Where lower door part optionally moves independently, or follows as component the

Official title: {where lower door part optionally moves independently, or follows as component the movement of the entire door structure, e.g. by being hinged in a door frame or releasably connected to upper door part}

B60J5/104 (Where lower door part optionally moves independently, or follows as component the) appears on 23 US grants and 25 published applications in this corpus.