Abstract: The invention concerns a method for establishing a plug inside a main pipe, in particular a vertically or slantingly arranged pipe, where said pipe has firs and second ends, and where the plug is arranged inside the pipe at a distance from said first and second ends, where a liquid surface is provided at least inside the pipe, below the level at which it is desirable to establish the plug, where a buoyant layer is established on top of said liquid surface, and where a plug material is placed on top of ‘said buoyant layer as well as a plug established according to the method. The buoyant layer can be granular, liquid or solid material. The plug is made of foam material, expandable material or cement-based material such as concrete.

Abstract: An electroacoustic transducer comprising a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween, the magnetic circuit comprising a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further comprises a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: An electroacoustic transducer includes a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween. The magnetic circuit includes a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further includes a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: An electroacoustic transducer comprising a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween, the magnetic circuit comprising a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further comprises a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: An improved insulated cover for removable mounting onto a spa or hot tub or the like, wherein the cover is hinged to accommodate folding of the cover to a compact size and shape suitable for convenient shipment and/or storage. The cover comprises a foldable base including a pair of structural membranes formed from a relatively high tensile strength fabric and sewn together on a midline to define a central hinge, and secured together at their peripheries to defined a pair of pockets within which are mounted a pair of insulation panels of relatively stiff foam or the like. In some embodiments, a foldable frame ring formed in hinged or separable half sections may be mounted to the structural membranes at the peripheries thereof. A decorative top sheet is stretched over the foldable base, and a peripheral margin thereof is wrapped over the periphery of the base and radially constricted for retention thereon by a drawstring or the like.

Abstract: An improved therapeutic spa or hot tub or the like, such as a spa or hot tub of the type described in U.S. Pat. No. 5,092,951, includes at least one and preferably a plurality of vibratory mechanical massage elements incorporated into the tub wall at selected locations to provide tub users with a therapeutic vibratory massage action. The vibratory massage element or elements are used in combination with conventional hydraulic air-water spa jets to provide the spa tub with improved therapeutic effect.

Abstract: An improved insulated cover is provided for removable mounting onto a spa or hot tub or the like to minimize thermal and evaporative losses, while additionally safeguarding against foreign objects and/or persons falling into the tub. In the preferred form, the insulated cover comprises a frame ring in combination with a structural membrane stretched across the frame ring with a peripheral margin of the membrane wrapped over the outer rim and radially constricted for retention thereon by a drawstring or the like. The constricted drawstring additionally secures an insulation plate or disk relative to the structural membrane and frame ring. The insulation plate fits with close clearance into the spa tub, when the frame ring is supported on the top of the tub wall. An outer insulation skirt may also be provided to project downwardly about the tub wall.

Abstract: The method of providing a spa tub, and comprising providing a load-bearing tub side wall having an inner side and an outer side, the tub having an interior to receive liquid; the tub side wall provided to include at least two wall sections, spaced about the interior, the sections assembled end-to-end to form the side wall to extend in a loop, the sections consisting of synthetic resin; each section having inner and outer panels extending upright throughout the major upright extent of the side wall.

Abstract: A heated therapeutic spa which comprises a spa tub containing water and having plumbing attached thereto, the tub having a wall which is a relatively good thermal conductor; a thermally efficient, insulating container comprising a load bearing outer wall, and a bottom wall; a plenum chamber formed between the tub wall and the container wall and extending about the tub wall; a motor and pump supplying circulating water to the tub and extending in the plenum chamber; a fan located to circulate air that converts heat from the motor into hot air exhausted into the plenum chamber; the fan operating to force the hot exhaust air to circulate around the tub wall, whereby the temperature of the air drops in flowing about the tub wall before returning to the motor.

Abstract: The method of providing a spa tub, and comprising providing a load-bearing tub side wall having an inner side and an outer side, the tub having an interior to receive liquid; the tub side wall provided to include at least two wall sections, spaced about the interior, the sections assembled end-to-end to form the side wall to extend in a loop, and providing a flexible liner extending at the inner side of said side wall to contain said liquid.

Abstract: The method of providing a spa tub, and comprising providing a load-bearing tub side wall having an inner side and an outer side, the tub having an interior to receive liquid; the tub side wall provided to include at least two wall sections, spaced about the interior, the sections assembled end-to-end to form the side wall to extend in a loop, and providing a flexible liner extending at the inner side of the side wall to contain the liquid.

Abstract: An improved insulated cover is provided for removable mounting onto a spa or hot tub or the like to minimize thermal and evaporative losses, while additionally safeguarding against foreign objects and/or persons falling into the tub. In the preferred form, the insulated cover comprises an outer frame ring defining a radially outwardly projecting rim, in combination with a structural membrane stretched across the frame ring with a peripheral margin of the membrane wrapped over the outer rim and radially constricted for retention thereon by a drawstring or the like. The frame ring and structural membrane cooperatively define an upwardly open pocket for receiving and supporting a selected insulation material. A flexible decorative top sheet is stretched across the frame ring to close the insulation pocket, wherein a peripheral margin of the decorative top sheet is wrapped over the outer rim and radially constricted for retention thereon by a drawstring or the like.

Abstract: In the method of forming a spa tub, the steps that include providing a tub side wall having an inner side and an outer side, the tub having an interior to receive liquid; and providing a recess inwardly of the outer side of the tub side wall and below the top level of the side wall, to receive at least one of the following elements: edge extent of a flexible outer jacket for the side wall, the jacket extending below said recess; edge extent of a shoulder jacket that extends over the top of the side wall; edge extent of a tub top cover.