Abstract: A TV camera picks up images of the first and second polarization-maintaining optical fibers, while light is irradiated to their side. First and second values are calculated based on the luminance peaks of the images by using an image processing unit connected to the TV camera. The axes of respective cores and respective stress applying members of the polarization-maintaining optical fibers can be easily aligned by moving the fibers such that the first and second values displayed on said display are equal.

Abstract: An optical fiber clamp, having a plurality of V-shaped grooves, stores coated optical fibers in the respective V-shaped grooves. The coated optical fibers are held by a pressing force of the clamp. A cushion portion, having an abrasion-resistant smooth film layer, is provided on the side of an optical fiber pressing surface of the clamp. The cushion portion applies a constant pressure to the optical fibers through the abrasion-resistant smooth film layer and absorbs any differences in the outer diameters and other dimensional peculiarities of the optical fibers. Thus, the optical fibers in the V-shaped grooves can be arranged and held uniformly, so that a batch fusion and connection can be performed on a multicore fiber with a minimum loss of connection. The optical fiber clamp minimizes axial displacements of respective optical fibers.

Abstract: A cable connecting box for accommodating and protecting the connecting portion of cables in narrow spaces while allowing any branch cables to be led out in a free direction from the cable conecting box. The structural arrangement of the cable connecting box has the following features: (1) an opening is formed at one side wall of a two-split case whereby the longer side edges of the opening are facing each other in the depth-wise direction of the case; (2) a core plate of an elastic material which fits between the casing halves seals the casing water-tight; (3) a plurality of cable receptacles are formed between the core plate and each of the casing halves by combining the semicircular grooves of the core plate with the semicircular grooves which are formed in the longer side edge of the opening in a manner to face the former semicircular grooves.

Abstract: A method and apparatus for connecting optical fibers using a grooved steel wire to position a pair of guide sleeves and a fitting sleeve into which a pair of optical fibers may be inserted so that end portions thereof bear against each other. A thermal melting adhesive sleeve and a thermal shrinking tube are provided to cover the steel wire, the guide sleeves and the fitting sleeve so that when the thermal melting adhesive sleeve and the thermal shrinking tube are heated, the thermal shrinking tube is shrinked while the adhesive sleeve is melted to integrate the steel wire, the fitting sleeve, the guide sleeves and the optical fibers with each other.

Abstract: A closure with improved sealing end surface plates for enclosing connecting portions of a plurality of sizes of a communication cable. The closure includes a sleeve-like closure body divided longitudinally into portions. The two portions are fastened and sealed. Grooves are formed on an inner surface of the closure body at opposite ends thereof to accommodate the sealing end surface plates interposed between the cable and the closure body. Each of the sealing end surface plates includes an annular rubber end plate and a pair of plastic side plates.

Abstract: A movable cable plow for dredging an underwater cable groove in a sea bed is disclosed wherein the plow is attached to a main body adapted to be pulled across the sea bed, such that it is adjustable vertically and angularly with respect to the main body. This allows the acurate control of the depth of the dredge groove. Also, a cable guide is pivotably attached to the plow, by way of a torsion spring hinge pin, so as to swing laterally with respect to the plow. This minimizes the lateral forces transmitted to the main body during the turning of the apparatus and, thereby, reduces the chances of the main body tipping over during the turning operation.