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US4052590A Expired / Lapsed US ⏱️ 0.0 years remaining

Electric appliance with intermittently staked sheathed heating element

Assignee: National Presto Industries Inc
•
Filing: 1976-10-28
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Granted: 1977-10-04
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Expires: 1996-10-28
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Abstract

Abstract The underside of the bottom wall of an electric cooker contains a sheathed electric heater element intermittently staked and keyed to the sides and base of a receiving channel to control and confine growth and resist twisting movement of the element therein during heating.

Inventors

  • 👤 Richard F. Anderl
  • 👤 Lawrence J. Tienor

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 23:38
CPC Classifications
A; A47; A47J; A47J27/00; A47J27/004; H; H05; H05B; H05B3/00; H05B3/68; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083; Y10T29/49826; Y10T29/49908; Y10T29/49915; Y10T29/49925

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 113 words
An electrically heated appliance having a heat-conductive metal wall containing a channel and a sheathed electric heater element intermittently staked in said channel, the sheath of said electric heater element having longitudinally spaced indentations in the material of its outer side into which correspondingly spaced segments of the outer edge of the opposed channel sides are pressed, intervening portions of said outer edges betwen said pressed segments being out of engagement with the heater element sheath, the material of the heater element sheath between said indentations closely engaging about and conforming to the side edges of said pressed segments thereby confining linear growth of the sheathed heater element in the channel during heating.
Claim 2
Dependent Claim 113 words
An electrically heated appliance having a heat-conductive metal wall containing a channel and a sheathed electric heater element intermittently staked in said channel, the sheath of said electric heater element having longitudinally spaced indentations in the material of its outer side into which correspondingly spaced segments of the outer edge of the opposed channel sides are pressed, intervening portions of said outer edges betwen said pressed segments being out of engagement with the heater element sheath, the material of the heater element sheath between said indentations closely engaging about and conforming to the side edges of said pressed segments thereby confining linear growth of the sheathed heater element in the channel during heating.
Claim 3
Dependent Claim 104 words
An electrically-heated appliance having a heat conductive metal wall containing a channel and a sheathed electric heater element in said channel, spaced segments of the outer edge of the opposed channel sides along the length of the heater element being indented into the sheath of the heater element and intervening portions of said outer edges between said indented segments being out of engagement with the heater element sheath, the underside of the sheathed heater element having surface to surface contact with the base of the channel, and the channel base having spaced narrow grooves into which material of the heater element sheath is keyed.
Claim 4
Dependent Claim 104 words
An electrically-heated appliance having a heat conductive metal wall containing a channel and a sheathed electric heater element in said channel, spaced segments of the outer edge of the opposed channel sides along the length of the heater element being indented into the sheath of the heater element and intervening portions of said outer edges between said indented segments being out of engagement with the heater element sheath, the underside of the sheathed heater element having surface to surface contact with the base of the channel, and the channel base having spaced narrow grooves into which material of the heater element sheath is keyed.
Claim 5
Dependent Claim 18 words
An electrically-heated appliance as claimed in claim 2 wherein some of said grooves extend laterally of the channel.
Claim 6
Dependent Claim 93 words
An electrically-heated cooker having a heat conductive metal bottom wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced pairs of interlocked projecting and receiving portions, and the outer side of the sheathed heater element being flattened along its length such that the heater element is keyed at spaced intervals along the length thereof by said projecting and receiving portions so as to confine growth of the heater element during heating.
Claim 7
Dependent Claim 93 words
An electrically-heated cooker having a heat conductive metal bottom wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced pairs of interlocked projecting and receiving portions, and the outer side of the sheathed heater element being flattened along its length such that the heater element is keyed at spaced intervals along the length thereof by said projecting and receiving portions so as to confine growth of the heater element during heating.
Claim 8
Dependent Claim 109 words
An electrically heated cooker having a heat conductive metal bottom wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced interlocked portions which confine linear growth of the heater element during heating, said interlocked portions comprising oppositely disposed segments of the channel outer edges indented into the material of the sheath of the heater element, the outer surface of the sheathed heater element being flattened along its length, and material of the sheathed heater element between the indented segments being forced outwardly and about said indented segments.
Claim 9
Dependent Claim 109 words
An electrically heated cooker having a heat conductive metal bottom wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced interlocked portions which confine linear growth of the heater element during heating, said interlocked portions comprising oppositely disposed segments of the channel outer edges indented into the material of the sheath of the heater element, the outer surface of the sheathed heater element being flattened along its length, and material of the sheathed heater element between the indented segments being forced outwardly and about said indented segments.
Claim 10
Dependent Claim 95 words
An electrically heated cooker having a heat conductive metal wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced interlocked portions which confine growth of the heater element during heating, wherein said interlocked portions comprise oppositely disposed segments of the channel outer edges intended into the sheath of the heater element and also include narrow grooves in the channel base into which are received ribs on the underside of the heater element sheath.
Claim 11
Dependent Claim 95 words
An electrically heated cooker having a heat conductive metal wall containing a channel and a sheathed electric heater element seated in said channel with its underside in surface to surface contact with the channel, said heater element and channel having spaced interlocked portions which confine growth of the heater element during heating, wherein said interlocked portions comprise oppositely disposed segments of the channel outer edges intended into the sheath of the heater element and also include narrow grooves in the channel base into which are received ribs on the underside of the heater element sheath.
Claim 12
Dependent Claim 24 words
An electrically heated cooker as claimed in claim 6 wherein the narrow grooves and received ribs extend laterally of the channel and heater element.
Claim 13
Dependent Claim 37 words
An electrically heated cooker as claimed in claim 6 wherein some of the narrow grooves and received ribs extend laterally of the channel and heater element, and others thereof extend longitudinally of the channel and heater element.
Claim 14
Dependent Claim 144 words
An electrically heated cooker having a bottom wall of heat conductive meatal with projecting inner and outer spaced walls which define a channel therebetween and a sheathed electric heater element seated in said channel and its terminal ends extending outwardly therefrom, oppositely disposed spaced segments of said inner and outer channel walls having their outer ends intended into the material of the sheath of the heater element and intervening segments of said outer edges of the channel walls being out of engagement with the heater element, the outer side of the sheathed heater element being flattened along its length, the sheath material on either side of the intended ends of said segments closely engaging about the side edges of the intended ends of said spaced segments, and the inner side of the sheathed heater element having close contact with the base of the channel.
Claim 15
Dependent Claim 144 words
An electrically heated cooker having a bottom wall of heat conductive meatal with projecting inner and outer spaced walls which define a channel therebetween and a sheathed electric heater element seated in said channel and its terminal ends extending outwardly therefrom, oppositely disposed spaced segments of said inner and outer channel walls having their outer ends intended into the material of the sheath of the heater element and intervening segments of said outer edges of the channel walls being out of engagement with the heater element, the outer side of the sheathed heater element being flattened along its length, the sheath material on either side of the intended ends of said segments closely engaging about the side edges of the intended ends of said spaced segments, and the inner side of the sheathed heater element having close contact with the base of the channel.
Claim 16
Dependent Claim 135 words
An electrically heated cooker having a bottom wall of heat conductive metal with projecting inner and outer spaced walls which define a channel therebetween, and a sheathed electric heater element seated in said channel with its terminal ends extending outwardly therefrom, oppositely disposed spaced segments of said inner and outer channel walls having their outer ends indented into the sheath of the heater element and intervening segments of said outer edges of the channel wall being out of engagement with the heater element, the outer side of the sheathed heater element being flattened along its length and the underside of the sheathed heater element having close contact with the base of the channel, said underside of the sheathed heater element having spaced lateral extending ribs which extend into receiving narrow grooves in the channel base.
Claim 17
Dependent Claim 135 words
An electrically heated cooker having a bottom wall of heat conductive metal with projecting inner and outer spaced walls which define a channel therebetween, and a sheathed electric heater element seated in said channel with its terminal ends extending outwardly therefrom, oppositely disposed spaced segments of said inner and outer channel walls having their outer ends indented into the sheath of the heater element and intervening segments of said outer edges of the channel wall being out of engagement with the heater element, the outer side of the sheathed heater element being flattened along its length and the underside of the sheathed heater element having close contact with the base of the channel, said underside of the sheathed heater element having spaced lateral extending ribs which extend into receiving narrow grooves in the channel base.
Claim 18
Dependent Claim 32 words
An electrically heated cooker as claimed in claim 10 wherein said laterally extending ribs and narrow grooves are aligned with the indented ends of the outer edge segments of the channel walls.
Claim 19
Dependent Claim 32 words
An electrically heated cooker as claimed in claim 10 wherein the channel base has longitudinally extending narrows grooves into which project longitudinal extending rib like portions of the sheathed heater element underside.
Claim 20
Dependent Claim 33 words
An electrically heated cooker as claimed in claim 12 wherein said longitudinally extending grooves in the channel bases are remote from the location of the outwardly extending terminal ends of the heater element.

References Cited (Backward Citations)

US1729673A Cited
US2826670A Cited
US2875312A Cited
US2944138A Cited
US3110796A Cited
US3389459A Cited
US3275801A Cited
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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) 1980-10-03 1981-04-04 1981-10-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-10-03 1985-04-04 1985-10-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-10-03 1989-04-04 1989-10-04 $7700.00 Window Closed / Lapsed

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