GB964788A - Improvements in or relating to underwater breathing apparatus - Google Patents

Abstract

964,788. Respiratory appliances. R. GALEAZZI. Oct. 27, 1960 [Oct. 28, 1959], No. 37016/60. Heading A5T. A pressure equalizing vessel for use with underwater breathing equipment such as that disclosed in Specification 964,787 comprises a vessel 10 mounted at 30 and 33 for pivotal movement about two horizontal axes and carrying weights 39 which, when the vessel is freely suspended, urge it into a position in which an opening 309 faces downwardly. A chamber 36 containing CO 2 absorbing material communicates with a hollow pivot 134 at one end and through a perforated wall 200 with the interior of the vessel. Exhaled gases pass from a distributing chamber 7 through a hose 9 and the other pivot 34 into the vessel and thence through the wall 200 into the chamber 36. Part of each exhalation may be exhausted from the vessel through non-return valves 40. The opening 309 is covered by a perforated plate 210 above which is mounted a flexible membrane 38 on bellows (not shown) which expand into the vessel when the external pressure increases, e.g. when the user submerges. In an alternative embodiment, Fig. 5, in which pivotal movement is possible about a vertical axis also, the CO 2 absorbing material is contained in the upper part 82 of the vessel, exhaled gases entering the vessel through a hollow pivot 74 and passing via a pipe 75 into chamber 82 through an aperture 83 covered by a perforated plate 86. In a slightly modified form of vessel the pivot 69 is also hollow and leads to a pipe 75 communicating with a second aperture 83. An aperture 84 has associated with it a float 89 urged towards the aperture by a spring 92 but sufficiently heavy to compress the spring when the float is out of water. In operation, when the vessel is upright and the float out of water, exhaled gases from which CO 2 has been removed in the chamber 82 pass through the aperture 84 into the body 85 of the vessel and flow back to be reinhaled, excess gases being exhausted through apertures 309. If the body 85 is flooded, the buoyancy of the float and the force of the spring, urge the float to close the aperture 84 and prevent water entering the chamber 82.