U.S. patent number 3,675,582 [Application Number 05/061,311] was granted by the patent office on 1972-07-11 for mass transportation system.
This patent grant is currently assigned to Teledyne Ryan Aeronautical Company. Invention is credited to Peter F. Girard, John M. Peterson.
United States Patent |
3,675,582 |
Girard , et al. |
July 11, 1972 |
MASS TRANSPORTATION SYSTEM
Abstract
A high speed mass transportation system, in which a train unit
rides in an arcuately concave, narrow guideway and is
aerodynamically supported on airfoils conforming to the arcuate
form of the guideway. The center mass of the vehicle is below the
center of radius of the guideway, which provides a self-stabilizing
and automatic banking action in high speed turns, so that
passengers are not subjected to lateral accelerations. The airfoils
are spaced several inches above the guideway at cruising speed, so
that the surface finish of the guideway is not unduly critical and
cost is minimized. Retractable wheels are provided for supporting
the train unit at low speeds and on flat surfaces. Propulsion may
be by means of direct thrust, such as a propeller, or by electrical
drive means, such as a linear induction motor.
Inventors: |
Girard; Peter F. (La Mesa,
CA), Peterson; John M. (San Diego, CA) |
Assignee: |
Teledyne Ryan Aeronautical
Company (San Diego, CA)
|
Family
ID: |
22034973 |
Appl.
No.: |
05/061,311 |
Filed: |
August 5, 1970 |
Current U.S.
Class: |
104/23.1; 244/2;
104/134 |
Current CPC
Class: |
B61B
13/08 (20130101); B60V 3/04 (20130101) |
Current International
Class: |
B60V
3/04 (20060101); B61B 13/08 (20060101); B60V
3/00 (20060101); B61b 013/08 () |
Field of
Search: |
;104/23R,23FS,134,138R
;244/2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: La Point; Arthur L.
Assistant Examiner: Keen; D. W.
Claims
Having described our invention, we now claim:
1. In a mass transportation system,
an elongated guideway having a concave trough of arcuate cross
section,
a vehicle, comprising an elongated body, with a plurality of
longitudinally spaced, vehicle supporting, aerodynamic lifting
airfoils mounted below the body substantially clear of aerodynamic
interference therewith, said airfoils extending transversely to the
length of the body and having arcuate dihedral conforming to the
cross section of said guideway, to operate in ground effect with
the guideway surface,
the radius of curvature of said guideway cross section being such
that the effective center of mass of the vehicle is below the
center of radius, when the vehicle is riding in the guideway,
and propulsion means mounted on said vehicle.
2. A mass transportation system according to claim 1, wherein said
body has a pair of legs fixed to and supporting each of said
airfoils, said legs being of streamlined cross section, at least
some of said legs each having a rearwardly extended lower portion,
with a rudder pivotally mounted thereon, and control means
connected to said rudders for selective operation thereof.
3. A mass transportation system according to claim 2, wherein at
least some of said legs each has a rearwardly extended lower
portion, with a rudder pivotally mounted thereon, and control means
connected to said rudders for selective operation thereof.
4. A mass transportation system according to claim 2, wherein said
control means includes roll sensing means in said vehicle, and
actuating means controlled by said roll sensing means to move said
rudders in a direction to oppose the sensed roll.
5. A mass transportation system according to claim 4, wherein said
control means further includes means for moving the rudders on each
pair of legs in opposite directions.
6. A mass transportation system according to claim 2, and including
wheels retractably mounted in at least some of said pairs of legs,
said wheels extending below said airfoils.
7. A mass transportation system according to claim 6, and including
actuating means for extending said wheels sufficiently to raise
said airfoils clear of a flat supporting surface.
8. A mass transportation system according to claim 6, wherein said
airfoils have downwardly projecting tip plates thereon, said wheels
being movable between a retracted position projecting below said
airfoils slightly further than said tip plates, and an extended
position in which the airfoils are supported clear of a flat
surface.
9. A mass transportation system according to claim 1, wherein
certain of said airfoils each has a flap pivotally mounted on a
trailing edge portion thereof to swing downwardly through a limited
range, and control means, sensitive to changes in pressure below
the respective airfoil, connected to each flap.
10. A mass transportation system according to claim 9, wherein said
control means comprises a cavity in the underside of the airfoil, a
pressure sensitive diaphragm mounted in said cavity and linkage
means connected from said diaphragm to the associated flap to lower
the flap when pressure below the airfoil increases.
11. A mass transportation system according to claim 1, wherein said
airfoils are spaced substantially equally along the length of said
body.
12. A mass transportation system according to claim 1, wherein said
airfoils include a forward airfoil below the extreme front portion
of said body, and an aft airfoil below the extreme rear portion of
the body.
13. A mass transportation system according to claim 12, wherein
said body has an underside portion of substantially arcuate convex
cross section conforming to said guideway, said airfoils being
positioned to hold the body at a positive angle of incidence
relative to the guideway surface and in ground effect proximity
thereto.
14. A mass transportation system according to claim 1, wherein said
guideway has slipstream deflecting baffles extending outwardly from
opposite sides and coextensive therewith.
Description
BACKGROUND OF THE INVENTION
In the field of mass transportation, many different proposals have
been made for increasing vehicle speed. Studies have determined
that a cruise speed of about 300 mph is practical for various stage
lengths, with reasonable acceleration and deceleration. At such
speed, wheels become impractical due to the loads and wear imposed
by very high rotational speed. A number of tracked air cushion
vehicles have been proposed or developed, in which a vehicle is
supported on a special track by pressurized air, to provide a low
friction bearing. Since air leakage must be minimized to maintain
the air cushion, clearances between the track and the vehicle are
small and the track must be precisely made, at high cost. This is
particularly true with high pressure air pad support, in which
clearance is a few thousandths of an inch. In addition to direct
support of the vehicle, cushioning or other support must be
provided for handling side loads and for stabilization in turns. In
any such arrangement, the air cushion requires a power source of
considerable size, which must be carried on the vehicle.
SUMMARY OF THE INVENTION
In the system described herein, the generated air cushion and its
attendant power source are eliminated, resulting in a lighter and
less complex vehicle. The guideway is a trough-like track of
arcuately concave cross section, and is readily constructed from
concrete with simple forms. The train unit, or vehicle, comprises
an elongated body supported on longitudinally spaced airfoils,
which extend transversely and conform to the arcuate shape of the
guideway. At high speed, the airfoils ride, in ground effect,
several inches above the guideway surface and provide lifting
support for the vehicle. The center of mass of the vehicle is well
below the center of radius of the guideway cross section, which
gives the vehicle an automatic rolling and self-stabilizing
capability in banked turns, thus avoiding subjecting the passengers
to lateral accelerations.
The airfoils are supported below the vehicle body on legs which
provide roll stabilization, and also contain retractable wheels
which are lowered to support the vehicle at low speeds and when
stopped. Certain of the wheels are steerable for maneuvering the
vehicle on a flat surface. By spacing the airfoils below the body,
the transverse span of the airfoils can be reduced, minimizing the
required width of guideway. Some or all of the airfoils are
provided with automatic flaps which vary the lift in accordance
with pressure fluctuations and thus aid in damping longitudinal
oscillations. Propulsion may be by propeller means at the rear of
the vehicle, or by electrical means such as a linear induction
motor.
The primary object of this invention, therefore, is to provide a
new and improved mass transportation system.
Another object of this invention is to provide a new and improved
system in which a vehicle rides in a concave guideway and is
aerodynamically supported on airfoils conforming to the guideway in
such a manner, that the vehicle is self-stabilizing in turns.
Another object of this invention is to provide a new and improved
system in which the vehicle has retractable wheels for support at
low speeds, and for handling and maneuvering out of the
guideway.
A further object of this invention is to provide a new and improved
vehicle which is adaptable to different means for high speed
propulsion.
Other objects and many advantages of this invention will become
more apparent upon a reading of the following detailed description
and an examination of the drawings, wherein like reference numerals
designate like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a propeller driven vehicle in a
section of guideway.
FIG. 2 is a perspective view of linear induction motor powered
vehicles in a covered dual guideway.
FIG. 3 is a top plan view of the propeller driven vehicle.
FIG. 4 is a side elevation view thereof, with the guideway shown in
section.
FIG. 5 is a side elevation view of the linear induction motor
powered vehicle.
FIG. 6 is a front elevation view, as taken from the right hand end
of FIG. 5.
FIG. 7 is an enlarged sectional view taken on line 7--7 of FIG.
5.
FIG. 8 is an enlarged front elevation view showing the cruising
position of the vehicle relative to the guideway.
FIG. 9 is a front elevation view showing the wheels extended.
FIG. 10 is a diagrammatic showing of the roll stabilizing
action.
FIG. 11 is a diagrammatic showing of displacement as caused by
excess speed in a turn.
FIG. 12 is a diagrammatic showing of the stable turning position of
the vehicle.
FIG. 13 is an enlarged sectional view taken on line 13--13 of FIG.
6, showing automatic flap structure.
FIG. 14 is a similar sectional view showing the flap lowered.
FIG. 15 is a diagram of the roll control rudders.
FIG. 16 is a side elevation view of a modified vehicle using only
two airfoils.
FIG. 17 is a top plan view of the arrangement of FIG. 16.
FIG. 18 is a front elevation view as taken from the right hand end
of FIG. 16.
FIG. 19 is a diagram of the banking action of the modified form of
the vehicle.
FIG. 20 is a transverse sectional view of a dual guideway.
FIG. 21 is a front elevation view of a leg with shock absorbing
means.
FIG. 22 is a sectional view taken on line 22--22 of FIG. 21.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Three forms of the train unit or vehicle are shown, a propeller
driven type 10, shown in FIGS. 1, 3 and 4 and a linear induction
motor driven type 100, shown in FIGS. 2, 5 and 6, both having
multiple airfoils spaced along the vehicle. Of these two, the
propeller driven type will be described in detail, the only
difference being in the means of propulsion and all other Figures
of the drawings being applicable to both types. The third type 140,
shown in FIGS. 16-19, uses only two airfoils at the front and rear
and can be operated in a very narrow guideway where space is
limited.
The vehicle 10 rides in a guideway 12 with a concave channel or
trough 14 of arcuate cross section, and having flange-like baffles
16 extending from opposite sides. At high speed the air flow
disturbance caused by the vehicle is considerable and the baffles
prevent debris from being sucked into the guideway. The guideway is
best made by conventional techniques with suitably reinforced
concrete poured in simple forms. A smooth finish layer may be added
on the arcuate face, as at 18 in FIG. 8, but may not be essential.
In a complete system the guideway would extend unbroken between
selected destinations and, at certain terminals, would open to flat
areas for vehicle servicing and related operations. In undulating
terrain the guideway could be supported on pillars or other
structure where necessary.
Since the vehicle operates in the performance range of a transport
aircraft, construction may follow accepted aircraft practises,
particularly for minimizing weight, no specific structural details
being shown. The vehicle 10 comprises an elongated generally
cylindrical body 20, with a suitably streamlined nose 22 and tail
section 24. In the tail section is a propulsion unit, shown as a
gas turbine engine 26 driving counter-rotating pusher propellers 28
through a gearbox 30. An air intake 32 on top of the body supplies
air to the engine and the exhaust outlet 34 is directly downwardly.
Flow directing means of well known type could be used to direct the
exhaust rearwardly to augment the propeller thrust. In the nose
section is a control cabin 36, the main cabin 38 having suitable
seats 40 and the body being provided with windows 42 and doors 44,
as necessary.
Spaced beneath the body 10 are longitudinally spaced airfoils 46,
each secured to the body by a pair of downwardly divergent legs 48.
Each airfoil is a small wing with suitably cambered surfaces for
efficient aerodynamic lift and having pronounced arcuate dihedral
conforming to the cross section of the guideway trough 14. Each
airfoil is mounted at a predetermined angle of incidence for
effective lift, depending on the airfoil section used, and the
required performance range. Six airfoils are shown, but any
suitable number may be used, the rearmost airfoil having extended
legs 50 to suit the tapered tail section 24. By spacing the
airfoils below the body, rather than making them side extensions
from the body, the transverse span can be reduced since the area
beneath the body is clear of aerodynamic interference and can be
effectively used. This allows the width of the guideway to be
minimized, resulting in low structural and right of way costs. Each
airfoil has downwardly projecting tip plates 52, which have an
aerodynamic purpose in controlling spanwise flow, and also serve as
skids to protect the airfoil from contact with the guideway. Each
leg is of streamlined cross section and has a rearwardly extended
lower portion 54, on which is a hinged rudder 56 controlled by a
suitable actuator 58, as in FIG. 7.
In each leg is a wheel 60 mounted on a bracket 62, which is on the
outer end of an arm 64, pivotally attached to the airfoil structure
inboard of the leg. As shown in FIG. 9, the wheels extend, swinging
about the inboard hinges 66 of arms 64, extension and retraction
being controlled by telescopic actuators 68 connected between the
upper portion of each bracket 62 and fixed structure in the
respective leg. In the extended position the wheels support the
vehicle with the airfoils clear of a flat surface 70. To facilitate
maneuvering the vehicle at terminal areas, the front and rear
wheels are mounted on steerable brackets 72, as in FIG. 7, and are
turned by actuators 74 coupled to any conventional steering system
adaptable to the vehicle. The other wheels are preferably similarly
mounted for steering and are free castering within a limited range
to avoid tire scrubbing. For convenience of handling, some or all
of the wheels may be provided with individual hub mounted drive
motors, indicated at 76 in FIG. 9. Electrical and fluid powered hub
drive motors for such a purpose are well known. In the retracted
position the wheels project slightly below the airfoils, preferably
beyond the tip plates 52 to avoid any contact of the airfoil
structure with the guideway in normal operation.
The lift of a wing operating in ground effect is essentially
inversely proportional to the distance of the wing above the
surface. Thus if a wing sinks toward the surface, the under surface
pressure and the effective lift increase, tending to lift the wing
to its normal stable position for the particular speed. This has a
natural damping effect on vertical oscillation and results in a
smooth ride. Damping may be augmented by means of automatic flaps,
such as shown in FIGS. 13 and 14. Some or all of the airfoils can
be fitted with flaps on portions of their trailing edges. In the
under side of the flapped airfoil is a cavity 78, in which is a
vertically movable diaphragm 80, biased to a neutral position by a
spring 82. A flap 84 is attached to the trailing edge portion 86 of
the airfoil by a hinge 88, to swing downwardly through a small
range. The flap 84 is connected to diaphragm 80 through a
connecting rod 90 and bellcrank 92 so that, when the diaphragm is
forced upwardly by an increase in pressure below the airfoil, the
flap is correspondingly pulled down, as in FIG. 14. The lowered
flap causes a considerable increase in lift for a slight variation
in the height H of the airfoil above guideway surface 14, providing
a very effective damping action.
The rudders 56 are primarily for roll control, but can also be used
for aerodynamic braking if required. A simple diagram of a typical
control system is shown in FIG. 15, in which a roll sensor 94, such
as a gyroscope, is coupled through a control valve 96 to actuators
58, to move both rudders in the same direction in response to a
roll deviation of the vehicle. The arrangement is comparable to a
simple one axis autopilot and various systems are well known. For
braking effect, a control unit 98 is coupled to actuators 58 to
move the rudders in opposite directions.
The vehicle 100 is similar in all respects except for the
propulsion means. The linear induction motor 102, the principles of
which are well known, comprises an armature 104 riding along a
stator rail 106. In FIGS. 5 and 6, the armature is shown as a
streamlined saddle element straddling the rail 106, which is above
the vehicle and supported by spaced stanchions 108. To allow for
deviations in height and rolling or banking actions of the vehicle,
the armature 104 is attached to a fin structure 110 on the vehicle
by an arm 112. The arm 112 has double universal joints 114 and a
roll axis bearing 116 at the forward end to accommodate the various
motions. Since the armature and stator rail can be made to close
tolerances by conventional techniques, the armature may be
supported by a pressurized air cushion, not shown, to reduce
friction. Power may be obtained from a power source in the vehicle,
or from conductors along the rail.
A development of the system is shown in FIG. 2, in which dual
guideways 14 are used to carry vehicles in opposite directions and
are covered by a roof 118. The arrangement is adaptable to the
vehicles 100 shown, or to the propeller driven type. Roof 118 is
supported by truss members 120, which include portions to hold the
stator rails 106.
The width of the guideway 14 is not excessive but, where space is
critical, the configuration shown in FIGS. 16-19 may be used. In
this form the vehicle is lowered as much as possible and the
airfoil span reduced to minimize the necessary guideway cross
section. The vehicle 140 has a streamlined body 142 with an
underside 144 which is arcuate in cross section to conform to the
guideway trough 146. Under the extreme forward portion of the body
is a forward airfoil 148 supported on short legs 150 and at the
rear is an aft airfoil 152 supported on legs 154. Both airfoils
have arcuate dihedral conforming to the trough 146 and are provided
with end plates 156. The airfoils are mounted at suitable angles of
incidence and positioned so that the body 142 also assumes a small
angle of positive incidence in cruising position, as shown in FIG.
16. The body is as low as possible in the guideway and rides in
ground effect, so contributing to the aerodynamic lift.
Propulsion is by means of a linear induction motor 158 connected to
the body by an articulated arm 160 and riding on a stator rail 162.
The legs 150 and 154 may be provided with rudders and the airfoils
may have flaps, as described for vehicle 10. Retractable wheels may
be mounted in the airfoils and legs, or could be in the body in
this configuration.
By lowering the body as much as possible, the radius R of the
trough can be minimized, while still keeping the vehicle center of
mass 164 well below the center of radius 166. The automatic banking
and stabilizing action, indicated in FIG. 19, is thus as described
above, the desirable performance characteristics being common to
each vehicle.
Where dual guideways are necessary to carry a heavy traffic load,
and space is critical, the arrangement shown in FIG. 20 may be
used. The structure includes a lower guideway 168 and a coextensive
upper guideway 170, which is spaced directly above the lower
guideway on posts 172. A roof 174 is supported above the upper
guideway on posts 176. The arrangement is adaptable to any of the
vehicle types described and provides for double the traffic flow
within the ground space of a single guideway.
For maximum ride comfort it may be desirable to control the dynamic
motion of the vehicle by some type of shock absorbing means,
particularly at low speeds when the vehicle is riding on its
wheels. In FIGS. 21 and 22, a typical airfoil supporting leg 178
has a telescopic lower portion 180 to which an airfoil 46 is
attached. Cushioning is provided by shock absorbers 182, secured
between suitable structural members 184 in upper leg 178 and a
structural member 186 in the lower portion 180. The shock absorbers
may be spring or other resilient types, or fluid types which would
allow ride adjustment. The wheel mounting, similar to that shown in
FIGS. 7 and 9 and correspondingly numbered, is adaptable to the
telescopic leg by attaching the upper end of the actuator 68 to a
racket 188 on the structural member 186.
In a typical operation, starting from a flat surfaces terminal, the
vehicle is moved on its wheels to the guideway, where the wheels
are almost entirely retracted to lower the airfoils to the guideway
surface. With the main propulsion unit in operation, the vehicle is
accelerated until the airfoils develop sufficient aerodynamic lift
to raise the wheels from the surface, when retraction can be
completed. If the wheels project sufficiently in the fully
retracted position, the intermediate position of retraction may not
be necessary. As speed increases the vehicle will rise to its
normal operating height in stable cruising configuration. It should
be noted that the vehicle will seek a stable level under a wide
range of loading conditions. When heavily loaded the vehicle will
ride lower, but the aerodynamic lift increases as the airfoil to
surface gap decreases, so the action is self-balancing.
If the vehicle is subjected to a rolling condition, by wind or any
other disturbance, indicated by the roll direction arrow 122 in
FIG. 10, the rudders 56 are deflected in the opposite direction to
counter the roll aerodynamically. The legs themselves provide a
degree of roll damping. In a simple rolling condition, or in stable
flight, the lift is equal along the full span of each airfoil as
indicated by the equal length directional arrows 124.
The arcuate form of the guideway 14 is ideal for making turns at
high speed. Since the center of mass 126 of the vehicle is well
below the center of radius 128 of the guideway, the vehicle will
tend to climb the extended outer wall 130 of a turn structure with
a banking action. In the ideal condition, shown in FIG. 12, the
acceleration load will be downwardly in the direction of a line 132
through the center of radius 128 and the center of mass 126, with
no lateral accelerations affecting the passengers. The lift is
constant along the airfoil, as indicated by arrows 134, and is
effectively directed toward the center of radius.
In the event that the vehicle is subjected to a lateral load, as by
excessive speed in a turn, the outboard portion of the airfoil, as
related to the direction of turn, will be forced closer to the
guideway surface. However, as shown in FIG. 11, the resultant lift
will be higher at the outboard portion of the airfoil, indicated by
graduated directional arrows 136 to 138, due to the non-constant
airfoil to surface separation. As a result, the vehicle will be
aerodynamically returned to the stable turn condition of FIG. 12,
with a self-stabilizing action.
The automatic banking and stabilizing action, without the need for
special guidance structure, ensures a smooth ride and greatly
simplifies guideway construction.
When approaching a destination, the vehicle is decelerated until
the load is transferred to the wheels. The wheel hub motors 76
could be readily adapted to spin up the wheels prior to contact
with the guideway, to reduce tire wear. If the vehicle is to leave
the guideway for lading and unloading, the wheels are extending to
raise the airfoils to clearance height.
It will be evident that the use of aerodynamic support in ground
effect, makes it possible to use a simple light weight vehicle,
requiring considerably less accessory and support equipment than a
comparable air cushion type vehicle.
* * * * *