US3801360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling the level of the pressure in the low pressure phase of an oscillating pressure impregnating process
Assignee: Boliden AB
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Filing: 1971-10-20
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Granted: 1974-04-02
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Expires: 1991-10-20
Abstract
Abstract A method in the impregnation of wood, and other material liable to boideterioration, when applying the oscillating pressure principle, in which the preservative solution and the material are subjected to alternating phases of high and low pressure and in which, during the low pressure phase, the preservative solution is drawn from a source of such solution to the treatment vessel and through said vessel while controlling the flow of solution thereto in a manner to maintain a set point pressure in said vessel which conforms with a predetermined pressure pattern.
Inventors
- 👤 S Dahlgren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:05
CPC Classifications
B; B27; B27K; B27K3/00; B27K3/02; B27K3/08; B27K3/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
64 words
A method according to claim 1, characterized by the steps of sensing the pressure in the treatment vessel during the low pressure phases, comparing said sensed pressure with a desired pressure value, and utilizing observed and recorded differences in said pressures to actuate means for controlling the flow of preservative solution from the storage tank to the treatment vessel during said low pressure phases.
Claim 2
Dependent Claim
18 words
A method according to claim 2, characterized by varying the desired pressure value during each low pressure phase.
Claim 3
Dependent Claim
18 words
A method according to claim 2, characterized by varying the desired pressure valve between sequential low pressure phases.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |