Invention Grant
- Patent Title: Hydraulical shifting device for an automatic transmission
- Patent Title (中): 用于自动变速器的液压换档装置
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Application No.: US13734049Application Date: 2013-01-04
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Publication No.: US08944232B2Publication Date: 2015-02-03
- Inventor: Thilo Schmidt , Markus Herrmann , Hans-Joachim Martin
- Applicant: ZF Friedrichshafen AG
- Applicant Address: DE Friedrichshafen
- Assignee: ZF Friedrichshafen AG
- Current Assignee: ZF Friedrichshafen AG
- Current Assignee Address: DE Friedrichshafen
- Agency: Davis & Bujold, PLLC
- Agent Michael J. Bujold
- Priority: DE102012200202 20120109
- Main IPC: F15B15/26
- IPC: F15B15/26 ; F16H63/34 ; F15B20/00 ; F16H61/02

Abstract:
A hydraulic shifting device for an automatic transmission for engaging and disengaging a parking lock. The shifting device comprises a parking lock cylinder (203) for actuating the parking lock, and a parking lock valve (201) which, for hydraulic control of the parking lock cylinder (203), can be switched to at least first and second shift positions. In this case the hydraulic shifting device comprises a further parking lock valve (202), and the two parking lock valves (201, 202) and the parking lock cylinder (203) are designed and connected with one another in such manner that the parking lock can only be disengaged by pressurizing the parking lock cylinder (203) if the two parking lock valves (201, 202) are each switched to a particular shift position.
Public/Granted literature
- US20130174722A1 HYDRAULICAL SHIFTING DEVICE FOR AN AUTOMATIC TRANSMISSION Public/Granted day:2013-07-11
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