Abstract: An optical fiber path joint member according to the present invention includes a main path having an inlet and an outlet at respective ends thereof; and at least one joint path joining to the main path in one direction at an angle of equal to or less than 45.degree.. A method of blowing an optical fiber is comprised of the step of blowing an optical fiber into a pipe through the optical fiber path joint member according to the present invention.

Abstract: A tube sheet is formed by integrating a plurality of tubes into the form of a sheet. The tube sheet is constricted in junction portions of the respective tubes so that the tube sheet is deformed in these junction portions. At least one such tube sheet is disposed around a center member to form a tube-aggregated cable.

Abstract: In an optical cable according to the present invention, a grooved spacer has a plurality of grooves in its circumference, and the cutting direction of the grooves is inverted at predetermined periods. Optical fibers are received in the respective grooves. On the circumference of the grooved spacer, a linear member is provided around the grooved spacer along the longitudinal direction of the optical cable at a predetermined period. The linear member is fixed to the grooved spacer by welding or bonding in the portions where they touch the outer circumferences of the grooved spacer so as to restrain the optical fibers. The linear member restraining the optical fiber to be taken out are cut in positions above the groove in which the optical fiber is received so that the required optical fiber can be taken out.

Abstract: Disclosed is a method of fusion splicing single-mode optical fibers, in which an offset distance D, between the axes of the optical fibers subjected to fusion splicing, is measured when the axes of the cores of the optical fibers are aligned with one another. The arc discharge time, current and/or energy is determined according to the measured distance D.

Abstract: A pair of V-shaped slot blocks mounted movably on a base in both the X and Y directions and a microscope for observing the opposed state of optical fibers contained on the blocks, are provided in an apparatus for fusion splicing optical fibers. The microscope is mounted movably in the X and Y directions under a base, thereby observing the opposed states of the optical fibers from below.