| 摘要 |
The present invention relates to a sequential gearbox 20. The gearbox comprises: a housing 30 comprising a case 31 and a cover 32; a first shaft 41 with an axis X 1 ; a second shaft 42 with an axis X 2 parallel to X 1 ; and at least one lay shaft 43 with an axis X r parallel to X 1 e X 2 . The first and the second shafts project from the housing, while the lay shaft is contained inside it. At least one gearwheel 44 is keyed onto each shaft. One shaft is designed for connection to an engine and the other shaft is designed for connection to a user appliance. The first and the second shafts may be connected together by means of gearwheels and the at least one lay shaft in a plurality of transmission configurations. The gearbox also comprises a control device 50 movable among a plurality of consecutive working positions. Each position of the control device defines a different transmission configuration. The control device comprises: a control shaft 51 able to assume a plurality of successive angular positions corresponding to the working positions of the control device. Moreover, the gearbox comprises at least one poppet ball 53 mounted so as to be pushed radially against the control shaft and able to engage in succession inside a plurality of radial recesses 35 formed in the control shaft and spaced circumferentially from each other. Co-operation of the poppet ball with each of the recesses defines a stable equilibrium position for the control shaft. |
