Abstract: A connector for connecting an optical fiber cable to an equipment adaptor, a flexible metal tube clad optical fiber cable including a flexible metal tube through which an optical fiber core rod extends and which is used for connection with an equipment, a relay adaptor for providing a connection between cables of different kinds, and a seamless metal tube clad optical fiber cable including a seamless tube through which an optical fiber core rod extends and which is used for wiring over a relatively long distance are disclosed individually and in combinations. The connector is connected to the flexible metal tube clad optical fiber cable, which is then connected through the relay adaptor to the seamless metal tube clad optical fiber cable. A certain element of the connector is formed of an insulator to provide an electrical isolation between the metal tube and the equipment adaptor.

Abstract: A coil of a tube is formed. The coil is vibrated while a threadlike piece is passed in through the inlet end of the tube so that a given point of the tube reciprocates along a helical path. Provision is made to ensure that inlet end of the tube does not cause a portion of the threadlike piece upstream of and close to that inlet end to move diametrically while being fed into the tube. Provision is also made to form a coil of the threadlike piece, from which the threadlike piece is pull out along the axis of the coil and fed to the inlet end of the tube by a conveying force resulting from the vibration of the coil of the tube. A feeder to supply the threadlike piece into the tube may be provided between the inlet end of the tube and a coil feeding device.

Abstract: A coil of a tube is formed. The coil is vibrated while a threadlike piece is passed in through the inlet end of the tube so that a given point of the tube reciprocates along a helical path. Provision is made to ensure that inlet end of the tube does not cause a portion of the threadlike piece upstream of and close to that inlet end to move diametrically while being fed into the tube. Provision is also made to form a coil of the treadlike piece, from which the threadlike piece is pulled out along the axis of the coil and fed to the inlet end of the tube by a conveying force resulting from the vibration of the coil of the tube. A feeder to supply the threadlike piece into the tube may be provided between the inlet end of the tube and a coil feeding device.

Abstract: The stream of the gas carries a thread held in the sealed container forward into and through the tube. The pressure of the gas in the sealed container is kept high enough to maintain the mean flow rate of the gas at any given point of the tube above the travel speed of the thread. A positive longitudinal surging motion is given to the thread advancing through the tube. A frictional force between the flowing gas and the peripheral surface of the thread, a static pressure working on an area corresponding to the cross-sectional area of the thread, and a difference between the static pressures on both sides of the surging portion of the thread work together to carry the thread forward.

Abstract: A method of inserting a thread through a tube, the stream of the gas carries a thread held in a sealed container forward into and through the tube. The pressure of the gas in the sealed container is kept high enough to maintain the mean flow rate of the gas at any given point of the tube above the travel speed of the thread. A positive longitudinal surging motion is given to the thread advancing through the tube. A frictional force between the flowing gas and the peripheral surfade of the thread, a static pressure working on an area corresponding to the cross-sectional area of the thread, and a difference between the static pressures on both sides of the surging portion of the thread work together to carry the thread forward.