Patent US4449976A successfully refreshed from Google Patents.
US4449976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for preserving continuity of intravenous flow
Assignee: Baxter International Inc
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Filing: 1981-11-09
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Granted: 1984-05-22
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Expires: 2001-11-09
Abstract
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.
Inventors
- 👤 Dean L. Kamen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:47
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/1411; A61M5/36; A61M5/40; Y; Y10; Y10T; Y10T137/00; Y10T137/2931; Y10T137/3003; Y10T137/3021; Y10T137/304; Y10T137/3052; Y10T137/3068; Y10T137/7287; Y10T137/7313; Y10T137/7323; Y10T137/7326
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
182 words
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.
Claim 2
Independent Claim
182 words
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.
Claim 3
Dependent Claim
35 words
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.
Claim 4
Dependent Claim
32 words
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.
Claim 5
Dependent Claim
50 words
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.
Claim 6
Dependent Claim
54 words
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.
Claim 7
Dependent Claim
32 words
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.
Claim 8
Dependent Claim
21 words
A device according to claim 6, wherein the float includes a cusp, the peak of which is located beneath the input.
Claim 9
Dependent Claim
24 words
A device according to claim 1, further comprising signalling means, for signalling when fluid level in the chamber has fallen to the predetermined level.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-22 | 1987-11-21 | 1988-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-22 | 1991-11-21 | 1992-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-22 | 1995-11-21 | 1996-05-22 | $7700.00 | Window Closed / Lapsed |