Patent ID: 7069800

Claim:
A method for changing gears of a vehicle transmission comprising the steps of: providing a gear changer assembly comprising: a housing including an outer wall and having a cylindrical cavity formed therein; a first piston mounted for reciprocal movement in said cylindrical cavity said first piston having a piston rod connected to slide out of said housing to provide a rod end extending therefrom; a gear selector connected to said rod end of said piston rod; an auxiliary piston inside said cylindrical cavity for reciprocal movement, said auxiliary piston including a projecting portion extending from said housing opposite said piston rod; a first duct through said housing into said cylindrical cavity; a second duct through said housing into an annular cavity formed around said auxiliary piston in said cylindrical cavity; a third duct, open at both ends and extending through said projecting portion of said auxiliary piston; a first sensor held in said housing for contact with said piston rod to detect a first position thereof; and a second sensor held in said housing for contact with said piston rod for detecting a second position thereof and further detecting a third position of said piston rod when said first sensor detects said first position, said piston rod moving between said first, said second and said third positions to move said gear selector for selection of a first gear wheel, a neutral position and a second gear wheel; placing said gear selector in the neutral position of the vehicle transmission by applying pressure through said second duct to move said piston rod for detection of said first position by said first sensor and detection of said third position by said second sensor; engaging the first gear wheel of the vehicle transmission by applying pressure through said first duct for moving said piston rod for detection of said second position by said second sensor; and changing the vehicle transmission between said first gear wheel and said second gear wheel by applying pressure through said third duct for moving said piston rod for detection of said second position by said first sensor, wherein said gear selector engages said second gear wheel.