GB2085485A

GB2085485A - Circular knitting machine for producing knitted goods with combed-in fibres

Info

Publication number: GB2085485A
Application number: GB8131653A
Authority: GB
Original assignee: Sulzer Morat GmbH
Current assignee: Sulzer Morat GmbH
Priority date: 1980-10-20
Filing date: 1981-10-20
Publication date: 1982-04-28
Also published as: IT1139521B; IT8124459A0; ATA413081A; GB2085485B; AT395867B; DE3039576A1; JPS57121654A; DE3039576C2

Abstract

Fabric knitted on the needle cylinder 5 has tufts 46 combed in from a doffer roller 19 supplied by feed rollers 17 and a drum 15. The roller 19 which has a card clothing is enclosed by a cover 42 with portions 43 and 48 which extend close to the needles to define a narrow gap 49. In this way tufts 46 which have already been pulled into the fabric and which may turn up because of electrostatic charges are prevented from catching in the card clothing of the roller 19. <IMAGE>

Description

SPECIFICATION Circular knitting machine for producing knitted goods with combed-in fibres The invention relates to a circular knitting machine of the category defined in the precharacterising clause of Patent Claim 1.

In circular knitting machines of this type (German Offenlegungsschrift 2,748,941) the problem frequently arises that during the passage of the knitting-needle hooks through the card clothing of a doffer roller those fibres which have already been combed in, and bound into the stitches held by the knitting needles, during a previous section of the process, e.g. on a previous knitting system, accidentally pass back into the region of the card clothing. This effect occurs especially during the processing of certain synthetic fibres, and is the result of electrostatic charging, which causes the fibres to turn up or be turned up. One result of this is that the fibres of the old stitches are caught by the hooks of the card clothing and are torn out of the finished fabric by these hooks due to the rotation of the doffer roller.This results firstly in subsequent damage to the already finished knitted goods, whilst secondly, during the pulling-out of the combed-in fibres, a considerable thrust or traction is exerted upon the sinkers arranged between the knitting needles, which prejudices their durability.

It is therefore the object of the invention to improve the circular knitting machine initially designated so that the fibres which have already been combed in and bound into the stitches cannot pass again into the card clothing of a doffer roller.

The characterising features of Patent Claim 1 are provided to achieve this object.

The invention has the advantage that although the cover extending into close proximity with the needle backs allows the unobstructed rising of the knitting needles for the purpose of picking up fibres, it nevertheless simultaneously covers the fibre bundles contained in already finished stitches and principally arranged on the backs of the knitting needles, and thereby prevents them from rising together with the knitting needles or from turning up due to electrostatic or other effects, whereby these fibres are effectively prevented from passing into the region of the card clothing and being entrained by the latter.

Further advantageous features of the invention appear from the sub-claims.

The invention is explained more fully below by an illustrative embodiment, in conjunction with the drawing wherein: Figure 1 shows a circular knitting machine of known construction; Figure 2 shows those parts of a circular knitting machine according to the invention necessary to an understanding of the invention; Figure 3 shows in elevation the card of the circular knitting machine according to Figure 2; and Figure 4 shows a detail of Figure 2 on a larger scale.

According to Figure 1 a known circular knitting machine for producing a patterned knitted goods 1 with combed-in fibres has a baseplate 2, in which a needle cylinder 5 equipped with knitting needles 3, and a sinker ring 9 equipped with sinkers 7, are mounted rotatably. Knitting needles 3 and sinkers 7 are controlled by cams in a customary manner, whilst a plurality of spaced knitting systems, each with a pattern device 11 by means of which the knitting needles 3 are selected to pick up fibres or not to pick up fibres according to the pattern, are arranged on the circumference of the needle cylinder 5.

Also provided on each knitting system is a card 12, which is attached to a frame 14 and serves to feed fibres with a specific property, e.g. a specific colour, to the knitting needles selected for knitting.

Each card 1 2 consists e.g. of a drum 1 5 with a card clothing 31, to which fibres are fed in the form of a slubbing 1 6 by means of a pair of feed rollers 17, and of a doffer roller or comb-in roller 1 9 with a card clothing 21, by means of which the fibres removed from the drum 1 5 are presented to the knitting needles 3 selected for knitting. The comb-in station is located at the point where the hooks of the knitting needles 3 travel through the card clothing 21 along a track extending substantially parallel to the axis of the doffer roller 19. The surfaces of the drum 15,ofthedoffer roller 21 and of the equalising roller 28 may be provided with a cover 41 in the manner to be seen from Figure 1.

The drive means 23 of the feed rollers 1 7 is controlled by means of a control device 25 so that, averaged over relatively short periods of time, the fibres are transferred from the drum 1 5 to the comb-in roller 1 9 in such a quantity as the pattern demands.

In order to equalise the supply of fibres present on the doffer roller 19, an equalising roller 28 may additionally be associated with this roller.

Circular knitting machines of the type described are known e.g. from German Patent Specification 1,201,509 and from German Offenlegungsschriften 2,115,721,2,343,886, 2,524,491 and 2,748,941, which are incorporated herein by reference.

As indicated by the reference numeral 29 in Figure 1, fibres already combed in can turn up in the region of the comb-in station and pass into the card clothing 21 of the doffer roller 19. These fibres are not those fibres which are intended to be combed freshly into the extended knitting needles at the comb-in station visible in Figure 1, but such fibres as were combed into the hooks of the knitting needles 3 and bound firmly into the fabric by knitting of a ground thread in a previous section of the process, e.g. at a previous knitting system in the direction of rotation of the needle cylinder 2. The relatively long ends of these fibre tufts are present particularly in the backs of the knitting needles 3 and are gradually drawn through the needle cylinder 2 together with the fabric 1 to the winding-on roller.

The circular knitting machine according to the invention as shown in Figures 2 to 4 serves to eliminate the said disadvantage. Like the circular knitting machine according to Figure 1, it contains a cover 42 which closely encloses the circumference of the doffer roller 1 9 or of the card clothing 21 at least along a region located behind the knitting needles 3 in the direction of rotation of the doffer roller 1 9. Additionally to Figure 1, however, the cover 42 is prolonged by a part 43 to a point 44 extending into close proximity with the needle backs.A restraining element arranged at the back of the knitting needles 3 and extending into close proximity with the needle backs is thereby created between the cylinder top edge 45 and the doffer roller 1 9 or the comb-in station, so that those fibre tufts 46 which have been bound into stitches already finished and suspended in the hooks or on the shanks of the knitting needles 3 can no longer turn up and pass into the region of the card clothing 21 even if the tendency to this exists because of electrostatic or other effects.

This can be seen particularly well from Figure 4, in which the region 47 framed in a circle in Figure 2 is illustrated on a larger scale, and which shows that the gap between the needle backs and the part 43 is so small that it effectively prevents the passage of fibres already present on the knitting needles or in their hooks.

According to Figure 3 the restraining element extends in the form of the part 43 of the cover 42 over the entire width of the doffer roller 1 9 extending in the axial direction and hence over the entire width of the comb-in zone, and advantageously does so in such a way that the fibres 46 to be held away are already covered by the part 43 when the knitting needles 3 are extended for the purpose of picking up fibres.

According to Figures 2 to 4 the cover 42 of the doffer roller 19 may also exhibit a part 48 which extends in the direction of rotation of the doffer roller 1 9 into close proximity with the fronts of the knitting needles 3, so that only a narrow passage gap 49 for the hooks of the knitting needles 3 is formed between the two parts 43 and 48. By this means fibres present on the fronts of the needles are additionally prevented from being able to pass into the region of the card clothing 21.

The part 43 is conveniently arranged so that the turning-up of the fibres is prevented irrespective of whether the knitting needles are extended to the knitting position or tuck position in the region of the comb-in station.

Further particular advantages of the restraining element according to the invention are that it prevents the ground fabric from rising into the region of engagement of the doffer roller 1 9 during the knitting-on of the circular knitting machine and can also be fitted subsequently by a few hand operations to circular knitting machines which were originally supplied and operated without a prolonged cover.

Claims

1. Circular knitting machine with a needle cylinder for producing knitted goods with combedin fibres, wherein at least one card is provided with a doffer roller which has a card clothing through which the knitting-needle hooks travel for the combing-in of the fibres, characterised in that the circumference of the doffer roller is provided, in a region located downstream of the knitting needles in its direction of rotation, with a cover closely surrounding the card clothing, which extends into close proximity with the needle backs and forms a restraining element for the fibres already combed in.

2. Circular knitting machine according to Claim 1, characterised in that the cover extends over a section of the circumference of the doffer roller arranged in front of and behind the knitting needles and exhibits only a narrow passage aperture for the knitting-needle hooks.