United States of America As Represented by the Secretary of the Air Force

Eric L Pollard

Thomas W Murphey

A collapsible and deployable hierarchical open lattice assembly comprised of hinge boxes of 12 battens connected by hinge nodes. The hinge nodes are made of a plurality of resilient flexure joints, each joint connected to a batten and giving said batten a 90-degree in-plane rotation capability with a neutral-shaped flexure in a deployed state and a deformed-shaped flexure in a compressed state, whereby a restorative moment is created tending to return said flexure to its neutral state. One or more trusses are formed by sets of four longerons connected to the hinge boxes by the resilient flexure joints. Multiple hub boxes connected by longerons may be used to create a hierarchical truss of trusses in either two or three dimensions. These assemblies may be collapsed to a linear dimension by shearing the hub boxes and trusses in a parallelogram manner. The folding kinematics occur in three stages, which may be performed either sequentially or simultaneously. Initially the trusses connecting the hub boxes are sheared. Then the hub boxes and trusses are sheared in one common dimension to reduce the assembly to a two-dimensional, planar configuration. Finally the hub boxes and trusses are sheared in a perpendicular common dimension to reduce the assembly to a one-dimensional, linear configuration.

Deployable heirarchical structure

A self-deployable, monolithic, open-lattice frame structure of resilient, tape-spring members. The structure is comprised of three or more longitudinal prismatic tape-spring members (longerons) and non-prismatic tape-spring members (battens) that are connected transversely to the longerons. The longerons can be reconfigured in a z-folding manner to compact the structure. The batten members have a twist at each end of the same magnitude and sense, such that when connected to the longerons, the concave surfaces of the battens substantially face along the longitudinal direction of the frame structure. This batten shape permits them to nest within adjacent battens when the structure is compacted.

Tape-spring deployable boom

A resilient flexure has one end attached within a cavity in a rigid member, and the other end attached within a cavity in a structural mode. The cavities are shaped to limit the flexure's bend radius. The member and the node have mating surfaces that abut to constrain the amount of rotation of the member. The aforementioned elements are shaped to prevent the strain in the flexure from exceeding its design limit when the joint is at its maximum angular deflection and the attached member is fully collapsed.

Resilient joint for deployable structures

A tape-spring shaped, articulating member used in deployable structures having a resilient, compliant hinge region and rigid non-hinge regions, thereby enabling a smaller fold radius and greater packaging efficiency. The increased compliance in the hinge region may be obtained by using a more compliant material in the hinge region or reducing the cross-sectional area in the hinge region. The hinge region may be reinforced with integrated shape memory alloy features serving as folding mandrels, to enhance structural stiffness and strength performance of the hinge, and to exhibit authority over the rate and sequencing of strain release when deployed.

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Albuquerque, NM, United States of America

Eric L Pollard