Abstract: An apparatus for attaching external stores or loads on a thin walled pole includes a first, open ended and externally threaded hollow sleeve defining a shoulder at one end, and a second, open ended and internally threaded hollow sleeve. An elliptical disk mounted to one end of the second sleeve defines a second shoulder. An other end of the first sleeve is threadable in an other end of the second sleeve to form a hollow sleeve assembly of variable length. The elliptical disk has an elliptical projection which fits in an elliptical hole of a thin walled pole when the hollow sleeve assembly is fitted therein. By using an external tool to relatively rotate the first and second hollow sleeves, one can tighten the hollow sleeve assembly to provide an expansive prestress and support for a bolt which passes through the hollow sleeve assembly for attachment of stores or loads.

Abstract: A borehole stress-meter includes a resiliently radially expandable hollow body within which can be positioned a gage plug having strain gages fixed thereto. The interior section of the hollow body is tapered, as is the gage plug so that advancement of the gage plug within the hollow body will cause the gage plug to become prestressed. The hollow body can be inserted into a bore drilled in earth material whose stress is to be measured by an installation or setting tool. Subsequently, the gage plug is advanced within the hollow body so as to prestress the gage plug. The setting tool is then removed and stress may be measured by an appropriate strain indicator.