GB822680A - Improvements in or relating to breathing apparatus for swimmers - Google Patents

Abstract

822,680. Respiratory appliances. GIRDEN, B. B. Nov. 6, 1957, No. 34558/57. Class 81 (2). A breathing tube for swimmers has a floatactuated balanced closure valve, so that it will not tend to be opened by pressure within the mouthpiece or mask. The type of valve preferred is a balanced butterfly valve 23, Fig. 3, mounted on a spindle 24 so that it can be closed by a float 27 on an arm 28, when the float tends to rise. Semicircular seatings 25, 26 are provided in the tube 12 for engagement by the vane 23 and the top of the tube carries a shroud 13 to prevent water splashing into it. The lower end of the tube 12 leads into a mouthpiece 11, Fig. 2, held on the user's head by a strap 29 and, in the form shown, the mouthpiece also communicates with an inflatable bladder 17, which serves as a rebreathing bag, so that the user can exhale and inhale instead of holding the breath continuously. A flap valve 19 is fitted at the bottom of the bladder so that water can be blown out when the user is at the surface. In a modified form, separate inlet and outlet tubes are used, the former communicating with the nose and the latter with the mouth. In this case the float-actuated valve is mounted in an outlet common to the two tubes so that, when closed, it prevents water entering the tubes but, at the same time, leaves a communicating space between them. If a bladder is fitted to the mouthpiece in this form it is inflated from the mouthpiece and air is withdrawn from it to the inlet tube through the outlet tube and communicating space. A third form of the apparatus has a mask fitted over the eyes and nose only but has a separate mouthpiece connected as in the foregoing embodiment.