Parking lock for automatic gearboxes of motor vehicles

• US 4,722,427 A
• Filed: 10/06/1986
• Issued: 02/02/1988
• Est. Priority Date: 10/18/1985
• Status: Expired due to Fees

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Lauven, Walter, Prumbaum, Gunter, Graef, Kurt
• Primary Examiner(s): Bonck, Rodney H.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/915,832
• Time in Patent Office: 484 Days
• Field of Search: 192/4 A, 192/4 R, 192/111 A, 188/31, 188/69, 188/72.7, 74/411.5, 74/470, 74/582, 74/104, 74/107
• US Class Current: 192/219.5
• CPC Class Codes: B60T 1/005 by locking of wheel or transmission rotation
• CPC Class Codes: F16H 63/3416 Parking lock mechanisms or brakes in the transmission
• CPC Class Codes: F16H 63/3483 with hydraulic actuating means

Abstract

A parking lock for an automatic transmission for motor vehicles, having a parking gearwheel mounted rotationally and rigidly on the output shaft of the transmission, includes a pivotable parking pawl adapted to engage the parking gearwheel, and actuating rod with a sliding sleeve (5) displaceable relative to the actuating rod against the force of an engagement spring, the parking pawl being adapted to be moved by the sleeve into an operative position, the actuating rod (8) being shaped by upsetting to form a thickened piston portion (11) which is received in the sleeve.

Claims

1. An automatic transmission parking brake comprising:

a parking gearwheel adapted to be fixed to a power output shaft of the transmission;

an actuating rod, an actuator sleeve defining a cylinder located at one end of said actuating rod;

a compression spring in said cylinder between said rod and said actuator sleeve adapted to resist relative movement between them;

said one rod end defining a piston movable within said cylinder, and said sleeve further defining a tapered shoulder;

a pawl mounted for oscillatory movement about a fixed pivot axis into and out of engagement with said gearwheel, said shoulder engaging said pawl to actuate the latter when said actuator rod is moved toward said gearwheel;

said cylinder being formed with a pneumatic fluid flow orifice between the interior of said cylinder and the atmosphere whereby relative movement of said sleeve relative to said actuator rod is cushioned.