Page 53 - Shawl Weaving Artisan - TT

B Harness system (The connection to the warp)

Part Description Function

Neck cord Strong cords connected to the bottom of To transmit the lifting motion from the hook
the hook. down to the harness cords.

Harness cord Longer cords that connect the neck cord To run from the jacquard machine down to the
to the mail eye. loom level.

Comber board A perforated board that keeps the To guide the harness cords to the exact
harness cords correctly spaced and position of the warp ends.
aligned.

Mail eye/heald wire A wire with a central eye through which The final connection that lifts the individual
the warp thread passes. warp thread.

Lingo A dead weight (thin metal rod) To pull the warp thread back down to the
suspended at the bottom of the mail eye/ bottom line of the shed when the hook is not
heald wire. lifted.

B Working mechanism: The Single Lift, Single Cylinder • The knives only engage and lift the hooks that
Jacquard operates on a Bottom-Closed Shed principle, were not pushed back by a blank card (selected
meaning the unselected warp threads rest at the lowest hooks).
possible position. • The selected hooks are lifted, which pulls the
The mechanism’s operation is synchronized with the loom attached Neck Cords, Harness Cords, and Mail
and cycles for every single weft insertion (pick): Eyes, thereby raising the corresponding warp
1 Selection phase (Selection of hooks) threads to form the top line of the shed.
• The Cylinder, carrying the chain of Pattern Cards, • The deselected hooks remain in their bottom
position, held down by the Lingo weight, forming
moves inward toward the row of Needles.
the bottom line of the shed.
• The front end of each needle is pushed against
the surface of the current pattern card. 3 Weft insertion and beat-Up
• The weft thread (pick) is inserted through the
- Selection (Warp Up): If the needle point aligns shed (the space between the top and bottom warp
with a hole in the card, the needle passes threads).
through the hole and enters a corresponding
perforation in the cylinder face. The needle • The sley/reed beats up the weft thread to the fell
remains in its original position. Consequently, of the cloth.
the Hook attached to this needle remains directly 4 Preparation for the next pick
in the path of the rising knives.
• The Griffe moves down, lowering all the selected
- Deselection (Warp Down): If the needle point hooks and warp threads back to the bottom position
aligns with a blank space (no hole) in the (bottom closed shed).
card, the card pushes the needle backward,
compressing the spring in the Spring Box. The • The Cylinder then rotates one face (typically 90
backward movement of the needle forces its degree for a four-sided cylinder) to present the
attached Hook to tilt or move out of the path of next pattern card to the needles for the next pick’s
the rising knives. selection.
• Once the selection is complete, the cylinder retracts. Key feature: In the SLSC mechanism, the griffe must
rise and fall, and the cylinder must oscillate and turn for
2 Lifting phase (Shed formation)
every single pick. This rapid movement limits the loom’s
• The Griffe (containing all the Knives) begins its speed compared to modern double-lift jacquards, where
upward vertical movement (Single Lift). the moving parts operate at half the speed.

Textile & Handloom: Shawl Weaving Artisan : (NSQF - 2024) R.T. Ex.No 1.3.28 43