US3794897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric railway speed control
Assignee: Individual
•
Filing: 1972-11-24
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Granted: 1974-02-26
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Expires: 1992-11-24
Abstract
Abstract Regenerative braking systems which have previously been used in association with electrically driven vehicles have been manually controlled whereas the present invention provides a governor which automatically controls the starting resistance of the series winding of the motor and the regenerative braking resistance of the motor in proportion to the speed of the vehicle. The starting resistance means and the braking resistance means vary in a series of steps which progressively decrease the starting and braking resistance as the speed of the vehicle increases and progressively decreases the starting and braking resistance as the speed of the vehicle decreases within predetermined limits so that the variation in the starting resistance is effective in the low speed range while the variations in the braking resistance are effective in the high speed range. In addition, the governor of the present invention is mounted directly onto the output drive shaft of the motor so that there is no danger of failure of the governor as a result of a failure of any transmission used to transmit power to the governor which might otherwise permit the motor to rotate at high speed while the governor is inoperative.
Inventors
- 👤 R Bradley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:28
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/02; H02P1/04; H02P1/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
In a self-propelled electric railway car or the like having drive wheel means for driving the car along a track and mechanical brake means for braking the car, the improvement of: regenerative braking motor means having output shaft means drivingly connected to said drive wheel means of said car, said regenerative motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means mounted on said drive shaft of said motor and operative in response to rotation of said drive shaft to control said starting resistance means and said braking resistance means as required in use.
Claim 2
Dependent Claim
128 words
In a self-propelled electric railway car or the like having drive wheel means for driving the car along a track and mechanical brake means for braking the car, the improvement of: regenerative braking motor means having output shaft means drivingly connected to said drive wheel means of said car, said regenerative motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means mounted on said drive shaft of said motor and operative in response to rotation of said drive shaft to control said starting resistance means and said braking resistance means as required in use.
Claim 3
Dependent Claim
143 words
In a self-propelled electric railway car which has a regenerative braking motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, the improvement of mechanical governor means operative in response to a predetermined speed of said car to control said starting resistance and said braking resistance as required in use, said mechanical governor being a two-stage governor, the first stage being operative at slow speeds to effect a step variation in said starting resistance which is balanced against the appropriate speed of said car, the second stage being operative at high speed to effect a step variation in the regenerative braking resistance which is balanced against the appropriate speed of the car.
Claim 4
Dependent Claim
143 words
In a self-propelled electric railway car which has a regenerative braking motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, the improvement of mechanical governor means operative in response to a predetermined speed of said car to control said starting resistance and said braking resistance as required in use, said mechanical governor being a two-stage governor, the first stage being operative at slow speeds to effect a step variation in said starting resistance which is balanced against the appropriate speed of said car, the second stage being operative at high speed to effect a step variation in the regenerative braking resistance which is balanced against the appropriate speed of the car.
Claim 5
Dependent Claim
34 words
A self-propelled railway car as claimed in claim 7 having mechanical braking means, said governor means being operative to activate said mechanical braking means for said car at a predetermined speed of said car.
Claim 6
Dependent Claim
189 words
In a self-propelled electric railway car or the like having drive wheel means for driving the car along a track and mechanical brake means for braking the car, the improvement of; regenerative braking motor means having output shaft means drivingly connected to said drive wheel means of said car, said regenerative motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means mounted on said drive shaft of said motor and operative in response to rotation of said drive shaft to control said starting resistance means and said braking resistance means as required in use, said governor being a two-stage governor, the first stage being operative at slow speeds to effect a step variation in said starting resistance which is balanced against the appropriate speed of said motor, the second stage being operative at high speed to effect a step variation in the regenerative braking resistance which is balaNced against the appropriate speed of the motor.
Claim 7
Dependent Claim
189 words
In a self-propelled electric railway car or the like having drive wheel means for driving the car along a track and mechanical brake means for braking the car, the improvement of; regenerative braking motor means having output shaft means drivingly connected to said drive wheel means of said car, said regenerative motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means mounted on said drive shaft of said motor and operative in response to rotation of said drive shaft to control said starting resistance means and said braking resistance means as required in use, said governor being a two-stage governor, the first stage being operative at slow speeds to effect a step variation in said starting resistance which is balanced against the appropriate speed of said motor, the second stage being operative at high speed to effect a step variation in the regenerative braking resistance which is balaNced against the appropriate speed of the motor.
Claim 8
Dependent Claim
33 words
A self-propelled railway car as claimed in claim 4 wherein said governor means is operative to activate said mechanical braking means for said car at a predetermined speed of rotation of said shaft.
Claim 9
Dependent Claim
79 words
A self-propelled electric railway car having a propulsion unit comprising regenerative braking motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means operative in response to a predetermined speed of said car to control said starting resistance and said braking resistance as required in use.
Claim 10
Dependent Claim
79 words
A self-propelled electric railway car having a propulsion unit comprising regenerative braking motor means having a series winding and a regenerative field winding which are not directly connected to one another, starting resistance means for said series winding of said motor, regenerative braking resistance means for said regenerative field winding of said motor, mechanical governor means operative in response to a predetermined speed of said car to control said starting resistance and said braking resistance as required in use.
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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |