Nikola Tesla U.S. Patent 1,119,732 - Apparatus for Transmitting Electrical Energy Patent Wrapper Page 71

1 OLDU tion is called to the fact that the streamers, issuing from the wire, are apt to gradually heat the support and thus impair its insulating qualities or else, by slowly crawling over its surface, establish a good conducting path, permitting in either case the high pressure current to follow and to cause damage. But if, in accordance with this invention, the insulator is provided with a conducting ccating on the outside, such injurious action will be rendered impossible. This way of supporting high tension lines is both cheap and reliable. Obviously, in all cases, the insulating supports of the terminals, hoods or shells should be carefully protected from water. When practical conditions render it necessary to use a greater terminal capacity than can be conveniently obtained with one piece of metal, or with a smooth and unbroken surface, I either employ a number of shells as a properly arranged, or make up a terminal of a plurality of elements each having a sufficiently large radius of curvature. Such a construction is shown in Fig. 5, in which the terminal D consists of a suitably shaped metallic frame, in this case a ring of nearly circular cross section, which is covered with half spherical metal plates 22, thus constituting a very large conducting surface, smooth on all places where the electric charge principally accumulates. The frame is carried by a strong platform which is expresslyprovided for safety appliances, instruments of observation, etc., which in turn rests on insulating supports F F. These should penetrate far into the hollow space formed by the terminal, and if the electric density at the points where they are bolted to the frame is still considerable, they may be specially protected by conducting hoods a4, similar to those before described. described. (5) 73 371-69 767