US3869853A - Friction bush - Google Patents

Friction bush Download PDF

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Publication number
US3869853A
US3869853A US337336A US33733673A US3869853A US 3869853 A US3869853 A US 3869853A US 337336 A US337336 A US 337336A US 33733673 A US33733673 A US 33733673A US 3869853 A US3869853 A US 3869853A
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US
United States
Prior art keywords
yarn
friction
bush
metal portion
bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US337336A
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English (en)
Inventor
Werner Doschko
Wolfgang Fohlisch
Alfred Wensch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Imperial Chemical Industries Ltd
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Imperial Chemical Industries Ltd
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Filing date
Publication date
Application filed by Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
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Publication of US3869853A publication Critical patent/US3869853A/en
Anticipated expiration legal-status Critical
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Classifications

    • D—TEXTILES; PAPER
    • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
    • D02G1/02—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics by twisting, fixing the twist and backtwisting, i.e. by imparting false twist
    • D02G1/04—Devices for imparting false twist
    • D02G1/08—Rollers or other friction causing elements

Definitions

  • ABSTRACT A friction bush for imparting twist to a moving yarn is described wherein the bush overcomes the prior art problem of generated heat on the friction surface of elastomeric coated bushes. Generated heat buildup and corresponding degradation of the elastomeric surface is reduced by utilizing a highly conductive metal bush coated with a thin layer, i.e., less than about 2 millimeters of elastomeric material, as the friction surface, thereby providing rapid conduction of heat away from the frictional surface.
  • the present invention relates to improved friction bushes for imparting twist to moving yarns.
  • yarn may be twisted by passage through a rotating tube wherein the inner surface of the tube against which the yarn bears is a friction surface so that the rotation of the tube imparts a twist to the yarn. It has also been proposed to use a rotating cup, the inside and top surfaces of which provide friction surfaces against which the yarn is held by some form of yarn guide.
  • This type of device has the advantage that the yarn approaches and leaves the device from the same side thus making threading up easier.
  • the friction surface is generally provided by a thick rubber bush which is shaped to give the desired contact between the yarn and the bush.
  • the area where the yarn contacts the rubber becomes extremely hot during a long run which results in damage to both the yarn and the friction surface. Furthermore, the continual contact between the yarn and the friction surface tends to scratch and mar the friction bush which produces an uneven surface which can damage the yarn and necessitates renewal of the friction surface. In addition, as the friction bush wears, yarn of variable quality is obtained according to the part of the bush in contact with the yarn, thus yielding yarn of bad uniformity.
  • a friction bush for imparting twist to a moving yarn comprising a rotatable metal portion shaped to provide an area for contact with the yarn said metal portion being coated over at least that part of its surface which contacts the yarn with a layer of friction material no more than 2 millimetres thick, said friction material having a shore hardness at room temperature greater than 30.
  • FIG. 1 is a plan view of a friction bush in accordance with the present invention.
  • FIG. 2 is a sectional view along the line 2 2 of FIG. 1 showing the cross-section of the bush;
  • FIG. 3 is a plan view of another friction bush in accordance with the present invention.
  • FIG. 4 is a sectional view along line 4 4 of FIG. 3 showing the interior curvature portion of the bush.
  • bush comprises a high heat conductive metal having coated thereover a thin layer of friction material l2.
  • the friction bush of the present invention may be such that the metal portion forms a bore through which the yarn passes and in this embodiment the metal should be shaped so that there is contact between the yarn and the friction surface as the yarn passes through the bore.
  • the bush may be of a type where the yarn approaches and leaves the bush from the same side and is held against the friction surface by a suitable form of yarn guide system.
  • the metal portion is cup shaped and coated with the friction material over the area of contact with the yarn, which may be the inside surface, the rim of the cup, or both.
  • the choice of metal is not critical although we prefer to use aluminium because with the high speeds of rotation that are used it is useful to have a light bush. Furthermore, aluminium has high heat transfer.
  • the form in which the metal portion is shaped should preferably ensure adequate contact between the yarn and the bush without any dramatic changes in yarn direction while it is in contact with the friction surface because dramatic changes in direction tend to result in yarn breakages.
  • the preferred shape will depend on the yarn path for example if the bush is formed with a bore we prefer that the entrance to the bore is tapered so that it is wider at the point where the yarn enters. In this way if the yarn enters the bush at an angle to the axis of the bore it will run up the tapered portion and through the bore, giving effective contact with the friction surface without any dramatic change in yarn direction.
  • the exit end of the bore is also tapered to allow a smooth exit for the yarn.
  • the coating on the metal which provides the friction surface may be of any suitable material providing it has a sufficiently high coeeficient of friction to ensure that twist is imparted to the yarn and providing it has a shore hardness at normal temperatures of at least 30. We do, however, prefer that the material has a shore hardness of at least 50 and preferably between 50 and 90.
  • Our preferred coating materials are the polyurethane rubbers having the properties specified above. In particular we prefer to use the Flexane polyurethanes rubbers as supplied by Devcon Limited.
  • the friction bushes of the present invention may be used to produce twist in any yarns having a positive friction surface.
  • the bush is rotated by any suitable means and the yarn is held against the friction surface so that the rotation of the bush imparts a twist to the yarn.
  • the friction bushes of the present invention are particularly useful in false twist processes in which the yarn first passes through a heater and then to the false twist bush so that the twist imparted by the bush runs back along the yarn into the heater zone where the heat 3 sets the yarn in its twisted state. After passing through the friction bush the yarn is untwistedto provide a bulked yarn.
  • the device can be used to false twist. drawn sythetic thermoplastic yarns, synthetic yarns drawn immediately before texturising and undrawn synthetic yarns, e.g., yarns from nylon 6, nylon 6.6, polyester etc.
  • false twisting is a process in which yarn is twisted so that the twist runs back along the yarn into a zone where it is heated and the twist set.
  • the action of the twist bush is two-fold in that it imparts a twist' in the yarn that is being fed to the bush and detwists the yarn as it leaves the bush.
  • the techniques of the present invention may readily be used in the twisting step of such a process;
  • the thin friction surface together with the metal backing has high heat conductivity and thus the heat generated by frictional contact between the yarn and the bush is dissipated. In this way yarn breakages and deterioration of the friction surfaces are reduced.
  • a friction bush for imparting twist to a moving yarn comprising a rotatable rigid metal portion shaped to provide an area for contact with the yarn said metal portion being coated over at least that part of its surface which contacts the yarn with a layer of frictional material no more than 2 millimetres thick, said friction material having a shore hardness at room temperature greater than 30.
  • a friction bush according to claim 1 in which the metal portion forms a bore through which the yarn passes.
  • a friction bush according to claim 1 in which the metal portion is cup shaped and the yarn approaches and leaves the bush from the same side thereof.
  • a friction bush according to claim 3 in which the bore of the bush is tapered so that it is wider at the point where the yarn enters the bore.
  • a friction bush according to claim 1 in which the metal portion is treated to enhance the adhesion between the metal and the friction material.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Sliding-Contact Bearings (AREA)
US337336A 1972-03-07 1973-03-02 Friction bush Expired - Lifetime US3869853A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1049872A GB1415191A (en) 1972-03-07 1972-03-07 Friction bush

Publications (1)

Publication Number Publication Date
US3869853A true US3869853A (en) 1975-03-11

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Family Applications (1)

Application Number Title Priority Date Filing Date
US337336A Expired - Lifetime US3869853A (en) 1972-03-07 1973-03-02 Friction bush

Country Status (8)

Country Link
US (1) US3869853A (enrdf_load_stackoverflow)
JP (1) JPS48103851A (enrdf_load_stackoverflow)
BE (1) BE796162A (enrdf_load_stackoverflow)
DE (1) DE2311172A1 (enrdf_load_stackoverflow)
GB (1) GB1415191A (enrdf_load_stackoverflow)
IT (1) IT981028B (enrdf_load_stackoverflow)
LU (1) LU67156A1 (enrdf_load_stackoverflow)
NL (1) NL7303038A (enrdf_load_stackoverflow)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2443238C3 (de) * 1974-09-10 1987-07-09 FAG Kugelfischer Georg Schäfer KGaA, 8720 Schweinfurt Reibrotor zum Friktionsfalschdrallen von synthetischen Fäden

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2936567A (en) * 1955-07-19 1960-05-17 British Nylon Spinners Ltd Twisting of textile filaments
US3527043A (en) * 1968-01-05 1970-09-08 Chavanoz Moulinage Retorderie Means and process for producing a false twist by friction
US3537250A (en) * 1968-07-05 1970-11-03 Alexander W P Mackintosh Means for imparting twist to yarns
US3643412A (en) * 1969-07-18 1972-02-22 Nippon Rayon Kk Method and apparatus for the production of crimped yarns
US3719035A (en) * 1971-05-05 1973-03-06 R Gilchrist Textile apparatus
US3724196A (en) * 1970-05-28 1973-04-03 Celanese Corp High speed texturing of synthetic continuous filament yarn
US3745755A (en) * 1971-01-20 1973-07-17 Spinner Oy Improvement in a false twist spindle in a filament false twist crimping machine

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2936567A (en) * 1955-07-19 1960-05-17 British Nylon Spinners Ltd Twisting of textile filaments
US3527043A (en) * 1968-01-05 1970-09-08 Chavanoz Moulinage Retorderie Means and process for producing a false twist by friction
US3537250A (en) * 1968-07-05 1970-11-03 Alexander W P Mackintosh Means for imparting twist to yarns
US3643412A (en) * 1969-07-18 1972-02-22 Nippon Rayon Kk Method and apparatus for the production of crimped yarns
US3724196A (en) * 1970-05-28 1973-04-03 Celanese Corp High speed texturing of synthetic continuous filament yarn
US3745755A (en) * 1971-01-20 1973-07-17 Spinner Oy Improvement in a false twist spindle in a filament false twist crimping machine
US3719035A (en) * 1971-05-05 1973-03-06 R Gilchrist Textile apparatus

Also Published As

Publication number Publication date
NL7303038A (enrdf_load_stackoverflow) 1973-09-11
BE796162A (fr) 1973-09-03
LU67156A1 (enrdf_load_stackoverflow) 1973-05-22
GB1415191A (en) 1975-11-26
JPS48103851A (enrdf_load_stackoverflow) 1973-12-26
IT981028B (it) 1974-10-10
DE2311172A1 (de) 1973-09-13

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