crown gear
gear which has teeth that project at right angles to the face of the wheel, allowing rotary motion to be shifted 90 degrees
en-GB/ˈkɹaʊn ˈɡɪə/
en-US/ˈkɹaʊn ˈɡɪɹ/
gear which has teeth that project at right angles to the face of the wheel, allowing rotary motion to be shifted 90 degrees