ANESTHESIA REBREATHING APPARATUS RESERVOIRS FOR ANESTHESIA REBREATHING APPARATUS

摘要

1427431 Valves M L HENKIN 16 Jan 1973 [17 Jan 1972] 2297/73 Heading F2V [Also in Division A5] Anaesthetic apparatus (see Division A5) includes a pressure relief valve which vibrates to emit an audible alarm when open and a oneway valve which opens in response to exhalation of the patient, the pressure relief valve may comprise an elastic disc valve 240, Fig. 16, which vibrates when open and which closes against a cup-shaped recess 244 in a wall 216 and has an elastic shaft 248 supporting a retaining flange 250 and a pull tab 253 by which it is assembled and held in an aperture in the recessed part of the wall 216. Alternatively, the pressure relief valve may comprise an elastic sleeve 400, Fig. 26, secured at its ends about a portion of a breathing tube 402 of the anaesthetic apparatus, an intermediate portion of the sleeve being held against the breathing tube by an elastic band 410. The breathing tube 402 has an aperture 408 beneath a portion of the sleeve 400 on one side of the elastic band 410, the elastic sleeve having a slit 412 in its other portion which opens to relieve pressure in the breathing tube and produce audible vibrations when the pressure is sufficiently great to overcome the constricting effect of the elastic band on the sleeve. The one-way exhalation valve comprises a valve element 218, Fig. 14, having two pins 220, 224 received in wells in the valve having, the valve element being slightly stressed and thus bowed about an axis through the pins 220, 224 and conforming to its curved valve seat 226.