Abstract A lightweight precision dish structure for reflectors, particularly large parabolic microwave reflectors for space applications. The dish structure has a laminated reflector dish with a central core and bonded facing sheets of differing coefficients of thermal expansion, and a rigid reinforcing ring secured by adjustable fastening means to the rear convex side of the reflector dish and having a coefficient of thermal expansion closely approximating the resultant coefficient of the dish. The reinforcing ring and its adjustable fastening means permit initial adjustment of the dish to a precise parabolic or other configuration and prevent later thermal distortion of the dish as a consequence of the differing coefficients of its core and facing sheets in an adverse, asymmetric thermal environment.
A lightweight precision reflector dish structure comprising a laminated reflector dish including a central core having a front concave face and a rear convex face, and facing sheets conforming and bonded to said core faces: said core and facing sheets having differing coefficients of thermal expansion such that said dish tends to creep in a thermal environment, thereby creating wavelike distortions within a concentric annular region of said dish adjacent its rim; a relatively rigid reinforcing ring of smaller diameter than the rim diameter of said dish concentrically surrounding the rear side of said dish within said annular region; adjustable fastening means joining said ring and dish at a number of positions uniformly spaced about said ring; said fastening means being adjustable to remove said distortions and conform the front facing sheet to a selected surface of revolution; and said ring having a coefficient of thermal expansion closely approximating the resultant coefficient of thermal expansion of said dish.
Claim 2
Dependent Claim
158 words
A lightweight precision reflector dish structure comprising a laminated reflector dish including a central core having a front concave face and a rear convex face, and facing sheets conforming and bonded to said core faces: said core and facing sheets having differing coefficients of thermal expansion such that said dish tends to creep in a thermal environment, thereby creating wavelike distortions within a concentric annular region of said dish adjacent its rim; a relatively rigid reinforcing ring of smaller diameter than the rim diameter of said dish concentrically surrounding the rear side of said dish within said annular region; adjustable fastening means joining said ring and dish at a number of positions uniformly spaced about said ring; said fastening means being adjustable to remove said distortions and conform the front facing sheet to a selected surface of revolution; and said ring having a coefficient of thermal expansion closely approximating the resultant coefficient of thermal expansion of said dish.
Claim 3
Dependent Claim
33 words
A reflector dish structure according to claim 1 wherein: said fastening means comprise screws passing through said ring and threaded in said dish and adapted to receive shims between said ring and dish.