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:
Nov. 17, 1987
Filed:
Oct. 02, 1984
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An automatic transmission has lower side and higher side friction engagement devices, with the lower side one being engaged and the higher side one being disengaged when a lower speed stage is engaged, while the lower side one is disengaged and the higher side one is engaged when the speed stage one higher than that lower speed stage is engaged. A control device for the transmission includes a shift valve for switching actuating fluid pressure between the lower side and the higher side friction engagement device and for draining the other one thereof, to provide the lower or the higher speed stage. An upshift smoothing valve is interposed in the drain path for the lower side friction engagement device for providing a higher flow resistance when a value representing engine output is relatively high and for providing a lower flow resistance when the value representing engine output is relatively low. Thus upshifting shock is reduced, particularly under low engine output conditions, in which overlapping of the engagement of the lower side and the higher side friction engagement devices is reduced. Optionally, the upshift smoothing valve may provide its higher or lower flow resistance, according as to whether the value representing engine output prevails over the actuating pressure for the higher stage friction engagement device, in a relationship between them, or not.