Abstract: In a crop stripping apparatus for harvesting grain from standing crop, the height of an overhead hood (18) is adjusted in response to the position of the top of the crop. A sensor housing or nose (34) protrudes forwardly from the hood (18) and has a sloping undersurface (35) which contacts the crop. A pair of cooperating sensors (37) and (38) sense the position of the top of the crop by contact of one or both or neither of the sensors with the top of the crop. The crop slides along the undersurface (35) of the nose (34) with minimum disturbance to the grain heads by the effect of the sensing operation. The nose (34) is mounted in such a manner that the undersurface (35) is maintained at a constant inclination to the ground during vertical movement of the nose (34).