Control for oxygen enrichment of breathing air - has rotatable disc which varies size of air and oxygen inlets

摘要

A patient is supplied with breathing air which is enriched with oxygen. The breathing apparatus has a mixing chamber with inlets (10-11) for air and for oxygen. These inlets can be covered by a rotatable plate with a spiral slot (12). The plate can be rotated about the shaft (13) with the edges of the slot partly or wholly covering the inlets. In one extreme position of the rotatable plate one of the inlets (10) lies within the slot and so is fully open whilst the other inlet lies outside the slot and is fully closed. As the plate is rotated the inlet (10) is gradually closed whilst the inlet (11). ADVANTAGE - Simple control of the degree of oxygen enrichment.