US3656469A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-circulation apparatus for self-cleaning oven and the like
Assignee: Burger Eisenwerke AG
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Filing: 1970-05-25
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Granted: 1972-04-18
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Expires: 1990-05-25
Abstract
Abstract An electric motor mounted in a compartment adjacent an oven or other food-treatment chamber carries a pair of centrifugal fans, one in the chamber and one in the compartment. Each fan has on each axial face an array of radially extending vanes or blades. The two central arrays of vanes confronting each other flank the outlet of a conduit open at its inlet to the ambient atmosphere so that air is drawn in through the conduit, then drawn axially in both directions, into the chamber and into the compartment, and then expelled radially to form a gas barrier at this opening. The vanes turned toward the motor draw cooling air in over this motor and the vanes directed into the chamber circulate the gases therein. The fans are rotationally coupled together only by a few angularly spaced bolts, in the cooling-air stream, surrounded by sleeve-like insulating spacers, to prevent heat conduction back to the motor.
Inventors
- 👤 Anton Ladislaus Jung
- 👤 Erhard Ledwon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:49
CPC Classifications
F; F24; F24C; F24C14/00; F24C14/02; A; A21; A21B; A21B1/00; A21B1/02; A21B1/24; A21B1/26; F04; F04D; F04D25/00; F04D25/02; F04D25/08; F04D25/082; F04D29/00; F04D29/58; F04D29/5806; F04D29/582; F04D29/5853
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
224 words
An apparatus for thermally treating comestibles comprising: means forming a generally closed chamber; means for establishing a food-treatment temperature in said chamber; and blower means having a drive motor outside said chamber and a rotor connected to said motor and including centrifugal-fan means for circulating gases in said chamber, for drawing air over said drive motor, and for introducing gases into said chamber, said centrifugal-fan means including a pair of centrifugal fans, one of said fans being inside said chamber and the other being outside said chamber, said chamber having a wall formed with an opening, said rotor extending through said opening, said fan in said chamber having a first face turned toward said motor and bearing an array of radially extending vanes and a second face turned away from said motor and bearing an array of radially extending vanes, said opening defining an annular gap around said rotor, said centrifugal-fan means further comprising means cooperating with said vanes on said first face and forming a gas barrier at said gap for preventing issue of gases from said chamber through said opening, the last-mentioned means including a conduit for feeding a gas to a location immediately adjacent said gap, whereby on rotation of said fans said gas is drawn through said gap into said chamber by said array of vanes on said first face.
Claim 2
Independent Claim
224 words
An apparatus for thermally treating comestibles comprising: means forming a generally closed chamber; means for establishing a food-treatment temperature in said chamber; and blower means having a drive motor outside said chamber and a rotor connected to said motor and including centrifugal-fan means for circulating gases in said chamber, for drawing air over said drive motor, and for introducing gases into said chamber, said centrifugal-fan means including a pair of centrifugal fans, one of said fans being inside said chamber and the other being outside said chamber, said chamber having a wall formed with an opening, said rotor extending through said opening, said fan in said chamber having a first face turned toward said motor and bearing an array of radially extending vanes and a second face turned away from said motor and bearing an array of radially extending vanes, said opening defining an annular gap around said rotor, said centrifugal-fan means further comprising means cooperating with said vanes on said first face and forming a gas barrier at said gap for preventing issue of gases from said chamber through said opening, the last-mentioned means including a conduit for feeding a gas to a location immediately adjacent said gap, whereby on rotation of said fans said gas is drawn through said gap into said chamber by said array of vanes on said first face.
Claim 3
Dependent Claim
83 words
The apparatus defined in claim 1 wherein said fan outside said chamber is formed with a first side turned toward said motor and bearing an array of radially extending vanes and a second side turned away from said motor and bearing an array of radially extending vanes, whereby on rotation of said rotor said gas is drawn axially in two directions from said location by said arrays of vanes on said first face and on said second side to form said gas barrier.
Claim 4
Dependent Claim
36 words
The apparatus defined in claim 2 wherein said array on said first face is of higher gas-displacing capacity than said array on said second side to form a pressure differential across said opening constituting said barrier.
Claim 5
Dependent Claim
51 words
The apparatus defined in claim 3, further comprising means forming a compartment adjacent said chamber and against said wall for forming an air-circulation path over said motor, said conduit passing through said compartment and having one end open to a supply of said gas and another end opening at said location.
Claim 6
Dependent Claim
85 words
The apparatus defined in claim 1, further comprising a pair of mounting elements each connected rotationally to one of said arrays of vanes and connecting means extending between said elements and constituting the sole rotational coupling between said drive motor and said fan outside said chamber, said connecting means including a plurality of elongated connectors radially spaced from said axis and angularly spaced from one another, each connector having one end fixed in one of said elements and another end fixed in the other element.
Claim 7
Dependent Claim
30 words
The apparatus defined in claim 5 wherein said one of said elements is rotationally fixed on said array of vanes on said fan outside said chamber turned toward said motor.
Claim 8
Dependent Claim
43 words
The apparatus defined in claim 5 wherein said connecting means further includes a plurality of sleeves of insulating material each surrounding one of said connectors and having one end abutting one of said elements and another end abutting the other of said elements.
Claim 9
Dependent Claim
19 words
The apparatus defined in claim 7 wherein each of said sleeves is formed with at least oNe heat-radiating vane.
Claim 10
Independent Claim
193 words
An apparatus for the treatment of goods with a gas, comprising a treatment chamber having a wall provided with an opening, and a fan arrangement mounted in said opening, said fan arrangement including: a first axial-intake radial-outflow blower in said chamber and rotatable to circulate a treating gas therewithin; a second axial-intake radial-outflow blower rotatable about a common axis with said first blower and disposed axially rearwardly thereof with respect to said chamber and having a smaller capacity than said first blower for inducing a stream of treatment gas to flow into said chamber; a third axial-intake radial-outflow blower rotatable coaxially with said first and second blowers and disposed axially rearwardly of said second blower for diverting a portion of said stream away from said chamber and creating therefrom a cooling flow for restricting mixing of the treatment gas with ambient air; a fourth axial-intake radial-outflow blower rotatable coaxially with said first, second and third blowers and disposed axially rearwardly of said third blower for generating a primary cooling flow of ambient air; and an electric motor operatively connected to all of said blowers for driving same and disposed in said primary flow.
Claim 11
Independent Claim
193 words
An apparatus for the treatment of goods with a gas, comprising a treatment chamber having a wall provided with an opening, and a fan arrangement mounted in said opening, said fan arrangement including: a first axial-intake radial-outflow blower in said chamber and rotatable to circulate a treating gas therewithin; a second axial-intake radial-outflow blower rotatable about a common axis with said first blower and disposed axially rearwardly thereof with respect to said chamber and having a smaller capacity than said first blower for inducing a stream of treatment gas to flow into said chamber; a third axial-intake radial-outflow blower rotatable coaxially with said first and second blowers and disposed axially rearwardly of said second blower for diverting a portion of said stream away from said chamber and creating therefrom a cooling flow for restricting mixing of the treatment gas with ambient air; a fourth axial-intake radial-outflow blower rotatable coaxially with said first, second and third blowers and disposed axially rearwardly of said third blower for generating a primary cooling flow of ambient air; and an electric motor operatively connected to all of said blowers for driving same and disposed in said primary flow.
Claim 12
Dependent Claim
22 words
The apparatus defined in claim 9, further comprising duct means opening between said second and third blowers for delivering said stream thereto.
Claim 13
Dependent Claim
20 words
The apparatus defined in claim 10, further comprising means for connecting a source of freezing fluid to said duct means.
Claim 14
Dependent Claim
14 words
The apparatus defined in claim 10, wherein said duct means opens into the atmosphere.
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) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |