Knitting machines

A control system which allows a plurality of shapes to be knitted by a simple change of profile cam (80). The profile cam (80) controls in a desired variable manner the feed rate of elastic or ground yarns to control the shape of a garment. The shape can also be controlled by further profile cams (200, 202, 204) to control both elastic and ground yarns and in a dial and cylinder circular knitting machine to alter the dial height while the machine is in motion, thereby further controlling the width of a garment.

With reference now to FIG. 1, the control system is shown in conjunction 
with a dial and cylinder true rib knitting machine but it may be used with 
other types of knitting machine. Such machines are well known and the 
knitting portion of the machine will not be described in detail. 
The dial portion of the machine is indicated generally at 10 and the 
cylinder at 20. They are driven, in known manner, by gear trains 12, 14 
and 22, 24, respectively, the drive gears 12, 22 being fixed to a main 
drive shaft 30 driven by a belt and pulley arrangement 32, 34 driven from 
a pulley 36 mounted on the main drive motor 38 for the knitting machine. 
The motor 38 is mounted onto a main frame 40 which may form the base of 
the machine (if bench mounted) or may be fitted with legs (not shown) for 
free standing operation. 
The shaft 30 is journalled at two points 42, 44, the journal 44 being in a 
plate 46 which supports the dial and cylinder arrangement 10, 20. Plate 46 
is mounted in a fixed relation to plate 40 by any convenient means, e.g. 
welded struts (not shown). 
In a normal knitting machine the drive shaft 30 is terminated at a height 
as shown by dotted line 31 just above gear 12. The dial 10 is adjustable 
while the machine is stationary by a knurled nut adjuster arrangement 11 
which when raised increases the intake per stitch of ground yarn GY. As 
shown for a typical machine, there are a plurality (e.g. 3) ground yarns 
and a single elastic yarn feed. In the known knitting machines the dial 
height determines the yarn required by the machine and the machine pulls 
the yarn required, the yarn being held in cones on overhead gantries as 
indicated in dotted outline. As an alternative to allowing the yarn to be 
pulled by the dial the yarn can be metered to give a required length of 
yarn particularly in the case of the elastic yarn EY by a driven belt 
arrangement DB for the cone spools. This is well known and will not, 
therefore, be described in further detail. 
In the control arrangement of the present invention in FIG. 1 means is 
provided for adjusting the feed rate of the elastic yarn EY which is now 
shown as a continuous line EYV. 
The arrangement is as follows. The shaft 30 is extended in an upward 
direction and is journalled in a bearing 62 in an upper plate 60. Bearing 
62 is surrounded by a sliding collar 64 which is free to move vertically 
on extended shaft 30. (It is noted here that the arrangement shown is 
diagrammatic for explanation only.) The collar 64 can be forced to bear 
down in a direct linear manner onto a variable speed drive pulley 66, 
fixed on the shaft 30, and which (in well-known fashion) cooperates with a 
mating pulley 68 via belt 70 such that on pressure being applied to pulley 
66 the belt 70 is adjusted and forces a change in the position of pulley 
68 thereby speeding up the rotation of pulley 68. The downward movement of 
pulley 66 is resisted by filling the shaft distance between pulley 66 and 
gear 12 with collars 72, 74, 76. Downward pressure on collar 64 is 
achieved in a direct linear manner by a profile cam 80 (preferably made 
from steel plate of, for example 3/8" to 1/2" thick) which is rotatably 
mounted on a shaft 82 driven by an electric motor 84 via a gearbox 86. 
Motor 84 and gearbox 86 are rigidly mounted onto top plate 60 by supports 
85, 87. The shaft 82 can be driven at a relatively slow speed by gearbox 
86 and hence the profile cam 80 turns slowly. The speed of rotation of 
profile cam 80 can be further changed by using a variable speed motor 84 
controlled, for example, by an electronic controller 88 connected in the 
main electrical feed line 90. 
Thus, by virtue of the profile cam 80 rotating and providing a variable 
pressure on pulley 66 the speed of rotation of pulley 68 is affected. 
Pulley 68 is keyed onto a shaft 100 onto which a further preset ratio 
capstan drive 102, 104, 106 is connected to drive via pulley 106 a yarn 
feed control system 108, 110, 112. The capstan 102 and associated pulley 
106 are adjustable when the machine is stationary to set up the width of 
the workpiece by defining a fixed feed speed for the yarns controlled by 
the capstan. The variability of the yarn feed is then controlled (within 
the range set by the preset capstan) by the profile cam 80. Thus, before 
knitting is commenced the capstan is manually set to give the minimum 
width while the profile is also positioned at its minimum width position. 
The arrangement is such that via gearbox 108, and direction change device 
110, the "constant" feed device 112 can be controlled to feed the elastic 
yarn EYV at a rate determined by the rotational speed of pulley 106. Since 
pulley 106 is controlled effectively by the rotation of profile cam 80 
then it may be seen that the shape of the garment G knitted by the machine 
can be controlled by the shape of profile cam 80 and by the speed of 
rotation of profile cam 80 relative to the operating speed of the machine 
as controlled by motor 38. 
If it is assured (as normally) that motor 38 is a constant speed drive then 
the length of a profiled garment G will be controlled by the speed of 
rotations of profile cam 80 and the width variation will be controlled by 
the profile shape. The working limits being set by adjusting the capstan 
102. 
The embodiment shown in FIG. 1 is able only to control one type of yarn 
feed, although by a simple toothed belt arrangement for belt 104 it may 
easily be seen that more than one elastic yarn feed may be controlled. 
Additionally, one or more of the ground feed yarn or non-elastic yarns may 
be controlled in a variable manner as a fixed ratio of the variable 
elastic yarn feed. 
The arrangement shown in FIG. 2 provides for all three main criteria to be 
controlled, elastic yarn, ground yarn and dial height, by three separate 
profile cams or contours, respectively 200, 202 and 204. The contours are 
driven from a gearbox and shaft arrangement 206, 208 driven by a variable 
speed motor 210 with dial speed adjuster 212. (A separate drive could be 
used for each profile 200, 202, 204, if desired.) 
As described for FIG. 1, the profile cam 200 acts on the variable speed 
drive pulley 66 via collar 64 and as shaft 208 is rotated the speed of 
elastic yarn feed controlled via the arrangement shown in FIG. 1 is varied 
as the machine knits. 
In FIG. 2, for clarity and simplicity, the main knitting mechanism is not 
shown nor is the yarn feed. Where possible for parts which perform the 
same or similar functions as in FIG. 1, the same reference numerals are 
used. Thus, the pressure applied by the contour 200 is resisted by collars 
72, 74, 76 and this causes the pulley 66 to close up, thereby speeding up 
the supply of elastic yarn. Similarly, when the contour becomes convex 
thereby relaxing pressure on pulley 66, the supply of elastic yarn is 
slowed down. 
In FIG. 2 the dial and its main gear is shown to the left of the main drive 
gear 12. A further gear 13 is entrained with gear 14 and is thereby driven 
at the same speed as gear 12. A further shaft 30' is mounted to rotate 
with gear 13 and a further variable speed pulley, not shown but similar to 
pulley 66, is mounted on the upper end of shaft 30' to cooperate with 
profile cam 202. Thus, by means of a further variable speed pulley the 
ground yarn supply can be controlled. If it is not required to vary the 
feeding speed of the ground yarn relative to the elastic yarn but to keep 
it constant, then the ground yarn can be fed by suitable attachments to 
the other end 208' of shaft 208. 
The operation of the profile cam or contour 204 will now be described. 
As the contour 204 rotates, it depresses or releases the see-saw 
arrangement 220 which is spring urged by a compression spring 222 in the 
dial mechanism to maintain a shaft 224 in a downwardly direction. Shaft 
224 is an extension of the shaft through the center of the dial mechanism 
and raising or lowering shaft 224 thereby adjusts the dial height (and 
hence the garment size) in the same manner as knurled nut 11 in FIG. 1. 
See-saw 200 comprises a centrally pivoted lever 230 provided with roller 
bearings 232, 234, to prevent excessive friction, at either end. The lever 
230 is pivoted at 236 in an upstanding fork 238 mounted on plate 60. The 
roller bearing 234 is sandwiched between two plates 240, 242 mounted in a 
spaced-apart manner on shaft 224 by spacing member 244, shaft 224 being 
provided with an upper bearing 246. Thus, as contour 204 rotates so, in 
conformity with the contour, the dial height of the machine is altered, 
thereby altering the width of the knitted garment. 
Initial height can be set by adjusting the position of components 240, 242, 
244 on shaft 224 by screw thread 248. 
With reference now to FIG. 3, the arrangement of FIG. 2 can be shown in 
diagrammatic plan view and in FIG. 4 the capstans 102 and 102' which 
respectively control the feed speeds of the elastic and the ground yarn 
can be seen. Capstan 102 is preset and then its speed is controlled, as 
described with reference to FIG. 1, and capstan 102' is controlled by 
profile cam 202 in a similar manner. (In FIG. 4 the dial height control is 
omitted for clarity.) Pulley 68 and capstan 102 thereby control the speed 
of feed of the elastic yarn and a similar pulley 68' via a capstan 102' 
the speed of feed of the ground yarn. 
Profile cams 80 (FIG. 1) and 200, 202, 204 are readily replaced, being held 
on their respective shafts by, for example, set screws. The profile cams 
are thereby also readily positioned with respect to each other so that a 
garment is correctly fashioned. 
Garments may, therefore, be produced in an enormous variety of ways. In 
FIG. 1, if the motor 84 is switched off the knitting machine will produce 
parallel tubular fabric at a width determined by the position of profile 
cam 80. With the motor 84 rotating at high speed the machine will produce 
variable width fabric with the "pattern" produced by profile cam 80 being 
repeated over short lengths. With motor 84 rotating at slow speed the 
pattern length will be longer. 
With the arrangement shown in FIGS. 2 to 4, the shape of the garment can be 
influenced by the shape of all of the three profile cams and by the speed 
at which they are rotated. 
With reference now to FIGS. 5 and 6, the manufacture of complex shapes 
produces a problem in ensuring that they are correctly folded for 
subsequent processing. (Here it should be explained that in circular 
knitting machines, or indeed other types of knitting machines, garments 
are produced continuously and are subsequently separated in a finishing 
process. This is normal practice and, therefore, will not be described 
further.) 
For circular knitting machines the knitted garment "emerges" from the 
cylinder in a rotational manner because of the method of knitting. The 
arrangement shown in FIG. 5 rolls up the garment and additionally ensures 
that it is not creased when rolled. 
The garment G is knitted in a direction shown by arrow 300. The garment G 
is wound on a roller 302, the roller rotating in the direction shown by 
arrow 304 (by means not shown). The roller 302 is journalled in a frame 
306 which is rotated in a horizontal plane in a direction shown by arrow 
308 to thereby complement the rotation of the garment G as it is knitted. 
With parallel tubular garments there is little problem in rolling them up 
as they are all the same width (even though they may subsequently be cut 
into shorter lengths). 
With the control system according to the present invention, garments of 
considerable width variation can be produced and this, therefore, creates 
problems in rolling them. In FIGS. 5 and 6, there is shown a second 
collection roller means generally indicated at 320 which comprises two 
non-driven rollers 322, 324. These rollers are rotatably mounted in 
bearings on extended leg portions 326, 328 of frame 306. The rollers 322, 
324 are mounted as shown in FIG. 6 only a short distance apart and the 
garment G passes between the rollers. On commencement of the knitting 
action an elongate portion of a garment G is knitted (or several garments 
if short), and this is threaded through rollers 322, 324 and affixed to 
roller 302 for subsequent take up. Prior to threading through rollers 322, 
324 an omega shaped expanding element 330 is inserted as shown inside the 
garment. The element 330 can expand freely in the direction of arrow 332 
and, therefore, maintains the garment G in a flat condition through 
rollers 322, 324 and hence onto roller 302. 
Element 330 may be constructed, as shown with a length of flexible plastic 
piping 334, with suitable end pieces 336, 338 which serve to prevent the 
piping 334 from being drawn through the rollers. 
The control system allows the production of various shaped garments in one 
piece. 
FIG. 7 shows a graduated compression bandage shaped to conform to a male or 
female leg. All yarns may be controlled, the circular bandage, therefore, 
having the natural shape as shown. The bandage can be made to exert any 
desired pressure throughout the leg length by appropriate control. 
At present such bandages are made in parallel fabric and, therefore, do not 
exert a graduated pressure on the leg, but either generally exert too much 
or too little pressure on the leg at different positions. The present 
invention (see FIG. 2) makes it possible to graduate all yarns and to be 
able to multi-feed the elastic yarn to make a ratio of one ground yarn to 
one elastic yarn or any other desired ratio. The presently used ratio of 
one elastic yarn to four ground yarns produces a helical marking on a leg 
when the bandage is removed showing clearly the poor pressure pattern, 
whereas a bandage made in accordance with the present invention will 
produce even pressure and at a controlled level. This is extremely 
important, for example, in the treatment of Deep Vein Thrombosis. 
FIG. 8 shows a pullover or sweater 200' made in one piece in a "sideways 
on" manner. The sweater 200' is commenced at one arm end 202' where the 
machine can be made (by adjustment of the dial height) to knit a small 
diameter garment and by successive alterations of dial height and yarn 
feed, as described with reference to FIG. 2, the width of the garment can 
be altered to the arms 204' wide body 206' and then reduced again to form 
the second arm 208' and cuff 210'. Elastic yarn can be used if required 
on, for example, the arms. The neck 212' of the sweater can be formed to a 
desired shape by cutting the tube and suitably finishing in known manner. 
FIGS. 9 and 10 show a pair of long pants (commonly known as "long johns") 
220'. They are made, as shown in FIG. 9, in one long piece with legs 222', 
224' and then a cut 226' is made for the upper opening. They are then bent 
to shape. 
The garments in FIGS. 7 to 10 are, of course, made continuously so that a 
finishing process will also be required at each end (e.g. 202', 210' in 
FIG. 8), but this finishing process can be simple and is well known in the 
trade. 
Though a true rib can be attached during a finishing process, it is 
possible to provide a "mock rib" by changing the dial height to provide a 
reduced stitch and by slowing down the rotation of the profile cam (or 
stopping it) to give a parallel fabric. 
FIG. 11 shows the type of finished garment that can be readily produced and 
shows a track suit made in four pieces, trousers 230', body 232' and arms 
234', 236'. 
Air vents 238' may be provided at any points in the pieces as shown. 
The garment may be made with elastic yarn to give a desired degree of 
stretch and the degree of stretch may be readily varied to give desired 
pressures, for example on the calf muscles to assist, for example, in a 
racing driver in blood flow to the head. It may be seen that such a suit 
could be designed to assist in medical conditions such as varicose veins 
or torn muscles while providing attractive clothing because it can be made 
multi-colored and styled as required. The garment can be made as a 
two-piece by suitable cutting and joining (e.g. in inside legs 240', 242' 
in a one-piece with a zipper 244' (shown dotted)). 
Thus, the machine, by being able to vary dial height and yarn feed and by 
being provided with a link between dial height and the speed of feed 
device 112 (FIG. 1), can be made to knit extremely wide widths and close 
or open knit garments thereby producing cuffs, polo necks and bodies of 
garments all on one machine. Obviously, there is a maximum size limit for 
each size of machine, but using elastic yarn feed the variation in width 
is considerable. Without elastic yarn feed the variation is less but is 
still useful in producing shaped garments. 
By suitable gearing the position of the profile cam (which can control (see 
FIG. 2) the elastic yarn feed, ground yarn feed and dial height) can be 
used to control the speed of the profile drive motor 210. This is shown in 
FIG. 3 wherein a further bevel gear arrangement 207 may be provided to 
drive a pulley and belt arrangement 207', 207" and pulley 207" may be used 
to move a dial speed controller 212 on motor 210. By selection of the gear 
ratios in arrangement 207 or by the relative size of pulleys 207', 207", 
the rate of change of motor speed with profile cam rotation can be 
adjusted. Thus, very complex shapes can be produced from one profile. 
It may be seen that other mechanical linkages between profile cam position 
and motor speed control can be used or an electronic control using, for 
example, a potentiometer could be used. It is also possible to control the 
speed of, for example, motor 84 by a simple computer program or paper tape 
to give varying lengths and/or widths of garments. If independent motors 
for control of elastic yarn feed, ground yarn feed and dial height are 
used, then each can be controlled from a single program, specifying, for 
example, voltages for speed control of each motor over periods of time, to 
produce a variety of sizes of garment all of similar shape. Such programs 
for the control of motors in paper tape form and the apparatus for 
effecting control of electric motors are well known and are, therefore, 
not described in any further detail. 
In a preferred embodiment the profile cam may be provided (see FIGS. 1 and 
3) with a pin 201 which signifies the start (or finish) position of a 
garment. This pin can be used to, for example, count the number of 
garments produced or it can be used to move a felt tip pen 201' which may 
be mounted in a spring loaded manner to strike the feed yarn 201" and 
thereby produce a mark (of suitable distinctive color) on the garment to 
accurately identify the cutting position between garments. Thus, the 
finishing operator can quickly and accurately separate the garments or 
this could be done automatically by a machine with suitable optical 
recognition equipment. 
The process is also particularly useful for production of garments such as 
leotards or swimsuits in which the ground yarn may be, for example, a 
lycra type giving the swimwear two-way stretch. Various styles and shapes 
can be made by simple alteration of the profiles controlling the feeds.