Group 34, Uprights
SM 765, Nov ’06 Upright Chain Inspection, Adjustment, and Replacement • 34-6-7
Chain Lubrication
Like all bearing surfaces, the precision-manufactured,
hardened-steel, joint-wearing surfaces of leaf chain
require a film of oil between all mating parts to prevent
accelerated wear.
Maintaining a lubricant film on all chain surfaces will:
• Minimize joint wear.
• Improve corrosion resistance.
• Reduce the possibility of pin turning.
• Minimize tight joints.
• Promote smooth, quiet chain action.
• Lower chain tension by reducing internal friction
in the chain system.
Laboratory wear tests show #40 oil to have greater ability
to prevent wear than #10 oil. Generally, the heaviest
(highest viscosity) oil that will penetrate the joint is best.
Whatever method is used, the oil must penetrate the chain
joint to prevent wear. Applying oil to external surfaces
will prevent rust, but oil must flow into the live bearing
surfaces for maximum wear life.
To prepare the chain for oiling, the leaf chain plates
should be brushed with a stiff brush or wire brush to clear
the space between the plates so that oil may penetrate the
live bearing area.
Oil may be applied with a narrow paint brush or directly
poured on. Chain should be well flooded to be sure the oil
penetrates the joint.
In locations difficult to reach, it may be necessary to use a
good quality oil under pressure such as an aerosol can or
pump pressure spray.
Chain Removal and Replacement
WARNING
!
The procedures for removing and replacing
chain sets involve hoisting and blocking com-
ponents.
• Do not walk or stand under raised forks.
• Keep your arms and fingers away from
moving parts of the upright.
• Do not reach through open areas of the
upright.
Failure to follow these warnings can result in
serious injury. See “Lifting, Jacking, and
Blocking” for safe blocking procedures.
General Guidelines
• Chain Movement - Make sure that the chain oper-
ating path is clear and that the chain articulates
freely through its full range of operation.
• Lubrication - Assure that the chain is well lubri-
cated with the heaviest oil that will penetrate the
void between the link plate apertures and the pins.
• Paint - Make sure the chain does not get painted
over at any time.
• Protection - Where necessary, as a protection from
atmosphere or sliding wear, the chain may be cov-
ered with a layer of grease. It should be noted,
however, that the grease will have to be removed at
a later date for chain inspection and relubrication.
• Chain Mountings - Double check to be sure all
chain fastening devices are secured and all adjust-
ments have been made to assure uniform loading
of multiple chain applications. Check chain
anchors and pins for wear, breakage, and misalign-
ment. Damaged anchors and pins should be
replaced.
• Sheaves - Sheaves with badly worn flanges and
outside diameter should be replaced. This wear
may be due to chain misalignment or frozen bear-
ings.
Lift Chains (Standard and TSUs)
To remove and replace the lift cylinder and/or carriage
chain set on standard and triple-stage uprights (TSU):
1. Attach a hoist strap on the carriage of the standard
upright or inner rail of the TSU.
2. Lift the carriage or inner rail slightly to create slack
in the chains. Block the carriage or inner rail up for
safety.
3. Remove the chain anchor pins on the outer rail and
pull the chains off of the sheaves on the inner or
intermediate rails.
To Next Page
Loading...
