Patent ID: 8851256

Claim:
A transmission between a primary drive shaft ( 1 ) and an outlet shaft ( 2 ), the transmission comprising: at least one housing ( 3 ) within which there are housed at least in part: a stepdown mechanism ( 4 ) comprising a driving member ( 5 ) meshing with a driven rotary member ( 6 ); two clutch mechanisms ( 7 , 8 ), one of the mechanisms ( 7 ) being progressive and the other mechanism ( 8 ) being non-progressive with a movable dog ( 16 ), whereby the driven rotary member ( 6 ) is suitable for being coupled/decoupled with or from the outlet shaft ( 2 ); and a clutch control device comprising first clutch control means ( 9 ) for driving the movable dog ( 16 ) of the non-progressive clutch mechanism ( 8 ) in axial movement along the outlet shaft ( 2 ) between two extreme positions, said first clutch control means ( 9 ) being capable of being actuated from outside the housing ( 3 ), and second clutch control means ( 10 ) mounted on the outlet shaft ( 2 ) to move under the action of the movable dog ( 16 ) moving axially in the clutching direction, by bearing contact against said movable dog ( 16 ), between i) an active position in which said second clutch control means ( 10 ) are interposed between the movable dog ( 16 ) and the progressive clutch mechanism ( 7 ) and form a member for transmitting axial movement from the movable dog ( 16 ) to the progressive clutch mechanism ( 7 ) in order to pass the progressive clutch mechanism from a declutched position to a clutched position, and ii) an inactive or retracted position in which the movable dog ( 16 ) is suitable for passing from an unclutched position to the clutched position of the non-progressive clutch mechanism ( 8 ); wherein the second clutch control means ( 10 ) comprise at least two spring blades ( 11 ) extending along the outlet shaft ( 2 ) and mounted diametrically opposite each other about said outlet shaft ( 2 ), said spring blades being coupled together, at or close to respective ends ( 11 A, 11 B) of said spring blades ( 11 ), by means of a ring ( 12 ) that is engaged on said outlet shaft ( 2 ) so as to be constrained to move together axially along said outlet shaft ( 2 ), said spring blades ( 11 ) being mounted to move axially on said outlet shaft ( 2 ) and having said movable dog ( 16 ) bearing thereagainst during the axial movement of the movable dog ( 16 ) from the unclutched extreme position towards a clutched position, thereby driving said spring blades ( 11 ) axially on said shaft ( 2 ) and deforming said spring blades elastically between an active position in which the movable dog ( 16 ) comes into abutment against said spring blades ( 11 ) to transmit its axial movement to the progressive clutch mechanism ( 7 ) via the spring blades ( 11 ) interposed between the movable dog ( 16 ) and the progressive clutch mechanism, and an inactive position in which the movable dog ( 16 ) slides along the spring blades ( 11 ) to pass the non-progressive clutch mechanism ( 8 ) from an unclutched position to a clutched position.