Patent ID: 7219782

Claim:
An apparatus for detecting a gear position in a gearbox of an automotive vehicle, wherein the vehicle on which the apparatus is operable includes an engine, a rotating shaft of the engine, the gearbox, an operable clutch between the engine and the gearbox for selectively connecting the engine to the gearbox and for disconnecting the engine from the gearbox; the gearbox comprising: at least a first and a second gear at respective first and second gear positions as regards respective first and second gear ratios; a split gear for defining at least two split gear positions relating to the first and second gear positions of the gearbox, one of the split gear positions being one of the first and second gear positions and the other of the split gear positions being of a gear ratio other than gear ratios of the first and second gear positions; a selector for selecting the split position of the split gear; and an output shaft of the gearbox; the apparatus for detecting comprising: a first detector for detecting a second value indicative of a speed of the engine or of the shaft of the engine on an engine side of the clutch; a second detector for detecting a value indicative of a speed of the output shaft of the gearbox or of a rotating shaft driven by the output shaft; a calculating arrangement operable to calculate a quotient of the first value indicative of the speed of the engine or of the rotating shaft of the engine to the second value indicative of the speed of the output shaft of the gearbox or of the rotating shaft driven by the output shaft of the gearbox, the calculating arrangement being operable to compare the calculated quotient with predetermined quotient values set in the arrangement for each of the gear positions of the gearbox and to set upper and lower limits about the quotient value for the respective gear positions, the calculating arrangement operable to determine whether each of the gear positions of the gearbox has the respective calculated quotient within the upper and lower limits for the respective gear positions; the selector for selecting the split position of the split gear being operable to send information about the selected split position to the calculating arrangement; and the calculating arrangement operable to respond to information received from the selector concerning the selected split position and being operable to eliminate as a possible gear position of the gearbox for the calculation any gear position not corresponding to the selected split position of the split gear selected by the selector and operable, based upon the quotient comparison, to then raise the upper limit and lower the lower limit around the quotient value for remaining gear positions which at the time correspond to the selected split position of the split gear.