Abstract: An automatically operating dump valve device for a boat, particularly for a life raft, including a hole made in the bottom of the boat and a flexible chute located under the bottom of the boat being connected in a sealed way to the edge of said hole, the chute is equipped with flotation means placed away from its connection with the hole in the bottom of the boat, by means of which arrangement, when there is no water in the boat, the flotation means bring the chute back up under the bottom of the boat sealing it and the water cannot get into the boat through the chute, whereas, when water is present in the boat and is drawn back towards the aforementioned hole, its weight forces the chute end to drop from the bottom of the boat despite the presence of the flotation means and the water flows out through the chute.

Abstract: The valve includes a closure disc (34) sealable at its rim to a valve seat (18) so that in this position the seat (18) and rim define between them an annular space (54) which is connected to a port (60) by passages (54, 56, 58) extending through a mating face (e.g. carbon fibre gasket (22)) of the valve seat (18). As shown the space (54) is a recess in the disc rim defined between fibre seal rings (46, 48) but other arrangements are disclosed in which the seal rings and/or recess may be accommodated in the valve seat. The port (60) may be used for leakage detection, pressure monitoring of bleeding or fluid injection.

Abstract: An integrally-moulded foot (3) and disc (2) for a swimming pool cleaner is disclosed. The disc (2) optionally may include tapering holes (17) at spaced intervals.

Abstract: Disclosed is an inflatable raft having an opening formed on one of its four side portions. A downward and then radially inward extended frame is formed around the opening for a top flange of a container to be radio heated thereto. The container has an accordion body. When the raft is inflated, the accordion container can be downward stretched to accommodate a can therein. And, when the raft is deflated, the accordion container can be collapsed along with the raft for convenient storage. The structure of the inflatable raft will not be adversely affected by the provision of the accordion container on the raft.

Abstract: Wheeled applicators for marking lines on various surfaces are detailed. Each applicator may include a head adapted to receive an aerosol dispenser containing line-marking fluid and a spray nozzle with a normally-closed valve. The head and dispenser further may be disposable.

Abstract: The present invention is directed to a biocidal water treatment composition, water treatment apparatus, and method of treating water to reduce levels of pathogens. The composition contains sources of copper, zinc, and silver metal ions within a crosslinked polymer matrix. Examples of these ion sources include copper sulfate, zinc sulfate, and silver nitrate. An example of the crosslinked polymer matrix is crosslinked chitosan, which also serves to clarify the water and release the metal ions over time. The product is easy to manufacture, and allows the use of decreased halogen sanitizer, as well as decreased copper ion, thereby decreasing the likelihood of staining. The product simultaneously provides good bactericidal and algaecidal properties, despite low levels of copper ion and low chlorine levels.

Abstract: A mixed hull inflatable craft convertible into a closed box for its storage or transport is disclosed. The hull has a rigid body (1) with a top edge (5), a plane to which is fixed an inflatable buoyancy tube (7), a rigid closing panel corresponding in contour to the edge and an inverted U-shaped profile (15) interlocking the tube to the hull. The profile overlaps the top edge (5) of the body and has a first groove (16) open upwards and inside the body, retaining a ring (18) carried by a flexible skirt (19) connected to the tube; a second groove (20) open upwards and outside the body, receiving the edge of the panel closing the body (1) in the closed box conformation and supporting the flexible skirt (19) of the inflated tube located outside the body in the craft conformation; and an elastomer bead (21) located on the outside under the second groove (20) forming a sealed bearing surface for the inflated tube (7) in the craft conformation.

Abstract: Pneumatic valve (1) for an inflatable object such as an inflatable boat, arranged so as to be partially embedded in an aperture (22) in the flexible wall (21) of the inflatable object carrying it and comprising a valve body (2) containing a valve mechanism (1) and two collars (18, 20) like truncated cones surrounding the valve body (2) and gripping between them in a leak-proof manner the portion of the flexible wall (21) peripherally bordering the aperture (22); the two collars (18, 20) belong to two respective rings (17, 19) removably attached to the valve body (2), and sealing means (16) are provided between the lower ring (17) and the valve body (2); thanks to which the valve body (2) can present a transverse dimension approximately identical to that of said aperture (22) of the flexible wall (21) and fitting the valve (2) to or removing it from the flexible wall (21) can be carried out entirely from the exterior of the flexible wall (21).

Abstract: Gear pump, or Moineau pump, comprising two helical gears one inside the other, the internal helical gear, which is rotary (the rotor) having one tooth fewer than the external helical gear, which is stationary (the stator), characterized in that the rotor and the stator are made of respective materials which have respective coefficients of thermal expansion which lead to respective expansions of the rotor and of the stator which are such that an approximately constant clearance is maintained between the rotor and the stator over a range of ambient temperatures spanning between about 15.degree. C. and about 300.degree. C.

Abstract: Inflatable mattress assemblies are disclosed. Typically including separately inflatable upper and lower components sealed one to the other, the assemblies nevertheless can create appearances of having been formed merely by laying each upper component atop the corresponding lower component. By incorporating inflatable frames around the central sections of each of the two components, the components may be sealed (welded) together at locations other than their extreme outer edges.

Abstract: An inflatable pneumatic enclosure 1 of constrained geometric shape, comprising two main walls 2, 3 held the one relative to the other, in the inflated state of the enclosure, in a pre-specified relative position by a multiplicity of flexible links 4 interposed between said walls 2, 3, an inflation valve 6 being fixed in one of said walls 2 for the inflation of the enclosure, characterised in that the valve 6 is of the embedded or semi-embedded type with a valve body 7 extending inside the enclosure 1 under said mounting wall 2 and in that a spacing body 8 extends between the valve body 7 and the opposite wall 3 of the enclosure and is fixed to these, said spacing body 8 being dimensioned so that the two aforementioned walls 2, 3 are held in a desired relative position in relation to that obtained by the surrounding flexible links.

Abstract: A spatial light modulator in the form of a deformable mirror device (110) receives from a frame store (116) data which has been formatted by a data formatter (114) subsequent to gamma correction in a ROM look-up table (112). The DMD (110) displays different light levels by being ON for selected periods of a series of durations 4, 8, 16 . . . 1024 varying in proportion to a basic period multiplied by powers of two. The shortest duration 4 for which the DMD can be turned on is a multiple of the basic period, and the series includes additional durations 5, 6 and 7 in the series between the shortest displayable duration 4 and the next power of two 8. Durations 1, 2 and 3 of less than the shortest displayable duration can be displayed by adjusting the turn-on time of a proportion of the adjacent mirrors. The longest duration for which the mirror can be turned on can be employed twice.

Abstract: Inflatable articles of clothing are disclosed. Using in many cases multiple plies of material impervious to air, inflatable pockets are created. Valves may also be included to facilitate introducing air into the pockets and, if necessary, to permit their deflation.

Abstract: A method and apparatus for driving a display device including a matrix array of deflectable mirror devices is described. The deflectable mirror devices are divided into blocks of N rows. Selected groups of mirror devices within each block are loaded with single bit data in a cycle of loading operations During at least some of the loading operations, two series of reset cycles are used enabling one single bit cycle in one group to terminate and another single bit cycle in another group to commence within a single loading operation. Active bit data may be loaded and displayed in the otherwise unused time intervals between the active bits.

Abstract: Bumpers and assemblies for swimming pool cleaners are disclosed. Such assemblies may include contoured frames to which flexible fins are attached to facilitate deflection of cleaners when obstacles are encountered. Side wings connecting the frame to the body of a cleaner may additionally be employed as part of the assemblies, as may a weight moveable about two axes. In use, the side wings both promote cleaner deflection and reduce body wear that otherwise would occur. The non-stationary weight permits continuous rebalancing of the cleaner depending on its location and orientation within a pool.