(19)
(11)EP 0 020 033 A3

(12)EUROPEAN PATENT APPLICATION

(88)Date of publication A3:
28.01.1981 Bulletin 1981/04

(43)Date of publication A2:
10.12.1980 Bulletin 1980/25

(21)Application number: 80301454

(22)Date of filing:  02.05.1980
(84)Designated Contracting States:
DE FR GB IT NL

(30)Priority: 04.05.1979 JP 5980079

(71)Applicant: SHIMANO INDUSTRIAL COMPANY LIMITED
 ()

(72)Inventor:
  • Shimano, Keizo
     ()

  


(54)Cycle derailleur with axially fixed pulley


(57) A cycle derailleur for use in switching a drive chain between different sprockets of a multi-stage sprocket assembly for changing gear which derailleur comprises a fixing member (1); a support member (2) connected to said fixing member (1) so as to be movable relative thereto; a return spring means (16) disposed for acting between said fixing member (1) and support member (2); a change-over frame (4) pivotally supported on said support member (2) via a first generally horizontally extending, in use, shaft (5); a coiled spring means (21) arranged for acting between said support member (2) and said change-over frame (4) for tensioning a drive chain of the cycle in use of the derailleur; a first pulley (6) rotatably mounted around said horizontally extending shaft (5); and a second pulley (8) rotatably supported on the change-over frame (4) by means of a second generally horizontally extending shaft (8) substantially parallel to said first shaft (5).
In order to maintain an axially fixed position of drive chain entry to the derailleur, the support member is connected to said fixed member via a third, generally vertically extending, in use, shaft (3), the principal, rotational axis of said first shaft (5) intersecting, substantially at right angles, an extension of the principal, rotational axis of said third shaft (3), whereby the position of the first pulley (6) in an axial direction thereof is maintained substantially fixed during pivoting of the change-over frame (4) about said third shaft (3) for gear changing.







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