VALVE FOR UNDERWATER AQUALUNGS SUPPLYING DEVICES

Abstract: Valve for underwater aqualungs supplying devices, including a pressure chamber (6) and a watertight compensation chamber (7) adjacent and watertight separated by a partition wall (8) and a shutter (9) including a tubular stem (91) inserted, at least in part, inside each chamber; the pressure chamber (6) is provided with means (3, B) to connect with to a pressurized gas source (R) and with a housing (11) suitable for cooperation with an end (92) connected with the shutter (9); the compensation chamber (7) is provided with at least on opening (71) communicating with the outside and a stem end (91) in the shape of an expansion enlarged head (93) connected with the valve outlet (12), and a coil spring (10) watertight driven into such chamber between the expansion head (93) and the partition wall (8). In said valve the enlarged expansion head (93) of the shutter (9) is encircled by a thermal insulating annular part (13) watertight positioned (14, 15) between said head and the side wall (72) of the compensation chamber (7).

Description: Valve for underwater aqualungs supplying devices The present invention refers to a valve , in particular for watertight aqualung supplying devices . As known the supplying devices valves are provided with a shutter, formed by a tubular stem and an enlarged expansion head, which can be axially moved and is housed in two watertight separated adjacent chambers: and one of these chambers, the said pressure chamber, is connected with a pressurized gas source and provided with an housing cooperating with the tubular shutter corresponding end, while the other chamber, said compensation chamber, is provided with one or more openings communicating with the outside, and has the tubular shutter corresponding end, which is in the shape of an expansion enlarged head, connected with the outlet of the valve, watertight driven into it. Within said expansion chamber is moreover housed a coil spring be- tween said expansion head and the opposite partition wall between the two said chambers . In valves like these, the supplied gas passing through the shutter expands into the expansion enlarged head zone, causing a remarkable cooling of said head and the shutter tubular stem, up to very low temperatures and next to the water freezing temperature. The construction of the known valves allows a thermal exchange between the coil spring and the expansion head and between the shutter tubular stem and the compensation chamber interior. The cooling extends then to the compensation chamber too . In the valves for underwater aqualungs supplying devices, in particular in the first stages of the two phases supplying devices , the compensation chamber is filled with water in substantially stable conditions within. The cold transmission, especially from the shutter expansion head, can produce the freezing of the water in the compensation chamber, causing a following inefficiency when not a valve blocking, due to the blocking of the shutter motion. Aim of the present invention is to embody a valve for underwater aqualungs supplying devices to eliminate the disadvantages of the previously described known valves , and where the shutter thermal insulation is improved beside reducing the weight of the same, improving the lubrication within the chamber keeping the mechanical resistance characteristics unchanged. This aim is reached by the present invention through a valve for underwater aqualungs supplying devices , where the expansion enlarged head is encircled by a thermal insulating annular part watertight positioned between said head and the side wall of the compensation chamber . According to one aspect of the present invention the thermal insulating material which the annular part is composed of, is a plastic material with, optionally, a suitably charging material further improving the insulation efficacy. Said material is composed, for instance, by empty microspheres embedded in the plastic material . The present invention will be better understood through the following description, to be considered as a not limitative description and referred to the only enclosed drawing, where Fig. 1 shows an axial section of an embodiment form of the valve according to the present invention with the shutter partially shown in open position and closed position of the valve . With reference to said figure the shown valve is the first stage of reduction of the pressure of the air, or a physiological mixture of oxygen and other suitable gasses , of an automatic two stages supplying device for underwater aqualungs. It is joined to the mouth B of a tap R applied on a cylinder (not shown) containing compressed air or an under pressure physiological mixture of oxygen and other gasses. The valve body 5 is joined to the mouth B of the tap R through an inlet tubular union 3 by means of a fastening assembly formed by a bracket 1 and a fastening screw 2 cooperating with said bracket. In the valve body 5 are longitudinally provided two coaxial chambers 6 and 7 which are separated by a partition wall 8 , where is provided a pipe 67 communicating between the two chambers. The first chamber 6, called pressure chamber, communicates with the mouth B of the tap R and the pressurized air or gas mixture is supplied into it; the second chamber, called compensation chamber, communicates with the outside through two openings 71, so that it, during the dive, fills with water at a pressure corresponding to the dive depth. In the pipe 67 is slidingly watertight housed the tubular stem 91 of a shutter 9, preferably in metal material such as stainless steel to ensure a better resistance both mechanical and chemical (saline, etc.) . The shutter 9 projects at one side of the pressure chamber 6 where it ends with a stem end 92 in the shape of a spout. The opposite end of such shutter 9 is realized so to have an enlarged conical shape, forming an expansion head 93 for the air or gas, watertight and slidingly drived into the compensation chamber 7. The expansion head 93 communicates with the outlet 12 of the valve provided on the compensation chamber 7 side turned to said expansion head. The spout end 92 cooperates with an housing 11, preferably of non metallic material, so to adjust the outflow of air or gas coming from the tap R mouth B and reaching the pressure chamber 6 and inall , through the shutter 9 , the valve outlet 12. As one can see , said shutter is shown in two positions : from the figure upper part respectively the opening position (with the end 92 separated from the housing 11) and the closing position (with the end 92 close to the housing 11) . In the compensation chamber 7 is provided a coil spring 10 interposed between the expansion head 93 and the partition wall 8 between the two chambers 6 and 7: the coils of said spring, in this embodiment form, are formed by a stainless steel core 101 covered by a thermal insulating material layer 102. As said before, because of the gas expansion, the compensation chamber 7 is subjected to a great temperature drop which can cause the freezing of the water coming from the openings 71. One of the main elements which cause , by cooling themselves , this drop in the temperature is certainly the expansion head 93 which, according to the invention, is covered with a thermal insulating annular part 13. Said part 13 is preferably made of thermal insulating plastic material, which can also include a suitable filling material , such as for instance empty microspheres embedded in the plastic to improve the thermal insulation. The annular part 13 encircling the head 93 has on the outer periphery a first watertight main ring (o-ring) 14 and a second ring 15 completing and improving the thermal insulation besides ensuring a better lubrication since it is useful both for spreading grease or other lubricant in the compartment formed between said rings 14 and 15 and the side wall 72 of the compensation chamber 7 , and for preserving the main ring 14 from dirt, sand and other damaging agents. A threaded bushing 16 is provided to hold together the annular part 13 and the enlarged head 93 , screwed on a stem length 91 , threaded as well , cooperating with said bushing. Moreover it is provided a further watertight ring 17 interposed between the bushing 16 and the shutter head 93. A further feature of the annular part 13 is represented by the fact that the main watertight ring 14 is set in an housing 131 having a width greater than that of the ring itself, so that it is a little movable as to the shutter 9 when performing its opening or closing stroke, that improves further the lubrication of the parts in motion. This last feature of the present invention, apart from the thermal insulating means , is applicable to any plunger or piston of a supplying device of the described type sliding within one or more chambers and provided with one or more watertight rings or bands . In addiction to the annular part 13 there are provided, for the shutter 9 part within the compensation chamber 7 , other thermal insulation means , according to previous patents of the present invention owner, it is to say: a sheath 18 on the stem length 91 before the threading, made of compressible thermally insulating material, in fact when the shutter is in opening position said sheath is stretched in its natural position, while when the shutter is in closing position said sheath is compressed; to complete the insulation it is moreover provided a further bushing 19 of thermal insulating material as well, placed around the threaded bushing 16 and projecting against the annular part 13. Thanks to the use of the annular part 13 and, optionally, of the other described insulating means, the cooling of the shutter 9 head 93 caused by the expansion of the air or gas within, does not spread to the compensation chamber 7 , it is to say to the water or liquid contained within. This way the water temperature within the compensation chamber 7 is always kept at a value greater than that of the head 93 and finally the shutter 9 and above the freezing temperature, at least for the length of time of a normal diving, that way avoiding the inefficiency or the eventual valve blocking an the connected risks for the user. Several are then the advantages which can be obtained by the valve for watertight aqualung supplying devices according to the embodiment form described by way of example, and several are the embodiment forms which can be realized to obtain such advantages within the enclosed claims .

Claims: CLAIMS 1. A valve for underwater aqualungs supplying devices , including a pressure chamber (6) and a watertight compensation chamber (7) adjacent and watertight separated by a partition wall (8) and a shutter (9) including a tubular stem (91) inserted, at least in part, inside each chamber, the pressure chamber (6) being provided with means (3, B) to connect it to a pressurized gas source (R) and with an housing (11) suitable for cooperating with an end (92) connected with the shutter (9) , the compensation chamber (7) being provided with at least an opening (71) communicating with the outside and a stem end (91) in the shape of an expansion enlarged head (93) connected with the valve outlet (12) , and a coil spring (10) watertight driven into such chamber (7) between the expansion head (93) and the partition wall (8) , characterized in that the enlarged expansion head (93) of the shutter (9) is encircled by a thermal insulating (14,15) annular part (13) watertight positioned (14, 15) between said head and the side wall (72) of the compensation chamber (7) . 2. A valve according to claim 1, characterized in that the annular part (13) is made of thermal insulating plastic material. 3. A valve according to claim 2 , characterized in that the plastic material of the annular part (13) contains a suitable filling material embedded within to further improve the thermal insulation. 4. A valve according to claim 3, characterized in that the filling material are empty microspheres . 5. A valve according to claim 1 , characterized in that the annular part (13) is positioned between the shutter head (93) and the compensation chamber (7) side wall (72) through two or more watertight rings (14, 15) . 6. A valve according to claim 5, characterized in that the watertight ring (14) positioned in the zone of the head (93) with greater diameter is set in a housing (131) realized so to allow an axial shift of said ring within said housing as to the axial movement of the shutter (9) . 7. A valve according to claim 1 , characterized in that the shutter (9) stem (91) includes close to the head (93) a threaded length cooperating with a threaded bushing (16) provided with a watertight ring (17) between the same and said shutter head. 8. A valve according to claim 7 , characterized in that the shutter (9) stem (91) includes inside the compensation chamber (7) a thermal insulation sheath (18) axially compressible and positioned between the partition wall (8) and the threaded bushing (16) . 9. A valve according to claim 7, characterized in that the shutter (9) includes a thermal insulation bushing (19) positioned around the threaded bushing (16) and abutting against the annular part (13) . 10. A valve according to claim 1 , characterized in that the spring (10) coils have a metal core (101) covered with at least one layer (102) of thermal insulating material .

Inventors: SEMEIA ROBERTO, SEMEIA, ROBERTO
Applicants: SCUBAPRO EUROP, SEMEIA ROBERTO, SCUBAPRO EUROPE S.R.L., SEMEIA, ROBERTO
Application year: 1999
Main classification: B63C11
IPC codes: B63C11