Automatic transmission parking brake for road vehicle has pawl engaging toothed wheel and pushed into engagement by electric motor driving threaded spindles and knee linkage

摘要

The parking brake mechanism has an electric motor (20) driving oppositely-threaded spindles (54,55) with nuts (56,57) hinged (51,52) to straight links (48,49). The ends of the links are hinged together to make a knee linkage (46) moving at right-angles to the spindles. A spring (28) pushes on a hinged link (40) on a pawl (2) with a tooth (41) engaging a toothed (42) wheel (3) on the gearbox output shaft.