GB2137234A - Yarn guide for flat knitting machine - Google Patents

Abstract

A flat knitting machine 10 has a pair of mutually inclined needle beds 16 and 17, above which are disposed guide rails 23 to 25. The guide rails carry slidable needle boxes 28 on which yarn guides 11, 12 and 13 are mounted such that yarn eyes 18 thereon are positioned close together in the region of the knitting needles. Each yarn guide comprises a single-piece, resilient arm having a tapered portion 36 (Fig. 3) adjacent its lower end, the sloping lateral edges 46 and 47 of this portion extending for a proportion of the overall length of the arm which is dependent upon the maximum possible amount by which the latter can deflect, so that when two of the yarn guides pass one another they touch only at these lateral edges, even when at their maximum deflection. <IMAGE>

Description

SPECIFICATION Yarn guide and flat knitting machine including same This invention relates to a yarn guide for a flat knitting machine, and to a flat knitting machine including such a yarn guide.

Typically, a flat knitting machine comprises a pair of mutually inclined needle beds, and at least one guide rail disposed above the needle beds and extending longitudinally thereof. A plurality of yarn guides are mounted on the guide rail or rails (more exactly on yarn guide boxes), each yarn guide comprising an arm fixed to the yarn guide box at its upper end and having a yarn eye at its lower end. A portion of the arm adjacent to the yarn eye is shaped so that its lateral edges taper inwardly towards the lower end of the arm. Often, a problem exists in bringing together the yarn eyes of a large number of yarn guides between the needles of the two beds, these needles being mutually facing and also being in the knitting position. Also, although the yarn eyes lie partly in a common path of movement, they nevertheless have to be moved past one another.

Conventional yarn guides of this type are constructed in two parts, one part (the top part) being rigidly fixed to the yarn guide box, the other part (the bottom part or head) which has the yarn eye being pivotably mounted on the top part against the action of a pressure spring. This construction enables the bdttom part to be deflected cut of the common path of movement by the bottom part of another yarn guide. The bottom part or head is produced as a forging, and in the area of the yarn eye has two lateral edges which slope towards one another at a relatively large angle of about 45 relative to the longitudinal axis of the arm. These lateral edges extend approximately up to the level of an upper end of the yarn eye and then taper towards the pivotal joint with the upper part of the arm (Form A, B, C to DIN 62 161).This means that this approximately rhombic shaped end area of the bottom part of the arm is of relatively wide design, which makes it difficult to bring a large number of yarn guides close together.

This is disadvantageous, particularly in cases where several pieces of knitting are to be produced on the flat knitting machine over the length of the needle beds, because the space between the individual pieces of knitting in which the yarn guides have their reversal point should be kept as small as possible.

Another conventional yarn guide in accordance with Form D to DIN 62 161 is indeed provided with lateral edges which extend more acutely and is therefore narrower, but this yarn guide has even more considerable disadvantages at the present time. Since the lower part of the arm is a forging in which a bore for the yarn eye is made, it is relatively thick: this not only poses difficulties in placing several yarn guides close together, but also creates problems in moving the yarn guides past one another.

With conventional yarn guides, in certain situations it is also possible that the pivotal bottom parts can become hooked up with one another, with the result that the yarn guides can be badly damaged. This can happen for example when three yarn guides have to be removed from an unfavourable disposition past one another at the same time, because the bottom part of one yarn guide is then deflected out so far that the bottom part of another can hook behind it without getting past it.

An object of the present invention is therefore to provide on the one hand a yarn guide for a flat knitting machine and on the other hand a flat knitting machine including such a yarn guide, where the yarn guides are designed such that they can be moved past each other w.ith room to spare and where it is ensured in particular that the yarn guides cannot become hooked up with one another.

According to a first aspect of the present invention, there is provided a yarn guide for a flat knitting machine, comprising a resilient arm formed as a single-piece component and having a first end which in use is secured to a yarn guide box of the knitting machine, a portion of the arm adjacent to a second end thereof being provided with a yarn eye and having lateral edges which taper inwardly towards the second end proper and which extend over a substantial proportion of the length of the arm, said proportion being dependent upon the maximum possible deflection of the arm during operation.

According to a second aspect of the present invention, there is provided a flat knitting machine comprising a pair of mutually inclined needle beds, at least one guide rail disposed above the needle beds and extending longitudinally thereof, and a plurality of yarn guides mounted on said at least one guide rail for movement therealong, each yarn guide comprising a resilient arm formed as a single-piece component and having a yarn eye at an end therof spaced from the respective guide rail, the yarn guides being arranged with their yarn eyes mutually adjacent to one another, a portion of each arm adjacent to said end thereof having lateral edges which taper inwardly towards said end proper and which extend for a proportion of the length of the arm, said proportion being selected such that the arms touch each other only at their said lateral edges, even at maximum deflection.

Because of its relatively long sloping lateral edges, the yarn guide of the invention is protected in an optimum way from being able to get hooked up with other yarn guides. This results from the fact that even at maximum deflection and with several yarn guides moving past each other, the guides cannot become hooked together due to their lower portions always being against one another at their oblique lateral edges. The yarn guides touch each other exclusively on these lateral edges so that they are deflected automatically through the lateral edges sliding off one another. These long lateral edges also mean that the bottom end of the guide (on which the yarn eye' is provided) can be made altogether thinner so that space is saved through this too.Furthermore, the yarn guide arm is a single-piece component and is designed to be elastically resilient: it can therefore be designed thinner because of this, thereby also permitting a possible thickness recuction in the area of the yarn eye. For the last-named reason, the yarn guide can also be produced more simply and more cheaply because an expensive mechanical system for producing the pivotal joint is no longer needed.

In one embodiment of the present invention, the sloping lateral edges run at a very acute angle in the region of 5" to 15 , preferably 9 . However, for pivotably hinged yarn guides these angles are increased by an amount equivalent to the swivel angle of the guide so that the acute angle is maintained even in a deflected-out state. The very acute slope not only gives the yarn guide arm a narrow build, but also enables several arms to slide past one another easily during their mutual deflection. This is helped further if, as is realised in another embodiment, the sloping lateral edges are provided with a chamfer.

In order for the yarn guide arms to pass each other without becoming hooked where wires for holding the knitting wide are used, the sloping lateral edges can be intersected at the free end of the arm by additional lateral sides which are inclined relative to the longitudinal centreline of the arm at an angle substantially larger than that of the lateral edges, preferably 40'.

As mentioned previously, in conventional yarn guides, the lower arm part is a forging which is relatively thick: although the lower arm part can be made more secure against abrasion through hardening or a coating this can be performed only on the whole of the lower arm part. In the yarn guide of the present invention however, partial hardening is possible, as will now be explained. In a particular example of the yarn guide of the invention, a recess is provided which opens onto the bottom end of the arm and into which a separate insert constituting the yarn eye is firmly received. In other words, the yarn eye is formed by a special insert which is made independently of the arm, and which can therefore on its own be improved with regard to resistance to abrasion.More particularly, the insert can be hardened in a simple manner which is specific for the purpose, or can be given a hard coating in the region of the borehole for the yarn eye without this having to be applied over the whole yarn guide arm. This is a great advantage because the operating conditions and materials required for the remainder of the yarn guide arm are completely different from those for the insert.

In the conventional yarn guide,a thickening is provided on one side on the forged lower arm part and the through bore for the yarn eye is worked into this thickened partion. The disadvantage here is that the bore for the yarn eye is accessible only from one side of the lower arm part. In order to avoid this, in a preferred embodiment of the present invention the insert is a generally lens-shaped element provided with a central, longitudinally extending through-bore, the insert being thicker than the yarn guide arm. Here, the recess (which is generally U-shaped) can be made longer than the insert, with the latter being set substantially flush with the free end of the yarn guide arm and being arranged symmetrically with respect to the longitudinal centreline of the arm.The yarn can thus be threaded into the bore of the yarn eye both from the front and also from behind, because it is possible to thread into the bore through the remaining unoccupied part of the recess.

The insert can be fixed in the recess in various ways, for example by clipping, clamping, sticking or soldering.

The invention will now be further described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an end view, partly in section, of a flat knitting machine according to the present invention including inner, outer and centre yarn guides.

Figure 2 is a front view of the outer yarn guide; Figure 3 is a view in the direction of arrow Ill in Figure 1; Figure 4 is a front view of the centre yarn guide; Figure 5 is a front view of the inner yarn guide; Figure 6 is a side view on an enlarged scale of a lower end of a yarn guide; Figure 7 is a side view of a yarn eye, for use with the guide shown in Figure 6; Figure 8 is a view of the yarn eye shown in Figure 7 from underneath; Figure 9 is an underneath view of the yarn eye as viewed in the direction of arrow IX in Figure 3; Figure 10 is a similar view to Figure 3, but showing an alternative form of yarn guide in a dismantled condition; and Figure 11 is a diagrammatic view of a still further form of yarn guide according to the present invention.

Referring first to Figure 1, there is shown a flat knitting machine 10 in which a plurality of yarn guides 11, 1 2 and 1 3 are arranged so that they lie close up against each other above a vertex line 14 of front and rear needle beds 1 6 and 17, which are mutually inclined. At their bottom ends 19, the yarn guides 11, 1 2 and 1 3 are provided with yarn eyes 18, and the aforementioned close arrangement of the yarn guides occurs both in a direction parallel to the vertex line 14 and also in a direction diagonally to this.Thus, on the one hand for example where there are several pieces of knitting next to one another in the needle bed, little room is lost for accommodating the yarn guides 11 to 13, and on the other hand the bottom ends 1 9 of all of the yarn guides find room between two working needles of the needle beds 16 and 17, even in the position shown in Figure 1 in which they are all lying close to each other.

Figure 1 shows, as well as the front and rear needle beds 1 6 and 17, two cam slides 21, 22 and a wire 34 for holding the knitting expanded. The knitting machine also includes a plurality of guide rails 23, 24 and 25 (three in the illustrated construction) which are parallel to one another. Each of these guide rails possesses two guideways 26 and 27 on which thread guide boxes 28 are disposed so that they can be moved longitudinally, and the individual yarn guides 11 to 1 3 are rigidly fixed on these boxes 28 by means of bolts 29. The yarn guide boxes 28 along with the yarn guides 11 to 1 3 are moved to and fro during the knitting operation in synchronism with the cam slides 21, 22, according to their respective selection.Since the guide rails 23 to 25 are arranged symmetrically with respect to the vertex line 14, the yarn guides 11 to 1 3 (which are of differing lengths) are also arranged symmetrically. Thus, the outwardlyfacing guideways 26 and 27 on the outer guide rails 23 and 25 respectively each carrying an outer yarn guide 11, the two other guideways 27 and 26 of the two outer guide rails 23 and 25,respectively, each carry a middle yarn guide 12, and the inner guide rail 24 carries on each of its two guideways 26 and 27 a respective inner yarn guide 1 3.

Each of the yarn guides 11 to 1 3 comprises a single-piece arm 31 to 33 respectively, as shown in Figures 2 to 5. These arms differ from one another only in their differing bending and,because their yarn eyes 18 all adopt essentially the same position above the needle beds 16 and 17, in their overall length. Each of the arms 31 to 33 is symmetrical with respect to its longitudinal centreline or axis, and is composed of an upper arm part 37 provided with fixing bores 41, a middle arm part 38, and a lower arm part 39 provided with a tapered portion 36, this portion 36 having a recess 42 for receiving the respective yarn eye 1 8.

Referring now to Figure 2, in each outer yarn guide 11 the middle arm part 38 is bent at an angle of 45 relative to the upper arm part 37, while the lower arm part 39 is bent in the opposite direction an an angle of 27 relative to the middle arm part 38. The dimensions in the illustrated embodiment are chosen such that the upper arm part 37 is a little longer than the middle arm part 38, and such that the lower arm part 39 is in turn a little longer than the upper arm part 37.

As can be seen in Figure 5, the arm 33 of each inner yarn guide 1 3 also has two oppositely directed bending points 43 and 44,whereby the angle between the upper and middle arm parts 37 and 38 is 12.5 , and the angle between the middle and lower arm parts 38 and 39 is 5.5 . The length ratios here are chosen such that the middle arm part 38 is a little longer than the upper arm part 37 and such that the length of the lower arm part 39 is less than that of the upper arm part 37.

With reference to Figure 4, the arm 32 of each middle yarn guide 1 2 is provided with only an upper bend point 43, such that the upper and middle arm parts 37 and 38 form an angle of 18 with one another. The length ratios here are chosen such that the overall length of the middle and lower arm parts 38 and 39 is somewhat more than double the length of the upper arm part 37. It will be apparent that the inner yarn guide arms 33 are shorter than the middle yarn guide arms 32 and these in turn are shorter than the outer yarn guide arms 31.

The yarn guide arms 31 to 33 are designed to be elastically resilient, and in the illustrated embodiment are made out of a hard spring steel strip. In the region of the upper and middle arm parts 37 and 38 the arms are provided with substantially parallel edges, while the portion 36 of the lower arm part 39 is provided with two lateral edges 46 and 47 which slope towards one another. The lateral edges 46 and 47 are disposed symmetrically to the longitudinal centreline of the yarn guide arm 31 and form at their upper end a broadening of the lower arm part 39. The lateral edges 46 and 47 taper inwardly towards the free end 19: in the yarn guide shown in Figure 3, these edges taper in such a way that the bottom end 1 9 has a breadth which is the same as or a little smaller than that of the arm parts 37 and 38. The two lateral edges 46 and 47 are inclined at an acute angle to the longitudinal centreline 28 of the arm: where the yarn guides 31 to 33 are rigidly fixed on the respective yarn guide box- 28, this angle is between 5" and 15 , preferably 9 . The two lateral edges 46 and 47 are provided over their whole length with a chamfer 49, both from the front side and from the rear side thereof.

If as shown in Figure 11, the yarn guide arm (e.g. 31') is mounted on the respective yarn guide box 28', so that it can swivel to both sides for technical knitting reasons, then the angle of inclination of the lateral edges 46 and 47 is increased on both sides by the angle of swivel.The yarn guide arm 31' here can be swivelled about an axis 66 on the yarn guide box 28' and is provided at an end thereof remote from the end 1 9 with a nose 67 which engages in a recess 68 in an adjusting slide 69. The nose 67 also engages in one of three locking notches 70 formed on a lower edge of a catch 71, this catch having its free end connected to a tension spring 72.

The swivel positions shown in Figure 11 by chain-dotted lines and by broken lines are achieved at the relevant reversal point of the yarn guides by means of a driving bolt 73 which also serves to carry the box 28'.

In each of the above described yarn guides, the portion 36 on which the lateral edges 46 and 47 are provided takes up a considerable proportion of the overall length of the respective arm or the main length of the lower arm part 39. In the yarn guide 11 shown in Figure 2, the portion 36 is a little shorter than the lower arm part 39, while in the yarn guide 1 3 shown in Figure 5 of the length of the portion 36 is approximately the same as the length of the lower arm part 39, i.e. the lower bend point 44 is in the region of the upper end of the sloping lateral edges 46 and 47. In the middle yarn guide 1 2 shown in Figure 4, the length of the portion 36 is somewhat smaller than half the total length of the middle and lower arm parts 38 and 39, and is about 1/4 to 1/3 of the overall length of the arm.

The portion 36 of the lower arm part 39 is, as can be seen to advantage in Figure 6, provided with a recess 42 for receiving the yarn eye 18. The recess 42 is approximately U-shaped and opens onto the bottom end 19 of the arm. Opposed lateral edges 51 of the recess 42 are wedge-shaped in transverse cross-section. Figures 7 and 8 show the yarn eye 1 8 which is in the form of a generally lens-shaped insert 52. This lens-shaped insert is a high quality casting which has been smoothed down or trimmed on all four sides so that it is approximately square in cross sction. At its centre, the insert 52 has a through borehole 53.The lateral sides of the insert 52 are provided respectively with grooves 54 and 56 which extend parallel to the borehole 53 and which taper inwardly in cross-section from the outside to the inside in correspondence with the wedge shape of the edges 51 of the recess 42. A generally triangular projection 57 is provided on a base wall of the groove 54 approximately centrally thereof in the longitudinal direction. A corresponding hollow 58 is formed in each edge 51 of the recess 42, one of these hollows being engaged by the projection 57.

Figure 9 shows the symmetrical fitting position of the lens-shaped insert 52 in the recess 42. During its installation, the insert 52 is pushed sufficiently far into the recess 42 for the projection 57 to engage in the appropriate one of the hollows 58. In this position, the bottom end of the insert 52 lies flush with the bottom end 19 of the yarn guide arm 31, 32 or 33. The length of the recess 42 is greater than that of the insert 52, so that a space 59 remains between the inner end of the insert 52 and the inner, curved end of the recess 42. The borehole 53 opens into this space 59 from the bottom end (see Figure 3), thereby giving access to the borehole 53 from both the front and rear sides of the arm portion 36.

As can be seen from Figure 9, the insert 52 ends laterally in the region.of the start of the chamfer of the lateral edges 46 and 47, and covers relatively little as regards the mean maximum thickness. In other words, the yarn guides 11 to 1 3 are relatively thin in the area of the yarn eye 8. Through the lens-shaped curvature of the insert 52, a corresponding continuation of the slope of the chamfer 49 on the lateral edges 46 and 47 is produced.

The lens-shaped insert 52 can, as illustrated, be held only in a form-locking manner in the recess 42. However, instead of the form-locking connection, it is possible instead to create a friction-locking connection, i.e. by squeezing the insert 52 into the recess 42.

Additionally or alternatively, the insert 52 can be secured in the recess 42 through adhesion or soldering. Since the insert 52 is a separate unit which is inserted after the manufacture of the yarn guide arm, it can be designed specifically having regard to the stress it is to withstand. More particularly, as mentioned preiously the insert 52 is produced as a high quality casting, and this can be hardened in a manner suitable to the purpose subsequent to the casting operation, because the insert is a part which is subject to considerable wear due to the yarn being drawn there-through. It is also possible to provide the insert 52 with a hard coating, for instance a ceramic coating, particularly in the region of the bore-hole 53, or to provide the borehold with a ceramic insert.If the yarn eye 18, which as mentioned is designed as an insert, is only clipped in, then it is possible to use it as a replaceable part so that it can be changed when the wear has become too great. The important thing here in any case is that the insert 52 can be manufactured, machined and heat treated differently from the arm 31, 32 or 33 in accordance with the different kind of stress it is likely to encounter.

Figure 10 shows a variant of the yarn guide, wherein additional sloping lateral sides 61 and 62 are provided on the end 19 of the arm. These sides extend outwardly from the point where the recess 42 opens onto the end 19, and are inclined at an angle of 40 to the longitudinal centre-line 48 of the arm so that they form an angle with the lateral edges 46 and 47 of the portion 36, respectively, i.e.

they cut or bevel the edges 46 and 47. In addition, the insert 52 is reduced in this area by the sloping sides 61 and 62. These slop- ing sides serve to ensure that, even in the case where wires 34 for holding the piece of knitting expanded are arranged between the needle beds 1 6 and 1 7 (Figure 1), the yarn guide arms with their respective yarn eyes 1 8 can be moved past the holding wires 34 without becoming hooked up.

As can be seen in Figure 1, the lower ends 19 of the yarn guide arms 31 to 33 (where the eyes 1 8 are provided) can be brought close to one another, whereby it is guaranteed that any one of these arms can be moved between the others or past them. Since the arms 31 to 33 are manufactured out of a spring steel strip, they can be deflected as they move past one another. A reciprocal deflection in a direction perpendicular to the vertex line 14 of the needle beds 16, and 1 7 occurs due to the inclined lateral edges 46 and 47, the chamfers 49 and the lens-shaped curvature of the insert 52. Both the slight thickness of the insert 52 and also the acute angle of the lateral edges 46 and 47 (which enable the arms 31 to 33 to be deflected and to slide past each other easily) contribute to this.Of great importance here is the length of the portion 36 or its lateral edges 46 and 47.

This length is selected such that even at the maximum possible deflection of the arm, two yarn guides are in contact with one another solely on the lateral edges 46 and 47. In other words, even in the case where two yarn guide arms move past each other and only one of them deflects, and where a third yarn guide arm has to be moved through between these two, the third yarn guide arm touches the yarn guide arm which is at maximum deflection only on the lateral edges 46 and 47 of the latter, so that a further deflection of one or other of the yarn guide arms takes place automatically through this third yarn guide arm. This movement phase described above, which is executed by the three yarn guide arms on one side, is not critical and is without problems, due to the provision of the elongated portion 36 provided with the inclined lateral edges 46 and 47. The same applies, where appropriate, with regard to guiding the yarn guides past the wires 34 for holding the piece of knitting extended, due to the provision of the additional sloping sides 61 and 62.

Claims (46)

1. A yarn guide for a flat knitting machine, comprising a resilient arm formed as a singlepiece component and having a first end which in use is secured to a yarn guide box of the knitting machine, a portion of the arm adjacent to a second end thereof being provided with a yarn eye and having lateral edges which taper inwardly towards the second end proper and which extend over a substantial proportion of the length of the arm, said proportion being dependent upon the maximum possible deflection of the arm during operation.

2. A yarn guide as claimed in claim 1, wherein the arm has a single bend therein adjacent to its first end, and said lateral edges extend over somewhat less than half the distance between the second end and the bend.

3. A yarn guide as claimed in claim 1, wherein the arm has two oppositely-directed bends therein, and said lateral edges extend over somewhat less than the total length of the arm or over the whole distance between the second end and the bend nearest thereto.

4. A yarn guide as claimed in claim 1, 2 or 3, wherein said lateral edges extend over approximately one quarter to one third of the total length of the arm.

5. A yarn guide as claimed in any preceding claim, wherein the arm is rigidly fixed to the yarn guide box in use, and said lateral edges are inclined at an angle of about 5" to 50' relative to a longitudinal centreline of the arm.

6. A yarn guide as claimed in claim 5, wherein said lateral edges are inclined at substantially 9" to said longitudinal centreline.

7. A yarn guide as claimed in any one of claims 1 to 4, wherein the arm is secured to the yarn guide box in use so that it can swivel through an angle of 0, and said lateral edges are inclined at an angle of about 5' + 8 to 1 5' + 8 relative to a longitudinal centreline of the arm.

8. A yarn guide as claimed in claim 7, wherein said lateral edges are inclined at substantially 9" + 8 two said longitudinal centreline.

9. A yarn guide as claimed in any preceding claim, wherein said lateral edges are provided with a chamfer.

10. A yarn guide as claimed in any preceding claim, wherein the arm is made from hard spring steel strip.

11. A yarn guide as claimed in any preceding claim, wherein the second end of the arm has lateral edges which form an angle with said lateral edges of said portion of the arm.

12. A yarn guide as claimed in any preceding claim, wherein a recess opens onto the second end of the arm, and an insert containing the yarn eye is firmly received in the recess.

1 3. A yarn guide as claimed in claim 1 2 when appended to claim 11, wherein the lateral edges of the second end extend outwardly from the vicinity of recess opening.

14. A yarn guide as claimed in claim 13, wherein the lateral edges of the second end are inclined at an angle of substantially 40 to a longitudinal centreline of the arm.

1 5. A yarn guide as claimed in claim 12, 1 3 or 14, wherein the insert is generally lensshaped and is thicker than the arm, and a bore extends longitudinally and approximately centrally through the insert.

1 6. A yarn guide as claimed in any one of claims 12 to 15, wherein the recess is generally U-shaped and is deeper than the length of the insert, the insert being substantially flush with the second end of the arm and being disposed symmetrically with respect to a longitudinal centreline of the arm.

1 7. A yarn guide as claimed in any one of claims 1 2 to 16, wherein the insert is clipped or squeezed into the recess.

18. A yarn guide as claimed in any one of claims 12 to 16, wherein the insert is stuck or soldered in the recess.

19. A yarn guide as claimed in any one of claims 1 2 to 18, wherein the insert has a pair of grooves on opposite lateral sides thereof which receive respectively opposed edges of the recess.

20. A yarn guide as claimed in claim 19, wherein at least one of the grooves has a projection on a base wall thereof which engages with a corresponding hollow in the respective edge of the recess.

21. A yarn guide as claimed in any one of claims 1 2 to 20, wherein the insert is a high quality casting.

22. A yarn guide as claimed in any one of claims 1 2 to 21, wherein the insert is hardened at least in the region of a yarn-receiving bore therethrough.

23. A flat knitting machine comprising a pair of mutually inclined needle beds, at least one guide rail disposed above the needle beds and extending longitudinally thereof, and a plurality of yarn guides mounted on said at least one guide rail for movement therealong, each yarn guide comprising a resilient arm formed as a single-piece component and having a yarn eye at an end thereof spaced from the respective guide rail, the yarn guides being arranged with their yarn eyes mutually adjacent to one another, a portion of each arm adjacent to said end thereof having lateral edges which taper inwardly towards said end proper and which extend for a proportion of the length of the arm, said proportion being selected such that the arms touch each other only at their said lateral edges, even at maximum deflection.

24. A knitting machine as claimed in claim 23, wherein the arm of each yarn guide has a single bend therein, and said lateral edges extend over somewhat less than half the distance between said end of the arm and said bend.

25. A knitting machine as claimed in claim 23, wherein the arm of each yarn guide has two opposite bends therein, and said lateral edges extend over somewhat less than the total length of the arm or over the whole distance between said end of the arm and the bend nearest thereto.

26. A knitting machine as claimed in claim 23, 24 or 25, wherein in each yarn guide said lateral edges extend over approximately one quarter to one third of the total length of the arm.

27. A knitting machine as claimed in any one of claims 23 to 26, wherein the arm of each yarn guide is rigidly fixed to the respective guide rail, and said lateral edges are inclined at an angle of about 5" to 15 relative to a longitudinal centreline of the arm.

28. A knitting machine as claimed in claim 27, wherein said lateral edges are inclined at substantially 9' to said longitudinal centreline.

29. A knitting machine as claimed in any one of claims 23 to 26, wherein the arm of each yarn guide is secured to the respective guide rail so that it can swivel through an angle of 8, and said lateral edges are inclined at an angle of about 5" + a to 15 + 8 relative to a longitudinal centreline of the arm.

30. A knitting machine as claimed in claim 29, wherein said lateral edges are inclined at substantially 9" + 8 to said longitudinal centreline.

31. A knitting machine as claimed in any one of claims 23 to 30, wherein said lateral edges of each yarn guide are provided with a chamfer.

32. A knitting machine as claimed in any one of claims 23 to 31, wherein the arm of each yarn guide is made from hard spring steel strip.

33. A knitting machine as claimed in any one of claims 23 to 32, wherein in each yarn guide said end of the arm has lateral edges which form an angle with said lateral edges of said portion of the arm.

34. A knitting machine as claimed in any one of claims 23 to 33, wherein a recess opens onto the second end of the arm of each yarn guide, and an insert containing the yarn eye is firmly received in the recess.

35. A knitting machine as claimed in claim 34 when appended to claim 33, wherein the lateral edges of said end of the arm extend outwardly from the vicinity of recess opening.

36. A knitting machine as claimed in claim 35, wherein the lateral edges of said end of the arm are inclined at an angle of substantially 40 to a longitudinal centreline of the arm.

37. A knitting machine as claimed in claim 34, 35 or 36, wherein the insert is generally lens-shaped and is thicker than the arm, and a bore extends longitudinally and approximately centrally through the insert.

38. A knitting machine as claimed in any one of claims 34 to 37, wherein the recess is generally U-shaped and is deeper than the length of the insert, the insert being substaktially flush with said end of'the arm and being disposed synmetrically with respect to a longitudinal centreline of the arm.

39. A knitting machine as claimed in any one of claims 34 to 38, wherein the insert is clipped or squeezed into the recess.

40. A knitting machine as claimed in any one of claims 34 to 38, wherein the insert is stuck or soldered in the recess.

41. A knitting machine as claimed in any one of claims 34 to 40, wherein the insert has a pair of grooves on opposite lateral sides thereof which receive respectively opposed edges of the recess.

42. A knitting machine as claimed in claim 41, wherein at least one of the grooves has a projection on a base wall thereof which engages with a corresponding hollow in the respective edge of the recess.

43. A knitting machine as claimed in any one of claims 34 to 42, wherein the insert is a high quality casting.

44. A knitting machine as claimed in any one of claims 34 to 43, wherein the insert is hardened at least in the region of a yarnreceiving bore therethrough.

45. Yarn guides for a flat knitting machine, substantially as hereinbefore described with reference to the accompanying drawings.

46. Flat knitting machines, substantially as hereinbefore described with reference to the accompanying drawings.