US3565011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-speed ground transportation system
Assignee: Individual
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Filing: 1968-05-07
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Granted: 1971-02-23
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Expires: 1988-05-07
Abstract
Abstract A high-speed ground transportation system comprises a duct through which a vehicle is adapted for propulsion as a free piston. Entrance and exit valves are provided adjacent the ends of the duct and the section of the duct between the valves is preevacuated. On opening the entrance valve, air pressure forces the vehicle into the section and after the vehicle has passed the entrance valve, the latter is normally closed to trap a slug of air between the valve and the rear of the vehicle. This trapped slug of air expands to apply propulsive force to the rear of the vehicle, with attenuation of the air behind the vehicle and compression of the air ahead of the vehicle. The exit valve opens when the pressure ahead of the vehicle reaches a predetermined magnitude for passage of the vehicle through the exit valve and into a station. The present invention relates to means for assuring that the vehicle will stop in a station in the event that the entrance valve fails to close, or closes too early, or closes only partially. This is achieved by opening the exit valve and thereby repressurizing the duct ahead of the vehicle, and doing so at such a time as to match the future energy loss of the vehicle with that which is necessary to stop the vehicle in the station downstream from the exit valve.
Inventors
- 👤 Lawrence K Edwards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:55
CPC Classifications
B; B61; B61B; B61B13/00; B61B13/12; B61B13/122
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
190 words
A high-speed ground transportation system comprising a duct, a vehicle adapted for propulsion as a free piston through the duct by differential air pressure on the ends of the vehicle, a valve for the duct at the entrance end of the duct adapted to close after the rearward end of the vehicle has passed thereby to trap a slug of propulsive air behind the vehicle in the duct, a valve for the duct at the exit end of the duct adapted to open as the vehicle approaches the exit valve for exit of the vehicle past the exit valve to a station, means responsive to the operation of the entrance valve for generating a signal indicative of the instantaneous position of said entrance valve, means responsive to said signal for calculating a time at which to admit atmospheric air into the duct ahead of the vehicle when said signal indicates an improper position of said entrance valve, and means for admitting said air at said time to flood the duct ahead of the vehicle with air to decelerate the vehicle and bring the vehicle to a stop in said station.
Claim 2
Dependent Claim
190 words
A high-speed ground transportation system comprising a duct, a vehicle adapted for propulsion as a free piston through the duct by differential air pressure on the ends of the vehicle, a valve for the duct at the entrance end of the duct adapted to close after the rearward end of the vehicle has passed thereby to trap a slug of propulsive air behind the vehicle in the duct, a valve for the duct at the exit end of the duct adapted to open as the vehicle approaches the exit valve for exit of the vehicle past the exit valve to a station, means responsive to the operation of the entrance valve for generating a signal indicative of the instantaneous position of said entrance valve, means responsive to said signal for calculating a time at which to admit atmospheric air into the duct ahead of the vehicle when said signal indicates an improper position of said entrance valve, and means for admitting said air at said time to flood the duct ahead of the vehicle with air to decelerate the vehicle and bring the vehicle to a stop in said station.
Claim 3
Dependent Claim
47 words
A high-speed ground transportation system as set forth in claim 1 wherein said means for admitting air is the exit valve of the duct and said calculating means is a computer preprogrammed in with the length and contour of the duct between the entrance and exit valves.
Claim 4
Dependent Claim
60 words
A high-speed ground transportation system as set forth in claim 2 further comprising means responsive to the weight of the vehicle for generating a signal which is a function thereof, said computer being responsive to a composite of said signals for providing an output signal indicative of said time, said exit valve opening means being responsive to said output signal.
Claim 5
Dependent Claim
42 words
A high-speed ground transportation system as set forth in claim 3 further comprising means responsive to atmospheric and duct pressures for generating signals which are functions thereof, said computer being responsive to a composite of said signals for providing said output signal.
Claim 6
Dependent Claim
66 words
A high-speed ground transportation system as set forth in claim 2 further comprising means responsive to the positions of the vehicle in the duct as it traverses the duct for generating signals which are functions thereof, said computer being responsive to a composite of said signals for providing an output signal indicative of said time, said exit valve opening means being responsive to said output signal.
Claim 7
Dependent Claim
231 words
A high-speed ground transportation system as set forth in claim 1 wherein said time is determined to bring the vehicle into the station at a moderate velocity, and further comprising braking means responsive to a second output signal from said calculating means for precisely controlling the stopping location of the vehicle in the station. 7 In a high-speed ground transportation system having a duct, a vehicle adapted for propulsion as a free piston through the duct by differential air pressure on the ends of the vehicle, a valve for the duct at the entrance end of the duct adapted to close after the rearward end of the vehicle has passed thereby to trap a slug of propulsive air behind the vehicle in the duct, and a valve for the duct at the exit end of the duct adapted to open as the vehicle approaches the exit valve for exit of the vehicle past the exit valve to a station; the method of bringing the vehicle to an emergency stop in the station upon failure of the entrance valve to close properly, comprising sensing any improper closing of the entrance valve and maintaining this valve open throughout the trip of the vehicle, and thereafter, at a time determined to bring the vehicle to a stop in the station, admitting atmospheric air into the duct ahead of the vehicle to decelerate the vehicle.
Claim 8
Dependent Claim
89 words
The method of claim 7 wherein said time is dEtermined by computer means preprogrammed with the length and contour of the duct between the entrance and exit valves, and further comprising generating a signal which is a function of the closing of said entrance valve, and sensing the weight of the vehicle and generating a signal which is a function thereof, said computer means being responsive to a composite of said signals for providing an output signal indicative of said time for admitting atmospheric air ahead of the vehicle.
Claim 9
Dependent Claim
35 words
The method of claim 8 further comprising sensing atmospheric and duct pressures and generating signals which are functions thereof, said computer means being responsive to a composite of said signals for providing said output signal.
Claim 10
Dependent Claim
94 words
The method of claim 7 wherein said time is determined by computer means preprogrammed with the length and contour of the duct between the entrance and exit valves, and further comprising generating a signal which a function of the closing of said entrance valve, and sensing the positions of the vehicle in the duct as it traverses the duct for generating signals which are functions thereof, said computer means being responsive to a composite of said signals for providing an output signal indicative of said time for admitting atmospheric air ahead of the vehicle.
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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |