GB297808A - Improvements in and connected with respiratory apparatus - Google Patents

Abstract

297,808. Deutsche Gasgl³hlicht- Auer - - Ges., and Hanseatische Apparatebau Ges. vorm. L. von Bremen. & Co. Sept. 29, 1927, [Convention date]. Respirators. - In closed-circuit respirators the excess pressure in the apparatus is relieved through an aperture opened positively by the action of a member adapted completely or partially to close the breathing circuit, for example the exhaling valve. As shown in Fig. 1a the exhaling valve t, co-operating with a seating d to control the breathing circuit, has also a seating d' upon a pipe f leading to a relief tube of capillary dimensions through which excess air is passed when the valve t opens. The valve t may comprise a disc or flexible membrane seating upon the ends of concentric tubes forming the breathing circuit : in these constructions the pipe f communicates with the valve casing. As shown in Fig. 5 a conical relief valve s is connected by a rod c with a resiliently mounted disc q displaceable by the current of exhaled air and moving into an enlarged part u of the breathing pipe. This device may be positioned close to the breathing bag and may take the place of an exhaling valve. In another construction a disc relief valve is connected by a rod directly to an exhaling valve such as t, Fig. 1a. Where a separate relief valve is provided this valve may be made to communicate with a relief tube such as f. In order to prevent blockage of the capillary portion of the relief tube by dirt or condensation this portion may be arranged in a protected position and in close juxtaposition to the filter cartridge.