US 3768504 A
Description (OCR text may contain errors)
United States Patent [1 1 Rentsch, Jr. Oct. 30, 1973 CHECK VALVE FOR USE WITH A Primary Examiner-Martin P. Schwadron SNORKEL TYPE BREATHING TUBE Assistant Examiner-David R. Matthews  Inventor: Samuel B. Rentsch, Jr., 242 Attorney john Hilton Hubbard St., Glastonbury, Conn. 0633 57 ABSTRACT  Flled: June 1972 A check valve for use with a snorkel-type breathing  Appl. No.: 264,206 tube comprising an annular member which is joined to the free end of a breathing tube and which defines a chamber which is sealed against the ingress of water CCHI. l37/409,Fl126i;/1l45f/01: when Submerged by a spherical ball elemenL The ha  Field of Search 137/63 R, 81, 409; i as i m merged m water and 18 oined to the annular member 128/145 R, 145 A, 147
by a spring WhlCi'l exerts a light biasing force on the ball causing it to sealingly engage a valve seat defined  References cued at one end of the annular member. The weight of the UNITED STATES PATENTS ball causes it to unseat when no longer submerged 2 thereby opening the valve to the passage of air. ra e a 13 Claims, 5 Drawing Figures PATENTED GET 3 0 I973 sum W 2 aws CHECK VALVE FOR USE WITH A SNORKEL TYPE BREATHING TUBE BACKGROUND'OF THE INVENTION v This invention relates in general to underwater breathing devices and more particularly to a check valve for use with a snorkel-type breathing tube.
A snorkel tube must be equipped with a check valve at its free end to avoid having the tube fill with water when fully submerged. When the tube fills with water the user must blow the tube free of water upon surfacing before drawing another breath. One type of check valve is use today employs a cage fixed to the inverted free end of the tube and housing a buoyant ball. When submerged, this ball floats upwardly thereby closing the open end of the tube. The device is most effective, however, only so long as the tube is held vertically, requiring the user not to turn his head when the tube is submerged. If the user fails to follow this procedure he must blow out water trapped in the tube upon resurfac- The general aim of the present invention is to provide a check valve employing a spring-biased, neutrally buoyant ball which is automatically maintained in a closed position when the device is submerged in any orientation and not merely when the device is kept vertically oriented. The ball acts against the spring by virtue of its own weight to open the valve when the device is no longer submerged and as long as the device is not vertical. Such a device has the advantage of automatically keeping the breathing tube free of water, thus greatly simplifying all forms of scuba and skin diving. The device also increases diving safety by eliminating the possibilty of the diver aspirating water while submerged. More important the device prevents repeated accidental aspiration of water when the snorkel device is in use on the surface in the presence of even the mildest of wave action. Such repeated aspiration of water has caused many experienced divers to panic and drown. For these reasons this device would be of great value in the training of new divers.
SUMMARY OF THE INVENTION This invention resides in a check valve for use in an underwater breathing device, which valve is automatically maintained in a closed position when submerged in water and will remain closed despite changes in the orientation of the device. The check valve comprises a spherical valve element which is seated on one end of an annular member by means of a spring. The valve ele ment in its preferred form comprises a spherical element which incorporates a trapped volume of air and an adjustable weight to achieve neutral buoyancy when submerged in water. Being neutrally buoyant, the spherical element requires only a slight spring force to 7 seat it firmly on the valve chamber when submerged and may thus unseat against the spring force when the device is no longer under water. Furthermore, the spring force is adjustable by means of a tension adjustment means which joins the spring to the annular member and which may be variably positioned to change the length of and thus the tension exerted by the spring.
DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of a device which embodies the invention in use by a swimmer.
FIG. 2 is a vertical sectional view of the device of FIG. 1 submerged in water, the valve being in its closed position.
FIG. 3 is similar to FIG. 2 but shows the device above the level of the water, and in its open position.
FIG. 4 is a vertical sectional view of an alternate configuration of the invention, the alternative device being submerged and the valve element incorporating an ad ditional trapped volume or air to achieve positive buoyancy, especially when oriented so that the free end of the snorkel tube points generally downwardly.
FIG. 5 is similar to FIG. 4 but shows the alternative configuration of FIG. 4 in an inverted position which allows the trapped air to bleed out.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A snorkel equipped swimmer is shown in FIG. 1 in the typical position for searching or studying the bottom of the ocean or lake. His face mask may be of conventional configuration and the fins on his feet are also of conventional construction. I-Iis snorkel tube 50 has a conventional mouth piece for clamping in his mouth, and it is J-shaped so that the upper end normally projects above the water at some convenient angle as shown. During the surface swimming shown in FIG. 1, the check valve at the upper end of the tube 50 will be open as shown in FIG. 3 to allow air to pass through the tube. When the swimmer surface dives so that the entire tube and check valve are submerged, the valve closesas shown in FIG. 2. The unique check valve to be described will remain closed as long as it is so submerged in spite of changes in its orientation from the normal due to the swimmers movements below the surface.
Turning now to the check,valve of FIG. 1 in greater detail, the valve comprises a spherical valve element or ball 12 which is adapted to being seated on one end of an annular member 20 carried at the free end of the tube 50. The ball 12 is connected to the member 20 by a spring 40. One end of this spring is fastened to the ball and the other end is attached to a spring tension adjustment element or spider 30. This spider is a spoked ring which is adapted to be 'threadably received in the annular member 20. The spider may thus be adjustably positioned within the member 20 thereby changing the length of the spring and hence the tension force it exerts on the ball.
Considering the spherical valve element 12 in greater detail, this element comprises a hollow ball defined by a generally thin plastic shell 14. This shell 14 is completely sealed to entrap within itself a known volume of air. The buoyancy of the hollow ball is balanced by providing a sufficient weight 16 of relatively heavy material within the ball to cause the ball to be neutrally buoyant when submerged in water. 1
The weight 16 may be known amount of mercury or equivalent material, such as small lead pellets, which readily adapt to the internal contour of the ball and which material is free to seek the lowest point within the ball. This ability of the weight to shift position is useful for two reasons. In air it changes the center of gravity with a suddeness that imparts an opening snap as momentum to the valve which insures proper and complete opening. When the valve is submerged, this shifting of the center of gravity diminishes the moment of force tending to open the valve and consequently insures its closure. The amount of weight utilized is determined by the weight of the volume of water displaced by the ball and may differ slightly for salt and fresh water.
The spherical element is further characterized by a spring housing 18. This spring housing is a sealed cylindrical well which is integrally formed with the shell of the ball. The housing extends radially inwardly from a circular opening in the shell and is sealed at is innermost end. A retaining flange 19 is located adjacent to the inner end of the housing and is utilized to retain one end ofa light tension spring 40. The opposite end of the spring 40 is attached to the aformentioned spring tension adjustment element or spider 30.
Considering this adjustment element 30 in greater detail, it may be seen to comprise a circumferential rim portion 32 and a plurality of inwardly extending spoke portions 34. The nexus of these spoke portions is located on the axis of the circular rim portion and forms a hub 36. This hub is in turn adapted to retain said opposite end of the spring 40. The outer surface of the rim portion 32 defines a series of external screw threads 33. These screw threads are adapted to be threadably engage with the inner wall of the member and thus provide a convenient means for changing the axial location of the adjustment element within the member 20, and hence changing the biasingforce of the spring 40 on the ball.
The annular member 20 is of generally hollow cylindrical shape, and may be made of injection molded plastic or other suitable material. One end of the member 20 is sealingly affixed to the free end of the J- shaped snorkel breathing tube 50.
The opposite end of the member 20 defines a valve seat, which valve seat comprises an inwardly sloping face 23. The flange face 23 is molded or machined to precisely match the external contour of the ball 12. When the valve is closed, the ball 12 mates with the flange face 23 and is held in place thereon by the force of the spring 40 thereby providing a water-tight seal].
The remaining inner wall of the valve housing member 20 defines an internal screw thread 25. These threads may be molded or machined and are adapted to mate with the screw threads defined by the outer face of the spring tension adjustment element 30.
FIG. 4 illustrates an alternative embodiment of the invention. As in the preferred embodiment, this alternative configuration comprises a spherical element 60 seated on an annular valve seat defined at one end of an annular member 70, and a spring 80 connecting the element 60 to the member 70.
The spherical element 60 differs from its counterpart in the preferred embodiment in that its plastic shell 62 defines two air chambers. One of these chambers, as in the preferred embodiment, is sealed to permanently entrap a volume of air. The second chamber, however, is open and has as its purpose the temporary retention of an additional volume of air within the ball. A lead ring 64 is expanded into a groove 66 defined by the shell and located around the opening of the second air chamber. This lead weight combines with the permanently entrapped volume of air to make the ball neutrally buoyant when submerged in water.
The effect of the temporaily retainable temporarily of air in the open chamber is to make the ball positively buoyant, at least until the trapped volume of air is lost as shown in FIG. 5..
When the valve is in its normal orientation, as shown in FIG. 4, a positive buoyant force due to the trapped air in the open chamber supplements the force of the spring to insure a tight seal between the ball and the valve chamber. As the valve is turned towards the extreme up-side-down position, shown in FIG. 5, this positive buoyancy which would now tend to unseat the ball is lost as the temporarily entrapped volume of air is lost from the open chamber.
The spring 80 is connected at one end to an annular protuberance on the external wall of the ball 60, and at its other end said spring is connected to a spring tension adjusting screw 85. This adjusting screw is adapted to pass freely through a hole in the end portion of the valve chamber 70 and is held in place by a lock nut 84. The length and tension of the spring 80 may then be adjusted by turning the adjusting screw 85 with respect to the lock nut 84.
The annular valve member 70 has an outer surface adapted to be sealingly engaged within the end portion ofa snorkel tube 75 as shown. A circumferential flange 72 located at the outer end portion of the valve member positions the member within the tube. The inner surface .of this flange 72 defines a valve seat 73 against which the ball 60 mates when the vavle is in its closed position, best shown in FIG. 4.
The inner end portion of the valve housing member 70 defines a spring tension adjusting screw support means. This support means preferably comprises a web or wall having a centrally located hole adapted to receive the adjusting screw 85, and a number of circumferentially spaced openings or holes 86. The purpose of the holes 86 is to permit the passage of air from the valve chamber into the breathing tube when the valve is in its open position shown in FIG. 5.
1. A check valve for a snorkel-type breathing tube comprising in combination a hollow valve element, an
annular member adapted to be sealingly affixed to one end of the breathing tube and defining a valve seat, a tension spring one end of which is connected to said valve element and the other end to the annular member, said spring exerting a light biasing force on the valve element causing said element to seat when submerged, and said element being internally weighted causing said element to unseat as a result of its own weight when it is not submerged, a spring tension adjust ment means at one end of the valve spring between the member and the spring to permit the spring force to be manually varied.
2. A check valve as defined in claim 1 wherein said valve element is further characterized by a hollow sealed chamber, said chamber having a volume of air permanently trapped therein, said valve element having a weight such theat the valve element is neutrally buoyant when sumberged in water.
3. A check valve'as defined in claim 2 wherein said valve element is further characterized by an outwardly open cavity, said cavity having as its purpose the temporary entrapment of a volume of air therein, said volume of air causing the otherwise neutrally buoyant valve element to become positively buoyant, said open cavity being so oriented that a positive buoyant force is provided supplementing the biasing force of the valve spring to insure seating of the valve element on the valve seat.
4. A check valve as defined inclaim 1 wherein said spring tension adjustment means is further characterized by a generally internal cylindrical threaded surface on said annular valve member, said adjustment means being further characterized by spider means threadably received in said annular member and connected to said spring for adjusting the biasing force of the spring on the valve element.
5. A check valve as defined in claim 4 wherein said spider means is further characterized by a circumferential rim portion, said rim portion having an outer surface, said surface defining screw threads and a plurality of radial inwardly extending spoke portions, the nexus ofsaid spoke portions forming an axially located hub portion, said hub portion providing a point of attachment for one end of the valvespring.
6. A check valve as defined in claim 1 wherein said annular valve member comprises a circumferential inwardly bevelled flange at one end thereof, said flange defining an annular valve seat, said seat utilized to sealingly engage the valve element, and said valve element being generally circular in contour for sealingly engaging said annular valve seat.
7. A check valve as defined in claim 6 wherein said spring tension adjustment means is further characterized by a spring tension adjust screw one end of which screw is connected to the spring opposite the end connected to the valve element, a web wall defined at one end of said annular valve member opposite said annular valve seat, and threaded means between said screw and said web wallto permit adjusting the tension force of said valve spring.
8. A check valve for a snorkel-type breathing tube comprising a valve element which is neutrally buoyant in water, a member aff xed to the free end of the tube and defining an annular valve seat, a spring connecting said valve element to said member, said spring being the only such connection for said valve element, and said spring exerting a light biasing force on said valve element to cause it to seat when submerged, said valve element having a circular contour in order to mate with said annular valve seat, and said valve element being so weighted that its weight tends to unseat the valve element when not submerged.
9. A check valve as defined in claim 8 wherein said spring tension adjustment means is provided between the spring and the said member to permit the spring force of said spring on the valve element to be varied.
' 10. A check valve as defined in claim 8 wherein said valve element comprises a hollow generally spherical element having a weight loosely received in its interior such that the valve element is neutrally buoyant when submerged in water, and such that the weight tends to gravitate toward a side portion of the hollow spherical valve element and thereby to tend to unseat said valve element when not submerged.
l 1. A check valve as defined in claim 10 wherein said valve element is further characterized by an outwardly open cavity, said outwardly open cavity extending inwardly of said generally spherical valve element approximately to the center thereof, and said cavity serv ing as a receptacle for one end of said spring, said spring comprising a tension spring acting between the inner end of said outwardly open cavity and said valve seat defining member.
12. A check valve as defined in claim 11 wherein said spring tension adjustment means is further characterized by a generally internal cylindrical threaded surface on said member, said adjustment means further including spider means threadably received in said member and connected to said spring for adjusting the biasing force of the spring on the valve element.
13. A check valve as defined in claim 12 wherein said member comprises an annular valve member having a circumferentially extending inwardly beveled free end valve element.