Improvements in or relating to respirator machines

Abstract

Abstract 971,953. Respiratory devices. BLEASE ANAESTHETIC EQUIPMENT Ltd. May 9, 1963 [June 15, 1962], No. 23218/62. Heading A5T. A respiratory device comprises a one-way exhaust valve 44 having its inlet in communication with an exhalation valve 42 and a passageway 46 through which gas is drawn and an admittance valve 52 biased shut and able to admit air to the passageway 46 when the bias is overcome, the device being such that when gas issues through the exhalation valve 42 at a rate lower than the rate at which it is drawn through the passageway 46 the exhaust valve 44 is closed and the pressure in the passageway 46 becomes subatmospheric, the maximum value of this subatmospheric pressure being determined by the bias on the admittance valve 52. On inflation of bellows 4 (which is biased shut by compression spring 8), by compressed air entering by inlet 6, needle 10 moves away from valve seat 12 and pivoted lever 14 comes in contact with movable stop 16 which opens valve 22. As bellows 4 collapse air is forced into bellows 18 and as bellows 18 expand bellows 48 expand. At this stage inhalation valve 36 is closed and the patient exhales through exhalation valve 42. Initially the rate of exhalation is greater than the rate at which gas is being drawn into bellows 48 and exhaust valve 44 is open to the atmosphere. When the rate of gas drops below that at which it is entering bellows 48, valve 44 closes and a subatmospheric pressure builds up in passageway 46 till the valve member 52 overcomes the bias of counterweight 56 to allow air to enter passageway 46. The pressure in the passageway 46 remains constant until the exhalation period is completed which is marked by contact 30 contacting movable stop 32 to close valve 22, by the closing of exhalation valve 42 and by the opening of inhalation valve 36 to permit bellows 18 to exhaust their contents to the patient. As bellows 18 deflate bellows 48 deflate, gas in bellows 48 escapes to the atmosphere through valve 58, and bellows 4 inflate to start another cycle.

Inventors

• 👤 John Henry Blease
• 👤 Roger Edward Wentworth Manley

Bibliographic Details