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:
Apr. 06, 1999
Filed:
Jul. 28, 1997
Harald Ludanek, Calberlah, DE;
Reinhold Haack, Brunswick, DE;
Bernd Cappelmann, Wendeburg-Neubruck, DE;
Volkswagen AG, Wolfsburg, DE;
Abstract
A twin-clutch transmission has first and second transmission input shafts and a transmission output shaft, each input shaft having an associated friction clutch. In the initial state, the first clutch transmits engine torque in a state of static friction and the second clutch is open. In a shifting operation the second transmission input shaft is brought to a synchronous speed, thus permitting the engagement of a selected gear. In order to prevent a condition in which both clutches are in static friction engagement, which would result in locking up of the transmission, the speed of at least one clutch is maintained in the range of sliding friction to a value in the vicinity of the synchronization speed until the torque to be transmitted has been transferred steadily from the first clutch to the second clutch. A synchronizer is used when shifting up in the overrun condition.