Knitting technology, Third Edition

Fig. 20.5
Cylinder cam system of an RTR rib loop transfer machine.
model, panels can thus be knitted in 1 
¥
1 rib, dial-only knit, interlock milano rib,
rib jacquard, or half- or full-cardigan, with selective patterning in rib transfer,
coloured stitches, miss, tuck, knit or raised cloque relief stitch. Articles that can be
knitted include vests and panties, cut and sewn sweater dresses and trouser suits,
jumpers, coarse-gauge cardigans, and sweaters.
As well as the original 13- and 15-inch diameter models, other diameters were
introduced, including 18, 20 and 22 inches to cater for more than one panel width
(separated by a needle-out line) and the knitting of high-shrinkage synthetic yarns

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Knitting technology
or coarse gauges. This concept was extended to a 33-inch diameter machine, with
flexibility of knitting width and economy in cutting waste achieved by removing the
block of needles not required, thus leaving a panel of floating threads.
Machine speeds range from about 16 to 32 rpm, according to machine design and
type of stitch being knitted, with the cam sections being between eight and twelve
in body diameters (and up to eighteen in the 33-inch diameter model). Gauges
extend to 16 npi for underwear or jerseywear down to 7 npi for knitwear, with the
coarse model having gauges of 3 and 6 npi.
20.3.1
The basic elements and camming arrangement of the RTR machine
The geometric selection employed on this machine has been previously described
(Section 11.9). Figures 20.5 and 20.6 illustrate the arrangement of cams for a six-
section machine; other models are similar. On the 33-inch diameter model, however,
each presser has 79 butts, with a maximum of 73 available for patterning. One is
removed to leave a gap. The remaining five are used for isolation purposes as
follows: all butts on, 2 out of 3, 1 out of 3, odd needles only, even needles only. The
dial needles are usually set-out with every third needle having a back butt for dial-
to-cylinder transfers or press-off for achieving 2 
¥
2 rib. Cylinder needle butts may
be set-out 1 short 2 long for 2 
¥
2 rib in the waist.
There is a jack-raising cam associated with each cylinder selection unit raising