Patent ID: 8268431

Claim:
A substantially seamless lengthened bamboo sheet, formed by lengthening a plurality of bamboo strips or blanks and assembling a plurality of lengthened bamboo strips or blanks together, the sheet comprising a first sheet surface defining a first plane and an opposing second sheet surface defining a second plane, said sheet is characterized by: a slot is formed on at least one end of each bamboo strip or blank, and a tenon corresponding to the slot is formed on the same end, wherein the slot and the tenon are located at said one end in locations distributed in the direction of length of said each bamboo strip or blank with the slot located inward from the tenon; wherein said slot and said tenon are mutually matched in shape, and the tenon on one bamboo strip or blank is embedded into the slot on another bamboo strip or blank at a joint for forming a lengthened bamboo strip or blank, and wherein the shapes of the tenon and the slot are such that an acute-angle inward incline is formed on an end edge of said tenon, and a corresponding incline is formed on an inner edge of said slot to match said inward incline of the tenon, the incline on the tenon arranged to meet the first sheet surface on the first plane at a first acute angle and the incline on the slot arranged to meet the second sheet surface on the second plane at a second acute angle, and wherein the slot and the tenon are shaped to prevent the joint from disengagement along the direction of said length.