Patent US4363316A successfully refreshed from Google Patents.
US4363316A
Expired / Lapsed
US
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Vessel for food preparation
Assignee: Wartsila Oy AB
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Filing: 1980-12-18
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Granted: 1982-12-14
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Expires: 2000-12-18
Abstract
Abstract A vessel for food preparation having a bottom made of two different members, one of which is the actual bottom of the vessel and the other a separate bottom plate which is attached to the bottom of the vessel by means of several spaced-apart spot-formed or generally small-area attachment points. When the vessel is heated there will initially be a considerable temperature difference between the two layers of the bottom construction, which will give rise to small buckles in the separate bottom plate between its attachment points. Inside these buckles the air slot between the two layers of the bottom construction grows and this slows down the heat transmission to the inner surface of the vessel.
Inventors
- 👤 Tiina Aakenus
- 👤 Pekka Mertanen
- 👤 Reijo Peltonen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:47
CPC Classifications
A; A47; A47J; A47J36/00; A47J36/02; A47J27/00; A47J27/02; A47J27/022
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
189 words
A vessel for food preparation having a side wall structure and a bottom, said bottom comprising: two plate members; a first of said two plate members forming an inner portion integral with said side wall structure and having an outer portion with a uniform surface; a second of said two plate members which is a separate member and has a surface facing the outer portion ofsaid first plate member and being uniform therewith, said second plate member being rigidly attached to an in contact with the uniform surface of said first plate member; several spaced-apart small-area attachment points for rigidly attaching said first plate member to said second plate member, said spaced-apart small-area attachment points having therebetween, at least in one direction along the mutual contact surfaces of said two plate members, an area of considerable length being free of attachment points between said two plate members; and the thickness of said second plate member and the distance between said attachment points being related so as to allow buckling of said second plate member due to thermal expansion thereof, thereby introducing an air gap between said two plate members.
Claim 2
Dependent Claim
189 words
A vessel for food preparation having a side wall structure and a bottom, said bottom comprising: two plate members; a first of said two plate members forming an inner portion integral with said side wall structure and having an outer portion with a uniform surface; a second of said two plate members which is a separate member and has a surface facing the outer portion ofsaid first plate member and being uniform therewith, said second plate member being rigidly attached to an in contact with the uniform surface of said first plate member; several spaced-apart small-area attachment points for rigidly attaching said first plate member to said second plate member, said spaced-apart small-area attachment points having therebetween, at least in one direction along the mutual contact surfaces of said two plate members, an area of considerable length being free of attachment points between said two plate members; and the thickness of said second plate member and the distance between said attachment points being related so as to allow buckling of said second plate member due to thermal expansion thereof, thereby introducing an air gap between said two plate members.
Claim 3
Dependent Claim
24 words
A vessel as claimed in claim 1, wherein said second plate member is attached to said first plate member by means of spot welding.
Claim 4
Dependent Claim
31 words
A vessel as claimed in claim 1 or 2, wherein said second plate member is made of a material having a greater coefficient of thermal expansion than said first plate member.
Claim 5
Dependent Claim
24 words
A vessel as claimed in claim 1, wherein said second plate member is attached to said first plate member by means of projection welding.
Claim 6
Dependent Claim
14 words
A vessel as claimed in claim 1, wherein said second plate member is annular.
Claim 7
Dependent Claim
69 words
A method of making a vessel of the kind claimed in claim 1 or 5, comprising the steps of: attaching a separate outer bottom plate to a vessel body of steel by means of spot-forming welding joints, and enamelling said vessel all over including said bottom plate after said attachment operation to form an enamelled steel vessel with a dark dust-enamel covered outer bottom surface on said bottom plate.
Claim 8
Dependent Claim
25 words
A vessel as claimed in claim 5, wherein said several spaced-apart small-area attachment points are close to the outer edge of said annular plate member.
Claim 9
Dependent Claim
35 words
A vessel as claimed in claim 1, wherein said second plate member is annualar and is provided with a central opening having a diameter of about half the outer diameter of said second plate member.
Claim 10
Dependent Claim
23 words
A vessel as claimed in claim 1 or 8, wherein the outer surface of said second plate member is enamelled with dust enamel.
Claim 11
Dependent Claim
44 words
A vessel a claimed in claim 8, wherein said several spaced-apart small-area attachment points includes one group close to the outer edge of said annular plate member and another group close to the inner edge surrounding said central opening of said annular plate member.
Claim 12
Dependent Claim
108 words
A vessel as claimed in claim 1, in which the surfaces of said first plate member and said second plate member facing each other are uniform when said first and said second plate members are in a cold condition and are designed to form said air gap when said vessel is heated, by introducing in said second plate member a greater degree of thermal expansion than in said first plate member due to a higher temperature caused therein by a hot base being in direct contact with said second plate member, whereas said first plate member is cooled by the material to be heated contained in said vessel.
Claim 13
Dependent Claim
19 words
A vessel as claimed in claim 1, wherein the outer surface of said bottom is enamelled with dust enamel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-13 | 1986-06-14 | 1986-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-13 | 1990-06-14 | 1990-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-13 | 1994-06-14 | 1994-12-14 | $7700.00 | Window Closed / Lapsed |