US 4,059,657 AGranted

Calibrated anesthetic vaporizer

AssigneeAirco, Inc.

InventorWayne W. Hay

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Abstract

Anesthetic vaporizer of the flow-through type having a calibrated flow control valve unit for proportional distribution of the inlet gas between a vaporizing chamber and a main bypass passage to obtain a desired anesthetic concentration. A rotary, multiple-port valve with a multiplicity of laminar flow-type passages in parallel is operable in discrete steps for adding the anesthetic vapor from the chamber in predictable increments to a preset flow of the inlet gas for proportional gas division. An auxiliary gas bypass for temperature compensation has a cone-type valve with restricted opening controlled by a temperature responsive motor in the vaporizing chamber. A wick assembly in the anesthetic vaporizing chamber guides the chamber gas through a multiplicity of parallel passages formed by stacked sheets of absorbent and corrugated materials respectively, to obtain maximum vaporization of the anesthetic.

Claims12

Dependent claims

An anesthetic vaporizer for adding the vapor of a volatile liquid anesthetic in predictable increments to a preset flow of gas comprising:

a. a gas inlet passage and a gas and vapor outlet passage,
b. a vaporizing chamber containing liquid anesthetic,
c. a rotary valve assembly for controlling passages connecting the vaporizing chamber to the inlet and outlet passages, and for bypassing the vaporizing chamber comprising a disc-like valve rotor and an enclosing cylinder-like body having a fixed circular seat for the rotor,
d. the rotor and seat being in planar contact and having in combination a plurality of ports and passageways arranged to form a first proportioning multiple-passage laminar-flow control path from the gas inlet passage through the vaporizing chamber to the outlet passage, and a second proportioning multiple-passage laminar-flow control path from the gas inlet through the valve bypassing the vaporizing chamber to the outlet passage,
e. the valve rotor having a calibrated operating dial and being angularly adjustable to proportion the flow between the first and second paths for adjusting the vapor concentration in the outlet mixture,
f. a third laminar-flow control path for connecting the gas inlet passage to the outlet passage to bypass the vaporizing chamber, said third path having a single variable restriction for laminar flow control that is defined by nested conical members with restricted spacing for preset minimum laminar flow,
g. temperature responsive means in the vaporizing chamber for varying the spacing between the conical members to thereby control gas flow in said third path and compensate for variations in the vapor pressure of the liquid anesthetic, and
h. the enclosing valve body defining an inlet gas chamber above the valve rotor and the valve rotor having an arcuate slot on its seating face that connects through a rotor port with the chamber, and with the gas inlet through the valve seat for admitting gas to the chamber, the rotor having diametrically opposite the arcuate slot spaced laminar flow type parallel passages defining an arc having a greater radius than the arcuate slot, the passages leading from the inlet gas chamber in divided flow to passageways in the valve seat that lead in turn respectively, to the vaporizing chamber and directly to the outlet passage to bypass the vaporizing chamber.

5 more elements

An anesthetic vaporizer for adding the vapor of a volatile liquid anesthetic in predictable increments to a preset flow of gas comprising:

a. a gas inlet passage and a gas and vapor outlet passage,
b. a vaporizing chamber containing liquid anesthetic,
c. a rotary valve assembly for controlling passages connecting the vaporizing chamber to the inlet and outlet passages, and for bypassing the vaporizing chamber comprising a disc-like valve rotor and an enclosing cylinder-like body having a fixed circular seat for the rotor,
d. the rotor and seat being in planar contact and having in combination a plurality of ports and passageways arranged to form a first proportioning multiple-passage laminar-flow control path from the gas inlet passage through the vaporizing chamber to the outlet passage and a second proportioning multiple-passage laminar-flow control path from the gas inlet through the valve bypassing the vaporizing chamber to the outlet passage,
e. the valve rotor having a calibrated operating dial and being angularly adjustable to proportion the flow between the first and second paths for adjusting the vapor concentration in the outlet mixture,
f. a third laminar-flow control path for connecting the gas inlet passage to the outlet passage to bypass the vaporizing chamber, said third path having a single variable restriction for laminar flow control that is defined by nested conical members with restricted spacing for preset minimum laminar flow,
g. temperature responsive means in the vaporizing chamber for varying the spacing between the conical members to thereby control gas flow in said third path and compensate for variations in the vapor pressure of the liquid anesthetic, and
h. the valve enclosing body has on its base side a horizontal labyrinth-like groove, and a partition plate between the vaporizing chamber and the valve body covers the groove to form a labyrinthean passage that connects the outlet of the vaporizing chamber with the rotary valve.

5 more elements

An anesthetic vaporizer for adding the vapor of a volatile liquid anesthetic in predictable increments to a preset flow of gas comprising:

a. a gas inlet passage and a gas and vapor outlet passage,
b. a vaporizing chamber containing liquid anesthetic,
c. a rotary assembly for controlling passages connecting the vaporizing chamber to the inlet and outlet passages, and for bypassing the vaporizing chamber comprising a disc-like valve rotor and an enclosing cylinder-like body having a fixed circular seat for the rotor,
d. the rotor and seat being in planar contact and having in combination a plurality of ports and passageways arranged to form a first proportioning multiple-passage laminar-flow control path from the gas inlet passage through the vaporizing chamber to the outlet passage, and a second proportioning multiple-passage laminar-flow control path from the gas inlet through the valve bypassing the vaporizing chamber to the outlet passage,
e. the valve rotor having a calibrated operating dial and being angularly adjustable to proportion the flow between the first and second paths for adjusting the vapor concentration in the outlet mixture,
f. a third laminar-flow control path for connecting the gas inlet passage to the outlet passage to bypass the vaporizing chamber, said third path having a single variable restriction for laminar flow control that is defined by nested conical members with restricted spacing for preset minimum laminar flow,
g. temperature responsive means in the vaporizing chamber for varying the spacing between the conical members to thereby control gas flow in said third path and compensate for variations in the vapor pressure of the liquid anesthetic,
h. the conical members in the third path constituting a conical valve and seat having a minimum closing clearance and having laminar flow characteristics throughout its variable clearance range, and the valve clearance is controlled by a thermal motor located in the vaporizing chamber at its outlet,
j. the conical valve being of the double-cone type with the inner cone connected to the thermal motor for varying the valve clearance, and the outer cone constitutes part of a fixed housing mounted within the valve body,
j. the thermal motor being of the metallic bellows type that is within and attached to a cylindrical housing that extends in depending relation from the cone valve housing, the depending house being disposed in the vaporizing chamber in the path of exhaust vapor therefrom, and
k. the depending motor housing is vertically adjustable with respect to the cone housing for causing adjustment of the minimum valve clearance.

8 more elements

Dependencies are inferred from the claim text.