Abstract: One example of this application provides the only portable hard cover (hot tub cover) on the market. One example of this application provides 2 caps per molding (instead of one cap). These are big advantages for consumer and reducing manufacturing cost. Different variations have been presented here, as well. In one application, we introduce a new hinge (and the related system) for the hot tub cover. In one example, the cover is too heavy. To remedy this, we have developed a spring lever that can be used for hard covers of various sizes and weights, because we can put different strength springs inside, to compensate for the weight differences, in different situations. This is much safer and easier for the user.

Abstract: One example of this application provides the only portable hard cover (hot tub cover) on the market. One example of this application provides 2 caps per molding (instead of one cap). These are big advantages for consumer and reducing manufacturing cost. Different variations have been presented here, as well. In one application, we introduce a new hinge (and the related system) for the hot tub cover.

Abstract: One example of this application provides the only portable hard cover (hot tub cover) on the market. One example of this application provides 2 caps per molding (instead of one cap). These are big advantages for consumer and reducing manufacturing cost. Different variations have been presented here, as well.

Abstract: One example of this application provides a method for manufacturing an above-ground heated pool used for swimming resistance exercise (exercise and swim spa), with an optional attached hot tub. Additionally, the rotationally-molded swim spa can support the addition of an integrated separate water vessel, used primarily for relaxation, that can maintain a separate water temperature from the swim spa section of the whole system. Other variations of this application have also been discussed.