Abstract: A method for electrically connecting two electrical lines. Each electrical line contains at least two electrical conductors that are insulated from each other, and one common sheath surrounding the electrical conductors. One of the two lines (2) is equipped with insulated conductors and is flexible, while the other line (1) has a stiff, tubular metal sheath. To produce a moisture-proof connection between the conductors of the electrical lines, first the sheath is removed from a section of the conductors of the flexible line (1) and insulation is removed from the conductors so that the ends are bared. The conductors prepared in this manner are placed in a flexible rubber seal (10) containing passage holes to separate the conductors. After that, the conductors of the flexible line (1) are electrically connected to the conductors of the other line (2) which protrude from the metal sheath. A metal tube (13) is then positioned over the entire connection area.

Abstract: In a method for producing internally grooved tubes for heat exchangers, a smooth metal tape is drawn from a circular supply, a rolling mill provides it with a number of grooves that are parallel to each other and run at an angle of 15.degree. to 45.degree. with respect to the lengthwise direction of the tape, the tape is continuously formed into a tube with a lengthwise slot, and the slot is welded. At least two groups of parallel grooves are rolled into the surface of the metal tape so that the grooves form a herringbone pattern.

Abstract: In a method for producing a lengthwise welded metal tube with an outside diameter of 1 to 6 mm, whereby a metal band is shaped into a lengthwise slotted tube by a forming tool, and the lengthwise slot of the tube is welded by a laser welding installation, the tube to be welded passes immediately before and immediately after the welding point area through a guide that guides the surface of the tube to keep the edges of the band in contact with each other and keeps the welded seam stress-free. The jaws of a clamping tool grip the welded tube immediately downstream of the guide to keep it from twisting.

Abstract: An electrical overhead cable includes: cabled electrical conductors (3); tensile strength support elements (1, 2); and optical waveguide elements made of metal coated tubes (4) containing optical fibers (9). The metal coating on the optical fiber-containing tubes is a thin, self-enclosed metal layer (5), which is in direct contact with the surface of the tube (4).

Abstract: In a device for welding thin metal sheets passing thereunder and, more particularly, a stationary, water-cooled welding device for welding the lengthwise edges of a metal band formed into a tube, under protective gas, with the aid of one or more non-fusing electrodes (10) located in the welding head, each electrode (10) is held by an electrode clamp (5) in a burner housing (1). The electrode clamp (5) is held in the burner housing by a clamp holder (3). A tube-shaped clamping rod (7) is located in a central passage of the clamp holder (3). The electrode (10) is held by a slotted end of the tube-shaped clamping rod (7). This enables the electrode (10) to be pulled upwards out of the clamp holder (3), together with the clamping rod (7).