Differential thermal expansion driven pump

• US 4,636,149 A
• Filed: 04/29/1986
• Issued: 01/13/1987
• Est. Priority Date: 05/13/1985
• Status: Expired due to Fees

• Current Assignee: NMT Medical Incorporated
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Brown, David C.
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Stout, Donald E.
• Application Number:
  US06/858,823
• Time in Patent Office: 259 Days
• Field of Search: 417/321, 417/322, 417/413, 417/568, 60/528, 60/529
• US Class Current: 417/322
• CPC Class Codes: F04B 43/04 Pumps having electric drive

Abstract

The biomedical pump includes a housing with an internal pump chamber defined by a first rigid concave wall formed by the pump body, and an opposed flexible wall defined by a diaphragm incorporating a heat responsive disc for a thermal-responsive pumping movement between a first position overlying and conforming to the body defined first wall and a second position outwardly spaced therefrom. An inlet passageway and an outlet passageway each communicate with the interior of the chamber through the pump body. Each passageway incorporates a one-way check valve for a directional control of the fluid flow in response to the heat induced diaphragm movement.

Claims

1. A biomedical pump for use in the measured pumping of a medicament or the like, said pump comprising:

a pump body;

a pump chamber in said body, said chamber being defined by a first wall formed by said body and an opposed second wall;

an inlet passageway through said body, said inlet passageway including an inlet port in communication with said chamber through said first wall;

an outlet passageway through said body, said outlet passageway including an outlet port in communication with said chamber through said first wall;

a flow inducing diaphragm including a bimetallic member, facing said first wall, and being selectively movable between a first position closely overlying and conforming to said first wall and sealing said ports and a selected second position which is outwardly spaced from said first wall, the side of said diaphragm facing said first wall defining said second wall and defining a selected volumetric interior space within said chamber between said first and second walls;

said diaphragm, in said first position, eliminating the selected volumetric interior space of said chamber;

said diaphragm bimetallic member being heat responsive for effecting regulated flexure of said diaphragm between said first and second positions in response to heating and cooling of said heat responsive bimetallic member to effect precise pumping of a selected volume of fluid defined by said selected volumetric interior space of said chamber, electrical conductor means coupled to said bimetallic member and extending outwardly therefrom;

said bimetallic member being selectively flexible by the control of the input of electrical energy thereto;

a support ring engaging said bimetallic member in a heat transfer manner and being capable of conducting heat away from said bimetallic member to expedite cooling of said bimetallic member; and

, means connected to said diaphragm and extending out of said pump body for indicating the selected second position of said diaphragm.

2. The pump of claim 1 wherein said bimetallic member is a disc, and said diaphragm also comprises an insulating gasket overlying said bimetallic disc inward thereof relative to said pump chamber.

3. The pump of claim 2 wherein the first wall of said pump chamber is concave with a central apex area, said inlet port opening through said apex area, said outlet port being annular and surrounding said inlet port in outwardly spaced relation thereto.

4. The pump of claim 3 wherein said bimetallic disc comprises a resistance heating element.

6. The pump of claim 1 wherein the first wall of said pump chamber is concave with a central apex area, said inlet port opening through said apex area, said outlet port being annular and surrounding said inlet port in outwardly spaced relation thereto.

7. The pump of claim 1 wherein said indicating means comprise a rod-like element affixed to and extending from the side of said diaphragm facing away from said first wall.

8. The pump of claim 7 wherein the extent said rod-like element extends from said pump body can be used to indicate the selected volumetric interior space within said chamber.

5. The pump of claim 1including a one-way valve mounted in each of said inlet and outlet passageways.

9. A biomedical pump for use in the measured pumping of a medicament or the like, said pump comprising:

a pump body;

a pump chamber in said body, said chamber being defined by a first wall formed by said pump body and an opposed second wall;

an inlet passageway through said body;

said inlet passageway including an inlet port in communication with said chamber through said first wall;

an outlet passageway through said body, said outlet passageway including an outlet port in communication with said chamber through said first wall;

a flow inducing diaphragm facing said first wall and being selectively movable between a first position closely overlying and conforming to said first wall and sealing said ports and a selected second position which is outwardly spaced from said first wall, the side of said diaphragm facing said first wall defining said second wall and defining a selected volumetric interior space within said chamber between said first and second walls;

said diaphragm, in said first position, eliminating the selected volumetric interior space of said chamber;

said diaphragm incorporating heat responsive means therein;

electrical conductor means coupled to said heat responsive means and extending outwardly therefrom;

regulated flexure of said diaphragm between said first and second Positions in response to the heating and cooling of said heat responsive means being controlled by the control of electrical energy to said heat responsive means;

a support ring engaging said diaphragm in a heat transfer manner and being capable of conducting heat away from said diaphragm to expedite cooling of said heat responsive means; and

, means connected to said diaphragm and extending from said pump body for indicating the selected second position of said diaphragm.

10. The pump of claim 9 wherein said heat responsive means is a bimetallic disc, and said diaphragm also comprises an insulating gasket overlying said bimetallic disc inward thereof relative to said pump chamber.

11. The pump of claim 9 wherein the first wall of said pump chamber is concave with a central apex area, said inlet port opening through said apex area, said outlet port being annular and surrounding said inlet port in outwardly spaced relation thereto.

12. The pump of claim 10 wherein said bimetallic disc comprises a resistance heating element.

13. The pump of claim 9 including a one-way valve mounted in each of said inlet and outlet passageways.

14. The pump of claim 9 wherein said first wall of said pump chamber is concave with a central apex area, said inlet port opening through said apex area, said outlet port being annular and surrounding said inlet port in outwardly spaced relation thereto.

15. The pump of claim 9 wherein said indicating means comprise a rod-like element affixed to and extending from the side of said diaphragm facing away from said first wall.

16. The pump of claim 15 wherein the extent said rod-like element extends from said pump body can be used to indicate the selected volumetric interior space within said chamber.

17. A biomedical pump for use in the measured pumping of a medicament or the like, said pump comprising:

a pump body;

a pump chamber in said body, said chamber being defined by a first concave wall within a central apex formed by said body and an opposed second wall;

an inlet passageway through said body, said inlet passageway including an inlet port in communication with said chamber through said apex area of said first wall;

an outlet passageway through said body, said outlet passageway including an annular outlet port in communication with said chamber through said first wall and surrounding said inlet port in outwardly spaced relation thereto;

a flow inducing diaphragm comprising a bimetallic member including a resistance heating element and an insulating gasket overlying said bimetallic member, said member having electrical conductor means coupled thereto and extending outwardly therefrom, said diaphragm facing said first wall and being selectively movable between a first position closely overlying and confirming to said first wall and said sealing ports, and a selected position which is outwardly spaced from said first wall, the side of said diaphragm facing said first wall defining said second wall and defining a selected volumetric interior space within said chamber between said first and second walls;

said diaphragm, in said first position, eliminating the selected volumetric interior space of said chamber, said bimetallic member being selectively heat responsive by the control of electrical energy thereto for effecting regulated flexure of said diaphragm between said first and second positions in response to heating and cooling of said heat responsive bimetallic member to effect precise pumping of a selected volume of fluid defined by the selected volumetric interior space of said chamber; and

a support ring engaging said bimetallic member in a heat transfer manner and being capable of conducting heat away from said bimetallic member to expedite cooling of said bimetallic member.

18. The pump of claim 17 including a one-way valve mounted in each of said inlet and outlet passageways.

19. The pump of claim 17 including a signalling element fixed to said bimetallic member and projecting outwardly therefrom.

20. The pump of claim 19 wherein said signalling element comprises a rod-like element affixed to and extending from the side of said diaphragm facing away from said first wall and the extent of said rod-like element extends from said pump body indicating the selected volumetric interior space within said chamber.