Vestil ACH-100 - Manual (Page 10)

LOAD CHAIN
Chain should feed smoothly into and away from the hoist
or hook block (500, 600 and 1000#, 226, 272 and 453 Kg.
units). If chain binds, jumps or is noisy, first clean and
lubricate it (see below). If trouble persists, inspect chain
and mating parts for wear, distortion or other damage.
Chain Inspection
First clean chain with a non-caustic/non-acid type solvent
and make a link by link inspection for nicks, gouges,
twisted links, weld spatter, corrosion pits, sitriations
(minute parallel lines), cracks in weld areas, wear and
stretching. Chain with any one of these defects must be
replaced.
Slack the portion of the chain that normally passes over
the liftwheel. Examine the interlink area for the point of
maximum wear (polishing, see figure 5). Measure and
record the stock diameter at this point of the link. Then
measure stock diameter in the same area on a link that
does not pass over the liftwheel (use the link adjacent to
the loose end link for this purpose). Compare these two
measurements. If the stock diameter of the worn link is
0.010 inches (0.254 mm.), or more, less than the stock
diameter of the unworn link, the chain must be replaced.
On the 500, 600 and 1000# (226, 272 and 453 Kg.) units,
repeat this examination of the chain that passes through the
hook block.
Also check chain for stretch using a vernier caliper as
shown in figure 6. Select an unused, unstretched section
of chain (usually at the loose end) and measure and
record the length over 11 chain links (pitches). Measure
and record the same length on a worn section of chain.
Obtain the amount of stretch and wear by subtracting the
measurement of the unworn section from the measurement
of the worn section. If the result (amount of stretch and
wear) is greater than 0.145 inch (3.7 mm.), the chain must
be replaced.
Use only a “Knife-edge” caliper to eliminate possibility of
false reading by not measuring full pitch length.
5
e. External evidence of excessive wear of brake parts -
see page 7.
f. Check the control station levers to make sure they
operate freely and spring back when released.
g. Check air supply hose and control hose for kinks, cuts,
leaks and damage.
h. Check the chain pin or dead end pin and chain stop
for wear and cracks.
i. Check for lubricant leaks at gasket between main
frame and gear housing. Tighten gear housing screws
to stop leak. If leak persists, replace gasket.
j. Inspect splines on first pinion shaft and motor coupling
for signs of wear or deterioration. Replace splined
parts if worn or damaged.
k. Check for air leaks at brake end cap. Replace piston
seals to stop leaks.
l. Check for air leaks at the joints of the motor. Tighten
screws to stop leaks. If leaks persist, disassemble
motor, see page 8, and replace seals.
m. Check for air leaks at joint between the supply block
and valve body. Tighten screws or replace gasket to
stop leaks.
n. Check for air leaks at o-rings on top and under valve
body. Tighten valve bolt or replace o-ring to stop leaks.
N NO OT TE E:: T To o p pe errffo orrm m s so om me e o off tth he e p pe erriio od diic c iin ns sp pe ec cttiio on ns s,, iitt iis s
n ne ec ce es ss sa arry y tto o p pa arrttiia alllly y d diis sa as ss se em mb blle e tth he e h ho oiis stt.. R Re effe err tto o
D Diis sa as ss se em mb blly y--A As ss se em mb blly y s stta arrttiin ng g o on n p pa ag ge e 8 8..
Any deficiencies noted must be corrected before the hoist
is returned to service. Also, the external conditions may
show the need for more detailed inspection which, in turn,
may require the use of nondestructive-type testing.
Any parts that are deemed unserviceable are to be
replaced with new parts before the unit is returned to
service. It is very important that the unserviceable parts
be destroyed to prevent possible future use as a repair
item and properly disposed of.
Hook Inspection
Hook damage from chemicals, deformations or cracks or
that have more than a 10
0 twist from the plane of the
unbent hook or excessive opening must be replaced.
Any hook that is twisted or has excessive throat opening
indicates abuse or overloading of the unit. Other load-
sustaining components of the hoist should be inspected
for damage.
On latch type hooks, check to make sure that the latch is
not damaged or bent and that it operates properly with
sufficient spring pressure to keep the latch tightly against
the tip of the hook and allow the latch to spring back to
the tip when released. See below to determine when the
hook must be replaced.
F Fiig gu urre e 4 4.. H Ho oo ok k IIn ns sp pe ec cttiio on n
F Fiig gu urre e 5 5.. C Ch ha aiin n W We ea arr A Arre ea as s
F Fiig gu urre e 6 6.. C Ch ha aiin n IIn ns sp pe ec cttiio on n