Knitwear Technology
Part One : Simple V-bed CAM
selection
Jimmy Lam
Institute of Textiles & Clothing
Learning Objectives
V-bed machine CAM geometry
 Double System Machines
 Needles and Jacks selection
 Pattern and limitation

Simple V-bed CAM geometry
All cams in V-bed machine are symmetrical
on both side (Why?)
 These cams include raising cam for moving
the needles to tuck or knit position; and
 Lowering cam and guide cam to control the
stitch length

V-bed Cam geometry
Can you tell the function of raising cam and stitch cam ?
Sl :LHS Stitch Cam
Sr :RHS Stitch Cam
Al :LHS Raising Cam
Ar :RHS Raising Cam
B :Clearing Cam C:Guide Cam
Function of raising cam

For high and low butt needles, if raising cam is
in full position
– All needles will move up;
If in half position, only the long butt needles
will move upward, short butt needles will miss
 If the raising cam is out of action, all needles
will miss

V-bed machine with transfer cam
Transfer cam is used to push the needle to the highest position
so that opposite needle can draw the loop from one needle
bed to the other.
Transfer cam

The requirements for loop transfer are
–
–
–
–
Transfer cam;
Receiving cam;
Needle racking in ½ or ¼ pitch; and
Special transfer needle
Transfer action
Loop is transferred
from one needle bed to
another needle bed via
transfer cam and
transfer needle
Double System Knitting
with high/low butt needle
Double System Knitting

Double system means two knitting courses can be
produced on one stroke of cam carriage.
Two cam boxes are housed in the same carriage so two
knitting courses can be produced
Can you name the following
structure in double knit systems ?
RR
RR
I
RR
RR
RR RR
I
RH RH
RR: All needles knit
F: All needles tuck
A: All needles miss
A RR
I
RR
A
F
RR
I
RR
F
RH:high butt knit, low butt miss
FR: high butt knit, low butt tuck
FH: high butt tuck, low butt miss
Patterning
Knitting pattern on jacquard knitting machine
depends on
 Yarn carrier change (colour change);
 Needle sett out;
 Stitch selection;
 Needle bed racking; and
 Cam function selection (knit/tuck/miss/transfer)

Please explain why the following pattern
cannot be produced on high/low butt needles
Needle and Jack selection
Needle and Jack

To increase the pattern scope, we can put jacks under
the needles, and have the option to select pattern via
needles and jacks
Needle and Jack selection
Both needles and jacks are used to make this pattern
Discussion
Why knitting cam is normally symmetrical on
both side ?
 What is the limitation of simple needle and jack
selection ?
 How can multi-jack selection increase the
pattern size ?
