Transportation vehicle guidance apparatus

A transportation vehicle for use in a mass transit system is provided with a laterally sprung guidance apparatus operative with a vehicle restraining guide beam included with the vehicle roadway, for restraining the removal of the vehicle in relation to that roadway while providing a desired improvement in the lateral ride quality of that vehicle.

CROSS-REFERENCE TO RELATED PATAENT APPLICATIONS 
Reference is made to U.S. patent application Ser. No. 684,057 filed on May 
6, 1976 and entitled Support Apparatus For Electrically Conductive Rail by 
W. R. Segar and R. A. Larson, and now issued as U.S. pat. No. 4,043,436, 
disclosing a power rail and power collector arrangement suitable for 
operation with the present modified vehicle guidance apparatus, and which 
patent application is assigned to the same assignee as the present 
invention. 
BACKGROUND OF THE INVENTION 
It is known to provide a transportation vehicle, as disclosed in U.S. Pat. 
No. 3,312,180 of E. O. Mueller and U.S. Pat. No. 3,672,308 of W. R. Segar 
for a mass transit system, with the vehicle being automatically controlled 
and self-steering along a roadway having spaced track surfaces and a 
centrally positioned vehicle restraining I-shaped guide member. The 
vehicle includes a guidance apparatus consisting of a plurality of guide 
wheels for each drive wheel axle and engaging and locking on of the 
vehicle to the I-shaped central guide member. Guide wheels are coupled to 
each drive wheel axle housing, such that the axle with its associated 
drive wheels and the vehicle will be steered by the guide wheels as the 
vehicle moves along the roadway. 
It is known in the prior art, as shown by U.S. Pat. No. 3,515,405 of W. R. 
Segar, to provide a transit vehicle axle suspension system including a 
spring support bracket having upper and lower arms rotationally fastened 
to the differential housing of the vehicle axle. A first spring member is 
vertically disposed between the vehicle body and the support bracket and a 
second spring member is horizontally disposed between the support bracket 
and the vehicle body, and if desired shock absorbers can be additionally 
employed to damp vertical and lateral movement of the vehicle axle 
suspension system. The axle suspension system permits each individual axle 
to rotate relative to the spring support bracket for negotiating minimum 
radius curves. 
SUMMARY OF THE INVENTION 
A laterally sprung guidance apparatus for a mass transit vehicle is 
provided for operation with a restraining guide beam included as part of 
the vehicle movement roadway, with the laterally sprung guidance apparatus 
providing vibration isolation from guide beam introduced lateral input 
forces as the vehicle moves along the roadway while retaining the desired 
physical lock on of the vehicle to the roadway. The guidance apparatus 
includes a vehicle coupling first member coupled to the drive wheel axle 
and a vehicle steering second member coupled to the guide wheels. The 
vehicle coupling first member is positioned within the vehicle steering 
second member, such that lateral motion between the second member and the 
first member is restrained and a resilient lateral force energy storage 
spring member is included therebetween. The spring rate of this spring 
member is selected in relation to the practical lateral force energy to be 
stored during the actual operation of the mass transit vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In FIG. 1 there is shown a roadway 10 for a mass transit vehicle 12 and 
including tracks 14 and 16 supported from a roadbed 18. A flanged guide 
beam 20 is positioned between the tracks 14 and 16 and supported by an 
element 22 between the roadbed 18 and the guide beam 20, which guide beam 
can have undesired physical irregularities in alignment position along its 
length. The self-propelled vehicle 12 includes a body 24 and moves along 
the roadway tracks 14 and 16 on support wheels 26 and 28, and is 
self-steering through operation of a guidance apparatus 30 including guide 
wheels 32 and 34. The wheels 26 and 28 are driven by an axle within an 
axle housing 38 fixed to a vehicle coupling member 40. A set of four 
opposing guide wheels including the guide wheels 32 and 34 is operative 
with the guide beam 20 as shown. The guide wheels each rotate about a 
vertical axle, with the upper ends of those vertical axles being fixed to 
the vehicle steering member 42. Each guide wheel includes a pneumatic tire 
pressed against the guide beam 20 to produce a preloading force. The guide 
beam 20 transmits lateral vehicle forces, such as vehicle centrifugal and 
steering forces to the roadbed 18. The guide beam top flange restrains and 
prevents the vehicle 12 from leaving the roadway 10. 
The vehicle 12 is driven by an electric motor operative with the axle 
within the axle housing 38, with one such motor being provided for each 
axle housing. Electric power is supplied to the vehicle by the energized 
power rails 44 supported by insulated member 46 and cooperating power 
collectors 48 are supported by the vehicle carried arm 50. In one 
particular embodiment of the present invention, the guide beam has a 
height of 12.5 inches, the guide wheels 32 and 34 extend below the guide 
wheel support member 42 a distance of 12 inches, the guide wheel normal 
unloaded diameter is 16.3 inches, the associated metal safety discs 33 and 
35 have a diameter of 14.5 inches and the running wheels 26 and 28 
included pneumatic rubber tires of 8:25-20 size. An article published in 
the Westinghouse Engineer for January 1969 at pages 9 to 15 disclosed a 
similar configuration of the guide beam, the roadway tracks, the power 
rails and the current collectors. 
In FIG. 2 there is shown a perspective view of the present vehicle guidance 
apparatus including the vehicle coupling member 40 to which the axle 
housing and the vehicle body are fastened and the vehicle steering member 
42 to which the guide wheels are fastened. Spring members 60 and 62 are to 
be positioned between the connector member 64 and the respective legs 66 
and 68 at a location adjacent the end member 70 of the member 42. Spring 
members 72 and 74 are positioned between the connector member 76 and the 
respective legs 66 and 68 at a location adjacent the end member 78 of the 
member 42. The leg 66 includes wear pads 80 and 82 and the leg 68 includes 
wear pads 84 and 86. The lower portion 88 of the vehicle coupling member 
40 includes a wear pad 90 and a wear pad 92. The upper portion of the 
vehicle coupling member 40 has a leg 96 including wear pads 98 and 100 and 
has a leg 102 including wear pads 104 and 106. 
In FIG. 3 the vehicle coupling member 40 is shown in normal operational 
position, with the lower portion 88 inserted below the end member 70 and 
between the legs 66 and 68 of the vehicle steering member 42 such that the 
spring members 60 and 62 are in compression between the connector member 
64 and the respective legs 66 and 68. This assembly can be accomplished by 
removing the connector member 64 from the lower portion 88 until after the 
lower portion 88 is in position as shown in FIG. 3 and then fastening the 
connector member 64 to the lower portion 88 with the spring members 60 and 
62 thereafter being provided as shown in FIG. 3. The spring members 72 and 
74 are in compression between the connector member 76 and the legs 66 and 
68. Two of the guide wheel vertical axles can be fastened to the leg 68 of 
the member 42, and two more of the guide wheel vertical axles can be 
fastened to the leg 68 of the member 42. 
The previous guidance structure was in accordance with the disclosure of 
above referenced U.S. Pat. No. 3,672,308 of W. R. Segar, with the guide 
wheels rigidly attached to the axle housing, and the only springing effect 
was provided by the guide wheel pneumatic tires in relation to lateral 
forces introduced by physical irregularities in the alignment of the guide 
beam. It is desired to provide a safety lock-on requirement of the mass 
transit vehicle to the roadway track structure, such that under no 
reasonably anticipated happening would the vehicle leave the roadway 
track. The guidance apparatus shown in FIG. 3 satisfies this safety 
lock-on requirement by providing the vehicle coupling member 40 separate 
from the vehicle steering member 42 and cooperating together such that 
lateral movement of the vehicle steering member 42 per se is permitted in 
relation to the vehicle coupling member 40 and the vehicle body, with the 
lateral spring members 60, 62, 72 and 74 providing the desired lateral 
force isolation therebetween. The spring rate of the spring members 60, 
62, 72 and 74 is selected in accordance with the measured practical 
magnitude of the lateral forces to be stored and that are reasonably 
applied between the vehicle coupling member 40 and the vehicle steering 
member 42. For example, when the mass transit vehicle is moving along the 
roadway at the intended speed of operation, such as 40 miles per hour, a 
spring rate of 2,000 pounds per inch is considered desirable for a mass 
transit vehicle weighing 40,000 pounds (gross vehicle weight). 
In reference to the guidance apparatus shown in FIG. 3 the axle housing is 
fastened to the vehicle coupling member 40 by bolts through the holes 100 
and by bolts through the holes 102. The vehicle drive wheels 26 and 28 
carry the vehicle coupling member 40 along the roadway tracks 14 and 16. 
The vehicle steering member 42 is supported by and rides on the lower 
portion 88 of the vehicle coupling member 40 through operation of the 
provided wear pads 90 and 92 of the lower portion 88 and the corresponding 
wear pads 91 and 93 of the vehicle steering member 42. These members 40 
and 42 are effectively locked together, with limited lateral movement 
being permitted through operation of the spring members 60, 62, 72 and 74, 
such that the guide beam irregularities cause spring member deflections 
rather than abrupt lateral motion of the entire car body 24. The latter 
spring members could comprise coil or leaf springs, air springs, hollow or 
solid rubber springs with the spring rate thereof selected to control the 
lateral deflection while providing a comfortable passenger ride on the 
vehicle. The lateral deflection of the vehicle should be kept within a 
predetermined and desired dynamic movement envelope in relation to 
practical widths of tunnels and station platform locations, and for 
example can typically be less than one inch of deflection of the vehicle 
steering member 42. 
In FIG. 4 there is shown a transverse section of a modified guidance 
apparatus operative with the flanged guide beam 20 positioned between the 
roadway tracks 14 and 16 and having the power supply rails 101 positioned 
above the guide beam 20. A modified vehicle coupling member 103 is 
provided and fastened to the axle housing and the vehicle body. A modified 
vehicle steering member 105 is provided and fastened to the guide wheels 
operative with the guide beam 20. 
In FIG. 5 there is shown a perspective view of the modified guidance 
apparatus shown in FIG. 4, including the modified vehicle coupling member 
103 to which the axle housing and the vehicle body are fastened, and the 
modified vehicle steering member 105 to which the guide wheels are 
fastened. The upper ends of the vertical axles of the guide wheels are 
supported by the brackets 106, 108, 110 and 112. The power collector arms 
are supported by the brackets 118 and 120. The spring member 122 is to be 
positioned between the member 124 of the vehicle steering member 105 and 
the member 126 of the vehicle coupling member 103. The spring member 128 
is to be positioned between the member 130 and the member 132. The spring 
member 134 is to be positioned between the member 136 and the member 138. 
The spring member 140 is to be positioned between the member 142 and the 
member 144, when the vehicle steering member 105 and the vehicle coupling 
member 103 are assembled together into normal operational positions, as 
shown in FIG. 6. 
In FIG. 6, the vehicle coupling member 103 is shown coupled with the 
vehicle steering member 105 in normal operational position. The spring 
member 122 is now in compression between the members 124 and 126. The 
spring member 128 is now in compression between the members 130 and 132. 
The spring member 134 is now in compression between the members 136 and 
138. The spring member 140 is now in compression between the members 142 
and 144. A radius arm 146 is connected between a bracket member 148 
fastened to the vehicle steering member 105 and a bracket member 150 
fastened to the vehicle coupling member 103. The radius arm 146 prevents 
movement of the vehicle steering member 105 in a direction perpendicular 
of the axle housing extending between the fastener plate 152 and the 
fastener plate 154 of the vehicle coupling member 103, and does permit 
relative lateral movement between those members 103 and 105 in a direction 
parallel to the axle housing and lateral to the roadway, but as restrained 
by the spring members 122, 128, 134 and 140. A coupling plate, such as 
restraining plate 156, having a wear pad 158, is fastened to each of the 
four corners of the vehicle steering member 105 and couples together the 
member 105 and the vehicle coupling member 103 to restrain any tilting of 
the member 105 in relation to the member 103.