Method for construction of a truss structure
AssigneeGeneral Electric Company
InventorAnthony P. Coppa
Life of this patent
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Abstract
A truss structure for use in a gravity-free environment is disclosed together with methods and apparatus for constructing the same. The structure, characterized by high stiffness and a precise self-determined geometry and having a prism-form with square right cross section, is constructed from a plurality of substantially identical triangular frame elements. The truss structure may be manually constructed from a multi-row chain of interconnected elements or from a four row network of elements. The structure may also be constructed using an automatic method wherein individual frame elements are fed from four stack support and feed units to a holding fixture having a square cross section.
Claims12
A method for constructing an elongate prism-form truss structure including a square cross section and four longitudinal edges parallel to a central longitudinal axis, said structure being constructed from a plurality of separate, planar, congruent, triangular frame elements each having A-, B- and C-sides opposite A-, B- and C-vertices respectively, the dimensions of each of said elements being defined by:
- ##EQU1## where .alpha.=included angle at A-vertex of <90.degree.,
- B length of B-side,
- C length of C-side, and
- N integer >1;
- said method comprising the steps of:
- (1) positioning said elements such that for each triad of elements to be joined the first and second elements lie in the same plane with their respective PG,38 C-sides aligned along one of said longitudinal edges and the third element is perpendicular to said last-recited plane, said positioning step placing the A-, C- and B-vertices of said first, third and second elements respectively in order adjacent one another along said one longitudinal edge;
- (2) joining said adjacent A-, C- and B-vertices to form a hinged joint;
- and
- (3) repeating steps (1) and (2) for successive triads of elements unilt a truss structure of the desired length has been constructed.
A method for constructing an elongate prism-form truss structure from a plurality of separate, planar, congruent, triangular frame elements, each of said elements having A-, B- and C-sides opposite A-, B- and C-vertices respectively, said A- and B-sides of each of said elements being substantially equal in length and said C-side being substantially 2/ .sqroot.3 times one of the shorter sides, said method comprising the steps of:
- (1) forming a chain of said elements having first and second parallel rows, said chain including successive pairs of mutually aligned C-sides to define a succession of parallel folding lines when said rows are positioned in a common plane, each A-vertex in each row of said chain being hingedly joined to the C-vertex of the adjacent element and each B-vertex in said first row forming a hinged joint with the proximate pair of hingedly joined A- and C-vertices in said second row;
- (2) in unison rotating the elements bordering the first one of said succession of folding lines in a predetermined sense through substantially 90.degree.;
- (3) at each successive folding line, simultaneously rotating the elements bordering said folding line, each of said rotations which occurs subsequent to the third rotation placing a hingedly joined pair of A- and C-vertices in said first row adjacent the B-vertex of one of said elements in said second row in position to form a hinged joint;
- (4) locking said rotated elements following each of said rotations;
- (5) joining the C-vertex of the first element in said first row of said chain to the proximate B-vertex of an element in the second row of said chain;
- and
- (6) upon each successive 90.degree. rotation, joining each said pair of hingedly joined A- and C-vertices in said first row to the adjacent B-vertex in said second row by forming a hinged joint therewith so as to close said truss structure;
- whereby the truss structure formed has a square cross section and four longitudinal edges formed by said folding lines parallel to a central axis.
A method for construction an elongated prism-form truss structure from a plurality of separate, planar, congruent, triangular frame elements, each of said elements having A-, B- and C-sides opposite A-, B- and C-vertices respectively, said A- and B-sides of each said element being substantially equal in length and said C-side being substantially 2/.sqroot.3 times one of the shorter sides, said method comprising the steps of:
- (1) forming a network comprising four rows of said elements disposed substantially in a common plane wherein the C-sides of the elements in the respective rows are mutually aligned so as to form a succession of folding lines in said plane, said network forming step comprising the further steps of:
- (a) hingedly joining the A-vertex of each element within each row to the B-vertex of the adjacent element in said row;
- and
- (b) forming a hinged joint between the C-vertex in each row and the proximate pair of hingedly joined A- and B-vertices in the preceding row, if any;
- (2) rotating the elements in the fourth row of said network in unison in a predetermined sense through substantially 90.degree. about their bordering folding line;
- (3) locking the elements in said fourth row against further rotation;
- (4) rotating the elements in the third row of said network in unison in a predetermined sense through substantially 90.degree. about their bordering folding line;
- (5) locking the elements in said third row against further rotation;
- (6) rotating each of the elements in said first row in the opposite sense through substantially 90.degree. about its corresponding folding line, whereby each C-vertex in said first row is brought adjacent a pair of hingedly joined A- and B-vertices in said fourth row;
- (7) locking each element in said first row against further rotation;
- and
- (8) joining each pair of hingedly joined A- and B-vertices in said fourth row to the adjacent C-vertex in said first row by forming a hinged joint therewith so as to close said truss structure;
- whereby said elongate truss structure has a central axis, a square cross section and longitudinal edges parallel to said central axis formed by said folding lines.
Dependencies are inferred from the claim text.