US3655941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental ceramic firing ovens
Assignee: Dentsply Sirona Inc
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Filing: 1970-12-22
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Granted: 1972-04-11
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Expires: 1990-12-22
Abstract
Abstract A dental firing oven of a compound type having two firing chambers in an upper housing and respectively provided for (1) firing porcelain dental products into fused condition and for (2) effecting preliminary burning of expendable materials, such as binders for the porcelain particles. The firing chambers open downwardly to receive products supported on product carriers movable toward and from a lower housing in which control and actuating mechanism is mounted for actuating said product carriers.
Inventors
- 👤 Wolfgang Eugen Schaun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:02
CPC Classifications
A; A61; A61C; A61C13/00; A61C13/20
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
246 words
A dental ceramic firing oven comprising a lower housing, an upper housing, and means supporting the same in spaced relation to and above said lower housing, a firing oven chamber for ceramic dental porcelain materials in said upper housing having an inlet opening in the lower end of said upper housing and electrical heating means therefor, a product carrier mounted for vertical movement relative to and supported by said lower housing, and mechanical means within said lower housing operable to move said product carrier toward and from said firing oven chamber inlet to support ceramic dental items for firing within said firing oven, in combination with a second oven chamber within said upper housing laterally spaced from said firing oven chamber and provided with an inlet opening in the lower end of said upper housing, electrical heating means for said second oven chamber to heat the same to a lower temperature than said firing oven chamber to pre-dry and pre-heat and burn out organic materials in dental ceramic products under conditions of controlled temperatures and time, a second product carRier mounted for vertical movement relative to and supported by said lower housing, additional mechanical means within said lower housing operable to move said second product carrier toward and from the inlet of said second oven chamber, and a timer operable to control the length of time said product carrier supports a dental product within said second oven chamber and then lower the same from said chamber.
Claim 2
Dependent Claim
246 words
A dental ceramic firing oven comprising a lower housing, an upper housing, and means supporting the same in spaced relation to and above said lower housing, a firing oven chamber for ceramic dental porcelain materials in said upper housing having an inlet opening in the lower end of said upper housing and electrical heating means therefor, a product carrier mounted for vertical movement relative to and supported by said lower housing, and mechanical means within said lower housing operable to move said product carrier toward and from said firing oven chamber inlet to support ceramic dental items for firing within said firing oven, in combination with a second oven chamber within said upper housing laterally spaced from said firing oven chamber and provided with an inlet opening in the lower end of said upper housing, electrical heating means for said second oven chamber to heat the same to a lower temperature than said firing oven chamber to pre-dry and pre-heat and burn out organic materials in dental ceramic products under conditions of controlled temperatures and time, a second product carRier mounted for vertical movement relative to and supported by said lower housing, additional mechanical means within said lower housing operable to move said second product carrier toward and from the inlet of said second oven chamber, and a timer operable to control the length of time said product carrier supports a dental product within said second oven chamber and then lower the same from said chamber.
Claim 3
Dependent Claim
35 words
The oven according to claim 1 in which said mechanical means to move said product lifting means toward and from the inlets of said oven chambers are adapted to be operated independently of each other.
Claim 4
Dependent Claim
44 words
The oven according to claim 1 in which said additional mechanical means to move said product lifting means of said second oven chamber is adapted to be operated intermittently of the means to move said product lifting means of said first mentioned oven chamber.
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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |