Blue Giant FMC - Hold down in Locked Position; Hold down in Unlocked Position

Group 03, Section 01, Page 8 Mechanical Dock Leveler – M and FMC
Issue Date: 10/01/01, Rev, 0 (Part #038-550E)
HOLD DOWN IN LOCKED POSITION:
The “one-way direction check” is created by
the action of the lower “Lock Roller” which is
held downward by the upper “Counter
Weight” roller.
In this position the “Lock Roller” is wedged
between the “Wear Strip” and the flat
surface of the “Rewind Wheel”. This
wedging action is sufficient to prevent the
“Rewind Wheel” from turning clockwise.
This prevents the cable from pulling outward
due to opposing lift spring force (which is
always present) attempting to lift the deck.
External force trying to lift the dock leveler
deck as explained earlier, (truck-load
lightening and forcing the lip and deck
upward) will not pull the cable through the
brake. Instead the “Float Spring” allows for
this necessary flexibility while maintaining a
positive contact from lip to truck.
HOLD DOWN IN UNLOCKED POSITON:
The “Handle Assembly” shown here pivots around the shaft on which it is mounted.
A short distance from this shaft is a horizontal “Stud” that is positioned underneath the
“Lock Roller”.
When the operator wishes to raise the deck he / she must pull up on the “Handle
Assembly” by pulling the “Operating Chain” upward. The horizontal “Stud” then lifts the
“Lock Roller” from its wedged position between the flat surface of the “Rewind Wheel”
and the “Wear Strip”.
This releases the cable and allows the deck to move upward as required. After the
deck reaches the desired level and the “Lip” is extended – the operator releases the
“Operating Chain” – walks up the raised deck and with his / her own weight forces the
deck and extended lip down to contact the truck floor.
During the “walk down” process the “Rewind Spring” is pulling and winding the
slackening cable back on the wheel until deck travel stops. The only way the deck can
move upward now is by overcoming the tension of the “Float Spring”.
The “Float Spring” allows the deck to raise with the truck bed. If there was no “Float
Spring” the cable or some other component would break.