Patent US3725757A successfully refreshed from Google Patents.
US3725757A
Expired / Lapsed
US
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Starting circuit for permanent split capacitor motor
Assignee: Thermo Electronics Inc
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Filing: 1971-05-13
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Granted: 1973-04-03
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Expires: 1991-05-13
Abstract
Abstract A starting circuit for a permanent split capacitor motor having a main field winding, a starting field winding, a running capacitor, and a supplementary starting capacitor. A thermal relay is provided having normally closed switch contacts coupling the supplementary starting capacitor across the running capacitor and a bimetallic element serially coupled with the starting winding and running capacitor across the main winding. The bimetallic element opens the switch contacts thereby to disconnect the starting capacitor in response to a first predetermined current flow in the starting wind-ing circuit and maintains the switch contacts open in response to a lower current flow.
Inventors
- 👤 H Ehrens
- 👤 C Slocum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:55
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/42; H02P1/44; H02P1/445
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
167 words
In a permanent split capacitor, single-phase, alternating current induction motor having a main field winding, means for coupling said main winding across a source of single-phase, alternating current potential, a starting field winding, a running capacitor, a supplementary starting capacitor, and normally closed switch contacts coupling said supplementary starting capacitor across said running capacitor,; a starting circuit comprising a first bimetallic element, said starting winding, first bimetallic element and running capacitor being serially coupled across said main winding, a second ambient temperature-compensating bimetallic element carrying one of said switch contacts, a movable contact element carrying the other of said switch contacts, and means coupling said first bimetallic element to said movable element for actuating the same to open said contacts in response to flexure of said first bimetallic element whereby said contacts are opened in response to a first predetermined current flow in said starting winding and maintained open in response to a second predetermined current flow in said starting winding less than said first current flow.
Claim 2
Dependent Claim
167 words
In a permanent split capacitor, single-phase, alternating current induction motor having a main field winding, means for coupling said main winding across a source of single-phase, alternating current potential, a starting field winding, a running capacitor, a supplementary starting capacitor, and normally closed switch contacts coupling said supplementary starting capacitor across said running capacitor,; a starting circuit comprising a first bimetallic element, said starting winding, first bimetallic element and running capacitor being serially coupled across said main winding, a second ambient temperature-compensating bimetallic element carrying one of said switch contacts, a movable contact element carrying the other of said switch contacts, and means coupling said first bimetallic element to said movable element for actuating the same to open said contacts in response to flexure of said first bimetallic element whereby said contacts are opened in response to a first predetermined current flow in said starting winding and maintained open in response to a second predetermined current flow in said starting winding less than said first current flow.
Claim 3
Dependent Claim
72 words
The starting circuit of claim 1 wherein said coupling means comprises a non-overcenter snap-acting spring whereby said movable contact element is actuated to open said contacts in response to flexure of said bimetallic element away from a normal position by a first predetermined amount, and said movable contact element is actuated to open said contacts in response to flexure of said bimetallic element toward said normal position by a second predetermined amount.
Claim 4
Dependent Claim
96 words
The starting circuit of claim 2 wherein said first bimetallic element is generally U-shaped, said second bimetallic element being elongated and having said one switch contact carried on one end, said movable contact element being generally elongated and having said other switch contact carried on one end, said spring coupling the outer end of said first bimetallic element and said one end of said movable contact element, and further comprising means for clamping the ends of the legs of said first bimetallic element and the other ends of second bimetallic element and said movable contact element.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |