The plate-like flexible member is pressed against a wall by a number

Official title: {the plate-like flexible member is pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the plane of the plate-like flexible member and each having its own driving mechanism}

F04B43/021 (The plate-like flexible member is pressed against a wall by a number) appears on 43 US grants and 34 published applications in this corpus.