EP0735174B1 - Latch needle for machines for making knitwear - Google Patents

Description

The invention relates to a latch needle for machines for the manufacture of knitwear, with one at one end a shaft carrying a needle hook, one in the longitudinal direction of the shaft extending tongue slot contains and with one in the tongue slot around a tongue axis pivoted needle tongue, the tongue slot a breakthrough in the area below the tongue axis to the needle shaft back and elastic on both sides deformable cheek pieces is limited, which in Areas of the upper edges of the tongue slot contact surfaces for assigned contact surfaces on the back of the tongue and the tongue slot in parts of different widths is divided.

To the impact of the needle tongue in the reserve too dampen and thereby damage the needle and the Avoid tongue, especially when in machines is used at high speed, it is known from DE-C3 2 714 607, the tongue receiving To design tongue or longitudinal slots in the shaft in such a way that the breakthrough to the bottom of the needle shaft containing short first longitudinal needle slot section one second needle longitudinal slot section connects with her Protrudes beyond the end of the open tongue and the is lower than half the height of the needle shaft, with the contact surfaces for the back of the tongue above the second The needle slot section. By the interaction of the the needle shaft cheeks flanking the longitudinal slot wedge-shaped flanks on the back of the tongue the cheekpieces when the needle tongue hits elastically spread apart, while at the same time Contact surfaces friction occurs. This will be a significant one Damping the impact achieved by both the tongue and the needle shaft are protected. The The wedge shape of the contact surface on the back of the tongue is already then given when the back of the tongue is rounded in the usual way is. In addition, through this training, that the tongue remains in the fully open position and in this position it remains free to move, i.e. does not get stuck between the needle shaft cheeks.

This latch needle has been excellent in practice proven. But it requires precise positioning and proper training of the contact surfaces for the Imprint forming the needle back on the top of the needle shaft. In addition, the needle shaft becomes thicker reduces the elastic deformability of the cheek pieces.

Basically similar is also one from DE-A1 3 335 908 known tongue needle designed, in which the tongue slot is divided into two parts, one with a breakthrough below the tongue axis first part in its width in the usual way accordingly the dimensions of the needle tongue is dimensioned and one on this first slot part on the Second side facing away from the needle hook Slot part a smaller width than the first slot part having. The width of the narrower second slot part is approximately 0.5 to 0.8 times the width of the first wider Slot part. The contact surfaces for the needle back are on the upper edge of the second narrower slot part arranged, which is also a breakthrough to Needle back. The narrowing of the tongue slit leads to correspondingly thicker cheek pieces and reduced elastic deformability.

By contrast, the elasticity of the Cheek cheeks in the area of the contact surfaces for the back of the tongue to improve and thus the desired damping the tongue when it hits the contact surfaces increase, was known from DE-A1 4 324 232 Tongue needle already completely on the two cheeks separating, from the contact surfaces to the back of the shaft continuous breakthrough provided. The width this continuous breakthrough can be larger, equal or smaller than the width of the tongue slot in the area of Tongue axis. This breakthrough extends into Longitudinal direction of the shaft to below the tongue axis, like this appropriate with regard to a perfect lint removal is, there is a risk that the tongue storage becomes unstable. However, as suggested alternatively, on Back of the needle a bridge below the tongue bearing provided, the lint removal is impaired, while the also proposed arrangement of two separated from each other by a bridge on the needle back Breakthroughs in the longitudinal direction of the shaft, apart from the insufficient stability, also for manufacturing reasons is out of the question.

In contrast, the object of the invention is that of the above-mentioned DE-C3 2 714 602 known in the Practice to improve tried and tested latch needles in the sense that they have lower demands on the production Formation of the contact surfaces for the tongue back provides and especially with thick needles without endangering the Tongue bearing an increased damping of the impact Tongue on the contact surfaces of the needle shaft results.

To solve this problem, the above is Tongue needle designed according to the invention such that the Tongue slot, seen from the needle hook, then on a narrow first slot part containing the opening has a second slot part of greater width, in the area of which the support surfaces are formed and which is lower than half the shaft height and below the Contact surfaces on the needle back is closed and that itself a third slot part connects to the second slot part, which is narrower than the second slot part.

The first slot part in the area of the tongue bearing is in its width in the usual way on the dimensions the needle tongue tuned so that it is undamped movable and sideways to the required extent is led. In that the subsequent second Slot part is wider, they are this slot part limiting cheek areas to a greater extent elastic deformable, with the result that even with thick Needles the impacting tongue in for high speed operation the required dimensions are flawless is dampened. Because of the versus the first Slot part increased slot width in the area of the contact surfaces these contact surfaces become correspondingly smaller, the exact training and positioning of the assigned shape impression in the cheek pieces with it only has a more subordinate meaning, because the flexible formed by the cheekpieces Slit walls beat the tongue in the reserve cushion effectively. Since the tongue slot below the Contact surfaces are closed and the length of the opening to the back of the needle shaft below the tongue support only that with a view to good lint removal needs to have the required length, the Needle from a perfect stability.

The one on the side facing away from the needle hook the wide second slot part adjoining third Slot section is in consideration of the stability of the Needle narrower. It causes one laterally resilient support in the area of the second wide Slit part of the narrow and highly flexible shaft cheeks.

The contact surfaces for the back of the tongue lie expediently essentially above the lowest Point or the deepest area of the second slot part, i.e. in a section where usually optimal elastic deformation conditions for the cheek pieces available. The length of this second slot part can be chosen appropriately; he usually towers the end of those lying on the contact surfaces opened tongue. Incidentally, is at least the second Slot part with advantage on its bottom wall in the longitudinal direction of the shaft curved, but the arrangement can also be made such that the second and / or third slit part near the opening to the needle back through an essentially straight surface area is limited, on the one to the top of the shaft tapering curved surface area connects.

The dimensioning of the width of the three slot parts is, as already mentioned, in the first slot part determined by the dimensions of the needle tongue while it in the second and third slot part depending on the Needle dimensions are chosen so that there are optimal damping properties for the needle tongue. In the Practice has a ratio of the width of the first Slot part to the width of the second slot part in the Range of about 2: 3 to 2: 5 often proven to be useful, while the ratio of the width of the second Slot part with the width of the third slot part Advantage can be in the range of about 7: 4 to 7: 6.5. A limitation is due to these proportions however not given. In some cases, too deviating width ratios are preferable.

Fig. 1 eine Zungennadel gemäß der Erfindung im Ausschnitt, in einer Seitenansicht teilweise aufgeschnitten.

Fig. 2 die Zungennadel nach Fig. 1 in der Draufsicht, wobei der Nadelhaken längs der Linie II der Fig. 1 weggeschnitten ist,

Fig. 3 einen Ausschnitt der Zungennadel nach Fig. 1 unter Veranschaulichung des Zungenschlitzes in einer Draufsicht entsprechend Fig. 2 und in einem anderen Maßstab und

Fig. 4 die Zungennadel nach Fig. 1 geschnitten längs der Linie III-III der Fig. 1 in einem anderen Maßstab.

In the drawing, an embodiment of the object of the invention is shown. Show it:

Fig. 1 shows a tongue needle according to the invention in a detail, partially cut away in a side view.

2 shows the top view of the latch needle according to FIG. 1, the needle hook being cut away along the line II in FIG. 1,

3 shows a section of the latch needle according to FIG. 1, illustrating the latch slot in a top view corresponding to FIG. 2 and on a different scale and

Fig. 4 shows the latch needle of Fig. 1 cut along the line III-III of Fig. 1 on a different scale.

The latch needle shown in detail in the figures is punched out of steel strip and has a shaft 1 with a needle hook at one end over a throat 2 3 connects and at least in the usual way one not shown in the drawing Needlefoot wears. In the shaft 1 there is a plane of symmetry 4 symmetrical tongue slits 5 formed in which a needle tongue 6 is pivotally mounted is. The needle tongue 6 is on a tongue axis 7 stored either in the form of from the tongue slot 5 shaft cheeks 8 delimiting on both sides pressed out bearing journal or from its own cylindrical bearing axis that exists in the cheek pieces 8 is held at the end. On their tongue axis 7 the tongue 6 is the opposite end with a tongue spoon 9 trained who with the tongue closed the tip of the Needle hook 3 engages, as shown in dashed lines in Fig. 1 is shown.

The tongue 6 is between the mentioned, in Fig. 1st Closed position illustrated by dashed lines and one in Fig. 1 shown in full lines open position swiveling in which it is a reserve occupies and with contact surfaces 10 on the back of Tongue spoon 9 rests on contact surfaces 11, which the shaft 1 in the area of the upper edges 12 of the tongue slot 5 are arranged.

The recessed on both sides of the tongue slot 5 Contact surfaces are in the shape of the contact surfaces 10 corresponding to the back of the spoon 9 of the tongue 6 Form impressions formed in the shaft 1. The Contact surfaces 10 on the back of the tongue spoon 9 are in turn designed as wedge-shaped flanks, if necessary, the normal rounding on the back of the tongue spoon is sufficient for this purpose.

The tongue slot 5 is in three parts 13, 14, 15 divided that seen from the needle hook 3 in Shaft longitudinal direction arranged next to each other are:

The first slot part 13 contains the tongue axis 7 and has an opening 16 below the tongue axis 7 to back 17. It is curved in a circular arc, its radius being indicated at 18 in FIG. 1. In the 2, 3 with 19 designated width of the first Slot part 13 is in consideration of the width dimensions the tongue 6 chosen so that the tongue 6 at their undamped pivoting movement around the tongue axis 7 laterally is led. This side guide ensures that the tongue spoon 9 properly in the closed position rests on the tip of the needle hook 3.

The second slot part 14 is also in the form of a circular arc curved, with its radius of curvature in Fig. 1 with 20 is designated. The center of curvature 21 lies on an imaginary line 22 that is perpendicular to the back of the shaft 17 aligned in the area of the two contact surfaces 11 runs, which can be seen in the area of this second slot part 14 are formed. The second Slot part 14 is deeper than half the shaft height. He is then the opening 16 to the back of the shaft closed by a web-shaped shaft part 23, the minimum height is indicated at 24 and on line 22 lies. This ensures that the two contact surfaces 11 above the lowest point of the second slot part 14 are located.

The width of the second indicated at 25 in FIGS. 2, 3 Slot part 14 is much larger than the width 19 of the first slot part 13. The ratio of the width 19 of the first slot part 13 to the width 25 of the second Slot part 14 is in the range of about 2: 3 to 2: 5, preferably 2: 3.

The length of the second slot part 14 in the longitudinal direction of the shaft is dimensioned so that the second slot part 14 over the end of those in the reserve Tongue 6 protrudes in the manner shown in FIG. 1, while on the other hand close to the Tongue axis 7 is sufficient; it also depends on the circumstances the respective latch needle, in particular the Shaft height and shaft thickness.

Finally, the third slot part 15 is also curved in a circular arc, its radius of curvature at 26 is indicated. It is usually much larger (twice and more) than the radius of curvature 18 of the first Slot part 13 and the radius of curvature 20 of the second Slot part 14. The two radii of curvature 18, 20 are by the way, usually about the same size or the Radius of curvature 20 of the second slot part 14 is larger (by 10 to 40%) as the radius of curvature 18 of the first Slot part 13. The third slot part 15 is for the back of the shaft 17 closed and causes an extension the web-like formed by the second slot part 14 Shaft part 23, the one indicated at 27 Minimum height in the order of the minimum height 24 des is second slot part 14, so that overall in the 1 can be inferred essentially gives a flat area along the web-like Shaft part 23 and its extension the two Slot parts 14, 15 limited on the bottom. Connects to him then a curved surface area 28 with which the third slot part 15 runs out to the top of the shaft.

In principle, it is of course also possible that Slot parts 14, 15 (and also slot part 13) are not exactly in the form of a circular arc, but, for example, in sections just to design, for example, by each Milling cutters in the longitudinal direction of the shaft is proceeded.

The third slot part 15 is narrower than the second Slot part 14. Its width is at 29 in FIGS. 2, 3 indicated and is chosen in practice so that the Ratio of the width 29 of the third slot part 15 to Width 25 of the second slot part 14 in the range of is about 4: 7 to 6.5: 7. The length of the third slot part 15 is in consideration of the elastic to be achieved Deformability in the area of the contact surfaces 11 chosen. The third slot part 15 protrudes in the longitudinal direction always over the wider second slot part 12 out.

In operation, the tongue 6 strikes with the wedge-shaped converging contact surfaces 10 of the back of their tongue spoon 9 on the contact surfaces 11. Since this in Areas of the particularly wide second slot part 14 are arranged, i.e. in an area where the cheek pieces 8 are thinner and therefore more elastic, the Impact of the tongue perfectly dampened. Because of through the larger slot width required greater distance of the the two backs 11 of the tongue back penetrate correspondingly deeper into the slot part 14, so that it is on the exact location of the bearing surfaces 11th containing shape impressions is not so important. This Effects are further optimized by the fact that the support surfaces 11, as already mentioned, immediately above the lowest point (at 24) of the curved - or at straight Slot part above the deepest area - slot part 14 lie.

The invention described above Formation of the tongue slot 5 with three different wide slot parts or sections 13, 14, 15 especially for high-performance needles for large and small circular knitting machines determined and especially for needles with a larger needle thickness, from about 0.48 mm. she can but also for tongue needles with a smaller thickness Find.

Claims (7)

1. Latch needle for machines for the manufacture of knitwear, with a shank (1) bearing a needle hook (3) at one end, said shank containing a sawslot (13, 14, 15) extending in the longitudinal direction of the shank, and with a needle latch (6) disposed in the sawslot to pivot around a latch axis, wherein in the region below the latch axis (7) the sawslot (13, 14, 15) has an opening to the back (17) of the needle blade and is bordered on both sides by elastically deformable shank cheeks (8), which have recessed bearing surfaces (11) for allocated abutment surfaces (10) on the back side of the latch in the region of the upper edges (12) of the sawslot, and the sawslot (13, 14, 15) is divided into sections of different width, characterised in that, viewed from the needle hook (3) and adjoining a narrow first slot section (13) containing the opening (16), the sawslot (5) has a second slot section (14) of larger width, in the region of which the bearing surfaces (11) are arranged and which is deeper than half the shank height and is closed below the bearing surfaces (11) on the needle back (17); and that a third slot section (15), which is narrower than the second slot section (14), adjoins the second slot section (14).
2. Latch needle according to Claim 1, characterised in that the second slot section (14) projects with its length beyond the end of the open needle latch (6) lying on the bearing surfaces (11).
3. Latch needle according to one of the preceding claims, characterised in that the bearing surfaces (11) lie essentially above the deepest point (24) or the deepest region of the second slot section (14).
4. Latch needle according to one of the preceding claims, characterised in that at least the second slot section (14) is curved in an arc shape in the longitudinal direction of the shank.
5. Latch needle according to one of the preceding claims, characterised in that the second and/or third slot section (14; 15) is bordered in the vicinity of the opening (16) by an essentially straight surface region, adjoining which is a curved surface region (28) extending towards the top of the shank.
6. Latch needle according to one of the preceding claims, characterised in that the ratio of the width (19) of the first slot section (13) to the width (25) of the second slot section (14) is within the range of about 2:3 to 2:5.
7. Latch needle according to one of the preceding claims, characterised in that the ratio of the width (29) of the second slot section (14) to the width (25) of the third slot section (15) is within the range of about 7:4 to 7:6.5.

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