GB2263485A

GB2263485A - Knitted structure

Info

Publication number: GB2263485A
Application number: GB9200940A
Authority: GB
Inventors: Charles Wilfred Colledge; John Stuart Macgilbert; Giles Timothy Gregory
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1992-01-16
Filing date: 1992-01-16
Publication date: 1993-07-28
Anticipated expiration: 2012-01-16
Also published as: GB9200940D0; GB2263485B

Abstract

A method of weft knitting a fabric, eg. for upholstery, with blocks of contrasting colour on a knitting machine having a pair of opposed needle beds (F, R) comprises knitting side-by-side a plurality of colours of yarn on groups of adjacent needles (5-8 and 9-12) of the front bed (F) in two adjacent courses and the loops are distorted and displaced in a wale-wise direction on the face of the fabric so as substantially to mask the other colours of yarn on adjacent two or four courses of fabric as appropriate in which courses the other colours of yarn are knitted only on the rear needles and which other colours are readily visible only on the back of the fabric. <IMAGE>

Description

Knitted Structure This invention relates to knitted structures and has particular reference to knitted structures, for use as upholstery fabric, in which there is provided three or more colours in the structure.

Knitted fabrics suitable for use in upholstered structures are described in British Patent Application 2,223,035. Such structures may be knitted on jacquard knitting machines. With increasing sophistication there is a requirement to knit upholstery covers which have more than two colours. Most jacquard knitting machines are two system knitting machines. A flat V-bed two system knitting machine comprises a pair of opposed needle beds in a generally rooflike configuration. The knitting needles are movable within tricks in the needle bed and may be individually selected by cams located within a cam box reciprocal along the needle bed. In a two system jacquard knitting machine there are two cams for each needle bed for each direction with the cams being laterally displaced in the direction of movement of the cam box.Thus one cam can select one set of needles and the next cam following behind in the cam box can select a second, optionally different, set of needles. When knitting with two colours of yarn, one colour can be knitted on needles controlled by one cam and the other yarn can be knitted on needles controlled by the second cam. Dial and cylinder machines operate in the same way.

It is possible to knit three colours of yarn on a two system jacquard machine. For example where one block or island of colour is required in a sea of a matrix colour, the machine may be operated so that the sea is produced by the matrix colour knitted on both the front needles (which produce the face of the fabric) and the rear needles (which produce the back of the fabric), but the first colour is knitted only on the rear needles. Where the block of colour is required, the matrix colour is knitted only on the rear needles whereas the coloured yarn is knitted on both the front and rear needles.

In such a circumstance the third colour is simply not used at all. The yarn carrier fitted to the machine and which feeds the third colour to the knitting heads as required simply stays in a parked position. As the knitted structure grows a loop of the third colour is formed down the fabric until such time as the third colour is brought into use.

Unfortunately, however, with such a system, it is not possible to knit three colours in a single course.

Normally, when operating a two system jacquard machine with three colours it is not possible to provide in a matrix of one colour, side-by-side blocks of two separate colours. In such a structure each of the two side-by-side blocks is striped with alternate courses of colour.

The course-wise direction is along the line of knitting, and the wale-wise direction is in the plane of the fabric at right angles to the course-wise direction.

The present invention provides a process whereby course-wise side-by-side blocks of two different colours may be knitted into a matrix i.e. three colours may be knitted in discrete areas with a two system jacquard knitting machine. Additional colour combinations may also be provided as set out below.

By the present invention there is provided a method of weft knitting a fabric onWa knitting machine having a pair of opposed needle beds and having a front bed containing individually selectable needles for knitting the visible face of the fabric, and a rear bed containing individually selectable needles for knitting the back of the fabric, the machine being an N system jacquard machine and having a cambox moveable over the needle bed to actuate the needles, the cam box having at least N laterally spaced cams for each needle bed, where N is at least two, the method comprising knitting side-by-side (N + 1) or (N + 2) colours of yarn displayed on a single face course wherein stitches of one colour of yarn in two adjacent courses on the front face are knitted on all of the front needles and are distorted and displaced in a wale-wise direction on the face of the fabric so as substantially to mask the other colours of yarn on adjacent two or four courses of fabric as appropriate in which courses the other colours of yarn are knitted only on the rear needles and which other colours are readily visible only on the back of the fabric.

Preferably there are two systems and three colours.

Further preferably the machine is a flat V-bed machine. The fabric may be a double jersey fabric. The yarn may be a textured continuous filament synthetic yarn having a yarn count in the range 550 to 850 decitex, preferably 650 to 800 decitex. The yarn may be polyester yarn and is preferably an air-textured polyester yarn. The knitting machine is preferably operated without pull down tension, and the machine preferably has a presser foot take down or is provided with sinkers. The machine preferably has a gauge of 10 to 14 and is further preferably a 12 gauge machine i.e. one having twelve needles per inch of bed length.

The fabric preferably has 4 to 6 wales per cm and from 10.5 to 22 courses per cm.

The yarn preferably is substantially inextensible and has a high coefficient of friction. Preferably the maximum extensibility of the yarn at break is 30%, but it may be in the range 10% to 25% or 15% to 23% or 20% + 3%. The coefficient of friction in the yarn, when measured against a metal post, for example using a Buckle and Pollitt machine and a standard metal post, may be in the range 0.1 to 0.25 or 0.12 to 0.2 or 0.13 to 0.17.

By way of example, embodiments of the present invention will now be described with reference to the accompanying drawings, of which: Figure 1 is a plan view of a three coloured jacquard fabric showing two contrast colours in a matrix colour, Figure 2 is a stitch diagram showing the first courses of Figure 1, Figure 3 is a stitch diagram showing the central courses of Figure 1, and Figure 4 is a stitch diagram showing the final courses of Figure 1.

Referring to Figure 1, this shows schematically a face of a block of three colour jacquard fabric knitted on a two system jacquard machine in using the process of the present invention. Shown schematically is an area generally indicated by 1 which comprises a matrix 2 of ground colour having side-by-side areas 3 and 4 of contrast colour 1 and contrast colour 2 respectively.

Normal production processes for the manufacture of such a three colour structure on a two system machine would result in a matrix 2 of ground colour having blocks of striped contrast colours 1 and 2.

The process of manufacture of the structure shown in Figure 1 is most readily understood by reference to the needle or stitch diagrams illustrated in Figures 2 to 4.

Figures 2 to 4 comprise schematically the stitch diagrams of the portion below the two zones 3 and 4 in Figure 2, the stitch diagrams of the portion encompassing the zones 3 and 4 in Figure 3, and the stitch diagram for the upper portion above the zones 3 and 4 in Figure 4. It will be appreciated that Figures 2 and 4 are completely identical.

Considering first the embodiment illustrated in Figure 2 this shows eight courses of structure knitted in four traverses of the cam box over the needle bed. The knitting machine used to knit Figure 2 is a conventional two system jacquard V-bed knitting machine in which each bed has a pair of cams laterally displaced so as to be able sequentially to operate selected needles on a single traverse of the cam box across the needle bed. Such two system V-bed knitting machines are well known. The first traverse from right to left as shown in Figure 2 will knit sequentially the courses 1 and 2. During the initial movement of the cam box, the ground colour is knitted on course number 1. In this case the ground colour is knitted on all of the front needles numbered F1 to 16 and on alternate rear needles numbers R1, 3, 5, 7, 9, 11, 13 and 15.

Contrast colour number 1 is then knitted immediately afterwards in course number 2 but is knitted only on the even numbered alternate rear needles.

On the reverse movement of the cam box from left to right, courses 3 and 4 are knitted. Firstly, course 3 is knitted in the ground colour on all of the front needle beds and on the even numbered rear needle beds. Subsequently, contrast colour number 1 is knitted on the rear needle beds only in course 4 in this case on the odd numbered alternate needles 1, 3, 5, 7, 9, 11, 13 and 15.

The second movement of the cam box to the left as shown in Figure 2 again knits the ground colour on all of the front needles and on alternate odd numbered needles on the rear. Subsequently on the same movement, contrast colour number 2 is knitted, this time only on the rear needles and on the alternate even numbered needles.

When the cam box is moved in the return direction the ground colour is knitted in course number 7 on all of the front needles and on the alternate even numbered needles at the rear. Finally, course number 8 is knitted immediately after course 7, in sequence, and in this case contrast colour 2 is knitted only on the rear needles on alternate odd numbered needles.

This knitting sequence produces a plain face bird's eye backed structure in which only the ground colour appears on the face of the fabric with the back of the fabric having a dotted bird's eye appearance.

This structure occupies the portion of the matrix 2 of Figure 2 below the zones or blocks 3 and 4.

Figure 3 is the stitch diagram showing how blocks 3 and 4 are knitted so as to appear solid coloured blocks without either the ground colour or the second contrast colour appearing in block 3 or the ground colour or the first contrast colour appearing in block 4. In Figure 3 the blocks 3 and 4 are each shown four stitches wide and the two edged zones are also four stitches wide so that the total width of the fabric shown in Figure 1 is 16 stitches.

The first course knits both the ground colour and contrast colour number 1. The first passage of the needle box from right to left knits in course number 1 the ground colour on all of the odd numbered rear needles and on needles numbers 16 to 13 and 4 to 1 inclusive on the front needles. Subsequently in the same passage of the cam box the second cam selected for knitting with contrast colour number 1 knits all the even numbered needles on the rear bed but only needles numbers 8 to 5 inclusive on the front bed.

In the return movement of the cam box the cams select for course number 3 and for knitting with the ground colour alternate even numbered rear needles and only the front needles from 1 to 4 and 13 to 16 inclusive. Subsequently during the same movement of the cam box, contrast colour number 1 is knitted on the rear needles on every alternate odd numbered needle and on the front needles on needles 5 to 8 inclusive.

During the second reciprocal movement of the cam box, the ground colour and contrast colour number 2 are knitted.

In course number 5 it can be seen that the movement of the cam box from right to left first knits the ground colour on alternate odd numbered needles on the rear bed and on needles numbers 16 to 13 and 4 to 1 inclusive on the front bed. Subsequently, during the same movement of the cam box, contrast colour number 2 is knitted on every alternate rear bed needle, on the even numbered needles, but only on the front bed on needles numbers 12 to 9 inclusive.

On the return movement of the cam box, the ground colour is knitted in accordance with course number 7 on every alternate rear needle on the even numbered needles, and on only the front needles 1 to 4 and 13 to 16 inclusive.

The final course of the sequence is illustrated in number 8 where contrast colour number 2 is knitted only on the odd numbered alternate rear needles and on the front needles only on needles numbers 9 to 12.

If the structure of Figure 4 is then knitted subsequently, and it can be seen that the structure of Figure 4 is identical to that of Figure 2, again a fabric will be produced having on its face a plain coloration equal to the ground colour and having a bird's eye backed structure.

It will be seen by examination of the bird's eye backed structure illustrated in Figure 2 that overall the same number of stitches are formed on the rear bed as are formed on the front bed. There is, therefore, a perfect balance between the front and rear beds and the structure is inherently balanced. When, however, the structure illustrated in Figure 3 is considered, it can be seen that although the same number of stitches are knitted on the front and rear beds for needles 1 to 4 this is not the case for needles 5 to 12. Needles 13 to 16 also have the same number of stitches knitted on the front and rear beds.

In the case of needles 5 to 8, however, it can be seen that in the first four courses the same number of stitches are formed on the needles on the front bed as are formed on the rear bed. However, in courses 5 to 8 although stitches are formed on the rear bed on needles 5 to 8, no stitches are formed on the front bed. Similarly, for needles 9 to 12, in courses 1 to 4 stitches are formed on the rear bed but not on the front bed whereas in courses 5 to 8 an equal number of stitches are formed on the front and rear beds.

If the structure is knitted on a fine gauge machine such as a 12 gauge machine, and if the structure is knitted from relatively inextensible yarn - typically a polyester yarn particularly an air textured polyester yarn having a yarn count in the region of 550 to 800, and if the yarn is relatively a high friction yarn the stitches formed on the front needles in courses 1 to 4, needle numbers 5 to 8 are displaced in a wale-wise direction to overlie the "gaps" in the courses 5 to 8 on the front face where the front needles have not been knitted upon. This means that when the structure is looked at, only the contrast colour number 1 is visible in the region knitted on needles 5 to 8 inclusive.

Similarly, only contrast colour number 2 is visible in the region knitted upon needles 9 to 12. The ground colour is visible only in the region knitted on needles 1 to 4 inclusive and 13 to 16 inclusive. It can be seen, therefore, that the structure illustrated in Figure 1 has separate blocks of different contrast colour 1 and contrast colour 2 in a matrix of a ground colour. Such an appearance is conventionally only obtainable by the use of a three system jacquard machine, but by the process of the present invention, a two system jacquard machine can be used to form a knitted structure with three colours of the type which appears to have been knitted on a three system jacquard knitting machine.

It will further be appreciated that it is possible to knit four colours side-by-side on a two system jacquard machine in which case the stitch diagram shown in Figure 4 would be extended by a further four courses in which the courses 9 and 10 were produced by ground colour and contrast colour 3 and courses 11 and 12 are produced by ground colour and contrast colour 3.

Because of the need to have a relatively inextensible yarn for maximum colouring purposes. It is not practical to extend the knitted stitches in a given contrast colour over more than 2 additional contrast colours.

Because it is required that the structure should be in a state of imbalance from front to rear, lest the yarn knitted on the rear needles is "robbed" into the front face and hence shows up on the front face (given that the yarn in the rear is masked by the front face) it is preferable that the knitting machine be operated without any significant pull down tension other than that required to keep the fabric from tangling if there is a tendency for it so to do.

Preferably, therefore, the knitting machine incorporates a presser foot or sinkers to force down the knitted fabric as it is formed rather than pull down to pull away the structure and to hold the structure down on the needles.

Claims

CLAIMS 1. A method of weft knitting a fabric on a knitting machine having a pair of opposed needle beds and having a front bed containing individually selectable needles for knitting the visible face of the fabric, and a rear bed containing individually selectable needles for knitting the back of the fabric, the machine being an N system jacquard machine and having a cam-box moveable over the needle bed to actuate the needles, the cam box having at least N laterally spaced cams for each needle bed, where N is at least two, the method comprising knitting side-by-side (N + 1) or (N + 2) colours of yarn displayed on a single face course wherein stitches of one colour of yarn in two adjacent courses on the front face are knitted on all of the front needles and are distorted and displaced in a wale-wise direction on the face of the fabric so as substantially to mask the other colours of yarn on adjacent two or four courses of fabric as appropriate in which courses the other colours of yarn are knitted only on the rear needles and which other colours are readily visible only on the back of the fabric. 2. A method as claimed in claim 1 in which there are two systems and three colours. 3. A method as claimed in claim 1 or 2 in which the knitting is carried out without pull down tension. 4. A method as claimed in claim 1,2 or 3 in which the yarn is a polyester continuous filament yarn. 5. A double jersey knitted upholstery fabric in at least three colours, in which a stitch knitted in one course is stretched and displaced in a wale-wise direction to appear to be in a different course. Amendments to the claims have been filed as follows CLAIMS II -

1. A method of weft knitting a fabric on a knitting machine having a pair of opposed needle beds and having a front bed containing individually selectable needles for knitting the visible face of the fabric, and a rear bed containing individually selectable needles for knitting the back of the fabric, the machine being an N system jacquard machine and having a cam-box moveable over the needle bed to actuate the needles, the cam box having at least N laterally spaced cams for each needle bed, where N is at least two, the method comprising knitting side-by-side (N + 1) or (N + 2) colours of yarn displayed on a single face course wherein stitches of one colour of yarn in two adjacent courses on the front face are knitted on all of the front needles and are distorted and displaced in a wale-wise direction on the face of the fabric so as substantially to mask the other colours of yarn on adjacent two or four courses of fabric as appropriate in which courses the other colours of yarn are knitted only on the rear needles and which other colours are readily visible only on the back of the fabric.

2. A method as claimed in claim 1 in which there are two systems and three colours.

3. A method as claimed in claim 1 or claim 2, in which the knitting machine is a flat V-bed machine.

4. A method as claimed in any preceding claim, in which the yarn is a textured continuous filament synthetic yarn having a yarn count in the range 550 to 850 decitex.

5. A method as claimed in claim 4, in which the count of the yarn is in the range 650 to 800 decitex.

6. A method as claimed in any preceding claim, in which the knitting is carried out without pull down tension.

7. A method as claimed in any preceding claim, in which the yarn is a polyester continuous filament yarn.

8. A method as claimed in any preceding claim, in which the knitting machine has a gauge of 10 to 14.

9. A method as claimed in any preceding claim, in which the knitting machine has a gauge of 12.

10. A method as claimed in any preceding claim, in which the fabric has 4 to 6 wales per cm and from 10.5 to 22 courses per cm.

11. A method as claimed in any preceding claim, in which the yarn is substantially inextensible and has a high coefficient of friction.

12. A method as claimed in claim 11, in which the maximum extensibility of the yarn at break is 30%.

13. A method as claimed in claim 12, in which the maximum extensibility of the yarn at break is in the range 10% to 25%.

14. A method as claimed in claim 13, in which the maximum extensibility of the yarn at break is in the range 15% to 23%.

15. A method as claimed in claim 14, in which the maximum extensibility of the yarn at break is 20 + 3%.

16. A method as claimed in claim 11, in which the coefficient of friction in the yarn is in the range 0.1 to 0.25.

17. A method as claimed in claim 16, in which the coefficient of friction in the yarn is in the range 0.12 to 0.2.

18. A method as claimed in claim 17, in which the coefficient of friction in the yarn is in the range 0.13 to 0.17.

19. A method of weft knitting substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

20. A double jersey knitted upholstery fabric in at least three colours, in which a stitch knitted in one course is stretched and displaced in a wale-wise direction to appear to be in a different course.