US4349727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heater unit
Assignee: DALTON ELECTRIC HEATING Co Inc
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Filing: 1974-10-08
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Granted: 1982-09-14
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Expires: 1994-10-08
Abstract
Abstract An elongated heater unit including an elongated resistor helix, terminals connected to the ends of the helix, at least a first surrounding metallic sheath, powder insulation material disposed within the first sheath and spacing the resistor helix from the sheath. The sheath is provided with at least one indentation and/or groove extending along at least a portion of the length of the first sheath. The method for constructing the heater unit includes forming the indentation by means of a roll with a protrusion, by utilizing a mandrel, by utilizing a temperature sensitive member or by utilizing a reducing sheath.
Inventors
- 👤 John W. Churchill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:27
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/42; H05B3/44; H05B3/02; H05B3/06; H05B3/48; H05B3/52; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49087; Y10T29/49089; Y10T29/49091
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
303 words
A heater unit comprising resistor means, terminal means connected to the ends of said resistor means, first surrounding elongated metallic sheath means, compacted powder insulation material disposed within said first sheath means and spacing said resistor means from said first sheath means, said first sheath means being provided with indentation means extending along at least a portion of the length of said first sheath means, said first surrounding elongated metallic sheath means including at least one sheath in the form of two substantially parallel adjacent leg portions interconnected by a return bend portion formed of said one sheath bent back upon itself and being integral with the adjacent parallel extending leg portions, said terminal means being provided at the adjacent ends of said one sheath and having said resistor means connected therebetween, said resistor means extending in the direction of said one sheath and being spaced therefrom by said powder insulation material, each of said leg portions of said one sheath having in cross section, at least a first flat surface portion and arcuate surface portions forming a closed loop, said at least first flat surface portions of each leg portion being adjacent and facing one another, said indentation means extending along at least a portion of at least one of said leg portions, said resistor means being a resistor helix having a cross-sectional configuration generally corresponding to the cross-sectional configuration of said one sheath, said indentation means being formed as a groove bounded at least in part by generally facing surface portions of said first sheath means, temperature sensing means being disposed in said groove for sensing the temperature of the heater unit, and second sheath means encasing and in thermal conductive contact with at least a portion of both said leg portions and said temperature sensing means disposed in said groove.
Claim 2
Dependent Claim
303 words
A heater unit comprising resistor means, terminal means connected to the ends of said resistor means, first surrounding elongated metallic sheath means, compacted powder insulation material disposed within said first sheath means and spacing said resistor means from said first sheath means, said first sheath means being provided with indentation means extending along at least a portion of the length of said first sheath means, said first surrounding elongated metallic sheath means including at least one sheath in the form of two substantially parallel adjacent leg portions interconnected by a return bend portion formed of said one sheath bent back upon itself and being integral with the adjacent parallel extending leg portions, said terminal means being provided at the adjacent ends of said one sheath and having said resistor means connected therebetween, said resistor means extending in the direction of said one sheath and being spaced therefrom by said powder insulation material, each of said leg portions of said one sheath having in cross section, at least a first flat surface portion and arcuate surface portions forming a closed loop, said at least first flat surface portions of each leg portion being adjacent and facing one another, said indentation means extending along at least a portion of at least one of said leg portions, said resistor means being a resistor helix having a cross-sectional configuration generally corresponding to the cross-sectional configuration of said one sheath, said indentation means being formed as a groove bounded at least in part by generally facing surface portions of said first sheath means, temperature sensing means being disposed in said groove for sensing the temperature of the heater unit, and second sheath means encasing and in thermal conductive contact with at least a portion of both said leg portions and said temperature sensing means disposed in said groove.
Claim 3
Dependent Claim
27 words
A heater unit according to claim 1, wherein said groove is symmetrically disposed with respect to the first flat surface portions of each of said leg portions.
Claim 4
Dependent Claim
22 words
A heater unit according to claim 1, wherein said second sheath means provides the heater unit with a substantially cylindrical outer configuration.
Claim 5
Dependent Claim
29 words
A heater unit according to claim 1, wherein said temperature sensing means include a liquid-filled sensing bulb for providing an output indicative of the temperature of the heater unit.
Claim 6
Dependent Claim
46 words
A heater unit according to claim 1, wherein said temperature sensing means includes a thermocouple member disposed within the groove and having a thermocouple junction in thermal conductive contact with said first sheath means for providing an output indicative of the temperature of the heater unit.
Claim 7
Dependent Claim
27 words
A heater unit according to claim 1, wherein said temperature sensing means includes a thermistor for providing an output indicative of the temperature of the heater unit.
Claim 8
Dependent Claim
54 words
A heater unit according to claim 1, wherein said temperature sensing means provides an output indicative of the temperature of the heater unit, and means responsive to the output of said temperature sensing means for controlling electric power supplied to said heater terminal means to maintain the heater unit temperature within a predetermined range.
Claim 9
Dependent Claim
25 words
A heater unit according to claim 1, wherein said second sheath means extends the entire length of said leg portions and said return bend portion.
Claim 10
Dependent Claim
26 words
A heater unit according to claim 1, wherein said second sheath means extends outwardly beyond the ends of said leg portions having said terminal means thereat.
Claim 11
Dependent Claim
26 words
A heater unit according to claim 1, wherein said temperature sensing means includes a thermocouple member having a thermocouple junction disposed beneath said second sheath means.
Claim 12
Dependent Claim
23 words
A heater unit according to claim 1, wherein said second sheath means directly contacts both said leg portions and said temperature sensing means.
Claim 13
Dependent Claim
16 words
A heater unit according to claim 11, wherein said second sheath means is a metallic sheath.
Claim 14
Dependent Claim
293 words
A heater unit comprising resistor means, terminal means connected to the ends of said resistor means, first surrounding elongated metallic sheath means, compacted powder insulation material disposed within said first sheath means and spacing said resistor means from said first sheath means, said first sheath means being provided with indentation means extending along at least a portion of the length of said first sheath means, said first surrounding elongated metallic sheath means including at least one sheath in the form of two substantially parallel adjacent leg portions interconnected by a return bend portion formed of said one sheath bent back upon itself and being integral with the adjacent parallel extending leg portions, said terminal means being provided at the adjacent ends of said one sheath and having said resistor means connected therebetween, said resistor means extending in the direction of said one sheath and being spaced therefrom by said powder insulation material, each of said leg portions of said one sheath having in cross section, at least a first flat surface portion and arcuate surface portions forming a closed loop, said at least first flat surface portions of each leg portion being adjacent and facing one another, said indentation means extending along at least a portion of at least one of said leg portions, said indentation means being formed as a single groove extending in the longitudinal direction of said first sheath means, a temperature sensing means being disposed in said groove, and further comprising second sheath means encasing at least a portion of both said leg portions and said temperature sensing means disposed in said groove, said second sheath means contacting said first sheath means and said temperature sensing means along a major portion of the interior of said second sheath means.
Claim 15
Dependent Claim
293 words
A heater unit comprising resistor means, terminal means connected to the ends of said resistor means, first surrounding elongated metallic sheath means, compacted powder insulation material disposed within said first sheath means and spacing said resistor means from said first sheath means, said first sheath means being provided with indentation means extending along at least a portion of the length of said first sheath means, said first surrounding elongated metallic sheath means including at least one sheath in the form of two substantially parallel adjacent leg portions interconnected by a return bend portion formed of said one sheath bent back upon itself and being integral with the adjacent parallel extending leg portions, said terminal means being provided at the adjacent ends of said one sheath and having said resistor means connected therebetween, said resistor means extending in the direction of said one sheath and being spaced therefrom by said powder insulation material, each of said leg portions of said one sheath having in cross section, at least a first flat surface portion and arcuate surface portions forming a closed loop, said at least first flat surface portions of each leg portion being adjacent and facing one another, said indentation means extending along at least a portion of at least one of said leg portions, said indentation means being formed as a single groove extending in the longitudinal direction of said first sheath means, a temperature sensing means being disposed in said groove, and further comprising second sheath means encasing at least a portion of both said leg portions and said temperature sensing means disposed in said groove, said second sheath means contacting said first sheath means and said temperature sensing means along a major portion of the interior of said second sheath means.
Claim 16
Dependent Claim
23 words
A heater unit according to claim 13, wherein said groove has a depth of approximately one half the diameter of the heater unit.
Claim 17
Dependent Claim
36 words
A heater unit according to claim 1, wherein said temperature sensing means is a liquid-filled sensing bulb and said groove is provided with a radiused bottom portion for matching the contours of the liquid-filled sensing bulb.
Claim 18
Dependent Claim
34 words
A heater unit according to claim 13, wherein said resistor means is a resistor helix having a cross-sectional configuration corresponding to the cross-sectional configuration of said first sheath means, said cross-sectional configuration being non-semicircular.
Claim 19
Dependent Claim
22 words
A heater unit according to claim 13, wherein said second sheath means provides the heater unit with a substantially cylindrical outer configuration.
Claim 20
Dependent Claim
29 words
A heater unit according to claim 17, wherein said temperature sensing means includes a liquid-filled sensing bulb for providing an output indicative of the temperature of the heater unit.
Claim 21
Dependent Claim
32 words
A heater unit according to claim 13, wherein said groove is in mating contact with said temperature sensing means along a major portion of the surface area of said temperature sensing means.
Claim 22
Dependent Claim
26 words
A heater unit according to claim 19, wherein said groove is in mating contact with said temperature sensing means along the lowermost portion of said groove.
Claim 23
Dependent Claim
25 words
A heater unit according to claim 13, wherein said one sheath is completely filled with compacted powder insulation, said terminal means including end cap means.
Claim 24
Dependent Claim
15 words
A heater unit according to claim 21, wherein said resistor means is a resistor helix.
Claim 25
Dependent Claim
19 words
A heater unit according to claim 21, wherein said indentation means is a deformed portion of said one sheath.
Claim 26
Dependent Claim
16 words
A heater unit according to claim 13, wherein said second sheath means is a metallic sheath.
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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) | 1985-09-13 | 1986-03-15 | 1986-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-13 | 1990-03-15 | 1990-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-13 | 1994-03-15 | 1994-09-14 | $7700.00 | Window Closed / Lapsed |