GB692987A - Improvements in and relating to collapsible aerials - Google Patents

Abstract

692,987. Aerials. ULTRA ELECTRIC, Ltd. March 27, 1952, No. 7915/52. Class 40 (vii). A collapsable radio aerial comprises a plurality of juxtaposed leaves of spring metal of progressively decreasing length attached to one another at one common end and forming sections of progressively varying thickness the leaves of each section being kept together by connecting means allowing them to slide longi. tudinally relative to one another. The aerial is normally mounted at its lower end on, for example, the top plate F of a transducer and the leaves secured together at their top ends. For this purpose slots 1 may be provided right througt the leaves and pins 2a with suitable retaining heads passec through them. In a modification, Fig. 3 (not shown), a tongue extends from the top of each leaf (except the longest) and passes through a slot in the remaining leaf or leaves which it secures by being turned upwardly on the far side. In another modification, Fig. 4 (not shown), bands are welded to the top of the leaves and pass round and retain the remaining leaves. The aerial may be wound in a coil and retained collapsed by passing of the coil between the brackets 3 and retaining it by a pin passing through the holes 3a. The spring leaves are preferably arcuate in section, the aerial being collapsed by coiling it with the convex face outwards.