46
fi g. 3.11
fi g. 3.12
fi g. 3.13
3 - B
RIDGES
Bridge Setups
Bearing Bridge
(requires the use of two motorized units and two bearing bridge adapters – sold separately)
A bearing bridge is the assembly of a bridge structure that will be installed between two
motorized units in a multiple units installation. The standard M2 Series bearing bridge
structure will include two 6' (1,8 m) bearing bridge adapters at each end of the bearing
bridge.
For the installation of a bearing bridge structure using a fl ush bearing bridge adapter, refer
to p. 110 of the
Accessories
section.
Installation
1-
Choose a clear, level surface close to the work area where the bridges can be
temporarily set down to assemble the bearing bridge structure. To make sure that
all the link plates are above the ground, set down wood cribbing or mast sections laid
horizontally before lowering the bridges in place.
2-
Using a rough terrain forklift or a crane, lift and lower a bridge on top of the wood
cribbing or the laid down mast sections.
3-
Lift another bridge and align it carefully with the bridge it must be attached to. Assemble
the top part of the bridge to the other bridge using four 1" x 2" long (
GR5
) bolt
and nut assemblies through the
four
outer assembly sockets
(fi g. 3.6, p. 44) in the
front and back.
Do not tighten the bolt and nut assemblies yet
.
4-
Attach the bottom part of the bridge to the other bridge using link plates and pins
sets (4) at the bearing setting (fi g. 3.11).
5-
Tighten the nut and bolt assemblies
(4) at the top of the bridges to 100 lb-ft (136 N-m)
of
torque.
B = Bearing bridge setting
Link plate bearing setting
WARNING
When raising or lowering motorized units linked by a bearing bridge, any
bridge slope should not to exceed a maximum of 2º or
1" / 24" (2,5 cm / 61 cm).
Safety guidelines
1-
In a bearing bridge setup (multiple units), it is mandatory to install any additional
cantilever
bridge
after
the bearing bridge structure has been installed to avoid throwing
the structure off balance. Dismantle all the components of the structure in reverse order.
2-
It
is
mandatory
that two qualifi ed operators handle all rise and descent operations
and coordinate the motion of the two motorized units linked by a bearing bridge to
ensure that the structure slope does not exceed 2º or 1" / 24" (2,5 cm / 61 cm). Refer
to p. 5 of the
Motorized Unit
section for the defi nition of a qualifi ed operator.
3-
It is also important to make sure that the safety chains (two at each end) are properly
hooked at all times (see step 10 of the installation instructions on p. 47).
6-
Repeat steps 2 through 5 to assemble the complete bearing bridge structure using
as many bridges as is required and allowed, making sure that a 6' (1,8 m) bearing
bridge adapter is installed at each end of the bearing bridge. For more information on
the number of bridges allowed in a setup, refer to the
Load Capacities
section on p. 80.
7-
Measure the length of the bearing bridge structure and subtract 9" x 2 = 18"
(23 cm x 2 = 46 cm) to obtain the ideal distance between the two motorized units.
8-
Make sure that the ideal distance is kept between the two motorized units installed
in order to have an overlap of 9" (23 cm) at each end of the bearing bridge structure.
