Patent GB-539949-A (GB)
Title: Improvements in or relating to yarn or like winding machines
IPC: B65H59/20
Filed: 1940-03-29
Abstract: 539,949. Winding yarns &c. UNIVERSAL WINDING CO. March 29, 1940, No. 5726. Convention date, March 31, 1939. [Class 120 (ii)] A yarn or like winding machine having a device for tensioning the yarn in its path to the winding mechanism, the tension applied to the yarn is relieved at the start of the winding operation by a tensionrelieving device which actuates the tension device ; the tension-relieving device is operated before the commencement of the winding operation and is rendered inoperative after the winding operation has started. As shown the tension-relieving device is applied to the machine described in Specification 520,083, the yarn in its path from the supply spool C to the bobbin b being wound, passing between the members 51, 52 of a grid tensioning-device the member 51 being fixed and the member 52 being pivoted on a rod 55 and having an arm 60 connected to a weighted cord 61 which urges the member 52 towards the fixed member 51. An electromagnet 75, energized from the circuit controlled by a switch that initiates the operation of the donning mechanism of the machine, is disposed adjacent the member 52 of the tension device with its core 76 forming an extension of an ram 77 which is joumalled in a bearing 79 on a bracket 80 and is normally held by gravity against a lug 81 projecting from the bracket. After a full bobbin has been doffed, the donning operation is initiated and the magnet 75 is energized and causes its core 76 to attract the member 52 of the tension device and swing it away from the member 51 to relieve the tension on the strand y, this relief taking place just before winding recommences and continuing for a brief period thereafter ; the magnet is then de-energized and the member 52 swings back into its operative position under the action of the weighted cord 61. In a modification, Fig. 6, in which the yarn is wound on a core T by a thread guide 105 traversed in a counterweighted frame 107 by a cam on a shaft 104 on which the frame 107 swings, the tension device is formed by a pair of discs 130, 131 between which the yarn y passes and which are pressed together by a spring 138 on a rod 132 having a collar 133 engaging a flexible diaphragm 135 disposed against the rim of the disc 130, the corresponding diaphragm of the disc 130 abutting against the cap-shaped bracket 124 carrying the tension device. An electromagnet 155 is mounted in an arm 156 carried from the bracket 124 with the core 162 of the electromagnet disposed a slight distance from the collar 133 and the electromagnet is in a circuit containing a mercury switch 170 carried by a holder 171 pivoted on an arm 173 projecting from the machine frame and connected by a rod 179 with the weighted piston 178 of a dash pot 177. The yam in its passage from the tension device to the core T passes under a drop wire 145 carried by a dogging quadrant 109 pivoted on a pin 110 on the machine frame and having a shouldered lug 115 co-operating with a detent 119 on an arm 118 on the starting and stopping shaft 116 carrying a hand lever 117 and when the lever 117 is rocked to connect the driving means with the winding spindle 103 a pivoted latch 190 at the end of the arm 118 rides up and engages the switch holder 171 and tilts the latter so that the contacts therein are bridged and the circuit containing the electromagnet 155 is closed ; the core 162 then attracts the collar 133 and slides the spindle 132 to relieve the pressure of the tension discs on the yarn. As the movement of the hand lever 117 is continued the detent 119 engages the shoulder of the lug 115 to complete the clutching of the drive and the latch 190 rides off the end of the switch holder 171 which is slowly returned to its original position by the weighted piston of the dash-pot, air beneath the piston escaping slowly through a vent 182, the circuit containing the electromagnet is broken and the discs of the tension device are pressed against the yarn. When a strand breaks or becomes exhausted the drop wire 145 is released, its end 148 engages a rotating toothed disc 180 on the cam shaft 104, and the wire and consequently the quadrant 109 are raised so that the parts 115, 119 are disengaged ; the hand lever 117  is then swung back to declutch the drive, the latch 190 moving beneath the switch holder 171 in position to raise the latter and release the pressure of the tension device when the machine is restarted.