Patent ID: 7594566

Claim:
A locking device ( 30 ) for preventing a rotating motion of a shaft ( 14 ) in relation to a housing ( 16 ) of a transmission/drive unit ( 10 ), said locking device ( 30 ) comprising a first locking element ( 32 ); a second locking element ( 34 ) that is movable in relation to the first locking element ( 32 ) by an electromagnet ( 44 ) and at least one return element ( 42 ) so that in a locked state the locking elements ( 32 , 34 ) engage with each other in an axial direction ( 15 ) by means of a form-locking engagement ( 85 ); at least one acoustic damping element ( 28 ) axially situated between the electromagnet ( 44 ) and the form-locking engagement ( 85 ); and an additional acoustic damping element ( 29 ) axially situated between the first locking element ( 32 ) and the second locking element ( 34 ) to reduce noise generation as the locking elements ( 32 , 34 ) engage with each other in said form-locking engagement ( 85 ).