Check valve

• US 4,141,379 A
• Filed: 05/16/1977
• Issued: 02/27/1979
• Est. Priority Date: 05/16/1977
• Status: Expired due to Term

• Current Assignee: Cutter Laboratories, Inc. (Bayer AG)
• Original Assignee: Cutter Laboratories, Inc. (Bayer AG)
• Inventors: Manske, Reinhold R.
• Primary Examiner(s): Nilson, Robert G.
• Application Number:
  US05/796,923
• Time in Patent Office: 652 Days
• Field of Search: 128/214 R, 128/274, 137/496, 137/550, 137/859, 137/854, 137/517, 210/117, 210/430
• US Class Current: 137/496
• CPC Class Codes: A61M 2039/242 designed to open when a predetermined pressure or flow rate has been reached, e.g. check valve actuated by fluid
• CPC Class Codes: A61M 2039/2433 Valve comprising a resilient or deformable element, e.g. flap valve, deformable disc
• CPC Class Codes: A61M 2039/246 being fixed along all or a part of its periphery
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: F16K 15/1402 having an integral flexible member cooperating with a plurality of seating surfaces
• CPC Class Codes: F16K 15/144 the closure elements being fixed along all or a part of their periphery
• CPC Class Codes: Y10T 137/7783 Valve closes in responses to reverse flow
• CPC Class Codes: Y10T 137/7869 Biased open
• CPC Class Codes: Y10T 137/8122 Planar strainer normal to flow path

Abstract

An improved check valve is disclosed for use in a system for sequentially delivering primary and secondary solutions through a common conduit. The check valve comprises a hollow housing with an inlet and an outlet connected to an enlarged intermediate portion. Sealed at its periphery in the enlarged portion is a flexible diaphragm characterized by having foraminous means in at least its outer portion and imperforate means in its central portion. The imperforate means is spaced from a valve seat surrounding the passage at the inner end of the inlet so that when the primary solution flows from the inlet to the outlet, it will pass freely around the imperforate means and through the foraminous means. When an increase in pressure, even though slight, is exerted against the diaphragm caused by flow of the secondary solution in the direction of the outlet to the inlet, the diaphragm moves towards the inlet causing the imperforate means to seal against the valve seat and stop the flow of the primary solution.

Claims

1. A check valve in a system for administering parenteral solutions comprising an elongated hollow housing having an enlarged portion between an inlet and an outlet, a thin flexible screen sealed peripherally within the enlarged portion and lying transversely to the inlet, means for supporting the screen, the support means being located in that part of the enlarged portion adjacent the outlet, a valve seat adjacent the passage at the inner end of the inlet, a thin resilient impervious disc separate from the screen and lying between the screen and the valve seat and adapted for releasably sealing the passage of the inlet, the screen and the disc being spaced from the valve seat with the screen being in an unflexed condition when the valve is in its normally open position whereby liquid flowing in the direction of the inlet to the outlet will pass freely around the disc and through at least a portion of the screen, whereas liquid when flowing in the direction of the outlet to the inlet effects movement of the screen against the disc sufficient to cause the disc to contact the valve seat and stop the flow of liquid when the pressure of the liquid at the outlet exceeds the pressure of the liquid at the inlet by at least about one inch of water.

2. The check valve of claim 1 wherein the support means comprises a plurality of ribs extending radially around the passage of the outlet.

3. The check valve of claim 2 wherein the foraminous member is a screen having a porosity of between 5 and 75 microns.

4. The check valve of claim 3 wherein the valve seat comprises a rounded annular projection surrounding the passage of the inlet.

5. The check valve of claim 4 wherein the resilient disc is substantially square.

6. A check valve in a system for administering parenteral solutions comprising a hollow housing having an enlarged portion between an inlet and an outlet, a thin flexible screen sealed peripherally within the enlarged portion and lying transversely to the inlet, the screen having a porosity in the range of about 5 to 75 microns, a plurality of ribs extending radially in that part of the enlarged portion adjacent the outlet for supporting the screen, a valve seat comprising a rounded annular projection surrounding the passage of the inlet, a thin resilient unattached disc positioned between the valve seat and the screen and having an area smaller than the area of the screen but sufficient to span the valve seat, the disc and the screen being spaced from the valve seat and with the screen being in an unflexed condition when the valve is in its normally open position, whereby liquid flowing in the direction of the inlet to the outlet passes freely around the disc and through the screen, whereas liquid flowing in the direction of the outlet to the inlet effects movement of the screen against the disc sufficient to cause the disc to contact the valve seat and stop the flow of liquid when the pressure of the liquid at the outlet exceeds the pressure of the liquid at the inlet by at least about one inch of water.