Classifications

• • 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
  • D03D47/367—Monitoring yarn quantity on the drum

Definitions

• the hardness at least of the surface contacted by the yarn windings amount to more than 1000 Hv, preferably in a range of up to about 2000 Hv (Vicker's hardness).
• the protective layer is formed with a lower side extending at least substantially parallel to the surface.
• the lower side carries a metallic coating forming the reflective surface.
• the protective layer and the reflector surface form a structural unit, namely a reflector body of rectangular, rectangular and rounded, oval or round shape.
• the reflector body e.g., may have a rounded shape with an outer diameter of about 6.0 mm and a thickness of about 1.0 mm.
• the edge of the surface contacted by the yarn windings may expediently be rounded to avoid trouble with the yarn windings.
• the recess contains a foss-like groove defining the opening edge of the recess and encompassing at least one inner fixing boss, the top side of which is located below the height of the opening edge of the recess.
• the reflector body is fixed by the bonding agent or the pottant on the top side of the fixing boss.
• the bonding agent or the pottant fills the groove at least partially and such that it extends to the outer edge of the reflector body to seal the transition from the fixing boss to the reflector body and also the transition from the reflector surface to the protective layer.
• the top side of the fixing boss is smaller than the lower side of the reflector body.
• This dimensional relationship allows to easily fit the reflector body accurately in the recess.
• the bonding agent or the pottant expediently, fills the preferably foss-like groove up to the full height of the surface of the protective layer or almost up to this height. This measure results in the avoidance of any inappropriate depression where lint, avivage or contamination might otherwise collect.
• the reflector body preferably at least the surface contacted by the yarn windings, is plane.
• the surface, or even the entire reflector body may have a convex curvature at least substantially similar to the convex peripheral curvature of the storage drum.
• a high quality reflector surface can be achieved by metal vacuum vapour deposition on a separate carrier or on the protective layer.
• the metal is evaporated by electronic beam energy while it is deposited in an evacuated surrounding.
• the carrier or the protective layer may be well polished with an optically correct and even surface quality for the reflector surface.
• the reflector surface may be provided on a separate carrier, e.g. on a metallic plastics or glass carrier, which either just abuts or is bonded to or is spaced apart from the protective layer, alternatively.
• a yarn feeder F in Fig. 1 as conventionally used e.g. for feeding a yarn Y to a textile machine, e.g. a weft yarn Y to a weaving machine or a knitting yarn Y to a knitting machine, is provided with a housing 1 and a housing sub-unit 2.
• a yarn storage drum 3 is stationarily or rotatably provided on a central shaft.
• the storage drum 3 is provided to carry windings 9 of the yarn Y.
• the yarn windings 9 move forward in axial direction on the peripheral surface 6 of the storage drum 3.
• the yarn feeder is equipped with at least one optoelectronic yarn sensor S comprising components in the housing 1 and/or in the housing sub-unit 2 and in the storage drum 3.
• the yarn feeder F shown as an example in Fig. 1 is a weft yarn feeder for a weaving machine.
• the storage drum 3 is kept stationary by means known per se, while the central shaft is driven to rotate a winding-on element 4 fixed to said shaft.
• the incoming yarn Y enters the housing 1 in Fig. 1 from the left side through a hollow section of the drive shaft and is wound by the winding-on element 4 in adjacent, preferably somewhat separated, yarn windings 9 on the peripheral surface 6 of the storage drum 3.
• the textile machine withdraws the yarn Y overhead the storage drum 3 in a consumption-depending kind of manner.
• a drive motor 7 for the winding-on element 4 is comprised in the housing 1.
• the drive motor 7 is controlled by control device 8.
• the control device 8 is receiving control signals from the yarn sensor S.
• the drive motor 7 is e.g. controlled such that the yarn Y is wound on the storage drum surface 6 until the first (leading) yarn winding 10 reaches a detection zone 11.
• the yarn sensor S responds to the presence of said first yarn winding 10 and stops or decelerates the drive motor 7, which only starts or accelerates again as soon as the detection zone 11 again is "cleared" or free from yarn windings.
• the yarn sensor S instead could alternatively e.g. be a so-called yarn withdrawal sensor responding and/or counting each yarn winding being withdrawn from the yarn feeder, or a so-called reference sensor, or a so-called input yarn sensor, or a so-called yarn break sensor.
• the structure of all yarn sensors just mentioned is principally similar.
• the yarn sensor S has at least one light source L, and at least one signal generating receiver R (a light diode or a phototransistor), both connected into a circuitry 12, and a reflector surface B.
• the reflector surface B is located below the peripheral surface 6 of the storage drum 3 in order to reflect light emitted by the light source L back towards the receiver R.
• the reflector surface B is located behind a protective layer 5, e.g.
• the protective layer 5 and the reflector surface B preferably, constitute a prefabricated reflector body P of the yarn sensor S.
• the amorphous ceramic material may be chosen e.g. from the following group: Sapphire glass, Zirconium glass, Hafnium glass, Quartz glass or crystalline Al-Oxide glass (AL 3 0 3 ) glass, or a similar light transparent amorphous ceramic material.
• the reflector body P may have a rectangular, a rectangular and rounded, an oval or a round plate or disc shape and e.g. with substantially uniform thickness.
• a round reflector body P may have an outer diameter of about 6.0 mm and a thickness of about 1.0 mm.
• the surface 13 is plane, or, alternatively, in case of a circumferentially curved periphery surface 6 of the storage body 3 convexly curved in circumferential direction of the storage body 3 as well. In this case even the entire reflector body P may be curved.
• Fig. 3 illustrates one possibility to fit the reflector body P, e.g. the one in Fig. 2, in the storage drum 3 of the yarn feeder F.
• a recess 20 is formed in the peripheral surface 6 of the storage body 3 (the periphery 6' may have a circumferential curvature) a recess 20 is formed.
• the opening edge 19 of the recess 20 is defined by a preferably annular (endless, foss-like) groove 18 enclosing an inner fixing boss 21 (or several separate fixing bosses indicated by dotted lines at 22), the top side 23 of which is situated below the height of the opening edge 19 or the periphery surface 6 of the storage drum 3.
• the top side 23 is smaller than the lower side of the reflector body P.
• the surface 13 is essentially flush with the periphery 6.
• the periphery 6 has the curvature (indicated in dotted lines as 6')
• at least the surface 13 can have a similar curvature.
• the reflector body P may be fixed by a mechanical fastening arrangement.
• the reflector surface B on the lower side 14 of the protective layer 5 may be smaller than the lower side 14.
• the reflector surface B is not continuous (uniform) as shown but consists of a stripe pattern of parallel and spaced apart reflective and non-reflective stripes (a solution known per se).

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Optical Elements Other Than Lenses (AREA)
• Forwarding And Storing Of Filamentary Material (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20291095

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Citations (1)

Family Cites Families (5)

• 2003
  • 2003-04-21 SE SE0301181A patent/SE0301181D0/xx unknown
• 2004
  • 2004-04-21 CN CN 200480010725 patent/CN1777556A/zh active Pending
  • 2004-04-21 EP EP04728560A patent/EP1618058A1/de not_active Withdrawn
  • 2004-04-21 WO PCT/EP2004/004229 patent/WO2004094285A1/en not_active Ceased
  • 2004-04-21 JP JP2006505219A patent/JP2006524170A/ja active Pending

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events