ABSTRACT
Group drive or four-spindle tape drive: Single tape drives two spindles on one side of the machine and two further spindles on the other side of the machine in a group of four. When changing from one side to the other the tape passes around a drive cylinder (tin roller – old system) or Bakelite drive pulley (new system) and 1-2 tension rollers (jockey pulleys). Dead weight or spring loaded jockey pulleys ensure good, uniform tensioning of the tape (Fig. 6.2 (i)). The power is transmitted to tin roller or pulley shaft via flat or V-belt from main shaft. Use of lightweight tape and Bakelite pulley offers less frictional resistance to drive. Thereby force required to drive low mass frictional bodies is less, consumes less power, and makes drive economical.
Less driving force also reduces tape tension or contact pressure for accurate drive transmission. Thereby pulley and tape wear get reduced, adds to their life and also allows working at low noise level. The greater angle of wrap (110° to 120°) around the smaller diameter wharve guarantees constant rotation speeds by significantly avoiding tape slippage. This results in reduced count and twist variations, thus produces better yarn quality. If tape breaks or need to be replaced, only four spindles are out of production, helps in realizing higher machine efficiency.
