Elastic bag for artificial respiration apparatus

Claim 1

AN EXPANSIBLE BAG FOR ARTIFICIAL RESPIRATION APPARATUS, COMPRISING A FIRST RING-SHAPED PART, A SECOND RINGSHAPED PART ARRANGED ON EACH END OF SAID FIRST RING-SHAPED PART AND CONCENTRICALLY ARRANGED IN RESPECT TO SAID FIRST RING-SHAPED PART BEING OF A SIZE TO FIT INTO SAID FIRST RING-SHAPED PART, SAID SECOND RING-SHAPED PART BEING JOINED TO SAID FIRST RING-SHAPED PART AROUND ITS PERIPHERY ADJACENT ONE SIDE BY AN ELASTIC PORTION THEREOF OF REDUCED WALL THICKNESS, SAID SECOND RING-SHAPED PART BEING COLLAPSIBLE WITHIN SAID FIRST RING-SHAPED PART AND CONSTRUCTED SO AS TO BE RETAINABLE THEREIN WITHOUT HOLDING MEANS FOR FEDUCING THE AXIAL LENGTH OF SAID BAG, AND MEANS CLOSING EACH END OF SAID FIRST AND SECOND RING-SHAPED PARTS, EACH SAID SECOND RING-SHAPED PART BEING CONNECTED TO SAID FIRST RING-SHAPED PART BY AN ELASTIC PORTION OF REDUCED WALL THICHNESS AND EACH BEING COLLAPSIBLE WITHIN SAID FIRST RINGSHAPED PART FOR REDUCING THE AXIAL LENGTH OF THE BAG, SAID FIRST RING-SHAPED PART BEING OF THIN WALLED CONSTRUCTION FOR SENSING VARIATIONS OF PRESSURE WITHIN THE BAG THROUGH FOR WALL, SAID MEANS CLOSING EACH END OF SAID AND SECOND RING-SHAPED PARTS, COMPRISING A VALVE CLOSING THE OUTER END OF EACH OF SAID SECOND RING-SHAPED PARTS, SAID SECOND RING-SHAPED PARTS BEING COLLAPSIBLE WITHIN SAID FIRST RING-SHAPD PARTS AND BEING AUTOMATICALLY RETAINABLE THEREIN UPON COLLAPSING TO REDUCE THE AXIAL LENGTH OF THE BAG.