DE8708793U1 - Punched knitting tool for textile machines, in particular knitting or warp knitting machines - Google Patents

Description

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g 'd'Sohn &^Ethst_Beckeft needle factory

CpmmandiferGeseilscha^t/ Parkwgg 2> 747Q Albstädt-Ebingen

Punched knitting tools for textile machines» in particular knitting or warp knitting machines

The innovation relates to a punched knitting tool for textile machines, in particular knitting or warp knitting machines, with a shaft made of steel, which has at least one preferably elongated recess with an opening opening out on the upper side of the shaft, into which a flat, T-shaped molded part is inserted, one leg of which protrudes through the opening to form a control foot and through the other leg of which two bearing parts are formed, which interact with elastic members arranged in the recess, wherein the T-shaped part is supported directly against the shaft on the side of the edge of the recess opposite the opening.

Knitting tools include latch needles, point needles, slide needles, needles without latches, e.g. plush hooks for the production of plush goods, as well as sinkers.

As knitting speed increases, knitting machine needles are exposed to correspondingly increased loads, which often lead to breakage after a short period of operation at one of the most vulnerable points, namely the hook. The reason for this is the sudden stress exerted on the needle foot by the cam parts of the knitting machine, which leads to longitudinal stresses introduced via the needle foot.

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Shock waves are transmitted via the needle shaft to the calf hook, where, when superimposed with longitudinal vibrations, they cause premature material fatigue.

With the measures known from DE-PS 28 20 925, namely coupling the needle foot to the shaft via at least one slightly flexible , highly elastic section designed like a web and thus ensuring that the impact energy introduced into the needle foot is converted into bending work, an effective way has been shown for the first time to avoid hook breakages in high-speed circular knitting machines and thus to considerably extend the service life of the needles.

In order to increase the stability of these needles if necessary without sacrificing the advantageous properties mentioned, two thin bars arranged at a distance can be used to connect the needle foot to the shaft according to the teaching of DE-OS 30 14 751.

It is known from DE-PS 33 14 809 that, when the knitting speed is further increased, with knitting needles in which the needle foot is coupled to the needle shaft via at least one of the elastically low-height bars, a free space delimited by the bar - or, in the case of several bars, several free spaces delimited by these - can be provided with a vibration-damping

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Material _that is firmly attached to the needle shaft* This improves the stability of the highly elastic areas, which has a beneficial effect on the service life at very high knitting speeds.

All the knitting machine needles mentioned above work reliably today at high operating speeds

hook breakages would occur. However, they require very complicated tools and complex production technology to manufacture.

In an effort to counteract the occurrence of needle hook breakages as knitting speed increases, other considerations have already become known (DE-PS 26 10 078) which assume that excessive acceleration of the needle hook in the longitudinal displacement direction when the needles hit the drive or take-off cam parts is the sole cause of hook breakage. In order to prevent abrupt accelerations on the needle head, which is at risk of breakage, the needle foot and the needle head are formed on separate needle shaft parts which are connected to one another via damping intermediate links. The needle foot is formed by one leg of an essentially T-shaped punched part, the other or cross leg of which forms two bearing parts with parallel flanks which are inserted into a cutout in the actual needle shaft to protect against the effect of synthetic rubber.

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existing elastic intermediate links are supported and guided so that they can be moved to a limited extent in the direction of movement of the needle. The T-shaped molded part lies completely flat against the associated parallel, flat edge surface over the entire length of its cross leg. Apart from the fact that with the latch needles commonly used today for high-speed knitting machines with an average shaft height of approx ^. 3.3 mm and an _average shaft thickness of 0.4 mm, the fastening surface for the elastic intermediate links mentioned is extremely small (approx. 0.66 mm) and accordingly it can be difficult |

should ensure a permanent attachment of the '

To ensure the correct positioning of the intermediate links on the needle shaft, | the intentionally high elasticity of the intermediate links * means that with each extension or retraction movement of the needle, the position of the needle foot f relative to the needle shaft in the needle's longitudinal direction S changes slightly. This inevitably leads to a ?

Deviation from the original working length of the needle in the non-accelerated state, which can result in an uneven stitch pattern, particularly when producing fine fabrics.

A latch needle with a control foot that is longitudinally movable to a limited extent in an associated recess in the needle shaft and is formed on a T-shaped punched part is also known from DE-PS 26 36 008, whereby this needle, which was created for a special needle selection device, does not have any elastic cushioning between the needle foot and the needle shaft. The needle shaft with exchangeable needle feet

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which are rigidly connected to the needle shaft via dovetail guides, is also known from JP-OS 57-139549.

Based on the prior art explained, the invention is based on the object of creating a punched knitting tool for textile machines, in particular for high-speed knitting and warp knitting machines, which is economical and relatively easy to manufacture and is characterized by a long service life and high working precision when used at high knitting speeds.

To solve this problem, the knitting tool mentioned at the beginning is characterized according to the innovation in that the edge of the recess on the side opposite the opening has an area that protrudes from the adjoining parts of the edge, on which the T-shaped molded part is supported, that between the edge of the recess and the two- I

i the bearing parts, the bearing parts are each surrounded by free spaces on three sides, in the area of which the edge of the recess and/ |

or the bearing parts have profiling, and |

that the free spaces are provided with a vibration-damping ^

Material that is firmly connected to the edge of the recess and the bearing parts.

The needle shaft with its recess and the T-shaped part forming the needle foot and its bearing parts can be easily

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are usually manufactured using rigid dies. Since the free spaces that accommodate the vibration-damping material are bordered by relatively long edge areas that also have a profile, relatively large anchoring surfaces are available for the vibration-damping material, which ensure that this material is securely anchored and thus that the entire knitting tool has a long service life, even under high loads. The edge area opposite the opening of the recess, which projects into the recess and is located near the back of the shaft, forms an exact support for the foot, so that the foot height always remains exactly constant. Furthermore , it has been shown that the arrangement of the vibration-damping material in the spaces surrounding the bearing parts of the T-shaped molding ensures that the vibrations resulting from the control shocks exerted by the lock members on the foot are strongly dampened.

In a preferred embodiment, the recess on the upper side of the shaft is delimited on both sides of the opening and/or on the back of the shaft by a narrow web that has a maximum height of 1.1 mm and a length of at least 2 mm. These very low and therefore highly elastic webs form very easily bendable sections at which the foot is coupled to the shaft; they cause the impact energy introduced into the foot to be converted into bending work and thus dampen the longitudinal shock waves emanating from the foot, surprisingly

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It has been shown that the excellent damping properties of the free spaces filled with the vibration-damping material are even improved by arranging the foot in the middle between the two low bars on the upper side of the shaft, and in addition, in contrast to the situation with knitting tools with a foot integrally formed on the shaft, the foot can even carry out a limited amount of elastically inhibited torsion under the influence of the stress exerted by the lock parts, which has proven to be very advantageous.

In a practical embodiment, the leg of the T-shaped molded part forming the foot is fitted into the opening of the recess with little play, whereby the leg of the molded part forming the foot is fixed in a form-fitting manner in the longitudinal direction of the shaft. Under certain conditions of use, however, it can also be advantageous if the leg of the T-shaped molded part forming the foot defines two gap-like spaces with the edge of the opening, which are filled with the vibration-damping material. Despite the fact that in this case there is no longer any form-fitting support of the foot in the longitudinal direction of the shaft by the webs forming the edge of the opening, the evasive movement of the foot in the longitudinal direction of the shaft that occurs under load is also so small in this case that it can be neglected in the calculation because it has no influence on the uniformity of the stitch pattern.

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The area of the guide rail that serves to support the shaft of the T-shaped part that forms the foot and that projects into the recess can expediently also be shorter than the opening width. It can even be shortened to such an extent that the T-shaped part can carry out a limited, small tilting movement in the recess, for which this area acts as a tilting support. In the majority of cases, however, it is advantageous if the projecting area has a surface that is parallel to the shaft back and on which the T-shaped part is supported with an associated parallel surface.

The profiling provided in the edge delimiting the free spaces can advantageously have recesses that are open at the edge towards the respective free space and can be produced relatively easily. It has proven to be advantageous if the recesses are partially circular. The profiling can also have areas of reduced wall thickness that are embedded in the vibration-damping material and thus additionally contribute to an effective anchoring of the vibration-damping material to the edge. In a practical embodiment, these areas of reduced wall thickness can be formed by depressions that, starting from opposite sides, extend symmetrically to the longitudinal center plane of the shaft or the molded part. Such depressions can be produced in a simple manner by embossing or similar operations.

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As a rule, the T-shaped molded part is made of sheet steel, whereby it is produced without great effort in the form of a stamped part. However, designs are also conceivable in which the T-shaped molded part is made of plastic. Such a plastic can be selected in such a way that a particularly favorable sliding pairing with the lock or stiffening parts of the machine that interact with the FOOT is achieved.

The drawing shows examples of the subject of the innovation. They show:

Fig. 1 a knitting tool according to the innovation, in a side view, in detail, showing the shaft and a foot,

Fig. 2 the knitting tool according to Fig. 1, cut along the line II-II of Fig. 1,

Fig. 3 a knitting tool according to the innovation, in a modified embodiment and in &bull;a representation corresponding to Fig. 1, and

Fig. 4 the knitting tool according to Fig. 3, sectioned along the line IV-IV of Fig. ₄ 3.

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The knitting tool shown in detail in Fig. 1, 3 is, for example, a latch needle intended for a knitting machine, of which only the shaft 1 is shown. The shaft 1 and the working part (not shown)/e.g. the needle head with the needle hook of the knitting tool are punched out of steel of the appropriate thickness.

Iii the shaft 1 has an elongated recess 2, from which an opening 3 leads to the upper side 4 of the shaft. The recess 2 is symmetrical to the longitudinal symmetry line of the shaft 1 indicated at 5, which runs parallel to the upper side 4 of the shaft and the back of the shaft 6, and to the central axis of the opening 3, which runs at right angles to it and is designated at 7. The opening is delimited on both sides by the end faces 8 of two low webs 9 arranged adjacent to the upper side 4 of the shaft, which are parallel to one another and to the longitudinal axis 7, which in turn form the upper limit of the recess 2 and whose height is at most 1.1 mm. The length of the webs 9, measured from the edge of the opening 3 to the respective associated end of the recess 2, is indicated in Fig. 1 at 11; it is at least 2 mm.

On the opposite side, ie adjacent to the shaft back 6, the recess 2 is also limited by two low webs 12, the

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Height 13 at most 1.1 mm and the length 14 is also at least 2 mm. The two webs 12 extend from the respective end of the recess 2 to an edge region 15 of the recess 2 which is aligned symmetrically to the central axis 7 and opposite the opening 3 and which is designed to protrude into the recess relative to the adjoining parts 16 of the edge of the recess 2. This protruding region 15 carries a support surface 17 which is aligned parallel to the longitudinal center plane 5 of the shaft 1 and which, in the embodiments shown, is shorter than the width of the opening 3.

A T-shaped molded part is inserted into the recess 2, which is usually made as a stamped part from steel, but in certain cases can also be made from plastic. The molded part 18 has the same thickness as the shaft 1. One of its legs 19, which protrudes through the opening 3 on the upper side 4 of the shaft, is rounded at the end and forms a control foot for the knitting tool. The other leg, which runs transversely to it, forms two parallel, identically shaped bearing parts 2G, which extend at right angles from the first leg 19 and lie entirely in the recess 2.

The bearing parts 20 are narrower than the recess 2; they also do not reach to the ends of the recess 2, with the result that the bearing parts are each surrounded on three sides by a free space 21 in the manner shown in Figs. 1 and 3.

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uiejeben, which extends on one side to
to the edge of the first leg 19 and on
the other side extends to the projecting edge region 15.

In the area of the two open spaces 21, both
the edge of the recess 2 as well as the edge of the bearing parts 20 each with a pro-

filierung 22 or 23. The profiling f

22 faces the open space 21 with open edges and partially |;

circular recesses 24, between which |

gusset-like areas 25 of reduced wall thickness &psgr;

which are symmetrical to the longitudinal mean S

plane of the shaft 1, as shown in &iacgr;

can be seen in Fig. 2 and 4. Corresponding i

Areas of reduced wall thickness, which are in the manner of j

are formed with part-circular recesses, for

i are also used in the profiling 23 of the bearing parts 20 1

present; they are marked 26. \

The two free spaces 21 are filled with a vibration-damping plastic material 27, which is
Edge of recess 2 and the two bearing parts
20 in the area of the profiles 22, 23 is firmly connected. The areas 25, 26 of reduced wall thickness are integrated into the vibration-damping material.

material 27, whose anchoring is thereby

has been further improved. ]

In addition to the following materials, vibration dampening materials are used:
Plastics such as polyurethane, polyamide etc., also
other elastic materials, including metals,

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e.g. aluminum, comes into question.

In the embodiment according to Fig. 1, 2, the T-shaped molded part 18 is supported on the one hand via a parallel surface on the support surface 17 of the projecting edge region 15 and on the other hand is fitted with its leg 19 into the opening 3 without play, which ensures that the control foot formed by the leg 19 always maintains exactly the same foot height and the same position in the longitudinal direction of the shaft with respect to the shaft 1 - regardless of the load conditions.

The modified embodiment shown in Fig. 3, 4 differs from that according to Fig. 1, 2 only in that the leg 13 of the T-shaped molded part 18 forming the control foot with the edge of the opening 3, i.e. with the end faces of the two webs 9, delimits two gap-like spaces 28, each of which is connected to the adjacent free space 21 and is also filled with the vibration-damping material 27. This embodiment is particularly suitable for knitting tools with a thicker shaft 1.

Otherwise, the embodiment according to Fig. 3, 4 is completely identical to the embodiment explained with reference to Fig. 1, 2; identical parts are therefore designated with identical reference numerals, whereby a further explanation is unnecessary.

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Claims (1)

ff« ···* pt ■ · Patenianwilte Dr.-lng. R. Rüger DIpl.-lng. H. P. Barthelt Representative at the European Patent Office European Patent Attorneys Webergasse 3 · PO Box 348 · D-73G0 Esslingen (Neckar) 24 June 1987 Telephone Stuttgart Gm 7 rÜa-1 (0711)3565,59und359619 Fax (0711) 35 99 Telex 7256 610 smru Telegram Patent Protection Esslingenneckar Protection claims 1. Punched knitting tool for textile machines, in particular knitting or warp knitting machines, with a shaft made of steel, which has at least one, preferably elongated recess with an opening opening out on the upper side of the shaft, into which a flat, "I-shaped molded part is inserted, one leg of which projects through the opening to form a control foot, and through the other leg of which two bearing parts are formed, which interact with elastic members arranged in the recess, the T-shaped part being supported directly against the shaft on the side of the edge of the recess opposite the opening, characterized in that the edge of the recess (2) on the side opposite the opening (3) has a region (15) which projects relative to the adjoining parts (16) of the edge, on which the T-shaped molded part (18) is supported, that between the edge (16) the recess (2) and the two bearing parts (20) the bearing parts (20) are each formed with free spaces (21) surrounding them on three sides, Korn*«!! b«it»ch· Bink AQ, branch E»«lln _fl eri Hl. 3CM aijtpü Ali TJoyMif^oälsOli&äliStüjlB'äft «24 51'70Ö (BU! 600100 70) &bull;t &bull; s &igr; &bull; « · .^ &igr;&igr; in the area of which the edge of the recess (2) and/or the bearing parts (20) has profiles (22, 23) and that the free spaces (21) are filled with a vibration-damping material (27) which is firmly connected to the edge of the recess (2) and the bearing parts (20). - Knitting tool according to claim 1, characterized in that the recess (2) on the upper side (4) of the shaft is delimited on both sides of the opening (3) and/or on the back of the shaft (6) by a narrow web (9, 12) which has a height (io) of a maximum of 1.1 mm and a length (11) of at least 2 mm. 3. Knitting tool according to claim 1 or 2, characterized in that the leg (19) j of the T-shaped molded part (18) forming the foot fits into the opening with little play (3) is fitted. 4. Knitting tool according to claim 1 or 2, characterized in that the leg ( C9 ) of the T-shaped molded part (18) forming the foot delimits, with the edge of the opening (3), two gap-like spaces (28) which are filled with the vibration-damping material (27). 5« Knitting tool according to one of the preceding claims, characterized in that the projecting area (15) carries a surface (17) parallel to the shaft back (6), on which the T-shaped molded part (18) is supported with an associated parallel surface. 6. Knitting tool according to one of the preceding claims > characterized in that the forward-cut region (15) is shorter than the width of the opening (3), &bull; · ift«» » &iacgr; t * 11 · * # # it· « » « Il I « t t $ &mdash; t 7. ^ &igr;&igr; ti * · < · Y I III KLI 7* Knitting tool according to one of the preceding claims/ characterized in that the profile extension (22, 23) has recesses (24) open at the edges towards the respective free space (21)* 8i Knitting tool according to claim 7, characterized in that the recesses (24) are partially circular* &Ogr;* Knitting tool according to one of the preceding claims, characterized in that the profiling (22, 23) has regions (25, 26) of minimum wall thickness which are embedded in the vibration-damping material (27). &igr;&ogr;. Knitting tool according to claim 9, characterized in that the areas (25, 26) of reduced wall thickness are formed by depressions which, starting from opposite sides, extend symmetrically to the longitudinal center plane of the shaft (1) or of the T-shaped molded part (18). &igr; 11. Knitting tool according to one of the preceding claims, characterized in that the T-shaped molded part (18) consists of steel. 12. Knitting tool according to one of claims 1 to 11, characterized in that the T-shaped molded part (18) consists of plastic. - 4 - I