Knitting technology, Third Edition

Fig. 19.2
Shimatronic SEC cam system [Shima Seiki].

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Automatic power flat knitting
229
The presser jack is selectively positioned so that its pressing butt is aligned with
one of three presser cam paths (A, H or B), where it can be pressed downwards by
a 
presser cam
in the cam-carriage. The needle jack can also be sunk out of action
by manually pushing it under wire (iii).
The presser cam is a flat plate actuator in the cam-carriage that can be tipped so
that it presses down onto the butt of a presser jack placed in its path. There are two
presser cams (Fig. 19.4) projecting from beneath each raising cam (2):
The 
lower presser
(the 
miss presser
) covers the full width of the raising cam for
presser jacks in either the H or B positions, causing the knitting butt to be out of
action at miss before it can be lifted to tuck height.
The 
higher presser
(the 
tuck presser
) covers the top of the part of the raising cam
and when in action will cause needles in the A track to remain at tuck height. When
the tuck presser cam is tilted slightly, it will miss the presser butts in the A position
B H A
19
t
s
r
e
20
(II)
(i)
d
c
(IV)
(V)
(III)
b
+
a
Fig. 19.3
Knitting elements.
Tuck Presser
Miss Presser
2
Tuck Presser
A
H
B
Misss Presser
* Normal position for the tuck and miss pressers
in indicated by
A Position
H Position
B Position
Fig. 19.4
Presser cams.

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230
Knitting technology
and those needles will continue to follow the raising cam profile and be lifted to
knit height.
There are 4 possible combinations of knit, tuck and miss:
1
Tuck presser cam tipped (A knit). Miss presser cam untipped (H knit, B miss).
2
Tuck presser cam tipped (A knit). Miss presser cam tipped (H miss, B knit).
3
Tuck presser cam untipped (A tuck). Miss presser cam untipped (H knit, B miss).
4
Tuck presser cam untipped (A tuck) Miss presser cam tipped (H miss, B knit).
The head of the 
pattern selector jack
(e) rests on top of the presser, against its butt.
When the selector is cammed forward, it moves the presser from position B to
forward position A. Cancellation cams (9, 10, 11) move the presser from A to B.
When the cam is out of action, the presser is guided only to intermediate position
H for re-selection.
The selector has a tail butt (t) for raising it. Butt (r) is used to return the selec-
tor to the start position for re-selection. Selection butt (s) corresponds to one of 6
positions of the bank of actuator-selecting cams. The selection butts are set-out in
descending echelon order.