US3620306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for foam generation
Assignee: Kidde Inc
•
Filing: 1969-01-14
•
Granted: 1971-11-16
•
Expires: 1989-01-14
Abstract
Abstract A method and means of generating high expansion foam by spraying foaming agent onto a mesh through which gas (usually air) is blown. Pressure sensors on either side of the mesh sense the pressure differential across the mesh and through control means ensure a constant pressure differential despite changes in back pressure.
Inventors
- 👤 Denis Shepherd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:28
CPC Classifications
A; A62; A62C; A62C5/00; A62C5/002; Y; Y10; Y10S; Y10S261/00; Y10S261/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
64 words
A system as in claim 1 further comprising means for comparing the measured pressure differential with a predetermined pressure differential and for producing an error signal representative of the difference between the two; and means responsive to the error signal for controlling the rate of gas flow reaching the mesh from said gas producing means in a manner to maintain said predetermined pressure differential.
Claim 2
Dependent Claim
58 words
A system as in claim 1 in combination with a second container into which the foam is being expelled from the mesh, said pressure differential measuring means comprising first transducer means located within said first-mentioned container to measure the pressure upstream of said mesh and second transducer means located within said second container to measure the pressure therein.
Claim 3
Dependent Claim
43 words
A system as in claim 1 wherein said means for measuring the pressure differential comprises first and second transducer means located respectively upstream and downstream of said mesh, each of said transducer means producing an electrical output signal corresponding to the pressure measured.
Claim 4
Dependent Claim
43 words
A system as in claim 2 wherein said means for measuring the pressure differential comprises first and second transducer means located respectively upstream and downstream of said mesh, each of said transducer means producing an electrical output signal corresponding to the pressure measured.
Claim 5
Dependent Claim
43 words
A system as in claim 3 wherein said means for measuring the pressure differential comprises first and second transducer means located respectively upstream and downstream of said mesh, each of said transducer means producing an electrical output signal corresponding to the pressure measured.
Claim 6
Dependent Claim
99 words
A system as in claim 5 wherein said means for measuring said pressure differential comprises first comparator means for producing a first signal corresponding to the difference in pressures measured by said two transducer means, means for producing a reference signal corresponding to a predetermined pressure differential, second comparator means for receiving said first and said reference signals and responsive thereto to produce an error signal corresponding to the difference between said measured pressure differential and said predetermined pressure differential, and means responsive to said error signal for controlling the rate of flow of the gas reaching said mesh.
Claim 7
Dependent Claim
99 words
A system as in claim 6, wherein said means for measuring said pressure differential comprises first comparator means for producing a first signal corresponding to the difference in pressures measured by said two transducer means, means for producing a reference signal corresponding to a predetermined pressure differential, second comparator means for receiving said first and said reference signals and responsive thereto to produce an error signal corresponding to the difference between said measured pressure differential and said predetermined pressure differential, and means responsive to said error signal for controlling the rate of flow of the gas reaching said mesh.
Claim 8
Dependent Claim
33 words
A system as in claim 1, wherein said means for controlling the flow rate of the gas reaching said mesh comprises a variable shutter located between said mesh and said gas producing means.
Claim 9
Dependent Claim
47 words
A system as in claim 1 wherein said means for producing the gas flow comprises a fan and means for driving said fan, and said means for controlling the flow rate of the gas reaching said mesh comprises means for controlling the speed of said driving means.
Claim 10
Dependent Claim
47 words
A system as in claim 1 wherein said means for producing the gas flow comprises a fan with at least one blade, and said means for controlling the flow rate of the gas reaching the mesh comprises means for varying the pitch angle of the fan blade.
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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |