GB842890A - Improvements in or relating to apparatus for maintaining artificial respiration - Google Patents

Abstract

842,890. Respiratory appliances. MANLEY, R. E.W. Jan. 10 1958 [Oct. 12,1956], No.31104/56. Class 81(2). In artificial respiration apparatus the gas is supplied to the patient through a bellows or similar arrangement, the bellows co-operating with means for controlling the flow of gas to and from the bellows and having a jockey weight for applying an adjustable moment to the bellows in order to determine the pressure supplied to the patient. The bellows 12, fig. 2 is mounted between the top plate 11a of a casing 11 and a rectangular frame 14 mounted on a horizontal pivot 15. The frame 14 carries an arcuate arm at its free end and this has a fixed stop 16 and adjustable stop 18 which co-operate with toggle mechanism for actuating control valves, the effect being such that a lever 24, fig. 4, is raised and lowered at the upper and lower limits of the bellows movement. The lever 24 is secured to a rod 22 which is made to snap from one extreme position to the other by a spring 26. Abutments 30a, 30b, attached to the rod 22 consequently drive a lever 31 connected to a valve plunger 29 which, in its righthand position, connects ports 21a, 21b to allow gas to pass from the bellows to the face mask and, in its left-hand position, connects ports 21c, 21d, to allow gas to pass from the mask to atmosphere through a pipe 32. The gas supply is led into the bellows and inflates it until the trip mechanism is actuated, whereupon the gas supply is cut off by a valve not shown and communication between ports 21a, 21b allows the bellows to collapse, under the action of adjustable weight 33, and pass the gas into the lungs. On complete collapse of the bellows the trip is again actuated and the lungs are emptied through ports 21c, 21d while the bellows is again being inflated. Adjustment of the setting of the weight 33 determines the pressure at which the gas is maintained as it passes into the lungs.