5-2. INSPECT LOWER BLOCK.
a.Check lubrication of all parts. If the thrust bearing is not equipped with a grease fitting, lubricate with SAE No. 50 oil. Also lubricate the shank of the hook which passes through the lower block body.
b.Check each sheave to ensure rope groove is smooth and free from burrs, or other surface defects.
c.Check each sheave for freedom of rotation; replace bearings if defective.
d.Make certain that dowel pin, holding the hook nut to the hook, is securely in position.
e.If hook is equipped with a safety latch or rotational lock, check to determine that they are in good operating condition.
f.Check throat opening of hook. (Refer to Figure
NOTE: Hooks and hook openings shown are based on hooks normally furnished with standard hoists. For dimensions of hooks having a special size, shape or material, consult the Muskegon, Michigan factory. For hooks with certain kinds of safety latches it may be necessary to remove latch to measure hook opening.
g.Hooks showing signs of cracks must be replaced. Hooks should be inspected at least once per year using dye penetrants, magnetic particle or other suitable crack detecting methods.
|
|
| HOIST | HOOK | CORRECT "L" |
|
| ||||
|
|
| RATED | ||
|
|
| LOAD | SIZE | DIMENSION |
|
|
| (IN TONS) | (STANDARD) | (NEW HOOK) |
|
|
| 1/2 | G | |
|
|
| 1 | G | |
|
|
| 2 | H | |
|
|
| 3 | I | |
| 11202A |
| 5 | J | |
|
|
Figure 5-1. Proper Hook Opening.
(Shown with latch removed for clarity.)
h.Check wear of the hook, especially at the saddle and replace if badly worn.
5-3. INSPECT UPPER BLOCK AND HOIST SUSPENSION.
a.Check upper block sheaves (when hoist is so equipped) for wear, damage and freedom of rotation. If sheaves do not rotate freely, disassemble block and inspect bearings. Replace worn or damaged bearings, washers, pins or sheaves.
b.Make certain that all sheaves, bearings and hanger pins are free of foreign material and properly lubricated. Bearings without grease fittings are lubricated for the life of the bearing and require no further lubrication. After inspection, lubricate all upper block lubrication fittings.
c.Make certain that rope guide pins are not bent, loose or otherwise distorted; guide pins must have close clearance to sheave flange to keep rope in sheave grooves.
d.Check hoist suspension bolts on lug suspended hoists; make certain that bolts are secure, properly tightened and free from damage.
e. Inspect suspension lug at top of hoist frame for damage, cracks, hole elongation or other signs of wear. On all hoists, the suspension lug is integral with hoist frame and the entire frame must be replaced when suspension lug is damaged and requires replacement.
WARNING
Do not operate a hoist having worn or damages suspension bolts.
f.Reinstall all parts following procedure in reverse of disassembly.
a.Disconnect electrical power to hoist, remove electrical compartment cover (Figure
b.Check condition of contactor assembly, transformer, and limit stop and reverse switches.
Page 9