US4255088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid pumping system having means for detecting gas in the pump
Assignee: Valleylab Inc
•
Filing: 1979-06-14
•
Granted: 1981-03-10
•
Expires: 1999-06-14
Abstract
Abstract An improved liquid pumping system wherein gas within the pump may be detected to indicate an error in desired flow rate or displaced volume. The system may be shut down if excessive gas is detected in the pump. Further, the flow rate may be corrected to the desired rate.
Inventors
- 👤 David W. Newton
- 👤 John M. Gibilisco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:50
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/36; A61M5/365; F; F04; F04B; F04B49/00; F04B49/10; G; G01; G01F; G01F1/00; G01F1/74; G01F11/00; G01F11/02; G01F11/021; G01F11/029
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
69 words
Liquid pumping apparatus comprising a pump for pumping a liquid; and gas detecting means disposed in the pump for detecting within said pump the presence of gas which may undesirably affect the liquid delivery rate of said pump where said gas detecting means senses the compressibility of the fluid within said pump to determine the presence of said gas where said gas is compressible and said liquid is not.
Claim 2
Dependent Claim
69 words
Liquid pumping apparatus comprising a pump for pumping a liquid; and gas detecting means disposed in the pump for detecting within said pump the presence of gas which may undesirably affect the liquid delivery rate of said pump where said gas detecting means senses the compressibility of the fluid within said pump to determine the presence of said gas where said gas is compressible and said liquid is not.
Claim 3
Dependent Claim
36 words
Apparatus as in claim 1 where said gas detecting means senses the compressibility of the fluid within said pump to determine the presence of said gas where said gas is compressible and said liquid is not.
Claim 4
Dependent Claim
24 words
Apparatus as in claim 1 where said gas detecting means senses the internal pressure and internal volume of said pump to determine said compressibility.
Claim 5
Dependent Claim
33 words
Apparatus as in claim 3 where said gas detecting means includes means responsive to change of said internal pump pressure with respect to change of said internal pump volume to determine said compressibility.
Claim 6
Dependent Claim
41 words
Apparatus as in claim 1 including means for cyclicly operating said pump and where said pump includes means for restraining the flow of said liquid in or out of said pump for at least a predetermined portion of each pump cycle.
Claim 7
Dependent Claim
21 words
Apparatus as in claim 5 where said gas detecting means detects said gas during said predetermined portion of each pump cycle.
Claim 8
Dependent Claim
12 words
Apparatus as in claim 6 where said pump is a piston pump.
Claim 9
Dependent Claim
24 words
Apparatus as in claim 7 where said gas detecting means senses the internal pressure and internal volume of said pump to determine said compressibility.
Claim 10
Dependent Claim
26 words
Apparatus as in claim 8 where said gas detecting means senses the position of the piston of said piston pump to determine said internal pump volume.
Claim 11
Dependent Claim
33 words
Apparatus as in claim 8 where said gas detecting means includes means responsive to change of said internal pump pressure with respect to change of said internal pump volume to determine said compressibility.
Claim 12
Dependent Claim
27 words
Apparatus as in claim 10 including means for establishing a predetermined level of detected gas which may undesirably affect the said liquid delivery rate of said pump.
Claim 13
Dependent Claim
26 words
Apparatus as in claim 11 including indicating means responsive to said gas for detecting means indicating that the level of detected gas exceeds said predetermined level.
Claim 14
Dependent Claim
52 words
Apparatus as in claim 11 including means for setting said pump to operate at a predetermined liquid delivery rate and control means responsive to said gas detecting means for controlling said pump to operate it at said predetermined liquid delivery rate in spite of the presence of said gas within the pump.
Claim 15
Dependent Claim
51 words
Apparatus as in claims 12 or 13 where said gas detecting means includes means for generating pulses proportional to the position of the piston of the piston pump and means for counting the number of pulses that occur during a predetermined change of said internal pump pressure to determine said compressibility.
Claim 16
Dependent Claim
31 words
Apparatus as in claim 14 where said indicating means is responsive to a predetermined count in said counting means to indicate when said level of detected gas exceeds said predetermined level.
Claim 17
Dependent Claim
30 words
Apparatus as in claim 14 where said control means is responsive to at least one predetermined count in said counting means to operate said pump at its predetermined delivery rate.
Claim 18
Dependent Claim
27 words
Apparatus as in claim 1 including means for establishing a predetermined level of detected gas which may undesirably affect the said liquid delivery rate of said pump.
Claim 19
Dependent Claim
25 words
Apparatus as in claim 17 including indicating means responsive to said gas detecting means indicating that the level of detected gas exceeds said predetermined level.
Claim 20
Dependent Claim
52 words
Apparatus as in claim 17 including means for setting said pump to operate at a predetermined liquid delivery rate and control means responsive to said gas detecting means for controlling said pump to operate it at said predetermined liquid delivery rate in spite of the presence of said gas within the pump.
Claim 21
Dependent Claim
51 words
Apparatus as in claims 18 or 19 where said gas detecting means includes means for generating pulses proportional to the position of the piston of the piston pump and means for counting the number of pulses that occur during a predetermined change of said internal pump pressure to determine said compressibility.
Claim 22
Dependent Claim
31 words
Apparatus as in claim 20 where said indicating means is responsive to a predetermined count in said counting means to indicate when said level of detected gas exceeds said predetermined level.
Claim 23
Dependent Claim
30 words
Apparatus as in claim 20 where said control means is responsive to at least one predetermined count in said counting means to operate said pump at its predetermined delivery rate.
Claim 24
Dependent Claim
37 words
Apparatus as in claim 1 including means for establishing a predetermined level of internal pump pressure corresponding to a pump outlet occlusion and means for detecting that the pressure within said pump has exceeded said predetermined level.
Claim 25
Dependent Claim
43 words
Apparatus as in claim 1 including means for establishing a predetermined level of internal pump pressure corresponding to a lack of liquid being supplied to said pump and means for detecting that the pressure within said pump is less than said predetermined value.
References Cited (Backward Citations)
US2406179A
Cited
US2765743A
Cited
US3559644A
Cited
US3855515A
Cited
US3981620A
Cited
US3847507A
Cited
US4137011A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |