Housing arrangement 8 for a drill rig, especially adapted for damping sound, said drill rig comprising a feed beam holder 3, a feed beam 4 being movably attached to the feed beam holder 3 and having a drill end 41 and a rear end 42, and a drilling machine 5 being movably attached to and movably along the feed beam 4, said housing arrangement 8 comprising a casing 7, and said feed beam 4. A media reservoir stores the medium prior to discharge, and a conveying device includes a discharge opening and a dosage chamber. In the event of a collision, the breakaway link will break to reduce the likelihood of breakage of any other part of the coating head assembly. The center seat assembly may be configured to enable the mounting of a rearward-facing infant car seat when in a folded position.