Control of the shift points of an automatic transmission for temporary acceleration increase

Claim 1

Method of controlling the provision of a substantial discrete offset in a normal gearshift pattern of a vehicular automatic transmission interposed between an internal combustion engine and drive wheels of a vehicle, said engine having an accelerator pedal for increasing and reducing the power output of the engine during driving of the vehicle, said offset being constituted to put quickly at lower value the vehicle speed at which a shift to a lower gear for a given engine load is produced in response to operation of a switch when said accelerator pedal is fully depressed, compared to the value of vehicle speed at which said shift to a lower gear would occur at the same engine load in said normal gearshift pattern of said transmission, and to restore fully said normal gearshift pattern automatically thereafter, in which method, in accordance with the invention, a change of the condition of said switch resulting from reducing the amount of depression of said accelerator pedal has no responsive effect on the persistence of said offset; said offset is also provided when the engine load oversteps a first predetermined threshold value of said engine load; said offset is also provided when said accelerator is depressed at a rate that exceeds a predetermined rate; said offset is terminated when a predetermined time has elapsed since said offset was provided; said offset is terminated when the load of said engine has fallen below a second predetermined value of engine load; said offset is terminated when the speed of said engine has increased beyond a first predetermined threshold value of engine speed, and said offset is terminated when the speed of said engine has decreased beyond a second predetermined threshold value of engine speed.