Patent ID: 6092345
Filing Date: 2000-07-25
Classification: B44C,E04D

Abstract:
A method of cutting a multi-layer shingle comprised of an anterior layer and a posterior layer, to have a natural, random appearance comprising the steps of:conveying an anterior sheet of shingle material along a predetermined longitudinal path, past a first cutting roll;cutting the anterior shingle layer longitudinally with the first cutting roll as the sheet of shingle material is delivered therepast by cutting the anterior shingle material into an upper headlap area and a lower tab area, with the tab area comprising a plurality of tabs separated by longitudinally space apart slotted openings;severing both anterior and posterior layers of material transversely to predetermined spaced apart lengths L, measured longitudinally;and wherein the step of cutting the anterior shingle layer longitudinally includes cutting a predetermined cutting design therein for the tab area of the anterior shingle layer, with said design having a repeatability occurring longitudinally, with said repeatability R in the longitudinal direction, being defined by the formula: ##EQU5## and where x=the number of full tabs in the anterior shingle layer and wherein any two partial tabs at ends of the shingle layer count together as a full tab; and where n=a whole number no smaller than -50, no greater than 50 and not equal to zeros;whereby the design repeatability in the longitudinal direction is different than the length of the shingle in the longitudinal direction, enabling a seemingly random appearance to shingles when laid-up on a roof.