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

Types of Jacquard shedding mechanism:-

(2) Double-lift and single cylinder Jacquard shedding mechanism:-

STRUCTURE OF DOUBLE-LIFT AND SINGLE CYLINDER JACQUARD SHEDDING MECHANISM:-

There are two griffes used in the double-lift Jacquard Shedding mechanism. Eight knives are mounted on each griffe. In the double-lift Jacquard, two hooks are used for one end. Both the hooks paired to each other through a pairing link. The section needle has two kinks in it. These two kinks (eyes) are engaged with two hooks . The pressure spring is fitted at the rear end of the needle towards the cylinder. The front end of the needle passes through the needle board. A pattern gets mounted in front of the front end of the needle. The doubled end of the hook rests upon a slotted grid. Two hooks gets paired with each other. The upper end of the neck cord firstly passes through the hole of the tug board. The lower end of of the neck cord is connected with the upper end of the harness cord through the S-link. The lower end of the harness cord passes through hole of the comber board. The lower end of this harness cord gets connected with the upper end of the heald wire. A lingo (dead weight) is hanged at the lower end of the heald wire to bring down with the help of this lingo self gravity.

Fig. of double-lift and single cylinder jacquard.

WORKING OF DOUBLE-LIFT , SINGLE CYLINDER JACQUARD MECHANISAM -

The double-lift and single cylinder jacquard receives motion through the bottom shaft. A sprocket wheel is mounted on the bottom shaft of the loom. This sprocket wheel is connected to the another sprocket wheel mounted on the jacquard shaft through a chain. The eccentric cam imparts up and down movement to the griffes. Both the griffes make a reciprocating motion. When one griffe reaches the top dead centre position of the jacquard. Both griffes change their positions after the half revolution of the jacquard shaft. The selection of the hooks takes place according the punching of hole in the card when the griffe reaches the bottom dead centre. The pattern cylinder pushes the front end of the needle . If there is a hole punched in cards , the front end of the needle enters into the perforated pattern cylinder and the respective hook gets engaged with a respective knife. If there is a blank portion in the card , the respective needle get pushed toward the spring box and the respective hooks get engaged from the knife. The reciprocating griffes carry engaged hooks in upward direction. The heald wire also makes in an upward direction with the hooks because the hook gets connected to the heald wire by the neck cord and harness cord. Thus the end drawn through the eye of the heald wire goes in an upward direction. The lingo brings the hooks in downward position. After half revolution of jacquard, the other set of hooks get engaged with the second griffe according to design and this griffe carries the engaged hook in the upward direction. Semi-open shed form in this jacquard. Two hooks are used to lift one end.

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