Upright TM 12 Series User Manual

Elevating Assembly Section 3 - Service & Repair
Pa
g
e 3-22 505115-000
C
HAIN
T
ENSION
I
NSPECTION
Refer to Figure 3-16: “Elevating Assembly,” on pageSection 3-20.
The lifting chains are self-adjusting and should always be close to the same tension. This tension should
be checked annually to ensure that there are no problems with this system. To do this task a spring scale
will be needed with 20kg (44 lb.) capacity.
1. Place 227kg (500 lbs.) in the platform including the weight of the person testing the chain tension.
2. Remove the
chain inspection cover (8) and raise the platform approximately 10cm (4 in.) until the outer
inspection hole lines up with the inner inspection hole.
3. Attach the spring scale to one of the outer chains and pull until the chain makes contact with the inner
surface of the mast section. Note the scale reading.
4. Repeat step 3 on the other outer chain.
5. Compare the scale readings. The readings for each chain in the outer set should be within 20% of each
other.
6. Repeat steps 3 - 5 for the inner set of chains. The readings for each chain in the inner set should be
within 20% of each other.
IMPORTANT: If the readings are not within 20%, then a problem exists that is causing unequal chain tension.
Investigate the problem and repair or replace the worn components.
C
HAIN
E
LONGATION
I
NSPECTION
Figure 3-17: Chain Elongation Inspection
At five-year intervals, the
chains should be removed from
the mast and the entire length
of the chain inspected for
excessive wear and elongation.
Follow the procedure below to
disassemble the elevating
assembly. With the lift chains
removed, hang them vertically from something capable of holding 100kg (220 lbs.). Inspect the chains
thoroughly, looking for cracks in the chain links, kinks in any portion of chain, and excessive corrosion.
Complete the following elongation test:
1. Attach approximately 25kg (55 lbs.) to the lower end of each chain.
2. Measure the distance between 50 pins. This distance should be 63.5cm - 65.5cm (25 in. - 25¾ in.).
3. Remove the weight and measure the same on the other three chains.
If the chains have elongated beyond the indicated range, replace the lift chain sets. Before reinstalling the
lift chains, take this opportunity to thoroughly clean and lubricate the entire chain. Reassemble the elevat-
ing assembly as described below.
MEASURE DISTANCE OF 50 PITCHES
PITCH
ONE

Upright TM 12 Series Specifications

General

Brand	Upright
Model	TM 12 Series
Category	Lifting Systems
Language	English