The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 14, 1995
Filed:
Mar. 13, 1992
Kazuya Hayafune, Okazaki, JP;
Mitsubishi Jidosha Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
In a speed change control method for an automatic transmission for vehicles with a plurality of gearshift positions, the frictional resistance of a road surface is detected, gearshifting to at least a lowest-speed gearshift position is prohibited if the frictional resistance of the road surface is judged to be low. Preferably, gearshifting to at least the lowest-speed gearshift position is prohibited when starting the vehicle from a stopped position if the frictional resistance of the road surface is judged to be low. The frictional resistance of the road surface is determined to be low when an occurrence frequency (%) of the detected frictional resistance value, being less than or equal to a first predetermined value, is more than or equal to a second predetermined value.