above the plate 75 are a bearing flange 79 a collar spacer 78 and a retaining ring 80 respectively the latter engaging an annual groove in the part 76b surrounding the screw 76 below the screw support 75 is a thrust bearing 81 and a collar spacer 78 mounted on the bottom of the plate support 72 and secured by cap screws 76 is a horizontally protruding foot plate 73 having its underside provided with alternating elongated ribs 73a 73b 73c and grooves 73d 73e and 73f respectively in operation the support plate 72 is set to a desired height and clamped in position by the cone point socket set screws 82 then labyrinth foot 73 is manipulated up or down as desired through rotation of screw 76 to set the gap above the substrate carrying the coating layer to be cured fig5 and 6 show in detail the applicator device for applying the curing vapor this includes a housing 84 extending within the chamber a and receiving vapor from a supply conduit 86 the housing 84 extends downwards to supporting footings 80 resting on cross members 88 on each side of the chamber a so that the housing 84 extends across the belt b slidable vertically within the housing 84 is an applicator nozzle chamber 89 having vertical sides 80 which slide against the sides of the housing 84 the nozzle chamber 89 has an inwardly extending part.