Interlock Gating

VD0: A second type of gating,

where needles are placed opposite

each other, is interlock gating.

This results in different performance.

In interlock gating,

cylinder and dial needles are

spaced so they're directly opposed.

To prevent needles from hitting each other

during the knitting cycle, opposing

needles are not selected at the same time.

When needle one in the cylinder is

knitting, the corresponding

needle one in the dial must rest.

This is achieved by the alternating

needles in the dial and the cylinder

never being activated at the same time.

This requires two cam

tracks for both needle beds.

Therefore, the location of the butts on

the needle shank must be in two positions.

Most commonly used are butts in short

and long configurations,

as seen in this illustration.

Needles with long and short butts are

alternately arranged in the cylinder,

and also in the dial.

VD2: During each feed or course of yarn,

only half the needles are used.

On course one,

only needles with long butt positions

knit, those placed in odd positions of the

cylinder and even positions of the dial.

On the second course of yarn or feed,

the short butt position needles knit

in even positions of the cylinder

and in odd positions of the dial.

Two feeds are required to complete a full

visual course of interlock knit,

whereas in one-by-one rib knitting,

only one feed is required

to make a visible course.

VD3: Look at the resulting structure

of an interlock fabric.

Follow one course across different

wales and you will see a complex knit.

Remember that two feeds are

required for one course of knit.

This first colored yarn knits on odd

dial and even cylinder needles.

The second colored yarn knits on odd

cylinder and even dial needles.

Because loops interlock and alternate

from the front to the back,

the structure of interlock fabric is much

more rigid and stable than that of a rib.

At closer inspection,

you can see that interlock is the meshing

or interlocking of two

one-by-one rib courses.

This prevents adjacent

wales from having mobility.

VD4: Different double-knit constructions can be

made on rib and interlock gated machines.

Needle selection by mechanical and/or

electronic systems, along with yarn

selection, determines the design effect.

VD5: A variation of an interlock knit can be

used to produce a structure that is tight

and stable,

where one course of fabric is attached

and interlocked while the next is not.

Ponte di Roma, used for women's dresses

and suits, is an example of this.

This fabric has the same

appearance on both sides.

VD7: Here's the notation

for this type of fabric.

During the first two feeds,

the machine knits interlock.

With the third feed, the machine knits

jersey on only the cylinder needles.

At feed four,

jersey is knit on only the dial needles.

It takes four yarn feeds

to make two visual courses.

Although it is smooth,

Ponte di Roma has a slight horizontal rib

appearance, and is thicker

and more stable than interlock.