US3612950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control system
Assignee: Individual
•
Filing: 1969-09-17
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Granted: 1971-10-12
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Expires: 1989-09-17
Abstract
Abstract Disclosed is a motor control system for energizing a motor which in turn drives a pump for pumping liquefied gases. A 3- phi alternator (alt.) supplies current to the motor. The alternator field winding is supplied with a first current by a low voltage circuit and with a second current by a current sensing circuit connected to sense the load current passing from the alternator to the motor and to generate a current which is a function of the load current. A single cutout relay having a first pair of contacts connected in the low-voltage circuit and a second pair of contacts connected in the current sensing circuit operates to disconnect both the low-voltage circuit and the current sensing circuit from the alternator field winding, and, thereby stop the motor and pump, whenever any one of several monitored parameters exceeds a chosen threshold value.
Inventors
- 👤 Thomas A Knott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:24
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
207 words
In a motor control system for energizing a motor wherein said motor drives a pump for pumping liquefied gases, the combination of an alternator for supplying a load current to said motor, said alternator having a field winding and supply lines connecting said alternator to said motor; a cutout relay having a single operating coil and first and second pairs of contacts; a lowvoltage circuit including a battery and said first pair of contacts, said low-voltage circuit being connected to supply current to said field winding; a current sensing circuit including said second pair of contacts, said current sensing circuit being adapted to sense said load current supplied from said alternator to said motor and to supply said field winding with a current which is a function of said load current; an energizing circuit including said battery for energizing said operating coil; and means for sensing an overheated condition of said motor and causing said operating coil to be deenergized, whereby said first pair of contacts are actuated to interrupt said low-voltage circuit and said second pair of contacts are actuated to interrupt said current sensing circuit to stop current flow in said field winding of said alternator and thereby stop said load current to said motor.
Claim 2
Dependent Claim
207 words
In a motor control system for energizing a motor wherein said motor drives a pump for pumping liquefied gases, the combination of an alternator for supplying a load current to said motor, said alternator having a field winding and supply lines connecting said alternator to said motor; a cutout relay having a single operating coil and first and second pairs of contacts; a lowvoltage circuit including a battery and said first pair of contacts, said low-voltage circuit being connected to supply current to said field winding; a current sensing circuit including said second pair of contacts, said current sensing circuit being adapted to sense said load current supplied from said alternator to said motor and to supply said field winding with a current which is a function of said load current; an energizing circuit including said battery for energizing said operating coil; and means for sensing an overheated condition of said motor and causing said operating coil to be deenergized, whereby said first pair of contacts are actuated to interrupt said low-voltage circuit and said second pair of contacts are actuated to interrupt said current sensing circuit to stop current flow in said field winding of said alternator and thereby stop said load current to said motor.
Claim 3
Dependent Claim
46 words
The motor control system set forth in claim 1 wherein said means for sensing an overheated condition comprises current transformer means operatively connected to said supply lines, said current transformer means causing said operating coil to be deenergized when said load current exceeds a predetermined level.
Claim 4
Dependent Claim
42 words
The motor control system set forth in claim 1 wherein said means for sensing an overheated condition comprises a tachogenerator operatively connected to said motor, said tachogenerator causing said operating coil to be deenergized when said motor speed exceeds a predetermined limit.
Claim 5
Dependent Claim
49 words
The motor control system set forth in claim 1 wherein said means for sensing an overheated condition comprises a pressure switch connected in said energizing circuit and adapted to be actuated and thereby deenergize said operating coil when the pumping pressure in said pump falls below a predetermined level.
Claim 6
Dependent Claim
34 words
The motor control system set forth in claim 1 further comprising a manual cutoff switch connected in said energizing circuit whereby said operating coil may be deenergized by actuation of said manual cutoff switch.
Claim 7
Dependent Claim
44 words
The motor control system set forth in claim 1 wherein said means for sensing an overheated condition comprises motor heat sensing means adjacent said motor, said heat sensing means causing said operating coil to be deenergized when said motor temperature exceeds a predetermined level.
Claim 8
Dependent Claim
38 words
The motor control system set forth in claim 1 further comprising alternator heat sensing means adjacent said alternator, said alternator heat sensing means causing said operating coil to be deenergized when said alternator temperature exceeds a predetermined level.
Claim 9
Dependent Claim
56 words
The motor control system set forth in claim 1 wherein said alternator is adapted to generate 3- phi current, said supply lines connecting said alternator to said motor are adapted to conduct 3- phi current and said current sensing circuit is adapted to sense said load current in only one of said 3- phi supply lines.
Claim 10
Dependent Claim
59 words
The motor control system set forth in claim 8 wherein said means for sensing an overheated condition of said motor comprises current sensing means connected in each of said 3- phi supply lines, said current sensing means causing said operating coil to be deenergized when said load current in any of said3- phi supply lines exceeds a predetermined level.
Claim 11
Dependent Claim
114 words
The motor control system as set forth in claim 1 wherein said current sensing circuit includes a current transformer having a primary winding connected to sense said load current and to generate a voltage across a secondary winding, a rectifier connected to said secondary winding and said second pair of contacts being connected across said secondary winding; said energizing circuit further including a third pair of contacts energized by said operating coil; and wherein said means for causing said operating coil to be deenergized comprises a trip switch operatively connected to said energizing circuit whereby when an overheated condition of said motor is sensed, said trip switch is actuated to deenergize said operating coil.
Claim 12
Dependent Claim
35 words
The motor control system as set forth in claim 10 wherein said trip switches include controlled rectifier devices having gate elements which are adapted to be actuated by said means for sensing an overheated condition.
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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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |