Abstract:
A collapsible-expandable truss structure 16 including first and second spaced surface truss layers (18, 20) having an attached core layer 22 is disclosed. The surface truss layers are composed of a plurality of linear struts 40 arranged in multiple triangular configurations with each linear strut being hinged at its center 41 and hingedly connected at each end thereof to a nodular joint 25. A passive spring 64 serves as the expansion force to move the folded struts from a stowed collapsed position to a deployed operative final truss configuration. Damper 62 controls the rate of spring 64 expansion for synchronized deployment of truss 16 as the folded configuration is released for deployment by restraint belts 72a and 73a synchronously extending under the control of motor (71) driven spools 72 and 73.
Abstract:
Metallized sheet-form textile materials of synthetic polymers or natural fibres, to which a metal layer has been applied by currentless wet-chemical deposition, are particularly suitable for use as reflectors for electromagnetic waves in the range from 10 MHz to 1000 GHz. In the case of stretched metallized fabrics, the reflecting radiation is partly polarized which can facilitate or improve the recognition of an object by radar beams. By periodically stretching and relaxing the fabric, it is even possible to modulate the reflected microwaves.
Abstract:
In order to provide coverage of a full 360 degrees of azimuth even when heeled a radar reflector consists of ten trihedral reflectors directed outwardly of a major axis the inner eight of which are formed in vertically displaced pairs of dihedral reflectors sub-divided by a divider portion which reflectors are positioned such that the apexes of the two central dihedral reflectors are relatively displaced about the major axis by an angle a and the apexes of the dihedral reflectors on each side of the central reflectors are displaced relative to the nearest apex of a central dihedral reflector each by an angle different to a, the arrangement being such that the spacing between the central axes of reflection of adjacent trihedral reflectors is in the range 25 degrees to 45 degrees. The reflector is suitable for use on small boats and other vessels and marine buoys.
Abstract:
Metallized sheet-form textile materials of synthetic polymers or natural fibres, to which a metal layer has been applied by currentless wet-chemical deposition, are particularly suitable for use as reflectors for electromagnetic waves in the range from 10 MHz to 1000 GHz. In the case of stretched metallized fabrics, the reflecting radiation is partly polarized which can facilitate or improve the recognition of an object by radar beams. By periodically stretching and relaxing the fabric, it is even possible to modulate the reflected microwaves.
Abstract:
A reflector for high gain antennae comprising a plurality of generally triangular shaped petals joined in edgewise overlapping relation, wherein the overlap gradually increases from rim to center of the reflector, so as to provide a mechanically stable paraboloid configuration. The petals are supported by a rigid rim structure constructed of preformed tubular sections.
Abstract:
A mechanism for deploying and retracting an isogrid structure particularly suited for use in supporting low weight reflective or absorbtive surfaces, characterized by a plurality of hinged isogrid panels stowed in an accordian folded stack arranged for automatic deployment into a long continuous strip or array. Two deployment arms in contact with the stack of panels are rotated to a position perpendicular to the stack, carrying with them the first panels. Thereafter the panels are extended by powered sprockets which engage the panel edges. A shutter bar sequentially releases pairs of panels during deployment. For retraction, the sprockets drive the panels back toward the stack where a creaser bar hinges pairs of panels which are thereafter folded into a stack by means of the shutter bar capturing and stowing each folded pair of panels.
Abstract:
This invention relates to an expandable truss paraboloidal antenna structure in which the truss structure of the reflector comprises hinged struts that form interconnecting, hinged, triangular truss modules that are aligned in two geometric planes with the struts terminating at junctions on the inner and outer surfaces of the paraboloidal shaped structure. The combination of hinge struts is packaged in a compact unit and then is deployed by being automatically unfolded outwardly by spring means in certain of the hinges.