Fluid flow control

• US 5,009,251 A
• Filed: 11/15/1988
• Issued: 04/23/1991
• Est. Priority Date: 11/15/1988
• Status: Expired due to Term

• Current Assignee: ISC Licensing Corporation
• Original Assignee: Baxter International Inc.
• Inventors: Pike, Kelly A., Hessel, Stephen R.
• Primary Examiner(s): Hepperle, Stephen M.
• Application Number:
  US07/271,730
• Time in Patent Office: 889 Days
• Field of Search: 137/599, 137/601, 137/636.1, 137/607, 137/863, 137/597, 137/561 A, 137/861, 604/246, 251/10, 251/9, 251/7
• US Class Current: 137/599.06
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: F16K 31/52416 comprising a multiple-way lift valve
• CPC Class Codes: Y10T 137/85938 Non-valved flow dividers
• CPC Class Codes: Y10T 137/87064 Oppositely movable cam surfaces
• CPC Class Codes: Y10T 137/87306 Having plural branches under common control for separate valve actuators

Abstract

Disclosed is a variable fluid flow controller for regulating the rate of flow from a source of fluid under pressure, comprising a plurality of unique flow restriction passagways, a valve associated with each passageway, and a rotatable cam for selectively opening any one of the valves while maintaining the remaining valves closed. The flow restriction passageway preferably comprises a channel etched on the surface of a first silicon wafer and enclosed by a second wafer to form a fluid flow passageway, one of the first or second wafers having a plurality of apertures therethrough for intersecting the passageway at various distances along its length.

Claims

1. A flow controller for regulating the rate of flow from a source of fluid under pressure, comprising:

(a) a housing having an influent, effluent port, and fluid flow path therebetween;

(b) a flow restriction channel in the flow path, for regulating the rate of flow, said restriction channel having an influent end and at least two effluent apertures along its length;

(c) a valve in the housing associated with each of the apertures along the flow path; and

(d) a single control for selectively opening any one of the valves and maintaining each additional valve closed;

wherein the opening of any one of the valves places in the influent port in fluid communication with effluent port by way of the a unique length of flow restriction channels associated with the open valve.

2. A flow controller as in claim 1, wherein the valve comprises a fluid passageway having a movable wall, and means of compressing the wall to prevent flow through the passageway.

3. A flow controller as in claim 2, wherein the fluid passageway is enlarged in cross-sectional dimension in the area of the valve to form a valve chamber for receiving the movable wall.

4. A flow controller as in claim 2, wherein the movable wall comprises a flexible elastomeric material.

5. A flow controller as in claim 4, wherein the fluid passageway comprises a groove formed on the surface of the housing, and an elastomeric gasket for enclosing the grooves to form a fluid passageway.

6. A flow regulator, comprising:

(a) a first plate having a flow channel on the surface thereof;

(b) a second plate, secured to the surface of the first plate and enclosing the flow channel to form a chip having a capillary tube therethrough;

(c) an influent port on the chip, in fluid communication with the capillary tube; and

(d) a plurality of effluent apertures on the chip, each in fluid communication with the capillary tube at a different distance along its length from the influent port.

7. A flow controller for regulating the rate of flow from a source of fluid under pressure, comprising:

(a) a housing having an influent port, an effluent port, and a fluid flow path therebetween;

(b) a plurality of flow restriction channels in the flow path, for regulating the rate of flow;

(c) a plurality of normally closed valves in the housing, each valve associated with a different flow restriction channel; and

(d) a single control, for selectively opening any one of the valves;

wherein opening any of the valves places the influent port in fluid communication with the effluent port by way of a unique flow restriction channel associated with the open valve.

8. A flow controller as in claim 7, wherein the flow restriction channels are formed on the surface of a silicon wafer.

9. A variable rate fluid flow controller for providing a predetermined delivery rate from a pressurized source of fluid medication, comprising:

(a) a housing having an influent port, an effluent port and at least two predetermined capillary flow paths therebetween such that each flow path has a different predetermined capillary length to provide a predetermined flow rate between the inlet port and the outlet port.

(b) at least two pinch valves in the housing, each pinch valve associated with one of said capillary flow paths; and

(c) a movable cam for selectively opening and closing the pinch valves.

10. A variable flow controller as in claim 9, wherein the flow paths are disposed in a series relationship between the influent and effluent ports.

11. A variable flow controller as in claim 9, wherein the flow paths are disposed in a parallel relationship between the influent and effluent ports.

12. A variable flow controller as in claim 9, wherein the flow paths comprise a length of flow restriction tubing having at least two effluent apertures thereon.

13. A variable flow controller as in claim 9, wherein the cam permits opening of any one of the pinch valves while maintaining all other pinch valves closed.

14. A variable flow controller as in claim 9, wherein each flow path comprises a flexible diaphragm which is compressed by the cam to prevent fluid flow through the flow path.

15. A variable flow controller as in claim 14, wherein the cam is rotatable.

16. A variable flow controller as in claim 15, further comprising a piston associated with each valve, the piston movable from a first position in which fluid is permitted to flow through the valve and a second position in which the flexible diaphragm is compressed to prevent fluid flow through the valve, the piston movable from the first to the second position in response to the rotational position of the cam.

17. A flow controller for regulating the rate of flow from a source of fluid under pressure, comprising:

(a) a housing having an influent port, an effluent port and a fluid flow path therebetween;

(b) a plurality of flow restriction channels in a series relationship along the flow path, for regulating the rate of flow;

(c) a plurality of normally closed valves in the housing, each associated with a different flow restriction channel; and

(d) a single control for selectively opening at least one of the valves;

wherein opening any one of the valves places in the influent port in fluid communication with the effluent port by way of a unique flow restriction channel associated with the open valve.