US4523070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low profile food rotator
Assignee: NORTHLAND ALUMINUM PRODUCTS Inc A CORP OF MN
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Filing: 1983-06-16
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Granted: 1985-06-11
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Expires: 2003-06-16
Abstract
Abstract A mechanically-driven, low-profile, portable turntable for use in cooking ovens, especially microwave ovens, for rotating food stuffs while cooking. All moving parts, except the power spring used to drive the turntable are formed from low loss plastic and the spring is contained in a microwave reflective case to preclude overheating thereof. The low profile is achieved by providing a unique drive mechanism for the turntable in which the power spring driven gear is made to partially surround and envelop the spring case. Further, the gear train cooperating with the main power spring driven gear and with a speed-controlling governor is effectively "wrapped" about the spring case in a concentric fashion with the individual gears in the gear train being vertically overlapped.
Inventors
- 👤 Jorgen A. Jorgensen
- 👤 Donald W. Nygren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:21
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6408; H05B6/6411
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
246 words
A portable turntable for use in a microwave oven, comprising: (a) a generally cylindrical housing member having a planar bottom, a cylindrical side wall projecting upwardly therefrom and an annular cover joined to the upper edge of said side wall defining a central opening in the top of said cylindrical housing; (b) a toroidal spring case secured to said planar bottom of said housing member, a central opening in said toroidal spring case, said spring case central opening being of a predetermined diameter; (c) a first gear member having gear teeth on the peripheral edge thereof and a central shaft projecting from a first major surface thereof, said shaft being journaled for rotation within said central opening in said toroidal spring case; (d) a spiral power spring disposed in said toroidal spring case; (e) means securing one end of said power spring to said spring case and means releasably connecting the other end of said power spring to said central shaft; (f) a generally circular turntable member concentrically attached to a second major surface of said first gear member and rotatable therewith; (g) a gear train comprising a plurality of overlapping gear elements journaled for rotation about vertical axes between said planar bottom and said annular cover of said generally cylindrical housing, one of said gear elements cooperating with said gear teeth on said first gear member; and (h) means coupled to said gear train for regulating the speed of rotation of said first gear member.
Claim 2
Dependent Claim
246 words
A portable turntable for use in a microwave oven, comprising: (a) a generally cylindrical housing member having a planar bottom, a cylindrical side wall projecting upwardly therefrom and an annular cover joined to the upper edge of said side wall defining a central opening in the top of said cylindrical housing; (b) a toroidal spring case secured to said planar bottom of said housing member, a central opening in said toroidal spring case, said spring case central opening being of a predetermined diameter; (c) a first gear member having gear teeth on the peripheral edge thereof and a central shaft projecting from a first major surface thereof, said shaft being journaled for rotation within said central opening in said toroidal spring case; (d) a spiral power spring disposed in said toroidal spring case; (e) means securing one end of said power spring to said spring case and means releasably connecting the other end of said power spring to said central shaft; (f) a generally circular turntable member concentrically attached to a second major surface of said first gear member and rotatable therewith; (g) a gear train comprising a plurality of overlapping gear elements journaled for rotation about vertical axes between said planar bottom and said annular cover of said generally cylindrical housing, one of said gear elements cooperating with said gear teeth on said first gear member; and (h) means coupled to said gear train for regulating the speed of rotation of said first gear member.
Claim 3
Dependent Claim
36 words
The portable turntable as in claim 1 wherein said first gear member includes an integrally formed, downwardly offset, peripheral edge portion, said gear teeth being formed on the edge surface of said offset peripheral edge portion.
Claim 4
Dependent Claim
21 words
The portable turntable as in claim 2 wherein said spring case is at least partially surrounded by said first gear member.
Claim 5
Dependent Claim
87 words
The portable turntable as in claim 1 wherein said means for regulating the speed of rotation of said first gear means comprises: (a) a fly-wheel member secured to a shaft journaled for rotation about a vertical axis between said planar bottom and said annular cover to said housing, said shaft being drivingly coupled to said gear train; and (b) a plurality of fly-weights pivotally coupled to said fly-wheel member and displaceable under centrifugal forces to frictionally engage a surface fixed to said planar bottom of said housing.
Claim 6
Dependent Claim
47 words
The portable turntable as in claim 1 and further including: (a) a circular track affixed to the exterior surface of said cylindrical side wall of said housing; and (b) bearing means disposed in said track and cooperating with said circular turntable member proximate the peripheral edge thereof.
Claim 7
Dependent Claim
17 words
The turntable as in claim 1 wherein said spring case is made from a microwave reflective material.
Claim 8
Dependent Claim
13 words
The turntable as in claim 6 wherein said microwave reflective material is aluminum.
Claim 9
Dependent Claim
44 words
The turntable as in claim 1 wherein said means releasably connecting the other end of said spring to said central shaft comprises a unidirectional coupling means for winding up said power springs only when said turntable member is manually rotated in a predetermined direction.
Claim 10
Dependent Claim
40 words
The turntable as in claim 1 wherein said vertical axes of said plurality of gear elements in said gear train form a locus of points defining a generally circular arch concentric with said central shaft of said first gear member.
References Cited (Backward Citations)
FR460489A
Cited
US4216727A
Cited
US4258630A
Cited
US4456805A
Cited
US4254319A
Cited
US4434343A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |