Let Off Motion

The motion which delivers the warp from the warp beam at the required rate that a suitable constant tension by unwinding it from a flanged bobbin called let off motion.
Functions of let off motion:
  1. To apply tension on warp to help to form a clear shed.
  2. To deliver the warp sheet from the warp beam.
  3. To provide the warp and filling space during weaving.
Shirley Let Off Motion:
Construction: The warp which supplied from the warp beam and passed over the floating back rest. The floating back rest is connected with an angular lever arm and other end if the lever is fulcrum. The beam barrel is joined with a roller. On the weight lever, the sliding weight is placed which can slide left and right as and when required.
Working Principle:
  1. Constant take up rate equal to the constant let off rate, when warp tension is increases.
  2. Constant rate take up increases.
  3. Floating roller deflect to the left side.
  4. Arm deflects to the left side.
  5. The weight lever moves to the upward.
  6. Sliding dead weight deflect to the left side.
  7. As a result let off motion increases.

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