Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04B—KNITTING
  • D04B15/00—Details of, or auxiliary devices incorporated in, weft knitting machines, restricted to machines of this kind
  • D04B15/38—Devices for supplying, feeding, or guiding threads to needles
  • D04B15/48—Thread-feeding devices
  • D04B15/482—Thread-feeding devices comprising a rotatable or stationary intermediate storage drum from which the thread is axially and intermittently pulled off; Devices which can be switched between positive feed and intermittent feed
  • D04B15/484—Yarn braking means acting on the drum
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/34—Handling the weft between bulk storage and weft-inserting means
  • D03D47/36—Measuring and cutting the weft
  • D03D47/361—Drum-type weft feeding devices
  • D03D47/364—Yarn braking means acting on the drum
  • D03D47/366—Conical

Definitions

• the invention relates to a yarn feeding device according to the preamble of claim 1.
• the yarn feeding device known from the technical information publication "Storage Feeder NOVAKNIT 1000", 11.905.004 DCNA/5 of the company Memminger-IRO GmbH, Dornstetten, DE, comprises a tension ring in the holder for co-operation exclusively with a rounded withdrawal rim of the stationary storage body.
• Tension rings having respective differing specifications alternatively can be installed into the holder, however, always for co ⁇ operation with the rounded withdrawal rim only.
• the adjustment mechanism is designed such that the holder stops after an adjustment travel in the direction towards the winding element before the free ends of the fingers of the tension ring slide from the rounded withdrawal rim on the cylindrical part of the storage body.
• the known yarn feeding device is recommended for flat knitting machines, chain knitting machines and for sock knitting machines, because then even small yarn tension variations can be adjusted precisely by the adjustment mechanism and by changing the contact pressure of the fingers at the rounded withdrawal rim.
• this needs time consuming manipulations of the adjustment mechanism. This can be tolerated in the above-mentioned application field of the yarn feeding devices since only a few such yarn feeding devices conventionally are installed at such knitting machines.
• yam feeding devices In practice at circular knitting machines many yam feeding devices have to be provided, in many cases more than sixty, each of which has a rotatable storage body.
• the storage body includes a circumferential protruding ridge close to the withdrawal rim for positioning a tension ring which is rotating together with the storage body.
• the free finger ends of the tension ring contact a cylindrical storage body section adjacent to the ridge with a pre-load for controlling the yam and for adjusting the yam tension.
• the yarn tension achieved by the co-operation between the tension ring and the cylindrical storage body section cannot be varied but for another yarn material or to achieve a different yarn tension, respectively, another tension ring has to be mounted instead.
• the known combination offers the important advantage of the same yarn tension at all of the many yarn feeding devices having the same storage body diameter. This is expedient at such knitting machines because of the large number of yarn feeding devices.
• yarn feeding devices cause problems when they are implemented at flat knitting machines, so-called body machines, chain knitting machines, sock knitting machines and similar knitting machines where individual yarn tensions are needed among the yarn feeding devices provided.
• Tension rings of the kind that are of interest here e.g. are known from DE 19 00 619 A.
• the stationary storage body assures a fine yarn control, in some cases even a yarn separation, and allows high withdrawal speeds for different yarn qualities.
• the construction of the adjustment mechanism allows to selectively use the tension ring in adaptation to the requirements at the respective knitting machine such that the yarn feeding device practically can be implemented at all knitting machine types. If it is necessary to have an individual yarn tension or to change the yarn tension very precisely, then the tension ring is placed with the adjustment mechanism at the withdrawal rim. Thanks to tapering withdrawal rim not only different individual yarn tensions can be adjusted by adjustment of the operative position of the tension ring but also very small changes to the yarn tension can be adjusted very precisely. The time and the labour needed therefor can be accepted because this is needed e.g.
• the tension rings are adjusted by the adjustment mechanism onto the cylindrical front end sections of the storage bodies.
• the tension ring offers the advantage of a very accurate yarn tension, so to speak a uniform yarn tension, without complicated manipulations of the adjustment mechanism for adjusting the yarn tension. In case that then the yarn tension needs to be changed or in case that another yarn quality has to be processed, then the tension ring is replaced without manipulations of the adjustment mechanism.
• the storage body is designed as a rod cage comprising carrying rods and separation rods in-between which separation rods are driven for a separation motion.
• the yarn separation even may be of advantage for the co-operation between the tension ring and the storage body which co-operation takes place outside the region of the rod cage structure.
• the diameter of the circle of the free finger ends is selected by approximately 2% to 5%, preferably about 3% to 4% smaller than the outer diameter of the cylindrical front end section.
• the tension ring is detachably positioned by its ring body in a ring-shaped holder of the adjustment mechanism.
• the holder sets the respective operative position of the tension ring, and in some cases, supports the tension ring against reaction forces from the yarn withdrawal.
• the detachable positioning expediently a latched positioning, allows a comfortable and prompt replacement of the tension ring.
• the tension ring is a so-called straw ring which is characterised in that the fingers extend substantially radially or conically inwardly from the ring body, that the fingers are flexible, and that the fingers define by their free finger ends a circle which is coaxial and parallel to the ring body.
• the inner diameter of the ring body larger by approximately 12% to 25% than the outer diameter of the cylindrical front end section.
• the tension ring expediently is a plastic form part the ring body of which may be pre-shaped for a latched positioning in the holder.
• the tension ring may be adjusted delicately and comfortably by an adjustment mechanism comprising a threaded spindle which is rotatable in the housing bracket, is fixed in axial direction thereto and which defines at least part of the adjustment range by a threaded section, and which, finally, has a rotation handle at the free end of the housing bracket.
• the threaded spindle penetrates a nut part of a holder sley.
• a guiding track for the holder sley is provided in the housing bracket.
• the adjustment mechanism of a particularly expedient embodiment additionally is equipped with a quick adjustment device for the threaded spindle or the tension ring, respectively.
• This quick adjustment device expediently can be adjusted promptly from the respective operative position into the passive position and vice versa, in order to adjust the tension ring in a single manual manipulation, even with one hand only, if e.g. a replacement of the tension ring, an adjustment operation or cleaning of the storage body, or the threading of a new yarn has to be carried out.
• the adjustment mechanism could be used without the quick adjustment device, however, this would be more time consuming, meaning that the add-on quick adjustment device is an option which increases the comfort for the user of the yam feeding device.
• the quick adjustment device is equipped with a bearing sleeve for the threaded spindle which bearing sleeve is rotatably supported in the housing bracket and has an adjustment handle.
• a thread-like pin-slot guiding structure is provided in the housing bracket and between the bearing sleeve and the rotational support of the bearing sleeve.
• the entire adjustment range of the adjustment mechanism having the integrated quick adjustment device jointly is defined by the length of the thread section and by the axial length of the pin-slot guiding structure such that a relatively short length of the threaded section is sufficient to bring the tension ring into all needed operative positions and also into the passive position.
• a tension ring is implemented into the yarn feeding device the fingers of which in a relaxed stated define a frustocone coat and which, preferably are inclined along the frustocone coat with mutual overlaps.
• each finger is tapered such that its thickness decreases in a direction to the free finger end, and if at the free finger end an inwardly directed thickened portion is provided as an enforcement.
• An expedient embodiment of the tension ring which also allows to optimally place the holder in the yarn feeding device is characterised by a holding flange which extends continuously in circumferential direction and which is directed outwardly, and is also characterised in that the circle defined by the finger ends is situated approximately in the plane of the holding flange which holding flange forms an edge of a substantially cylindrical collar at the other edge of which the fingers are provided with their root regions.
• Fig. 1 a perspective side view of a yarn feeding device
• Fig. 3 a partial axial section of the yarn feeding device
• Fig. 4 an embodiment of a tension ring in a perspective view and an axial sectional view
• FIG. 5 another embodiment of a tension ring in a perspective view and an axial section
• Figs 6 & 7 sides views, partially cut out to explain two operative positions of the tension ring of Fig. 4 in the yarn feeding device
• Figs 8 & 9 sides views, partially cut out to explain two operative positions of the tension ring of Fig. 5 in the yarn feeding device.
• a yarn feeding device F intended to be used at knitting machines of different types comprises in Figs 1 to 3 a housing 1 having a fixation 2, a rotatably driven winding element 3 including a yam eyelet 5, and a storage body 4 which is stationary in relation to the winding element 3.
• the storage body 4 is drum-shaped and has a cylindrical front end section 6 at the front in withdrawal direction, a front side withdrawal rim 15 which is rounded in this embodiment, and a rod cage structure RC between the cylindrical front end section 6 and the winding element 3.
• the rod cage structure RC comprises carrying rods 7 which are distributed in circumferential direction with intermediate distances and which are continued at least by their edge regions into the cylindrical front end section 6.
• Separation rods 8 are provided between the carrying rods 7 which separation rods 8 can be driven for a wobbling separation motion.
• the wobbling motion of the separation rods 8 is derived from an oblique rotatable bearing on a central driving shaft 26.
• the housing 1 has a housing bracket 9 extending in axial direction with a distance to the storage body 4, i.e., substantially parallel to the axis of the storage body.
• a fixation for a front side withdrawal eyelet 10 is mounted at the housing bracket 9.
• a ring-shaped holder H is mounted coaxially to the storage body 4.
• the holder H is adjustable in axial direction in the housing bracket 9 by means of an adjustment mechanism M in order to position the holder H in different positions relative to the storage body 4. Guiding tracks are formed for the holder sley 11 e.g. in a region 12 in the housing bracket 9.
• the adjustment mechanism M can be actuated by means of a rotary handle 13.
• a quick adjustment device Q is integrated as an optional feature into the adjustment mechanism M which quick adjustment device Q can be actuated by a handle 14.
• the withdrawal rim 15 in Fig. 2 is indicated in continuation of the cylindrical front end section 6 of the storage body 4. In the shown position the holder H somewhat overlaps the withdrawal rim 15.
• the holder H has an inwardly open latching groove 16 for a tension ring T as shown in Fig. 3, has a skirt in its upper region connected with the holder sley 11 , which skirt extends over a part of the circumference, and has a lower holding tooth 17.
• the partial axial section in Fig. 3 indicates the inner structure of the adjustment mechanism M in the housing bracket 9 and also indicates a uniform yarn tension operative position B, an individual yarn tension operative position A as well as two passive positions C and C of the holder H or of the tension ring T secured in the holder, respectively, in relation to the storage body 4.
• Figs 7, 9 as well show the position B, while Figs 6, 8 illustrate the position A.
• a threaded spindle 18 is connected with the rotary handle 13 which threaded spindle 18 extends from the free end of the housing bracket 9 into the interior of the housing bracket 9.
• the threaded spindle 18 has a threaded section 19 at an end side.
• a nut part 20 of the holder sley 11 is axially adjustable on the threaded section 19.
• the nut part 20 is connected by a carrier body 21 with the ring-shaped holder H.
• the holder sley 11 is guided in guiding tracks 22 of the housing bracket 9.
• the threaded spindle 18 is rotatably but is supported axially firm (in a rotary sleeve 23 of the quick adjustment device Q; if this is provided).
• the rotary sleeve 23 is rotatably supported in a rotary bearing 30 of the housing bracket 9.
• a pin-slot guiding structure 24, 25 of spiral shape or helical form is provided between the rotary sleeve 23 and the rotary bearing 30.
• the pin 24 e.g. is placed in the rotary bearing 30 such that it protrudes inwardly into an engagement with a helical guiding groove 25 of the rotary sleeve 23. This arrangement instead could be inversed.
• the tension ring T which is detachably secured in the holder H, expediently is snapped-in, is a so-called straw ring having an outer ring body 27 (e.g. corresponding to DE 19 00 619 A the contents of which are incorporated herewith), from which ring body 27 at the inner side elastic fingers 28 protrude which are distributed regularly in circumferential direction and which have free finger ends 29 which lie (in a not deformed condition of the tension ring T) on a circle K which is coaxial and perpendicular to the axis of the storage body 4.
• the tension ring may be a plastic injection mould part. Intermediate spaces are provided between the root regions of the fingers 28 while the finger ends 29 overlap each other in circumferential direction. In some cases each finger may be tapered such that its thickness decreases towards the free end.
• the cylindrical front end section 6 has an outer diameter dz.
• the ring body 27 of the tension ring C has an inner diameter db.
• the circle K defined by the free finger ends 29 has a diameter dk.
• the diameter dk e.g. is smaller by 3 mm to 4 mm than the outer diameter dz or is smaller by 2% to 5%, preferably about 3% to 4%, than the outer diameter dz.
• the inner diameter db is larger than the outer diameter dz, e.g. by 15% to 25%.
• the tension ring T can be adjusted axially by means of the adjustment mechanism M by rotating the threaded spindle 8 and at least between the passive position C and the uniform yarn tension operative position B.
• the holder with the tension ring T may be adjusted only with the threaded spindle 18 even into the passive position C.
• the tension ring T can be adjusted by means of the quick adjustment device Q only by a partial rotation of the handle 14 in one go into the passive position C and back again such that, expediently, after the returning adjustment the former operative position as adjusted with the threaded spindle 18 is precisely re-set.
• the passive positions C, C are positions in which the tension ring T forms an intermediate gap with the withdrawal rim 15 and serve e.g. for threading a yarn or for a cleaning action.
• the fingers 28 or the finger ends 29, respectively are co-operating in contacting fashion with the cylindrical front end section 6 of the storage body 4, such that the fingers 28 in some cases may be bent further than in the individual yarn tension operative position A.
• the finger ends 29 are co-operating in contacting fashion only with the rounded withdrawal rim 15 (alternatively, the withdrawal rim 15 could be conical).
• the tension ring T performs in the uniform yarn tension operative position B a yarn controlling function and a yarn braking function which functions exclusively depend on a given diameter dz of the design of the tension ring and of the bending state of the elastic fingers 28.
• tension rings which are equal among each other at several yarn feeding devices F will generate equal yarn tensions with the tension rings located in the uniform yarn tension operative positions B, and, in particular, largely independent in which exact position the holder H is adjusted in relation to the cylindrical front end section 6.
• the adjusted braking effect will strongly depend on the axial relative position between the withdrawal rim 15 and the holder H or the tension ring T, respectively.
• Each adjustment of the holder H in Fig. 3 to the left side or to the right side from the shown individual yarn tension operative position A will change the braking effect and in turn the yarn tension.
• yarn feeding devices F which are identical among themselves e.g. are implemented at a flat knitting machine or a so-called body machine which normally only needs a few yarn feeding devices F, but which, in some cases, needs individual braking effects or yarn tensions, respectively, at the different yarn feeding devices F, then the braking effect is adjusted individually at each yarn feeding device with the help of the adjustment mechanism M by the co-action between the fingers 28 and the withdrawal rim 15.
• the quick adjustment device Q is an option only.
• the adjustment mechanism M instead can be designed even without the quick adjustment device Q.
• the entire adjustment range allowed by the adjustment mechanism M having the quick adjustment device Q is given by the length of the threaded section 19 and the added length of the pin-slot guiding structure 24, 25.
• the rotary handle 13 may be equipped in the handle 14 with a ball latching means in order to define single adjustment steps. Markings for the different positions of the holder H or the tension ring T, respectively, may be provided at the sides or the top of the housing bracket 9.
• the threaded section 19 expediently contains a fine thread in order to allow very fine adjustments.
• the tension ring namely is characterised in that several of these tension rings which are equal among each other produce almost identical yarn tensions without adjustment steps on cylinder sections of storage bodies which are dimensioned equally among each other, which e.g. is an enormous advantage in case of circular knitting machines, because circular knitting machines operate with a large number of such yarn feeding devices.
• the tension ring has the property to allow to delicately adjust individual yarn tensions in case of contacting co-action with the rounded or conical withdrawal rim of the storage body by slightly varying the contact pressure or the deformation of the fingers, respectively. That property of the tension ring e.g. is expedient in case of flat knitting machines or so-called body machines which are equipped with only a few of such yarn feeding devices and at which frequently individual yam tensions are needed. The manipulations needed for adjusting the individual yarn tensions can be accepted in case of flat knitting machines because of the small number of yarn feeding devices, in order to allow to knit an optimum product.
• These positive properties of the tension ring can come into action very well and in view to a proper yarn control in combination with a stationary storage body operating with yarn separation because the stationary storage body is equally well suited for a large range of most different yarn materials.
• the embodiment of the tension ring T shown in Fig. 4 e.g. is a plastic form part in one-piece design.
• the elastic fingers 28 when relaxed define a frustocone coat and follow with their free finger ends 29 the circle K. Inwardly directed thickened sections 32 are formed at the free finger ends in order to increase strength and wear resistance.
• the root sections of the fingers 28 are unified with the ring body 27 with circumferential intermediate distances.
• a circumferentially continuous radial holding flange 31 is formed at the ring body 27.
• the fingers 28 are positioned inclined within the cone coat, and, in particular, in the inclined direction in which the yarn is rotating below the tension ring T on the storage body during the withdrawal action.
• the fingers 28 overlap each other, i.e., each finger extends in circumferential direction over more than one root section of an adjacent finger.
• the arrangement and design of the fingers 28 having their free ends 29 and in some cases even the thickened sections 32 are as explained in connection with Fig. 4.
• the root sections of the fingers 28 are secured to the ring body 27 which, in this embodiment, is equipped with a substantially cylindrical collar body 33 carrying the radial holding flange 31.
• the circle K defined by the free finger ends 29 is situated approximately in the plane of the holding flange.
• Figs 6 and 7 illustrate the tension ring T of Fig. 4 in both operative positions A and B which respectively are adjusted by means of the adjustment mechanism M.
• the holder H is designed with a holding groove 34 into which the holding flange 31 is inserted. At one side of the holding groove an essentially radial support face 35 is provided for the holding flange 34. Furthermore, the holder A has a substantially cylindrical support surface at the other side of the holding groove 34 which support surface extends in the skirt shown in Fig. 1. Anyhow, the holder H may be a standard holder as is commonly used for other yarn braking elements as well.
• the holder H in Fig. 7 is adjusted into the operative position B such that the free finger ends co-act by radial contact with the cylindrical front end section 6 of the storage body 4. In the operative position B the fingers are bent somewhat more in relation towards the ring body
• Figs 8 and 9 again illustrate the operative positions A and B for the tension ring T of Fig. 5 which co-operates in the operative position A with the rounded withdrawal rim 15 and in the operative position B with the cylindrical front end section of the storage body 4.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Knitting Machines (AREA)

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• 2004
  • 2004-09-20 DE DE200410045497 patent/DE102004045497A1/de not_active Withdrawn
• 2005
  • 2005-08-24 CN CN 200580031575 patent/CN101023013A/zh active Pending
  • 2005-08-24 WO PCT/EP2005/009140 patent/WO2006032343A1/en active Application Filing
  • 2005-08-24 EP EP05782918A patent/EP1855973A1/de not_active Withdrawn

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