US3723932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal protective assembly
Assignee: General Electric Co
•
Filing: 1971-02-01
•
Granted: 1973-03-27
•
Expires: 1991-02-01
Abstract
Abstract A thermal protective assembly for an electrical component such as a motor has a field winding which uses a heat meltable alloy formed into a bent shape and connected in series with and resting on the field. The alloy receives conductive heat from the windings and is designed to melt before the I2R heating from a malfunction breaks the circuit. The bent form of the alloy is chosen to create an open circuit and ensure no puddling to bridge the opening on melting of the alloy. Additional means is provided to insulate the alloy from the field windings and to cover it from the ambient whereby it responds only to conductive heat.
Inventors
- 👤 H Miller
- 👤 G Vallone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:19
CPC Classifications
H; H02; H02K; H02K11/00; H02K11/20; H02K11/25
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
70 words
A thermal protective arrangement for a motor having a field winding comprising, a heat meltable alloy formed into an unsupported bent shape and connected in series with the field and freely resting thereon to receive conductive heat from said windings, said alloy being heat sensitive rather than current sensitive whereby it melts to open the circuit upon a selected field temperature and the unsupported bent shape ensures an open circuit.
Claim 2
Dependent Claim
70 words
A thermal protective arrangement for a motor having a field winding comprising, a heat meltable alloy formed into an unsupported bent shape and connected in series with the field and freely resting thereon to receive conductive heat from said windings, said alloy being heat sensitive rather than current sensitive whereby it melts to open the circuit upon a selected field temperature and the unsupported bent shape ensures an open circuit.
Claim 3
Dependent Claim
28 words
Apparatus as described in claim 1 having, means disposed between said alloy and field to electrically insulate therebetween, and means covering said alloy to shield it from ambient.
Claim 4
Dependent Claim
24 words
Apparatus as described in claim 1 wherein said alloy is bent in a U-shape to ensure said open circuit upon melting of said alloy.
Claim 5
Dependent Claim
28 words
Apparatus as described in claim 3 having means disposed between said alloy and field to electrically insulate therebetween, and means covering said alloy to shield it from ambient.
Claim 6
Dependent Claim
31 words
Apparatus as described in claim 4 wherein said alloy is selected to melt by direct conduction of heat from said field before the I2R heating from a malfunction breaks the circuit.
References Cited (Backward Citations)
US3201646A
Cited
US3168632A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |