GB1308638A - Automatic stop motion for carpet tufting machines - Google Patents

Abstract

1308638 Tufting machine; starting and stopping W JACKSON 1 July 1970 32001/70 Heading D1G A tufting machine is provided with driving and stopping means responsive to the breaking of the yarn to stop the machine with the needle in a raised position. The shaft 20 driving the needle bar 23 is driven, selectively. from a motor driven shaft 50 by either a pulley 49 connectible to shaft 50 by clutch 54 and connected to shaft 20 by belts 48 or through a speed reducer 61 by way of a belt 58, connectible to shaft 60 by an index clutch 62, and a chain 66 driving shaft 20 through an over-running or one way clutch 69. The shaft 20 is also provided with brakes 51 and an adjustable timing cam (72, Fig. 8 riot shown) having a lug (73) engagable with a lever (79) to separate the contacts of a needle position switch when the shaft and needle bar are appropriately positioned. Breakage of yarn 30, passing through a drop wire 39, is detected by the falling wire bridging contacts (41, 43, Fig. 3 not shown) to initiate stop motion by an electrical circuit (Fig. 10, not shown) including relays (K1-5) and time delay capacitors (113, 124). When wire 39 falls clutch 54 is de-energised to disconnect the direct drive to shaft 20. Brakes 51 are applied for one second to stop shaft 20, released and index clutch 62 energised so that shaft 20 is slowly driven through reducer 61 until cam (72) opens the needle shaft position switch contacts to de-energise clutch 62 and re-apply the brakes for one second. Inching controls are provided; apart from this the machine cannot be restarted until a reset button is pushed. Yarn breakage detection. The dropper 37 comprises an element 39 having a slot 42 embracing an insulated bar 41 presenting the required electrodes. The bar is tilted at 45‹ to accept part of the weight of the dropper, the remainder being taken by the unbroken yarn. This allows the device to be employed for yarns subjected to low tension. Other forms of sensors may, it is stated, be employed including light beams, lasers, and electrical contacts closed in response to decrease of fluid pressure.