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
• • 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
  • D04B15/44—Tensioning devices for individual threads

Definitions

• the invention relates to a yarn braking body according to the preamble of claim 1.
• a yarn braking body which is a precise frustocone coat made from smooth vacuum-shaped plastic material.
• the support part is a support ring firmly gripping the small diameter end of the frustocone coat and is installed as a separate part which comprises anchoring openings serving to hook in tension springs which extend radially outwardly from the support part and which hold the braking body in the coaxial operational position in contact with the rounded withdrawal rim of the storage body of the knitting yarn feeding device.
• the holding construction with the tensioning springs is structurally complicated. Manufacturing and assembling the support part at the yarn braking body needs several working steps.
• the knitting yarn runs off the storage body over the withdrawal rim and along the yarn braking surface at the inner side of the frustocone coat and at the same time rotates like the hand of a clock while it is pulled off axially through the small diameter end.
• the tension springs allow a certain movability of the yarn braking body and centre the yarn braking body on the withdrawal rim of the storage body.
• the yarn braking body is a wear part which in some cases has to be replaced relatively frequently. Due to the holding construction replacements are time consuming.
• the support part increases the mass of the braking body.
• the support part Since the support part is integrated as one piece into the frustocone coat the support part can be formed for fair costs during manufacturing the yarn braking body.
• the spherical support part is laid then with its spherical outer surface into a matching spherical pan for supporting the braking body.
• the support part is held by the contact pressure at the withdrawal rim of the storage body, and is centred by the spherical pan.
• the spherical support part forms so to speak a part of a spherical joint or a universal joint, respectively, which properly centres the yarn braking body on the withdrawal rim of the storage body.
• the yarn braking body can easily be replaced.
• the integrated spherical support part does not increase the mass of the braking body and also does not significantly influence the radial deformability of the frustocone coat in the region of the braking surface.
• the easily shapeable plastic material is used in order to form the spherical support part integrally with the frustocone coat.
• the rigidity of the support part which is slightly increased by the spherical form is sufficient for a stable suspension of the yarn braking body in the spherical pan without additional reinforcement measures.
• the same wall thickness is present in the yarn braking body in the frustocone coat and in the spherical support part.
• the wall thickness e.g. amounts to between 0.2 mm and 0.5 mm.
• the yarn braking body can be manufactured from a simple blank.
• the sphere radius of the spherical support part may be designed such that it reacts in an expedient relationship with the diameter at the large diameter end of the yarn braking body.
• the sphere radius e.g. may amount to between about 30% to 60% of the diameter.
• the wall thickness expediently is smaller than 1.0 mm, preferably even smaller than 0.5 mm. In case of a yarn braking body having a diameter of about 150 mm at the large diameter end the wall thickness may be about 0.3 mm.
• the cone angle of the regular frustocone coat should amount to between about 100° and about 130°. Expediently, the cone angle amount to 120°.
• the plastic material from which the yarn braking body is made should be a thermoplast, e.g. a polyester, PET or PVC. Such materials can be shaped easily and allow to achieve high durability and excellent surface properties.
• the yarn braking body expediently is made by, preferably thermal, vacuum shaping from a blank.
• the blank even could be a planar blank.
• At least the die surface used when shaping the inner surface of the braking body in the region of the braking surface should be polished in order to produce an inner surface in the yarn braking body which is truly smooth.
• the spherical support part should continue the frustocone coat without a transition or a step.
• the spherical curvature, so to speak, is nestled into the frustocone.
• the height dimension of the spherical support part measured in the direction of the axis of the frustocone coat should measure between about 15% to 35%, preferably less than 30%, of the height dimension of the yam braking body.
• the spherical support parts constitutes the small diameter end of the frustocone coat through which small diameter end the yarn will be withdrawn.
• the yarn may be withdrawn directly through the support part or, alternatively, with the help of a yarn eyelet which is placed at this location with or without a connection or a bonding to the yarn braking body.
• the outer diameter of the spherical support part should amount to about 2.5 to 4.5 fold of the inner diameter of the smaller diameter end. Alternatively, the outer diameter of the spherical support part could amount to between about 25% and 45% of the diameter of the large diameter end. In this fashion a sufficiently large contact surface is achieved in the ball joint.
• the inner surface of the frustocone coat, at least in the region of the braking surface, should have a smoothness which corresponds with a polished surface.
• Fig. 1 which in the left half is a side view of a yarn braking body and in the right half is a radial section of the yarn braking body.
• a yarn braking body B in Fig. 1 expediently for a not shown knitting yarn feeding device, is provided for a co-action with a rounded withdrawal rim of a drum-shaped storage body of a knitting yarn feeding device, in order to actuate or load the yarn with a relatively low braking force while the yarn is withdrawn inwardly over the withdrawal rim and at the same time is rotating like the hand of a clock.
• the yarn braking body is laid coaxially with the storage body from the front side against the withdrawal rim and is held in a suspension such that it is centred at the withdrawal rim but nevertheless remains somewhat movable.
• the yarn braking body B is a one-piece plastic material shaped part, e.g. made from a thermoplastic material P like polyester, PET or PVC.
• the yarn braking body B e.g. is manufactured by vacuum shaping on a forming die, in some cases even by thermal vacuum shaping.
• the yarn braking body B consists of a regular frustocone coat K and a spherical support part S which is integrated in one piece into the frustocone part K.
• the yarn braking body B has a large diameter circular end 1 having an opening 5 of a diameter D and a small diameter circular end 2 with an opening 4 of an inner diameter d.
• the frustocone coat K has a linear generatrice 3 and an axis Y.
• the spherical support part S is a stepless continuation of the generatrice 3 and has a sphere radius R e.g. between 30% to 60% of the diameter D.
• the centre Z of the sphere is situated on the axis Y of the frustocone coat K which axis Y is prolonged beyond the large diameter end 1.
• a yarn braking body B with a diameter D of about 110 mm and a cone angle ⁇ of 120° the sphere radius R is about 590 mm.
• the wall thickness x of the yarn braking body B is the same in the frustocone coat K and in the spherical support part S and amounts to between 0.2 mm and maximally 1.0 mm, preferably amounts to about 0.3 mm (in the case of a yarn braking body having a diameter D of 150 mm).
• the wall thickness in the spherical support part at least in part could be different from the wall thickness in the frustocone coat K.
• the respective edges in the openings 5, 6 in the large diameter end 1 and in the small diameter end 2 could be rounded.
• the inner surface of the frustocone coat constitutes at least in a region a ring-shaped, circumferentially continuous braking surface F. At least in the region of the braking surface F the inner surface should be very smooth, e.g. with a smoothness corresponding to a polished surface.
• the height h of the yarn braking body B in direction of the axis Y e.g. amounts in case of a diameter D of 110 mm to about 46 mm.
• the height h2 of the spherical support part S amounts to somewhat less than 30% of the height h and may amount to between about 15% to about 35% of the height h.
• the outer diameter dS of the spherical support part S amounts to about 2.5 to 4.5 fold of the inner diameter d of the small diameter end 2, or may be about 25% to 45% of the diameter D 1 respectively.
• the cone angle ⁇ in general may amount to between about 100° and 135°.
• a tangent drawn at the edge 6 of the opening 4 along the outer side of the spherical support part S either may be perpendicular to the axis Y or may include an angle with the axis Y which angle is smaller than 90°.
• the height hi of the frustocone coat K in each case is larger than the height h2 of the spherical support part S. In no case should the yarn braking surface F reach towards the spherical support part S.
• the outer surface of the spherical support part S also has a smoothness which corresponds to a polished surface.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Knitting Of Fabric (AREA)
• Spinning Or Twisting Of Yarns (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35197955

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (1)

Citations (3)

Family Cites Families (6)

• 2004
  • 2004-09-21 DE DE102004045725A patent/DE102004045725A1/de not_active Withdrawn
• 2005
  • 2005-09-08 EP EP05783070A patent/EP1796993B1/de not_active Expired - Fee Related
  • 2005-09-08 DE DE602005008457T patent/DE602005008457D1/de not_active Expired - Fee Related
  • 2005-09-08 CN CN2005800317326A patent/CN101023014B/zh not_active Expired - Fee Related
  • 2005-09-08 US US11/663,518 patent/US20070272322A1/en not_active Abandoned
  • 2005-09-08 WO PCT/EP2005/009674 patent/WO2006032376A1/en active IP Right Grant
  • 2005-09-16 TW TW094132167A patent/TWI308551B/zh not_active IP Right Cessation

Patent Citations (3)

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