Abstract: The apparatus of the invention is arranged to include facing table members, each having first and second pivotally mounted table plates relative to each table member to accommodate orientation of the tables with leveling and compass structure mounted to each table to enhance alignment. A sighting structure is arranged to include a light emitting housing to provide for alignment between the tables, as well as a range finder structure arranged to indicate spacing between the tables.

Abstract: A solar air heater comprises a plurality of elongate concentric flexible cylinders which define an outer annular insulating region, an inner cylindrical flow region and a positioning structure therefore. A plastic panel of indeterminate length may be folded upon itself and sealed to form the outer wall of the insulating annulus, the positioning structure and a middle wall. The cylindrical flow region is defined by a self-supporting tube which is inserted into the positioning structure and middle wall. Air flowing through the self-supporting tube is heated by available solar energy and the outer region, inflated by air at a pressure slightly above atmospheric pressure, acts as an insulator.

Abstract: A water mattress has a portion of its volume occupied by air or gas filled bodies which lower the total mattress weight and inhibit the under damped natural harmonic motion typical of conventional water mattresses. A method of fabricating the water mattress of the instant invention is also disclosed. The gas filled bodies comprise independent, elongate, parallel chambers having sidewalls which are secured to the bottom panel of the mattress. The chambers are positioned to float between the horizontal midplane of the mattress and its upper surface such that it exhibits the uniform force per area weight distribution characteristic found desirable in such devices. Air is supplied to the chambers through generally aligned access fittings on the chambers and water mattress.

Abstract: A water mattress having a portion of its volume occupied by air or gas filled bodies lowers the total mattress weight without sacrificing its desirable characteristics. The gas filled bodies comprise independent, elongate, parallel chambers having sidewall members which are secured to the bottom panel of the mattress. The chambers are positioned at approximately the horizontal midplane of the mattress such that it exhibits the conventional uniform weight distribution characteristics found desirable in such devices. Air is supplied to or released from the chambers through access fittings on the chambers and water mattress. The water filled mattress weighs substantially less than a conventional mattress having the same external volume. Furthermore, the chambers tend to inhibit the sloshing and highly under-damped natural harmonic motion typical of conventional water mattresses.

Abstract: A water mattress construction is disclosed. The construction involves a folded one piece vinyl sheet wherein the various panels are joined at the vertical corners, along the lengthwise lower edges and side to side across the middle of the bottom. By so locating the seams, not only are all but the vertical corner seams supported directly by the mattress frame, but they are also removed from the upper area of the mattress which is generally subjected to flexing. A cappable fitting to facilitate filling and emptying of the mattress is included. The various panels are joined by overlapping the vinyl material, and subsequently heat-sealing them to produce strong lapped seams throughout.

Abstract: A water mattress construction is disclosed. The construction involves a folded one-piece vinyl sheet wherein the only longitudinal seam is located on the bottom, thereby avoiding side seams on the mattress and wherein the end seams are located below the upper mattress surface. Lap seams are used throughout for additional strength.