import cadquery as cq
w0=cq.Workplane('XY',origin=(0,0,-9))
r=w0.workplane(offset=-41/2).cylinder(41,39).union(w0.sketch().segment((-37,-4),(-34,-4)).arc((-32,-3),(-30,-4)).segment((-7,-4)).segment((-29,-44)).segment((-22,-48)).segment((2,-4)).segment((37,-4)).segment((37,4)).segment((7,4)).segment((29,44)).segment((22,48)).segment((-2,4)).segment((-18,4)).arc((-27,2),(-37,3)).close().assemble().finalize().extrude(59))