Abstract: Breathing apparatus supplies air or oxygen to a patient and comprises a hand-held housing (10), a gas inlet on the housing, a gas outlet (12) on the housing (10), and a manual/automatic switch (16) on the housing for supplying gas either to a manually operable valve (40) or to a main valve (48) which delivers gas to the outlet on a cyclic basis. A trigger (22) on the housing (10) controls the supply of gas to the outlet through the manually operable valve (40).

Abstract: A breathing apparatus is described for supplying pulses of a breathable gas to a patient; the apparatus comprises a gas inlet (10) connectable to a source of breathable gas, an outlet (37) connectable to provide gas to the patient, a gas flow passage (14,15,34,36) extending between the inlet and the outlet, a main valve (16) located in the gas flow passage for interrupting the flow of gas to the outlet, a throttle (38) in the flow passage downstream of the main valve, a gas reservoir (42) and a valved duct (40,44) connected to supply gas to the reservoir from the part of the flow passage between the main valve and the throttle; the main valve includes a piston (24) that is slidable within a cylinder (22) to open and close the gas flow passage, which piston is biassed in one direction by a resilient member (28) and biassed in the other direction by the gas pressure within the reservoir.

Abstract: A valve system is described by means of which air can be supplied to a patient either automatically, i.e. in pulses from a control module (19), or under manual control. The valve system has a housing (10) containing an outlet end (16) connected to a face mask (11), a first channel (24) connected to the control module (19) via an annular line (21) for supply of pulsed air to the mask and a second channel (32) connected to a steady source of air via a line 28 for supply of air under manual control to the face mask. A main valve member (33) is provided that can slide between a first position (as shown) that allows gas to pass down the first channel (24) to the mask and closes off the second channel (32) and a second position that allows gas to pass down the second channel (32) to the mask and closes off the first channel (24). In the second position of the main valve (33), the supply of air to the patient is controlled by a manually operable second valve member (62) in the second channel (32).