Pressure unloading valve device for compressor

• US 4,037,994 A
• Filed: 03/31/1975
• Issued: 07/26/1977
• Est. Priority Date: 03/31/1975
• Status: Expired due to Term

• Current Assignee: Forrest M. Bird
• Original Assignee: Forrest M. Bird
• Inventors: Bird, Forrest M.
• Primary Examiner(s): Vrablik, John J.
• Assistant Examiner(s): Look, Edward
• Application Number:
  US05/563,692
• Time in Patent Office: 848 Days
• Field of Search: 417/299, 417/26, 417/33, 417/440, 417/442, 417/563, 417/298, 417/306, 417/557, 417/316, 128/145.6, 128/203, 128/145.5, 128/145.8, 128/142.3, 128/DIG. 17, 200/61.86, 200/83 Q, 251/191
• US Class Current: 417/316
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: F04B 49/24 Bypassing

Abstract

A valve device is disclosed for unloading pressure from a compressor of the type utilized in a medical respirator. The device is formed with a cylindrical chamber containing a compressible elastomeric member. Inlet and relief ports of the valve open into the chamber, and the inlet port is connected with the outlet of the gas compressor. Bistable actuator means is provided for moving a plunger within the chamber which in turn causes the cylindrical member to assume either a compressed or uncompressed state. In its uncompressed state a radial clearance between the outer wall of the elastomeric member and the chamber provides a flow path between the inlet and relief ports to bleed pressure from the compressor. In its compressed state the elastomeric member expands to occlude the flowpath and prevent pressure bleed-off from the compressor. A switch is provided to open and close a circuit between the compressor and a source of electrical power responsive respectively to the uncompressed and compressed states of the elastomeric member.

Claims

1. A device for use with a gas compressor having an outlet passage for directing gas to end use apparatus, including the combination of a valve body having at least one relief port and an inlet port in connection with the outlet passage of said compressor, means forming a chamber in the valve body for establishing fluid communication with said inlet and relief ports, a compressible elastomeric member mounted within said chamber, said member being sized to define in its substantially uncompressed state a clearance with the wall of the chamber, said clearance establishing a gas relief flow path through the chamber between said inlet and relief ports, said member in its compressed state contacting said chamber wall to occlude said relief flow path, and actuator means operable in one mode for causing said member to assume its compressed state and occlude the flow path while energizing said compressor, said actuator means further being operable in another mode for causing said member to assume its uncompressed state while said compressor is deenergized whereby gas pressure is relieved from the compressor outlet through said relief flow path and through the relief port of the valve body, said actuator means including a plunger slidably mounted for movement within the chamber, cam means operable for movement between a compressor-on and a compressor-off position, said cam means in the compressor-on position moving the plunger in a first direction for exerting a thrust force against the elastomeric member to cause the same to assume its compressed state, the cam means in said compressor-off position permitting movement of the plunger in a second direction away from the elastomeric member to cause the same to assume its uncompressed state, electrical contact means operable between first and second positions in which said gas compressor is operatively disconnected and connected, respectively, with a source of electrical power, and a second plunger disposed in operating engagement with said contact means, said second plunger being positioned in juxtaposed relationship with said elastomeric member whereby the latter undergoes respective elastic bulging and contraction between said compressed and uncompressed states for moving the second plunger to operate said contact means between respective second and first positions.

2. Apparatus for unloading trapped gas pressure from a compressor which is operated by a source of electrical power to supply gas under pressure through an outlet passage, the apparatus including the combination of a housing defining a cylindrical chamber, an inlet port in the housing connected with the outlet passage of the compressor for communicating gas therefrom into the chamber, a relief port in the housing for bleeding gas from the chamber, an elastomeric cylindrical disk mounted in the chamber, said disk being sized with a radial clearance from the cylindrical chamber, means forming a circular shoulder in one end of the chamber for supporting a peripheral end margin of the disk, a first plunger mounted for movement within the chamber on a side of the disk opposite said one end of the chamber, a cam rotatably mounted on the housing between first and second positions in operating contact with the first plunger, said cam in its second position urging the first plunger towards said one end of the chamber for compressing said disk whereby the outer surface thereof distends radially into sealing contact with the wall of the chamber for occluding communication between said inlet and relief port, said cam in its first position permitting movement of the first plunger in a direction away from said one end of the chamber whereby the outer surface of said disk is permitted to retract by the action of its plastic memory away from the wall of the chamber permitting fluid communication between said inlet and relief ports, means forming a circuit for connecting said source of electrical power with said compressor, said circuit means including electrical contact means operable between first and second positions for respectively opening and closing said circuit, and second plunger means operably connected with said contact means, said second plunger means having one end positioned in juxtaposed relationship with the disk whereby distension thereof responsive to movement of the first plunger as the cam is moved to said compressor-on position operates the contact means to said second position, and retraction of said disk responsive to movement of the first plunger as the cam is moved to said compressor-off position operates said contact means to said first position.

3. In a respirator unit for delivering a supply of gas to the airway of a patient, the combination of compressor means for discharging a supply of gas under pressure through an outlet, said compressor means being powered from a source of electrical energy, a valve body defining a cylindrical chamber, inlet port means formed in the valve body for communicating gas from the compressor outlet into the chamber, relief port means formed in the valve body for bleeding gas from the chamber, an elastomeric member mounted in the chamber, said member being sized and proportioned to assume an uncompressed state defining a radial clearance between the walls of the member and chamber and a compressed state in which the member radially distends into contact with the chamber walls for occluding flow through the chamber between the inlet and relief port means, bi-stable actuator means selectively operable between first and second positions in which said elastomeric member is respectively urged between its uncompressed and compressed states, and circuit means for opening and closing a conductive path between said source of electrical energy and said compressor when the elastomeric member is in its respective uncompressed and compressed states, the actuator means is mounted in one end of said chamber and includes an element which in said second position contacts the elastomeric member with a thrust force for causing the latter to assume its compressed state, said actuator means in its first position releases the element from the elastomeric member to permit the latter to assume its uncompressed state through the action of its plastic memory, and said valve body includes means forming a shoulder which surrounds a central opening at the opposite end of the chamber, said shoulder supporting the elastomeric member in an axial direction, sand said circuit means includes a switch operable between opened and closed modes, a plunger operably mounted with said switch, said plunger having one end extending into said valve body adjacent said central opening in juxtaposition with the elastomeric member whereby said member in its compressed state bulges through said central opening and exerts a thrust force against said one end of the plunger for operating the switch to its closed mode.

4. A respirator unit as in claim 3 in which said element of the actuator means comprises an additional plunger mounted for axial sliding movement in said one end of the chamber operably mounted with the elastomeric member, together with a cam having first and second angularly disposed lobes, said first lobe having a cam lift which is greater than said second lobe, and means for selectively actuating the cam to a position at which the first lobe engages the additional plunger and moves the same towards the elastomeric member for compressing the latter, said last mentioned means further activating the cam to another position at which the second lobe permits movement of the additional plunger away from the elastomeric member to permit the same to assume its uncompressed state.