Abstract:
Relief valve facilitating the underwater balancing of scuba divers&#39; inflatable articles, which is finely adjustable and extremely responsive, and is designed to ensure a high functionality by using simplified components to minimize the manufacturing costs.

Description:
SUMMARY 
     This invention relates to an adjustable relief valve for underwater inflatable articles, such as some types of diving suits and, more particularly, balancing jackets integrated with the bottles and to be worn as a normal jacket, said articles being presently widely used by scuba-divers. As a result of this wide use, many suggestions have been set forth which have been advantageously taken into consideration to provide an improved adjustable relief valve meeting all present requirements. The object of this invention is to provide such an improved valve which has several advantages resulting from various technical characteristics, to be defined in this patent specification. Specifically, the invention aims to ensure the utmost functionality by using relatively simple components which, additionally, minimize the maintenance requirements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The valve of the invention is shown by way of a non-limiting example in the accompanying drawing, wherein: 
     FIG. 1 is an axial sectional view of the valve, complete with adjustment bushing and with quick-relief pushbutton; 
     FIG. 2 is an exploded perspective view of said valve; and 
     FIG. 3 is a front view of a cap with rubber seal, adapted to be substituted for the components of the quick-relief pushbutton, which simplifies a valve in case the quick-relief effect is not required. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As can be appreciated from the Figures, the valve comprises a circular union-like base member 1 having a bottom threaded hub adapted to receive a threaded locking ring once said hub has been introduced into a suitable hole in the material constituting said inflatable article. Said base member includes an externally threaded flange for screwing thereon a threaded ring 2 to lock thereon a cylindrical body member 3 enclosing all the internal parts of the valve. Said cylindrical body member 3 is formed with a bottom shoulder rim to be engaged by said ring 2, and with a top through-hole for accommodating a pushbutton 4, said hole comprising an inside circular guide skirt which has an outer left-hand threading for securing thereon a ring member 5 formed with a plurality of peripheral teeth adapted to mesh with a similar circumference of teeth formed on said base member 1, said base member comprising centrally a seat for accommodating a sealing ring 6 co-operating with a thin, flexible, flange-like seal acting as well as a non-return membrane for the water. Said cylindrical body member 3 is formed, additionally, with a plurality of peripheral vent slots 8, while said pushbutton 4, axially slidable in the central hole of said body member 3, comprises an inside central stem 9 having a threaded lower end intended to be screwed into a disc-like member 10 provided with a depending hub 11, so that the movable valve assembly is held together. This assembly also comprises a coil spring 12 with a supporting washer 13 which is slidable on said stem 9, a very flexible disc-like valve member 14 acting as a non-return means for the water, a sealing ring 15 and a slotted centering and supporting disc 16. This disc is urged downwards by a coil spring 17 urging at the top thereof against said ring member 5 which is screwed with its left-hand threading on the annular skirt of said body member 3; therefore, the load of said spring may be adjusted by rotating said body member 3 which, for this purpose, is provided with a peripheral knurling. By means of this operation, therefore, the level of response of the valve may be adjusted, the sensitivity of the valve being very high since the attendant sealing components are made of rubber and are very thin and flexible. The valve, therefore, as required in this specific use, responds with great precision even to minimum pressure differentials, and enables a perfect balancing in any diving attitude and an absolute tightness owing to the non-return features of the components 7 and 14. 
     The above description relates to the normal version of the relief valve, i.e. the version comprising a quick-relief pushbutton. If this function is not required, the movable assembly comprising the parts 4-7-9-10-11-12-13-14-15-16 may be replaced with the parts shown in FIG. 3, namely a cap 18 with respective disc-like membrane 19 having as well a non-return function. 
     Changes and modifications may be made to the invention as described and shown herein without departing from the basic principles of the invention.