Patent US3677444A successfully refreshed from Google Patents.
US3677444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Micropump
Assignee: Boston Children's Hospital
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Filing: 1970-03-06
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Granted: 1972-07-18
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Expires: 1990-03-06
Abstract
Abstract A pump for delivering liquid at a relatively constant rate from a chamber having a compliant membrane wall which exerts a substantially constant resistive force when expanded under a pressure within the range of between zero and atmospheric and within the mechanical limits imposed on it. The outside surface of the membrane is located in a second chamber wherein the pressure is increased to atmospheric by diffusing gas through an elastomeric diffusion membrane. The pump is especially adapted for delivering microquantities of liquid at a constant rate for long periods.
Inventors
- 👤 Edward W Merrill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:00
CPC Classifications
F; F04; F04B; F04B43/00; F04B43/0009; F04B43/0054; F04B43/0072; A; A61; A61M; A61M5/00; A61M5/14; A61M5/142; A61M5/145; A61M5/148; A61M5/152; F04B43/02; F04B43/06; F04F; F04F3/00; F16; F16N; F16N13/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
126 words
A pump for delivering a liquid at a relatively constant rate comprising a first chamber and a second chamber for retaining liquid each defined by a separate rigid wall and a separate elastomeric membrane, means for filling the first chamber and second chamber with liquid, an orifice in each of said first chamber and said second chamber for removing liquid from said first chamber and second chamber, each of said elastomeric membranes exerting a substantially constant resistive force when expanded under a pressure within the range of between zero and atmospheric and within the mechanical limits imposed upon said elastomeric membranes, and a diffusion membrane located in a third chamber defined by said elastomeric membranes to permit gas diffusion from the atmosphere into the third chamber.
Claim 2
Dependent Claim
126 words
A pump for delivering a liquid at a relatively constant rate comprising a first chamber and a second chamber for retaining liquid each defined by a separate rigid wall and a separate elastomeric membrane, means for filling the first chamber and second chamber with liquid, an orifice in each of said first chamber and said second chamber for removing liquid from said first chamber and second chamber, each of said elastomeric membranes exerting a substantially constant resistive force when expanded under a pressure within the range of between zero and atmospheric and within the mechanical limits imposed upon said elastomeric membranes, and a diffusion membrane located in a third chamber defined by said elastomeric membranes to permit gas diffusion from the atmosphere into the third chamber.
Claim 3
Dependent Claim
87 words
A pump for delivering a liquid at a relatively constant rate comprising an elastomeric tube, said tube exerting a substantially constant resistive force when expanded under a pressure within the range of between zero and atmospheric and within the mechanical limits imposed upon it, means for filling the tube with a liquid, an orifice for removing liquid from said tube, said tube located in a second chamber and a diffusion membrane located in said second chamber to permit gas diffusion from the atmosphere into the second chamber.
Claim 4
Dependent Claim
87 words
A pump for delivering a liquid at a relatively constant rate comprising an elastomeric tube, said tube exerting a substantially constant resistive force when expanded under a pressure within the range of between zero and atmospheric and within the mechanical limits imposed upon it, means for filling the tube with a liquid, an orifice for removing liquid from said tube, said tube located in a second chamber and a diffusion membrane located in said second chamber to permit gas diffusion from the atmosphere into the second chamber.
Claim 5
Dependent Claim
22 words
The pump of claim 2 wherein the tube is surrounded by a porous retaining means to impose the maximum limit of expansion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |