Patent GB-1270083-A (GB)
Title: Yarn piecing apparatus for an open end spinning machine
IPC: D01H4/48
Filed: 1970-03-12
Abstract: 1,270,083. Break spinning machines, piecing arrangements, stop motions, thread guides, end catchers. DAIWA BOSEKI K.K. 12 March, 1970 [15 March, 1969; 16 Dec., 1969; 19 Dec., 1969], No. 12023/70. Heading D1D. [Also in Division F2] A travelling automatic yarn piecing device 10 for an open end spinning machine which is adapted to stop at a winding unit 1 in which the yarn has broken, comprises a package holder raising means 11 for disengaging the take up package from a traversing roller 3, a means 30 for rotating the disengaged package in both the winding and unwinding directions, means including a slit tube 22, 23, 24 for sucking the broken yarn end from the package, means 50 for gripping a portion of the yarn drawn out of the slit of tube 22, 23, 24 and transporting it to above the delivery outlet 4 of the spinning unit.  In Operation: Upon yarn breakage the travelling piecing unit 10 stops in front of the spinning unit 1 indicating yarn breakage and stops the feed of fibres to the unit. The package raising mechanism (Fig. 4, not shown) lifts the package 8 off the traversing roll 3. A rewinding roller 30 is then lowered onto the package to unwind the broken yarn end (Figs. 6 and 7 not shown) which is then sucked through tube 22, 23, 24 and emerge through the slit thereof to extend substantially as shown (see also Fig. 1 not shown). As the yarn slips out of the tube 22, 23, 24 it engages guide plate 52 and is held by yarn gripper 50 and the lower end of the yarn is cut. The yarn gripper 50 is then rotated through 180‹ to position the yarn end above delivery tube 4. More yarn is unwound from package 8 by device 30 and, if necessary, the yarn gripper 50 is released so that the yarn end is drawn into the delivery tube by the suction of the spinning rotor. Electromagnet 61 is actuated to initiate fibre feed to the spinning rotor to piece the yarn end. Rewinding roller 30 is then reversed to wind the pieced yarn and the package is lowered onto the traversing roll 3. The yarn gripper is retracted from tube 4 and the yarn is released. The stop motion lever 5 is thereby returned to its normal position. Upon completion of piecing, rod 49 returns the yarn to delivery rollers 22'. Stop Motion: This comprises a yarn sensing feeler 5 which carries a permanent magnet (73). The feeler moves on yarn breakage to close the contacts of switch 6 which de-energises a magnetic clutch (74) driving the fibre feed rollers (71), (Fig. 18, not shown). Package drive: During normal operation the package is driven by grooved traverse roll 3. The package is pushed upwards upon yarn breakage by a drive 12 which moves cam lever (14) to pivot push up arm 11 upwardly (Fig. 4 not shown). The package is rotated in either direction during piecing up by rewinding roller 30 which is driven from shaft 41 and lowered onto the package by the mechanism 33-39. End Catcher: The broken end is caught by suction tube 22, 23, 24 which is moved toward the package with rewinding roller 30. The tube is connected to a source of suction by operation of electromagnetic valve 25. The end emerges from a slit in the tube and is caught by yarn gripping device 30. In a first embodiment (Figs. 8-13 not shown), the end catcher comprises a V-shaped opening in the gripper body 50 leading to a channel (51). The yarn is held in the channel 51 by air flowing from a passage 55 which is co-axial with the channel (51). The yarn is guided into the opening by a shaped plate (52). In a second embodiment (Figs. 19-22 not shown) the gripper is formed by pivoted jaws (50) which are opened and closed by electro-magnet 66. This gripper is rotated through 180‹ on the end of its supporting arm 48 by rotation of shaft (63) by motor (68). The shaft (63) rotates cylinder 64 which is screw threadedly engaged therewith via the spring-loaded ball coupling (70). After rotating through 180‹, the gripper supporting arm (48) engages the right angle of the groove (65') in which it is guided during rotation, the ball coupling (70) then disengages upon continued rotation of the shaft (63) and the screw thread on the shaft (63) lowers the cylinder 64 and the gripper supported thereon to place the yarn end into the spinning unit tube 4 to effect piecing up. Snarl eliminator: Snarling of the cut end of the yarn is eliminated by sucking the cut end into tube (58) adjacent the cutter 60 (Fig. 16 not shown). The yarn end untwists and snarl is thereby removed. A second cutter (60') is then operated to cut off the end held in tube (58) so as to leave a snarl free end extending below gripper 50.  Yarn guide and reserve device: The length of yarn introduced into the delivery tube 4 during piecing up is controlled by the movement of roller 49 towards the spinning unit, (Figs. 17 and 18 not shown). The roller 49 has a rotatable threaded portion 47 so that upon successful piecing up the pieced yarn being wound rotates the roller and it eventually slips off the end of the threaded part.