import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,6))
r=w0.sketch().segment((-50,-22),(-41,-22)).arc((0,-46),(41,-22)).segment((50,-22)).segment((50,19)).segment((41,19)).arc((0,46),(-41,19)).segment((-50,19)).close().assemble().finalize().extrude(-12)