GB368979A - Improvements in or relating to wireless aerials - Google Patents

Abstract

368,979. Lattice-mast aerials. BLAW KNOX, Ltd., New Oxford House, Hart Street, Holborn, London.-(Assignees of Gerten, N. ; Douglaston, New York, and Jenner, R. L. ; East Orange, New Jersey, both in U.S.A.) March 5, 1931, No. 6936. Convention date, July 29, 1930. [Class 20 (i).] A mast capable of use as a wireless antenna, is supported primarily at its base and secondarily at one level only at or below the mid elevation of the mast, the secondary supports comprising either tension wires or strutting frames. The mast is of lattice construction formed from L uprights 11 disposed at the corners of a polygon and connected by cross bracing 14, the overlapping joints between the upright and the joints between the bracing members and the uprights being riveted and made with soft metal packing 53 which flows during the riveting operation and ensures good metallic connection at the joints. The lower ends of the main members 11 are riveted to a shoe 15 having a ball- and-socket connection with a pedestal 23 supported on three insulators 25 from a ground plate 28 or, alternatively, by a single cylindrical insulator. The mast is stayed by tension guys 31 connected by insulators 34 or, alternatively, 'by strut frames, the connections to the mast being in one plane, which is preferably the one from which the diameter of the mast lessens towards both ends. The length of the mast may be varied by the use of a pole 40 adjustably supported in a bracket 50 at the top of the mast, and platforms 41 and climbing ladders 46 are placed within the mast so as to provide access thereto. The pole is erected by first erecting an upper part of the mast as a temporary part 70 whereby the part 71 may be erected and stayed and then the part 70 can be placed in its final position. A good grounding for an antenna is formed of ground wires 80 disposed at about two feet apart connected by bonding wires 81 about the foundation 82 of the antenna, the diameter of circle or side of square of the grounding being about twice the height of the antenna.