mounted in radial recesses therein and provided with concave yarn-engaging faces 27 with central grooves 28, in which are located end fingers 29 having stems 30 extending axially through the plungers and provided with springs tending to force them inwards. Pins 31 pass through the stems 30 and slots 32 in the plungers and engage cam-slots 34 in a disk 35, which is movable relatively to the drum to an extent controlled by a pin-and-slot arrangement, so as to cause the pins 31 to enter the narrow parts 38 of the cam-slots 34 to withdraw first the end finders 29 into the grooves 28 and then the plungers 26 within the drum. When indication is made for weft-replenishment, connexions from the initiating-shaft free a latch 77 from a projection 104 on a lever 99 pivoted at 100, so that a clutchpart 85 keyed on the tappet-shaft 86 is free to be moved by a spring 87 to engage a loose clutchpart 90 and drive a spiral gear 91 and a companion gear 93 having a crank-pin 96 connected by a rod 97 to the lever 99. This lever is oscillated and, through a slot 102 and pin 103, moves the crosshead 21 along the rods 18, 19 so that the hollow drum passes over the bobbin to be transferred at the next operation. During this movement of the drum, pins 44, 45 thereon are acted upon by pivoted cams 46, 47 to rotate the drum against the action of its spring, the rotation of the disk 35 being stopped to cause the pins 31 to enter the wide parts of the cam-slots and the plungers 26 to move inwards so that the end finders 29 press against the yarn on the bobbin. When the pins 44, 45 snap over the cams, the spring rotates the drum in the reverse direction, one or more of the end finders 29 pick up the last spiral windings of the yam or the bobbin, the finders are withdrawn into their grooves 28 to grip the yarn, and then the plungers are withdrawn. The lever 99 then moves back the drum, and the free end of the yarn is unwound and extends to the finders in the drum, which is given a partial rotation as it approaches its normal position to release the finders from engagement with the yarn. The latch 77 engages the projection 104 as the lever 99 moves outwards and the clutch-parts 85, 90 are disengaged. Prior to the transfer of the bobbin at the next operation of the weft-replenishing mechanism, a toothed arm or wiper is swung by connexions from the indicating-shaft to cause it to pass across the entrance to the drum, engage the free end of yarn, and carry it into engagement with an anchoring-device, such as a piece of card clothing supported in a convenient position to hold it during the transferring operation and the initial flights of the shuttle. The invention may be used in connexion with non-automatic looms to present the bobbins to the weaver with the yarn end found and secured.