(19)
(11) EP 2 072 647 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
11.05.2011 Bulletin 2011/19

(43) Date of publication A2:
24.06.2009 Bulletin 2009/26

(21) Application number: 08020233.6

(22) Date of filing: 20.11.2008
(51) International Patent Classification (IPC): 
D01H 5/74(2006.01)
 D01H 5/78(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA MK RS

(30) Priority: 21.12.2007 JP 2007330694

(71) Applicant: Murata Machinery, Ltd.
Minami-ku Kyoto-shi Kyoto 601-8326 (JP)

(72) Inventors:
  • Ota, Naritoshi
    Kyoto-shi Kyoto 612-8686 (JP)
  • Sakamoto, Naotaka
    Kyoto-shi Kyoto 612-8686 (JP)

(74) Representative: HOFFMANN EITLE 
Patent- und Rechtsanwälte Arabellastraße 4
81925 München
81925 München (DE)

   


(54) Draft roller


(57) Irrespective of the material (yarn type) of a sliver to be processed, a generation of the cyclic unevenness caused by a groove pitch of a draft roller and an accumulation of foreign materials in the grooves during drafting process can be prevented. A draft roller according to the present invention is provided in a draft device of a spinning machine and has groove parts (29) formed on a roller surface (28) of the draft roller and having an inclination relative to an axial direction of the draft roller, wherein given that a diameter of the draft roller is R, the number of the groove parts is N, an inclination relative to the axial direction of the groove parts is θ, a fiber width of a sliver processed by the draft device is D and a circular constant is π, the draft roller satisfies a relationship πR/N < Dtanθ.







Search report