TYPES OF JACQUARD SHEDDING MECHANISM (single lift and single cylinder)

Types of Jacquard shedding mechanism:-

(3)single lif and single cylinder jacquard shedding mechanism:-

Objective of Jacquard shedding:-

1. The weave or design is created in the woven fabric by a shedding mechanism.

2. If loom is equipped with a tappet shedding mechanism then the lifting plan of the heald shaft get fixed.

3. The number of picks and ends per repeat gets limited in the tappet shedding. These limitations don’t allow us to create bigger motif (designs).

4. If the loom is acquired with dobby shedding, the weaving of small geometric motifs is possible because the dobby mechanism had the capacity to operate 28 heald shafts in different lifting made.

5. The weave or design having a large numbers of picks per repeat can be woven on a dobby loom.

6.  If the design repeat has more number ends per repeat than the number of jack lever present in the dobby then can not produce this kind of large design.

7. The jacquard shedding has the capacity to operate large number ends in different lifting modes.

8. We can produce the large floral design by using jacquard shedding.

9. The lifting of individual end get controlled in jacquard.

Structure of single lift and single cylinder Jacquard:-

1. The knives are mounted on the griffe. The griffe makes up and down movement.

2.  The lower end of hooks rest upon the grate.

3. A needle is engaged with each hook through the eye of a needle.

4. The front end of the needle passes through the hole of the needle board.

5. A pressure spring is fitted at the rear end of the needle . The pressure spring always pushes the needle towards the cylinder.

6. The pattern cylinder is mounted in front of the needle board. A Star wheel mounted at one side of the pattern cylinder.

7. The punched card chain is mounted over the pattern cylinder.

8. The lower end of each hook is connected with the upper end of the neck cord .

9. Now the neck cord passes through the holes of the tug board mounted just under the hook.

10. A S-link is connected with the upper end of the harness cord. This harness cord passes through the hole of the comber board mounted on the loom.

11. The lower harness cord is connected with the upper end of the heald wire gets connected with the lingo .

12. The jacquard receives rotary motion through a crank-shaft, the sprocket wheel and chain are used for motion transfer.

Fig of single lift single cylinder jacquard.

Working principle of single lift and single cylinder jacquard shedding mechanism:-

1. The jacquard shaft receive motion through sprocket wheel mounted on the crank-shaft.

2. The crank-shaft and jacquard shaft are connected through a sprocket chain.

3. The eccentric cams are used to provides upward and downward movement to griffe.

4. The griffe make one cycle of up and down movement when the crank-shaft complete one revolution.

5. The knife mounted on the griffe slightly comes down in comparison to the upper end of a hook . This position is also called the selection position.

6. Tow the punched card mounted over the pattern cylinder pushes the front end of the needle.

7. The blank portion of the card deflects the hook away from the knife.

8. If there is a hole in the card the needle gets entered into the hole of the perforated cylinder and the needle deos not deflect the hook away from the knife .

9. Now the lifting griffe carry the engaged hook in the upward direction.

10. Since the hook gets connected to the heald wire through the neck cord, and harness cord so that the end drawn in heald eye of the heald wire lifts upward with the hook.

11. The lingo (dead weight) attached with the lower end of the heald wire brings the heald wire in the downward position.

Ref:-https://www.textileadvisor.com