Abstract: A straightening press of the type wherein a workpiece is supported for deflection in a given direction by an anvil engageable with the workpiece. A reference spring is supported for deflection with the reference spring supports being serially interconnected with the anvil. In a preferred embodiment, a floating bridge carries the anvil and reference spring supports. Deflecting force applied to the reference spring, as by a ram, is transmitted to the workpiece via the floating bridge. A change in the differential displacement of the ram and floating bridge is detected to determine the onset of plastic deformation of the workpiece.

Abstract: A receptacle member, such as a plastic tray, is symmetrical about at least one axis and includes engagement elements of at least two, complementary interfittable forms. Two of the members are assembled in inverted, confronting relationship to one another so as to define compartments of regular configuration within the resultant container unit, which are symmetrical with respect to a medial plane therethrough.