Passenger boarding bridge

Passenger boarding bridge extendable sections are provided with roller assemblies supporting one extendable bridge section relative to a second extendable bridge section wherein the roller assemblies assist in reducing the downward load in the overlapping area of the bridge sections.

This invention relates to passenger boarding bridges for facilitating 
ingress to and egress from a parked aircraft generally, and more 
particularly to such bridges which are adjustable in length to accommodate 
variations in the distance between the door of a parked aircraft and the 
terminal gate. 
Passenger boarding bridges are desirable because they permit passengers and 
airline personnel to walk, or otherwise traverse the distance, between the 
gate of an airport terminal and a parked aircraft with ease, eliminating 
the need to climb stairs, and in relative comfort, protected from wind, 
rain, snow and ice created by local weather conditions. Typical bridges 
include two or three telescoping tunnels, which are rectangular in 
cross-section, the inner one of which is supported by a rotunda arranged 
to provide passage to and from the terminal through a door or gate and the 
outer tunnel by a drive unit which can position the outer end of the 
bridge adjacent a door of the parked aircraft. Changes in the length of 
the bridge, achieved by extending or retracting the telescoping tunnels, 
are necessary for a number of reasons, including the provision of a clear, 
unimpeded path for parking of the aircraft, accommodation of variations in 
the length of various aircraft types and the location of the passenger 
door thereon or different doors on a given type of aircraft, compensation 
for variations in the parked position of the aircraft, and/or clearance 
for the push vehicle and the aircraft as the aircraft is pushed back, or 
otherwise moves away, from the gate. 
Vertical forces or loads are imposed by each tunnel on the adjacent tunnel 
as a result of the weight of the tunnels themselves and the individuals, 
including their luggage and other carry-on items, and equipment, such as 
wheelchairs, for example, present in the tunnel. Since the tunnels must be 
moveable relative to each other, roller assemblies have been utilized to 
transfer the forces from one tunnel to the adjacent tunnel. In prior art 
bridges, these roller assemblies have included ones carried by the upper 
corners of the outer tunnel which roll on horizontal flanges at the upper 
corners of the inner tunnel. In the normal configuration of the bridge, 
these upper roller assemblies place a compressive load on the inner 
tunnel, which must be resisted by the side walls of the inner tunnel. As a 
consequence, the maximum roller loads are limited by the compressive 
strength of the side walls of the tunnels. 
The present invention provides a passenger boarding bridge which eliminates 
or significantly reduces the compressive loads imposed on side walls of 
the bridge, which reduces the size of side wall members for a given 
loading, which eliminates the need for high strength flanges on the upper 
corners of the inner tunnels, which reduces the number of roller 
assemblies, which is easier to install and maintain, and which can be less 
costly to manufacture.

Referring now to FIGS. 1-3, there is shown a passenger boarding bridge, 
indicated generally at 10, which has three telescoping sections or tunnels 
which are, following the convention in the industry, identified in the 
drawings as the A, B and C tunnels. The A tunnel is pinned to the rigid 
portion of a rotunda 14 to permit pivoting of the bridge 10 about a 
horizontal axis to allow the bridge to accommodate the elevation of the 
door sills on various aircraft. The portion of the rotunda 14 connected to 
the A tunnel is relatively rotatable, which permits the bridge 10 to pivot 
about a vertical axis defined by the point 15 in FIG. 1. The rotunda 14 is 
supported by a pedestal 16 secured to the ground and communicates with a 
vestibule 18, which can be of variable length, connected to the terminal 
building, with passage between the terminal building and the vestibule 
typically being through a lockable security door provided at the left side 
thereof, as viewed in FIGS. 1-3. The B tunnel slips over and encircles the 
A tunnel, and slips inside of and is encircled by the C tunnel. The C 
tunnel is supported by a drive unit 20 having a pair of vertically 
adjustable jacks 22, with one jack secured to each side of the C tunnel, 
to raise and lower the end of the bridge 10 adjacent the aircraft, and a 
pair of independently driven, ground-engaging drive wheels 24. A cab 26 is 
provided at the distal end of the C tunnel from where the two drive wheels 
24 and the jacks 22 may be controlled. Simultaneously raising and lowering 
both of the jacks 22, which may be screw jacks driven by reversible 
electric motors 28, for example, will respectively raise and lower the cab 
floor so that it is at the same elevation as the door sill of a parked 
aircraft. Simultaneously driving the wheels 24, which also may be powered 
by independently energized reversible electric motors, away from the 
rotunda 14 will extend the bridge 10, ultimately to the position shown in 
FIGS. 1 and 2, while simultaneously driving both wheels toward the rotunda 
14 will retract the bridge, ultimately to the position shown in FIG. 3. 
Independently driving the wheels 24 at different speeds and/or directions 
will cause the bridge 10 to rotate about the vertical axis 15 of the 
rotunda. 
Considering first the relationship between the A and B tunnels, which 
relationship is shown in FIGS. 4 and 6-8, each of the A and B tunnels has 
a floor 30 and 32 respectively. The floor 30 of the A tunnel spans the 
distance between and is secured to a pair of essentially parallel tubular 
beams 34, one of which is shown in FIGS. 4, 6 & 7 and the other one in 
FIG. 8, extending substantially the length of the A tunnel. Since each 
side of the A tunnel, and each of the B and C tunnels as well, is a mirror 
image of the other, a description of only one side will be sufficient for 
a complete understanding of the invention. In this regard, references to 
left and right will be as viewed from the rotunda 14 looking toward the 
cab 26, while inboard and outboard will refer respectively to the ends 
adjacent to and remote from the rotunda, and inward toward the middle of 
the tunnels and outward away therefrom. A roller supporting flange 36 
formed of a high strength material, such as T-1 steel, for example, is 
secured to and extends beyond an upward facing channel 38 to form a box 
member resting upon and secured to the beam 34. The floor 32 of the B 
tunnel also spans the distance between and is secured to a similar pair of 
beams 40, each secured to and supporting a similar box member formed by a 
flange 42 secured to an overlapping channel 44. A vertical plate 46 
attached to the inboard end of the beam 34 with upper and lower horizontal 
plates 48 and 50 respectively attached thereto. A stiffening web 52 is 
secured to all three plates 46, 48 and 50. A pair of flanged rollers 54 
are rotatably mounted on a triangular shaped carriage 56 and normally are 
engageable with and roll on the outward projecting portion of the flange 
36 associated with the A tunnel. The flanged portion 58 of the flanged 
rollers 54 engages the outer edge of the flange 36 and provide lateral 
positioning, alignment and guidance for the B tunnel relative to the A 
tunnel. The carriage 56 is pinned by pin 60 to an internally threaded rod 
end 62, so the loads on the rollers 54 are equalized. A bolt 64 passes 
through a hole in the lower plate 50 and engages the threaded rod end 62, 
with a lock nut 65 threaded onto the bolt 64 on the side of the plate 50 
opposite the head of the bolt 64, thereby securing the carriage to the B 
tunnel while permitting variations in the effective length of the rod 62. 
A pair of small rollers 66 are also rotatably carried by the carriage 56 
and are engageable with the lower surface of the channel 44 to transfer 
upward forces from the B tunnel to the A tunnel during load reversal 
caused by the center of gravity of the bridge passing outboard of the 
jacks 22, as occurs in most bridges when fully retracted, as shown in FIG. 
3. The entire assembly with the rollers 54 and 66 is typically referred to 
as a truck. At the outboard end of the A tunnel, the channel 38 and flange 
36 extend beyond the beam 34 and a bracket 68 is bolted thereto. A 
carriage 70 is pinned by pin 72 to the bracket 68 for equalizing the loads 
on a pair of flanged rollers 74 rotatably carried by the carriage and 
engageable with the inward projecting upper surface of the flange 42 
associated with the B tunnel. The flanged portion 76 of the rollers 74 
engage the inner edge of the flange 42. A pair of small rollers 78 are 
also rotatably carried by the carriage 70 and are engageable with the 
inner lower surface of the channel 44 to transfer reverse loads from the A 
tunnel to the B tunnel. Under normal conditions, the rollers 74 positioned 
at the outboard end of the A tunnel are forced against the flange 42 of 
the B tunnel. With respect to the A tunnel, this results in an upward 
force on the outboard end of the A tunnel, which force is always applied 
at the same point, while the load imposed on the A tunnel by the rollers 
56 attached to the B tunnel results in a downward force, the point of 
application being variable as the B tunnel is telescoped over the A 
tunnel. All loads between the A tunnel and B tunnel are transferred to the 
structural beams without being transmitted through the side walls. 
In a manner similar to the A and B tunnels, the floor 80 of the C tunnel is 
connected to and supported by a pair of beams 82, the right one being 
shown in FIG. 5 and the left one in FIG. 8. A flange 84 attached to and 
overlapping a channel 86 is supported on and secured to the beam 82 is 
engageable by a pair of flanged rollers 88, as best shown in FIGS. 7 and 
8. The rollers 88 are rotatably carried by a carriage 90 pivotally 
connected by pin 92 to a bracket 94 bolted to the outboard end of the beam 
40 and the overhanging channel 42. A pair of small rollers 96 are 
rotatably secured to the carriage 90 and are engageable with the lower 
surface of the channel 86 to accommodate load reversal. A bracket, similar 
to the one affixed to the inboard end of the beam 40, includes a 
horizontal plate 100 attached to the inboard end of the beam 82. A bolt 
104 extends through a hole in the plate 100 and engages an internally 
threaded rod end 102 and a lock nut to adjustably secure the rod end 
thereto. A carriage 106 is pivotally connected to the rod 102 and 
rotatably mounts a pair of flanged rollers 108 which are engageable with 
the upper surface of the flange 42 on the B tunnel and a pair of load 
reversal accommodating small load rollers 110. The load of the C tunnel 
normally acting downward through the rollers 108 exerts a downward force 
on the beam 40 of the B tunnel. Similarly, the rollers 88 carried by the B 
tunnel exert a downward force on the beam 82 of the C tunnel. During load 
reversal the small rollers 96 carried by the B tunnel exert an upward 
force on the bottom side of the channel 86 attached to the beam 82 of the 
C tunnel and the rollers 110 exert an upward force on the bottom side of 
the box member channel associated with flange 42, the box member attached 
to the beam 40 of the B tunnel. The forces encountered during load 
reversal are smaller, which is the reason only relatively small rollers 
are required. In either situation, the forces are transmitted directly to 
the main structural members, i.e. the beams 34, 40 and 82 and their 
associated channels 38, 44 and 86 and flanges 36, 42 and 84, of the bridge 
10, and consequently, the walls of the bridge are free from stresses. 
Referring to FIGS. 9 and 10, there is shown a means for laterally aligning, 
guiding and, if necessary, squaring the upper portion of the tunnels. 
Roller assemblies 120 and 122 are mounted on the A and B tunnel and have 
guide rollers 124 and 126 respectively engaging the B and C tunnels. Since 
the two assemblies are identical, a description of only assembly 122 will 
suffice. 
The roller 126 is rotatably mounted on a plate 128 and engages a wear strip 
130 affixed to a horizontal beam 132 extending the length of the C tunnel 
and forming a part of the truss structure supporting the roof 134. The 
plate 128 is supported by a U-shaped bracket 136 secured to the top of a 
roof cross member 138 for the B tunnel. The bracket 136 and the cross 
member 138 are provided with aligned rectangular openings 138. A block 140 
attached to the lower side of the plate 128 extends through and is 
slideable in the openings 137. An adjusting bolt 142 extends through a 
hole in a downward extending plate 144 and engages a threaded hole in the 
block 140, so that the adjusting bolt may move the roller 126 outward. 
Lock bolts 146 extend through slots 148 in the plate 128 to engage 
threaded holes (not shown) in the bracket 136 to secure the plate 128 to 
the bracket 136 once lateral adjustment of the roller 126 has been 
effected. If it is necessary to square the tunnel, the lock bolts 146 on 
roller assemblies on each side of the tunnel are loosened and the 
adjusting bolt on the side the upper portion must be moved to square the 
tunnel rotated to back the associated roller away from the wear strip, 
although the associated roller may not actually move away from the wear 
strip. The adjusting bolt on the opposite side is rotated to extend the 
associated roller outward until the tunnel is square. The adjusting screw 
that had been backed-off is then rotated until the associated roller is 
just bearing against its wear strip and all lock bolts are then tightened. 
The weight of the roof forming a part of each tunnel, as well as the weight 
of snow and ice accumulating thereon, must be transferred to the lower 
beams, e.g. 82, of the tunnel. This is achieved by a truss structure, as 
best shown in FIG. 3, which includes a plurality of vertical members 150 
and angled members 152 extending between and secured to lower beams 82 and 
the upper beams 132. With the loads imposed by the roof being transmitted 
to the lower beams through the truss structure, the side walls of the 
tunnel may be formed of glass panels, or other transparent material, which 
allow light into the tunnel and make the bridge appear less confining. The 
mounting of the glass panels is shown in FIGS. 11-13. Each glass panel is 
rectangular and extends between the mid-points of adjacent vertical 
members 150 of the truss structure, with a U-shaped channel 158 formed of 
rubber or similar material extending along each of its four sides. The 
channel 158 along the lower edge of the glass panel 156 rests in and is 
supported by a complementary bracket 160 having a vertically extending 
groove 162. The bracket rests upon a support member secured to the lower 
beam 82. An upstanding lip 166 formed on the support member 164 engages 
the groove 162 to retain the lower end of the panel 156. As shown in FIG. 
11 the support member 164 is affixed to the box member flanges such as 42 
in FIGS. 5, 36 in FIG. 6, and 84 in FIG 4. A similar bracket 168 extends 
along the upper edge of the panel 156 and has a horizontal extending 
groove 170 engaging a horizontal flange formed on a support member 174 
secured to the upper beam 132. A plurality of bolts 176 spaced along the 
width of the panel 156 secure the bracket 168 to the flange 172. The 
support members such as 164 and 174 may also be attached to the diagonal 
members of the truss structure where the elements are proximate each 
other. As shown in FIG. 13, the sides of adjacent panels 156 are retained 
by a vertical metal strip 180. The vertical member 150 of the truss 
structure is provided with an outwardly extending flange 182 having tapped 
holes 183 spaced along its length to accept bolts 184 that extend through 
aligned holes in the strip 180. The glass panels are thus held securely in 
place and are sealed, by compression of the channels 158, against water 
leakage and air infiltration. It has been found that with proper 
production methods the provision for vertical adjustment of the trucks is 
not necessary. The trucks shown in FIGS. 14 and 15 provide lateral, i.e. 
side to side, adjustment but do not adjust vertically; FIG. 14 being a 
view from the outside of the track on the right side of the outboard end 
of the A or B tunnel and FIG. 15 being the same truck viewed from the 
inside of the tunnel. A weldment 190 is affixed to and cantilevered from 
the outboard end of the lower beam of the tunnel. An outer leg 192 is 
formed as part of the weldment and creates, with an inner or trap leg 194 
secured to the weldment 190 by cap screws engageable with threaded holes 
therein, a clevis. The truck 198 is provided with a pair of flanged upper 
rollers and a pair of smaller lower rollers for reverse loading that 
function in the same manner as those described previously in connection 
with FIGS. 7 and 8. The truck is pivotally connected within the clevis by 
a pin 200. Since the thickness of the weldment 190 is greater than the 
thickness of the truck 198, the truck can be positioned along the length 
of pin 200 a distance equal to the difference in the two thicknesses, 
which difference for practical purposes needs be about 2.5 centimeters. An 
adjusting screw 202 engages a threaded hole in the inner leg 194 to 
position the truck 198 on the pin 200. Similar trucks 204 on the inboard 
end of the B and C tunnels are shown in FIG. 16, which trucks have pairs 
of upper flanged rollers and lower reverse loading rollers that function 
in the same manner as those described in connection with FIGS. 4-6. The 
trucks 204 are mounted on a pin 206 held between inner and outer legs 
respectively secured to the inboard ends of the lower beams. A plate 212 
is secured to the outer leg 210 by a cap screw 213 engaging a threaded 
hole in the outer leg. A bolt 214 passes through a hole in the plate 212 
and engages a threaded hole in the pin 206, which arrangement holds the 
pin 206 in place during normal operation while permitting removal of the 
pin 206 for replacement of the truck 204 when necessary. The span between 
the legs 208 and 210 is greater than the thickness of the truck 204 so the 
truck may laterally positioned on pin 206. Such lateral positioning is 
achieved by an adjusting screw 216 engaging a threaded hole in a bracket 
218 secured from the end of the lower beam to bear against the truck 204. 
The tunnels can be moved laterally relative to each other by loosening the 
screw 216 on the side toward which the inner tunnel is to be shifted and 
tightening the opposite screw 216. 
Instead of stabilizer rollers, such as those described in connection with 
FIGS. 9 and 10, sliding stabilizers may be provided on each side of the 
outboard ends of the A and B tunnels. A preferred embodiment of such 
stabilizers is shown in FIGS. 17 and 18. The stabilizer has a fixed 
portion 220, including a base member secured, such as by welding, to the 
upper cross member at the outboard end. A transverse member 222 is affixed 
to the base member with a socket set screw 224 engaging a threaded hole in 
the transverse member 222 to bear against a metal adjusting block 226. 
Four relatively thin layers of rubber 230 are trapped between the 
adjusting block 226 and a slider block 228 formed of a material having 
good wear and sliding characteristics, such as nylatron. The rubber layers 
230 and the slider block 228 are attached to the adjusting block 222 by 
cap screws extending therethrough and engaging tapped holes in the 
adjusting block 226, the heads of the cap screws being positioned in 
recesses in the slider block 228. Lock bolts extend through slots 232 in 
the adjusting block and engage threaded holes in the cross member to lock 
the slider block 228 in position when adjustment has been effected. The 
slider block 228 engages the downward extending leg of an L-shaped 
stainless steel strip 229 attached to the upper corners of the outer 
tunnel, i. e. the B or C tunnel when the stabilizers are affixed to the A 
or B tunnels respectively. The L-shaped strips 229, being positioned at 
the upper corners of the outer tunnel, serve both as a bearing surface for 
the slider block 228 and as trim to hide the juncture between the ceiling 
and the upper horizontal beam, e.g. 132, and/or any decorative covering 
applied thereto. In order to simplify installation and to provide a 
smooth, flat surface for the slider block 228, the L-shaped strip is 
preferably attached with double sided adhesive tape with mechanical 
fasteners, such as rivets, being used only at the ends thereof. In order 
to effect proper alignment when the A tunnel is pivoting on the hinge pin 
12, a similar slider is preferable provided at the inboard end of the A 
tunnel, with the base member affixed to the rigid frame portion of the 
rotunda 14 and the slider block engaging the upper sides of the inboard 
end of the A tunnel. 
In summary the invention herein comprises a passenger boarding bridge 
having inner and outer tunnels. The inner tunnel telescopes inside an 
outer tunnel. These inner and outer tunnels define an overlapping end on 
each tunnel. The tunnels also have roofs and floors which are supported by 
beams extending along each side of the floor. These beams are provided 
with flanges, having upper and lower surfaces, the flanges secured to each 
of the beams of the inner and outer tunnels. Support for the tunnel 
sections, relative to each other, is provided by a first roller assembly 
carried by the overlapping end of the inner tunnel. This first roller 
assembly is attached to the outboard end of the inner tunnel beams and 
rollingly engages the upper surfaces of the outer tunnel flanges. As 
second roller assembly is carried by the overlapping end of the outer 
tunnel and rollingly engages the upper surfaces of the inner tunnel 
flanges. This structure provides a structure whereby compressive forces on 
the side wall of the inner tunnel, as are normally imposed by a resultant 
downward load in the overlapping area, are reduced to those forces 
inherent in the weight of the roof and sidewalls. The compressive forces 
now seen in the improved structure are compressive force not resulting 
from said overlapping of said inner and outer tunnels.