Abstract: A method and apparatus for counterbalancing and spring-assisting the swinging movement of a horizontally hinged upwardly extending mass is disclosed wherein a spring (preferably a gas spring) and a mounting bracket or hinge of unique configuration is pivotally attached at one end of the spring, the bracket (hinge) including means for selective engagement and disengagement from the spring during pivotal swinging movement of the mass between alternate terminal positions and through an over-center position, in order to minimize the forces necessary to move said mass toward and through the over-center position.

Abstract: A uniquely constructed playing court having a generally rectangular configuration comprising front, rear and side walls and/or ceiling wherein the front and side walls are a composite of integrated prefabricated panels, the inner facing surfaces of said panels being sheets which, according to one highly unique aspect of the invention, are of polycarbonate material, said sheets being mounted upon corrugated members whose corrugations are filled with a high density foam and the space surrounding said corrugations is filled with a low density foam. Vertical conventional studs are used to mount the panels by using appropriate fastening means between the studs and the rear surface of the panels. In a particular configuration, clips are welded to the inner facing flanges of the studs, and mating clips are welded to the apices of the corrugations of the corrugated backing sheet so that the panels may be attached upon the studs in adjacent and adjoining relationship.