Abstract: The apparatus for applying granules to a coated asphalt sheet has a nozzle for holding an accumulation of granules, an opening at the bottom of the nozzle for discharging the granules onto the coated asphalt sheet, a buffer chamber positioned in communication with the accumulation of granules, and a vacuum source for reducing the pressure in the buffer chamber to stop the flow of granules through the opening.

Abstract: A method for applying granules to a moving asphalt coated sheet includes providing a nozzle for discharging granules onto a sheet having first and second edges. The nozzle is mounted for movement along a path which traverses the sheet and extends beyond the first and second edges to define first and second extension locations beyond the edges. The nozzle is moved along the path, and the discharge of granules is begun while the nozzle is adjacent or opposite the first extension location, and the discharge of the granules is ended after the nozzle has traversed the asphalt coated sheet and reached the second extension location so that the beginning and ending of the granule discharge do not occur between the first and second edges. The path and the speed of the nozzle can be adjusted so that the deposit of the granules applied to the sheet has a predetermined shape.

Abstract: A method and apparatus for applying granules to a coated asphalt sheet to form at high production speeds a variegated pattern having uniform edges between areas of different colored granules. Granules of a first color or color blend are applied to spaced first areas on a moving, tacky, asphaltic strip by dropping the granules onto the moving strip. The leading and/or trailing edges of each granule drop are trimmed off by cutting or deflecting to provide predetermined sharp leading and/or trailing edges to the first areas. Granules of a second color or color blend are then deposited on the strip by dropping on tacky second areas between the spaced first areas. If desired, one or both edges of the second color granule drops also may be trimmed, the second color granules may be deposited on only a portion of the tacky strip areas between the spaced first areas, and additional color granules may be applied to the remaining tacky areas to form shingles with three or more colored areas.