Spray coating methods

Claim 1

The method of externally coating a select portion of a cylindrical surface comprising the steps of positioning said portion of the surface adjacent a spray nozzle and at least one mask concentric with and surrounding the surface for defining a limit to said surface portion to be coated, shifting the mask transversely with respect to the surface so that the inner peripheral edge of the mask in the vicinity of the spray nozzle is in close proximity to the surface, and independently rotating the surface and the mask with respect to one another while applying spray material to said portion from the nozzle, said mask rotation being such that spray material collecting on the mask is centrifugally carried away from the inner peripheral edge thereof.

Claim 2

The method of externally coating select surface portions of cylindrical shells comprising the steps of conveying said shells to a preselected position in seriatim order, moving the first shell from said position into a work station with said surface portion being adjacent to a spray nozzle and at least one mask concentric with and surrounding the surface for defining a limit to said surface portion to be coated, shifting said mask transversely with respect to the surface so that the inner peripheral edge of mask in the vicinity of the spray nozzle is in close proximity to the surface, independently rotating said surface and the mask while applying spray material to said portion from the nozzle, said mask rotation being at a sufficient angular velocity to centrifugally carry accumulated material away from said inner peripheral edge, returning said first shell to said position after completion of the coating operation, advancing said shell out of said position and conveying a second shell to said position.