Cambox for a flat knitting machine

The invention is concerned with a knitting cambox system for a flat knitting machine with front and rear needle beds arranged gable-fashion and adapted for the production of multicolor knitted fabric a single pass of the machine carriage. An improvement is achieved in this invention by the interassociation of a plurality of independently-operable needle sinkers at the two sides of the knitting cambox so as to provide a timewise-staggered drawing-down of the stitches and increased stitch production.

This invention relates to a cambox for a flat knitting machine adapted to 
produce multicolour knitted fabric during a single pass of the machine 
carriage. 
The production of multicolour knitted fabric is nearly always dependent on 
the number of the camboxes and the number of available yarn guides and for 
this reason the colour combination of the fabrics which can be produced 
economically is considerably restricted. The control of the laying-in of 
the yarn and thus the multicolour production of knitted products is 
afforded by the cambox construction of the present invention. 
Hitherto flat knitting machines of standard type have been used to make the 
knitted products of the kind under discussion. Because of a limited number 
of available yarn guides and the enforced combination of cambox and 
colour-dependent yarn guides the production per cambox-type and pattern 
can be greatly limited. 
A further means of producing multicolour fabrics in one machine pass is 
described in DE-PS No. 99402. Using a presser cam part technique operated 
by a kind of Jacquard the needles are pattern-selected and, to form colour 
stitches, are introduced through three separate cam tracks of a 
timewise-staggered yarn-input arrangement thereafter to be drawn in 
together by a needle sinker-like part. The drawback of this arrangement, 
which incidentally fails to allow any very accurate placing of the colour 
stitches, is exhibited by typically poor pattern-adherence of the Jacquard 
knit. 
The object of the present invention is to provide a knitting cambox by 
means of which stitches for multicolour fabrics can be produced using a 
minimum of space. 
This is achieved in the present invention by the fact that a plurality of 
needle sinkers operable independently of one another are associated 
together at the two sides of the loop tuck cambox and that the control of 
the knitting elements is performed by presser cam parts which are 
pre-selected by electromagnetically-operated preselection systems arranged 
in advance of the knitting cambox.

FIG. 1 is a diagrammatic plan view of the front plate 11 of the cambox to 
which conventional control studs are attached. The arrow 12 at the upper 
part of the drawing shows the direction of travel of the cambox 13 which 
is thus the direction of travel of the carriage which moves over the 
needles or over the needle beds. Advantageously, the construction of the 
"loop-trapper knitting cam assembly", which is conventional and is 
referred to as a cambox for short, is, in a flat bar knitting machine, 
symmetrical. Because the overall construction of the cambox 13 is 
conventional further description thereof is unnecessary. What are 
important to the invention are the two sets of three stitch cams or needle 
sinkers 14, 15, 16 and 14', 15', 16' which are used with the cambox 13 and 
the usual purpose of which is to vary the flare length of the loops to be 
knitted. These stitch cams enable one to work with, as required, three 
different colors and loop adjustments and this is symbolized by the three 
notional, substantially reduced yarn guides I, II, III depicted above the 
cam pattern and shown in their standard inserting positions. The first to 
move are the three stitch cams or needle sinkers 14, 15, 16 which are 
initially placed in an upper position, as indicated by the arrows in FIG. 
1, in which they do not engage the needle butts located therebelow and 
thus are not in action. The next adjacent stitch cams or needle sinkers 
14', 15', 16' are individually programmed for movement by a control system 
(not shown here), either mechanically or by means of an electric motor, to 
their loop sinking position following stroke reversal and can be 
individully controlled in their working or operative position. The pattern 
selection is effected in each case by means of an electromagnetic selector 
system 17, 17' arranged in advance of the knitting cambox 13. The selector 
system 17, 17' operates the selector sinker (not shown) in dependence upon 
the direction of the stroke which, in consequence, acts on the needle butt 
18 and lifts the same into the operating position by means of driving 
members 23, 23' so that the needle butt or pusher 18 is brought into the 
path of the controllable presser cam parts 24, 24' and 25, 25'. It will be 
understood that the selector system and the selector sinkers themselves 
can be of a conventional construction and thus any further description 
thereof is not deemed to be necessary. 
Selected needles of colour I guided in the usual way are moved by the 
needle shanks or jacks 20 through the cambox channels 28 and drawn down or 
sunk by the stitch cams or needle sinkers 14'. During this performance the 
presser parts 24 to 25' are completely out of action, i.e., presser cam 
parts 24 to 25' are positioned so that they do not project beyond the 
surface of the cam plate and thus do not engage or control the 
jack-selector butts. 
Needles and needle shanks 20 of colour II moved in the same way as in the 
case of colour I through the cambox channel 28. In a parallel fashion, by 
programmed pre-selection by the selector system 17', the needle abutments 
18 are brought by the actuating parts into the path of the moving cambox 
parts 24 and 25'. The butt 19 of the needle shank or jack 20 is now 
pressed by the needle abutment or pusher 18 through the presser part 24' 
out of the needle channel 28 in the area of the marking 21 and, after 
passing of the needle abutment over the presser cambox part 24', is again 
released into the needle channel for drawing-down of the knitted stitch of 
colour II with the stitch cam or needle sinker 15'. The needle butt now 
follows a two-point pattern. 
Needles and needle shanks 20 of colour III move through channel 28 as in 
the case of colour I. In parallel with this the needle abutments 18 are 
moved out, i.e., lifted over the driving member 23' into the path of the 
operative presser cam parts 24 to 25' by the programmed pre-selection 
mechanism 17'. As the case of colour II the needle abutment 19 is pressed 
out of the needle channel 28 at marking 21. The needle abutments are now 
returned to the selection position by the retracting part 26, 26'. This is 
followed by an additional pre-selection by the selector system 17 with the 
result that the needle channel at marking 22 and after the ensuing 
release, can only be re-engaged by the needle sinker 16' to draw down 
colour III into the knitted stitch.