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CHECKING FOR TWIST IN LOAD CHAIN
Double-Reeved
The best way to check for twisting is to run the lower hook, without a
load, up to within about 2 feet (0.61 meters) of hoist. If the dead end
of the chain has been properly installed, a twist can occur only if the
lower hook block has been capsized between the strands of chain.
Reverse the capsize to remove twist.
Triple-Reeved
On these models, the load chain is dead-ended on top of the lower
hook block. If the chain has been properly installed, the only way
a twist can occur is if the lower hook block has been capsized
between the strands of chain. If this has occurred, two strands of
chain will be wrapped around each other. To remove this, reverse the
capsize.
LOWER HOOK BLOCK PIN
When removing or installing the lower hook pin, care must be taken
to prevent damaging the pin and/or hook block. These pins are
tapered groove pins and, as a result, they can only be removed
in one direction. To remove the pin, a V-Block, drift and hammer
(or slow-acting press) are required. The drift should be the same
diameter as the pin (5/16" diameter (7.94 mm) for Models A, AA,
B, C, & F, and 3/8" (9.52 mm) for models J, L, R, & RT. It should be
placed on the small end of the pin. The small end of the pin is the
end opposite the end on which the three grooves are visible. Place
the hook block in the V-Block and drive the pin out using the drift
and a hammer or slow-acting press.
To re-install the pin, the parts must be arranged the same as they
were when the pin was removed. To do this, use the small end of
the pin as a gage. First check the holes in the hook block body and
determine which hole is the largest. Place the hook body in the
V-Block with the larger hole on top. Next, check each end of the
hole in the lower hook chain block and determine which end is the
largest. Place the chain in the slot of the chain block and insert the
chain block, with the large hole on top, into the hook block body.
Align the holes in the hook block body with the hole in the chain
block and insert the small end of the pin in the hole. Push the pin in
by hand until it stops and then use a hammer or slow-acting press to
drive the pin into position so that the end of the pin is fl ush with the
outside surface of the hook block body.
Use of improper lower hook chain block pin as well as improper
installation of this pin can cause the pin to break and allow the
load to fall.
TO AVOID INJURY:
Use only CM-supplied, special high-strength lower hook chain
block pin to attach the chain to the lower hook block and install
the pin as directed above.
CHAIN STOP INSTALLATION
Place polyurethane stop block over loose end of chain and slide
past desired chain stop location. Place one half of chain stop on
chain. Then place other half on top of the fi rst half of chain stop.
NOTE: Be sure the half-circle cutout side of one stop block half is
aligned with hex cutout side. Place one (1) nut into hex cutout, insert
one (1) screw with one (1) lock washer through hole opposite nut,
and loosely tighten. Repeat for second connection. Tighten both
screw connections to ensure that they do not come loose.
VARIABLE SPEED ELECTRIC CHAIN HOIST WITH
OPTION
To
Liftwheel
Polyurethane Stop Block
Figure 10. Chain Stop
CUTTING CHAIN
CM load chain is hardened and it is diffi cult to cut. The following
methods are recommended when cutting a length of new chain from
stock or cutting off worn chain.
1. Use a grinder and nick the link on both sides (Figure 11). Then
secure the link in a vise and break off with a hammer.
2. Use a 7 inch (177.8 mm) minimum diameter by 1/8 inch (3.175
mm) thick abrasive wheel (or type recommended by wheel
supplier) that will clear adjacent links.
3. Use a bolt cutter (Figure 12) similar to the H.K. Porter No.
0590MTC with special cutter jaws for cutting hardened chain
(1 inch [25.4 mm]) long cutting edge.
Figure 11. Cutting Chain by Nicking
Figure 12. Cutting Chain with a Bolt Cutter
Cutting chain can produce fl ying particles.
TO AVOID INJURY:
• Wear eye protection.
• Provide a shield over chain to prevent fl ying particles.
10
Hex Cutout
Loose End
of Chain
Half-Circle Cutout
P/N: 192047082 (REV AD) 627NH March 2022
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