Method for labeling roofing shingles using binary coding scheme, and shingles produced by the method

Abstract

Information as to the location, date and shift of manufacture of roofing shingles is cut into an edge of the shingles as a coded sequence of slits. Preferably, the slit sequence is coded using a binary coding scheme, with a separate binary number group defining each of the shift, the month, the day and the year of manufacture, in addition to plant site identification information. Based on the easily-cut, binary-coded slit sequence, used in conjunction with the plant site identification information, a manufacturer can quickly isolate the time and place of a manufacturing defect. The method of providing a roofing shingle with a coded indication of the shingle's time of manufacture involves arranging a physically-ordered sequence of slit cutting knives, based on a sequence of binary digits, in which a slit cutting knife is provided in the physically-ordered sequence when a corresponding binary digit in the sequence of binary digits is a first value (e.g, 1), a slit cutting knife is omitted from the physically-ordered sequence when a corresponding binary digit is a second value (e.g., 0). The binary digits in the sequence of binary digits are arranged in plural fields that represent respective time periods collectively constituting the coded indication of the shingle's time of manufacture. The method also involves cutting the coded sequence of slits into the shingle using the slit cutting knives.

Dependencies are inferred from the claim text.