GB531339A - Machine for electrically heated metal bars and tubes - Google Patents

Abstract

531,339. Heating metals by electricity; couplings. SOC. ANON LOUVROIL MONTBARD AULNOYE. July 18, 1939, Nos. 20887 and 20888. Convention dates, July 27, 1938, and Sept. 6. 1938. [Class 39 (iii)] [Also in Group XXXVI] Metal bars or tubes p heated by passage through them of intense alternating current, which is led to the contact blocks f, g at the end of the bars by conductors formed as sectorshaped elements d forming together one or more hollow concentric cylinders horizontally adjustable on two coaxial opposed electrode supports one of which is fixed while the other is movable axially. Current is led to the machine by two adjacent annular discs 8, 9 insulated from each other, the disc 9 being connected by a flexible conductor 11 formed from copper foils with the cylinder d forming an electrode E' pressed against the bar p hydraulically or by a spring through a contact g which is water cooled at 7, and has a heat screen 6. Current is conducted from the disc 8 through a circle of brushes 12 pressed hydraulically or by spring on a metal cylinder 13, whence current passes through a similar ring of brushes 14 pressed on the cylinder by a spring 15 to a disc c and cylinder d to the contact g and so through the bar. The brushes are water-cooled and may be lifted by a cam on or off the cylinder. Flexible laminar copper connections 11 are introduced where shown. The electrodes are pressed through their heads T1, T2 against the end of the bar, and one electrode and the cylinder 13 slide and are horizontally adjustable on slides 23 on the bed of the machine. The brushes may press on the ends or inner surface of the cylinder 13 which is internally lined with refractory material 13b and cooled by metal pipes 27a. The cylinder normally moves with the electrode E2 and has slots 25 for water-cooled fingers 24 which move vertically and support the bar p until held by the electrodes, when it is heated to the desired temperature adjusted by a photo-electric cell. The bar is removed on sideways displacement of the cylinder, which may have a slot along its length for the fingers 24. This slot may be wide enough to allow the bar p to pass up or down therethrough and may be closed during heating by a cap from which the bar may hang. The cylinder may be hinged along its length and open to allow removal of the bar from the fingers, or be in two halves sliding laterally. The cylinder may be vertical and be lifted off the bar, which may be withdrawn downwards, being held by a fork on the lower electrode. The brushes may be replaced by flexible conductors welded thereto when the relative movement of the cylinder and the current supply members is small or nil. The cylinder may be telescopic with several rings of brushes, at least one such ring being rigid with one part of the cylinder. The brushes may however press on the electrodes.