Abstract: A radiation concentrating solar energy collector and a dual axis tracking support system which positions collector units to receive the maximum incident solar radiation are disclosed. A system of pressurized air is utilized as a multiple function medium which activates the tracking mechanism, inflates and supports the reflective concentrators and acts as the heat transfer medium.

Abstract: This invention reduces the weight and bulk of the hiker's backpack by eliminating the sleeping bag as a separate item. This is accomplished by providing insulating walls in the knapsack and providing the knapsack with a foldable insulating extension so that the insulated elongated knapsack can be attached to the bottom end of a parka to provide a continuous enveloping sleeping bag.

Abstract: A tightening and sealing device is made from plastic material and includes two members which can be coupled to each other. The member acting as the tightening element includes an internally threaded hollow cylinder divided into three cylindrical segments by longitudinal and axial slots spaced from each other by 120.degree.. Each segment has extending outwardly from an end thereof and centered between adjacent slots a flexible leg. The legs are joined to the end of an outer body which is concentric with the cylinder and which is internally cylindrical and externally polygonal. The second member which acts as the sealing element is composed of a cap-shaped element having an axial bore and an annular flange dimensioned to fit into a space between the concentric bodies forming the tightening element.