Fluid flow control device

• US 4,431,019 A
• Filed: 06/25/1981
• Issued: 02/14/1984
• Est. Priority Date: 06/25/1981
• Status: Expired due to Term

• Current Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Original Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Inventors: Kopp, Clinton V., Hitchcock, James, Miller, Martin
• Primary Examiner(s): Cohan, Alan
• Assistant Examiner(s): Rivell, John A.
• Application Number:
  US06/277,414
• Time in Patent Office: 964 Days
• Field of Search: 137/87, 137/98, 137/100, 251/61.1, 128/214 B, 128/214 R, 128/274, 210/137, 210/433.2, 210/637
• US Class Current: 137/87.04
• CPC Class Codes: A61M 1/3496 Plasmapheresis; Leucopheresis; Lymphopheresis A61M1/3472 takes precedence
• CPC Class Codes: G05D 11/003 using interconnected flow control elements
• CPC Class Codes: Y10T 137/2705 Pressure differential
• CPC Class Codes: Y10T 137/7848 Permits flow at valve interface

Abstract

A fluid flow control device comprises first, second, and third fluid conduits. The first and second conduits are adapted to communicate with separate sources of pressurized fluid. The third conduit includes an inlet portion in direct flow communication with the first conduit and an outlet portion communicating with the atmosphere. A flexible wall forms an interface between portions of the second and third conduits. In response to fluid pressure fluctuations in the second conduit, the flexible wall simultaneously meters the flow communication through both the inlet and outlet portions of the third conduit. The fluid pressure in the first conduit is thereby elevated until substantial equilibrium with the fluid pressure in the second conduit occurs.

Claims

1. A fluid flow control device comprising

a housing peripherally enclosing an interior area,

normally planar flexible wall means extending across said interior area to compartmentalize said interior area into first and second chambers,

means for forming a first upstanding ridge in said first chamber terminating in a generally planar first surface which faces said flexible wall means in a normally noncontiguous relationship,

means for forming second and third upstanding ridges in said first chamber positioned, respectively, concentrically inwardly and concentrically outwardly of said first upstanding ridge, forming an inner fluid flow path between said first and second upstanding ridges and an outer fluid flow path between said first and third upstanding ridges, said second and third upstanding ridges terminating, respectively, in generally planar second and third surfaces, each of which faces said flexible wall means in generally said same normally noncontiguous relationship as said first generally planar surface,

means for forming in said first upstanding ridge an inlet passage having an opening which extends through said first generally planar surface to conduct a first fluid into each of said inner and outer fluid flow paths subject to a determinable pressure,

means for forming in said first upstanding ridge an outlet passage having an opening which extends through said first generally planar surface in a region spaced from said inlet passage opening to conduct the first fluid from each of said inner and outer fluid flow paths, PG,23

means for forming spaced passages communication with said said second chamber for conducting a second fluid through said second chamber subject to a determinable pressure,

said flexible wall means being operative in response to fluid pressure differentials between said first and second chambers for displacement out of its normally planar position into farther and closer association with said openings of said inlet passage and said outlet passage in said first upstanding ridge to restrict the conduction of fluid through said inlet and outlet passages to establish and thereafter maintain substantial equilibrum between the pressure of the first fluid and the pressure of the second fluid, and

said first, second, and third ridges being operative for supporting said flexible wall means in a generally coplanar position while said flexible wall means is displaced in its closest association with said openings of said inlet and outlet passages.

2. A fluid flow control device according to claim 1

and further including means for breaking surface tension between said generally flexible wall means and said generally planar first surface adjacent to said openings of said inlet and outlet passages when said closest association between said flexible wall means and said openings occurs, whereby a continuous conduction of fluid occurs through said openings of said inlet and outlet passages, despite restrictions imposed by said flexible wall means.

3. A fluid flow control device according to claim 1 or 2

where said first, second, and third upstanding ridges are circular.

4. A fluid flow control device according to claim 1 or 2

wherein said opening of said outlet passage in said first ridge is oppositely spaced from said opening of said inlet passage in said first ridge.

5. A fluid flow control device according to claim 4

wherein said first, second, and third upstanding ridges are circular.