Dynamic Dynamic Load Modeling and Resonance Damping in Broad Harness Superstructures
Damping broad jacquard superstructure resonance stabilizes comber board deflection below half a millimeter, extending cord fatigue life and preserving shed clarity.
Lingo Return
Mechanical Reset
Gravitational pull represents the mechanical force used to restore jacquard harness cords to their lower position after selection by the lifter boards. In linen weaving, the lingo return relies on the suspended weights or springs attached to the bottom of each harness cord to pull the warp thread back into the bottom shed sheet. This rapid reset is necessary to clear the path for the weft insertion mechanism before the next pick occurs.
Without a rapid downward motion, the warp threads remain suspended and cause severe weaving faults.
Shed Closure
Traditional gravity weights known as lingos are often replaced by metal springs to achieve faster operation. The lingo return action must overcome the friction of the harness cord passing through the comber board. This mechanical resistance increases when lint and dust accumulate in the guide holes.
Operational Stability
The tension of the return system must be carefully adjusted to balance the rapid closing of the shed against the risk of thread breakage. High spring tension or excessively heavy lingos increase the static tension on the flax warp, which can lead to premature failure of delicate yarns. Operatives must regularly clean the comber boards and lubricate the guide surfaces to ensure that the return motion remains uniform across the entire width of the loom.
This maintenance prevents the formation of uneven selvedges and striping in the finished linen fabric.