Patent US1064931A successfully refreshed from Google Patents.
Patent US2550877A successfully refreshed from Google Patents.
US2550877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of heat expanding perlite while wiping furnace interiors
Assignee: Johns Manville Corp
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Filing: 1948-05-13
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Granted: 1951-05-01
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Expires: 1968-05-13
Abstract
No abstract record available.
Inventors
- 👤 William L Stafford
- 👤 Edward R Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:43
CPC Classifications
C; C04; C04B; C04B20/00; C04B20/02; C04B20/04; C04B20/06; C04B20/066
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
IN TREATING FINELY DIVIDED CRUDE HEAT EXPANDIBLE VOLCANIC GLASS BY DISPERSING PARTICLES THEREOF IN A HOT CARRIER GAS AND MOVING SAID GAS IN HEAT TRENSFER RELATION PAST A HEAT RADIATING SURFACE COMPOSED OF PREVIOUSLY EXPANDED VOLCANIC GLASS WHILE HEAT SOFTENING AND EXPANDING SAID GAS SUSPENDED PARTICLES, THE STEP COMPRISING PERIODICALLY WIPING EACH UNIT AREA OF SAID EXPANDED VOLCANIC GLASS SURFACE AT A RATE WHICH IS EFFECTIVE TO MAINTAIN A COMPARATIVELY SMOOTH STABLE SURFACE HAVING HIGH HEAT RADIATING AND INSULATING PROPERTIES AND TO LIMIT DEPOSITION AND BUILD UP OF EXPANDED VOLCANIC GLASS PARTICLES ON SAID SURFACE.
Claim 2
Dependent Claim
95 words
IN TREATING FINELY DIVIDED CRUDE HEAT EXPANDIBLE VOLCANIC GLASS BY DISPERSING PARTICLES THEREOF IN A HOT CARRIER GAS AND MOVING SAID GAS IN HEAT TRENSFER RELATION PAST A HEAT RADIATING SURFACE COMPOSED OF PREVIOUSLY EXPANDED VOLCANIC GLASS WHILE HEAT SOFTENING AND EXPANDING SAID GAS SUSPENDED PARTICLES, THE STEP COMPRISING PERIODICALLY WIPING EACH UNIT AREA OF SAID EXPANDED VOLCANIC GLASS SURFACE AT A RATE WHICH IS EFFECTIVE TO MAINTAIN A COMPARATIVELY SMOOTH STABLE SURFACE HAVING HIGH HEAT RADIATING AND INSULATING PROPERTIES AND TO LIMIT DEPOSITION AND BUILD UP OF EXPANDED VOLCANIC GLASS PARTICLES ON SAID SURFACE.
References Cited (Backward Citations)
US2044680A
Cited
US2431884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-30 | 1954-10-30 | 1955-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-30 | 1958-10-30 | 1959-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-30 | 1962-10-30 | 1963-05-01 | $7700.00 | Window Closed / Lapsed |