US3943504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor direction indicating device
Assignee: Westinghouse Electric Corp
•
Filing: 1975-02-25
•
Granted: 1976-03-09
•
Expires: 1995-02-25
Abstract
Abstract A direction indicating device for indicating the direction of rotation of a polyphase A.C. electric motor. A polyphase energy source having a frequency higher than the operating frequency of the electric motor impresses a rotating electromagnetic field in the windings of the motor. A pair of coil detectors, spaced a predetermined electrical distance apart, detects the rotating electromagnetic field and determines the direction of rotation of the electromagnetic field. The direction of rotation of the electromagnetic field, which is the same as the rotation of the electric motor, is displayed on a display apparatus.
Inventors
- 👤 Jan Vosicky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:22
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34; G01R31/343
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
A direction indicating device for indicating the direction of rotation of an A.C. electric motor having windings thereon, said device comprising; a source of electrical energy producing an electromagnetic field within said windings, means for sensing said electromagnetic field in said windings, and display means for indicating the direction of movement of said electromagnetic field in said windings, the direction of movement of said electromagnetic field in said winding indicating the direction of rotation of said motor.
Claim 2
Dependent Claim
77 words
A direction indicating device for indicating the direction of rotation of an A.C. electric motor having windings thereon, said device comprising; a source of electrical energy producing an electromagnetic field within said windings, means for sensing said electromagnetic field in said windings, and display means for indicating the direction of movement of said electromagnetic field in said windings, the direction of movement of said electromagnetic field in said winding indicating the direction of rotation of said motor.
Claim 3
Dependent Claim
31 words
The device of claim 1, wherein said A.C. electric motor is operable at a first predetermined frequency, and wherein said source of electrical power is operable at a second predetermined frequency.
Claim 4
Dependent Claim
17 words
The device of claim 2 wherein said second predetermined frequency is greater than said first predetermined frequency.
Claim 5
Dependent Claim
77 words
The device of claim 1, wherein said sensing means comprises a first coil pick-up and a second coil pick-up, said second coil pick-up being displaced a predetermined electrical distance from said first coil, pick-up, said electromagnetic field inducing a first electric current in said first coil and a second electric current in said second coil, said first electric current in said first coil having a predetermined phase relationship with said second current induced in said second coil.
Claim 6
Dependent Claim
61 words
The device of claim 4, wherein said display means comprises means for detecting the phase relationship between said first current and said second current, said phase relationship between said first current and said second current indicating the direction of rotation of said electromagnetic field, the direction of rotation of said electromagnetic field indicating the direction of rotation of said electric motor.
Claim 7
Dependent Claim
108 words
A gas turbine power plant comprising: a starting package having an A.C. electric motor disposed therein, said electric motor having windings thereon, and, an indicating device for indicating the direction of rotating of said electric motor, said indicating device comprising; an electrical energy source producing an electromagnetic field in said winding, means for sensing said electromagnetic field in said windings at a first and a second point, said electromagnetic field inducing a first and a second electric current in said sensing means, and, means for comparing the phase relationship between said first and said second electric currents to indicate thereby the direction of rotation of said electric motor.
Claim 8
Dependent Claim
108 words
A gas turbine power plant comprising: a starting package having an A.C. electric motor disposed therein, said electric motor having windings thereon, and, an indicating device for indicating the direction of rotating of said electric motor, said indicating device comprising; an electrical energy source producing an electromagnetic field in said winding, means for sensing said electromagnetic field in said windings at a first and a second point, said electromagnetic field inducing a first and a second electric current in said sensing means, and, means for comparing the phase relationship between said first and said second electric currents to indicate thereby the direction of rotation of said electric motor.
Claim 9
Independent Claim
60 words
A method of determining the direction of rotation of an electric motor comprising the steps: a. energizing the windings of said electric motor to produce a rotating electric field therein, and b. sensing the direction of rotation of said rotating electric field, said direction of rotation of said electric field corresponding to said direction of rotation of said electric motor.
Claim 10
Independent Claim
60 words
A method of determining the direction of rotation of an electric motor comprising the steps: a. energizing the windings of said electric motor to produce a rotating electric field therein, and b. sensing the direction of rotation of said rotating electric field, said direction of rotation of said electric field corresponding to said direction of rotation of said electric motor.
Claim 11
Dependent Claim
48 words
The method of claim 7 wherein said motor has windings therein and operates at a predetermined frequency, and wherein step (a) comprises the steps connecting an electric signal source to said windings, and, impressing an electric signal having a frequency greater than said predetermined frequency in said windings.
Claim 12
Dependent Claim
64 words
The method of claim 8, wherein step (b) comprises the steps detecting the rotating electric field at a first location in said windings detecting the rotating electric field at a second location in said windings comparing the phase relationship between currents induced by the rotating field at the first and second locations to determine the direction of rotation of the field within said windings.
References Cited (Backward Citations)
US2669126A
Cited
US2786978A
Cited
US2924773A
Cited
US3123818A
Cited
US3111841A
Cited
US3188620A
Cited
US3120655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |