Ingersoll-Rand 7792-A - Manual (Page 4)

4 Form 10590149-Edition 2
Routine Inspection
The type of application for a hoist varies so greatly it is
impractical to recommend an exact time-table for inspection
of the hoist. Where hoist is subjected to continuous operation
with capacity loads, it is recommended the unit be inspected
twice a week. If the application is less demanding, the unit
should be inspected twice a month. In general, the frequency
of inspection should be determined by the severity of the
application. The user of a hoist should be guided by any
existing federal, state or local regulations governing the use,
testing or inspection of the hoist.
If any damage or malfunction is evident do not operate hoist
until all repairs have been made and hoist tested for proper
operation.
The following points and areas are recommended for
inspection:
Load Chain and Anchor Points
• Visually check for nicked, gouged, twisted, bent,
corroded, rusted, worn or broken links. Check ends of
chain where chain is anchored to hoist frame and where
chain is fastened to lower hook. Check anchors and pins
• Check chain elongation with a vernier caliper as shown.
IF VISUAL CHECK REVEALS NO DEFECTS,
PROCEED AS FOLLOWS:
LAY USED CHAIN ON FLAT SURFACE AND MEASURE
BETWEEN FIVE (5) LINKS AS SHOWN.
MEASUREMENT SHOULD BE TAKEN ON PORTION
OF CHAIN WHICH HAS MOST PASSED OVER THE
POCKET WHEEL.
IF MEASUREMENT TAKEN IS (SEE TABLE) INCHES
OR MORE, CHAIN SHOULD BE REPLACED.
IT IS NOT INFERRED that a chain is safe prior to the
occurence of elongation of the chain. It is inferred ONLY, that
when said elongation is evident, the chain must be replaced.
Other factors, such as those mentioned as a visual check,
may render chain unsafe long before replacement due to
elongation is necessary. NOTE: New chain should never be
used on a worn pocketwheel, replace chain and pocketwheel
as a pair. Chain should also be replaced when replacing
brake shoes.
Hooks and Suspension
• Check upper and lower hooks and related parts for bent,
worn, cracked, broken or otherwise damaged parts.
• On trolley suspended models, check conditions of trolley
parts, trolley adapter and related parts.
• Check for loose bolts, nuts, or rivets.
Brake
1. Check brake operation - see Adjusting Brake, page 2.
2. Check brake linings and components. NOTE: When
replacement of brake shoes is indicated, they must be
replaced as a pair. Also replace chain at this time.
Gears, Bearings and Pocketwheel
• Check teeth on gears and motor shaft pinion.
• Check pockets of pocketwheel.
• Check bearings for noisy operation indicating wear.
Throttle Valve Head and Gears
• Check valve body, valves, and “O” rings on valves.
• Check gear teeth and bearings.
Air Motor
• Check end faces of rotor for roughness and blade slots
for wear or burrs. A new blade should slide in and out of
slots without binding.
• Check blades for wear, warpage or other damage.
• Check cylinder bore diameter for rough circular grooves
from scoring. A badly scored cylinder cannot be restored
by honing since it will only enlarge bore diameter,
widening seal point between rotor and cylinder, hindering
free exhaust of air and result in loss of speed and power.
• Check end plates for wear or scoring. Check bearings.
• Follow all operating and routine inspection procedures
prescribed in this manual.
• Disconnect air supply from hoist before performing
maintenance or service procedures.
• Never apply excessive pressure by a holding device
which may cause distortion of a port.
• Apply pressure evenly to parts which have a press fit.
• Apply even pressure to the bearing race that will be press
fitted to the mating part.
• Use correct tools and fixtures when servicing this tool.
• Don’t damage “O” rings when servicing tool.
• Use only genuine ARO replacement parts for this tool.
When ordering specify part number, description, tool
model number and serial number.
IDENTIFICATIONS
MARKINGS
NEW CHAIN
MEASUREMENT
REPLACE CHAIN
4.291 4.366
4.340 4.415
5/16
VERNIER CALIPER
NEW CHAIN
.8583 PITCH
DETERMINE TYPE OF IDENTIFICATION MARKINGS EMBOSED ON LOAD CHAIN
AND FIND DIMENSIONS IN TABLE
or ARO
OC
R
CORRECT
HOOK OPENING
1-1/4" ON 1-TON UPPER & LOWER HOOKS
1-3/8" ON 2-TON UPPER & LOWER HOOKS