Patent ID: 6208785
Filing Date: 2001-03-27
Classification: G02B

Abstract:
An optical fiber cable comprising:a cylindrical spacer having on its surface holical grooves reversing their direction at a given pitch; anda stack of ribbon optical fibers received in said groove;wherein:the reverse angle .o slashed. of the groove is 210.degree..ltoreq..o slashed..ltoreq.330.degree.;the groove has a size to contain a virtual circle therein whose diameter D is represented by equation:D=(W.sup.2 +(N.multidot.T).sup.2).sup.1/2where W is the width of the ribbon optical fiber, T is the thickness of the ribbon optical fiber, and N is the number of the ribbon optical fibers stacked in a groove;the angle .theta. formed between each side walls of the groove and a line connecting the center of the bottom of the groove and the center of the spacer varies periodically; andthe angle .theta. of the side wall on the inner side of the curvature of the center of the groove increases continuously and monotonously at least over the part extending from a position distant from a helical portion between adjacent reverse portions at approximately 90.degree. in a circumferential direction to the next reverse portion.