Device for preserving continuity of intravenous flow

• US 4,449,976 A
• Filed: 11/09/1981
• Issued: 05/22/1984
• Est. Priority Date: 05/21/1981
• Status: Expired due to Fees

• Current Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Original Assignee: Baxter Travenol Laboratories Incorporated (Baxter International Inc.)
• Inventors: Kamen, Dean L.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US06/319,222
• Time in Patent Office: 925 Days
• Field of Search: 128/214 R, 128/214 C, 128/214.2, 128/274, 137/182, 137/192, 137/399, 604/127, 604/247, 604/251-254
• US Class Current: 604/254
• CPC Class Codes: A61M 5/1411 Drip chambers A61M5/162, A61M5/1689, A61M5/40 take precedence
• CPC Class Codes: A61M 5/40 using low-level float-valve to cut off media flow from reservoir position detection of a floating member A61M5/1685
• CPC Class Codes: Y10T 137/3068 Float
• CPC Class Codes: Y10T 137/7326 Low level safety cut-off

Abstract

A device for reducing the rate of flow from a reservoir as the reservoir empties requires only a single chamber having an input, for receiving fluid from a reservoir, and an output port. There is a provision for sensing fluid level in the chamber, and a separate provision for reducing the flow through the output port when fluid level in the chamber has fallen to a predetermined level. In a preferred embodiment of the invention, fluid level is sensed by a float, which, after falling to a predetermined level, actuates a plunger that reduces flow through an aperature at the bottom of the chamber.

Claims

1. A device for preserving continuity of fluid flow from a reservoir, such device comprising:

a housing defining a chamber having an input for receiving fluid from the reservoir and an output port;

a float, within the housing, responsive to the fluid level in the chamber;

a mating valve and seat, located in the fluid path between the output port and the chamber;

such valve being mechanically linked to the float, and disposed so as to mate at an area of contact with the seat when the fluid level has fallen to a predetermined level;

such seat being formed as an annular face of the housing and defining an opening to the output port;

at least one of the valve and the seat having a groove on its surface extending entirely across the area of contact, so that when the valve is seated there is permitted flow only at a reduce rate through the groove past the valve to the output port, whereby the flow of fluid abruptly shifts to a reduced rate when the fluid level has fallen to the predetermined level.

2. A device according to claim 1, such device further comprising third means, for restricting non-vertical movement of the plunger within the chamber, so as to preserve orientation of the plunger with respect to the aperture.

3. A device according to claim 2, wherein the float includes a hole and the third means includes a guide, located in the chamber and affixed to the housing, projecting through the hole.

4. A device according to claim 2, wherein the float includes upper and lower portions, means for fluid to communicate between the upper and lower portions, and a periphery shaped so as to fit snugly against the housing and to restrict non-vertical movement of the float and plunger within the chamber.

5. A device according to claim 3, such device further comprising a base on which the guide is mounted, and wherein the base (i) is directly affixed to a part of the housing defining the upper portion of the chamber and (ii) includes a shoulder to limit upward travel of the float in the chamber.

6. A device according to claim 1, wherein the float includes a surface shaped so as to permit rapid and uniform flow of drops of fluid emanating into the chamber from the input.

7. A device according to claim 6, wherein the float includes a cusp, the peak of which is located beneath the input.

8. A device according to claim 1, further comprising signalling means, for signalling when fluid level in the chamber has fallen to the predetermined level.