1, Overhead Trolley Inspection Procedure

　　The following procedure may be used to inspect trolleys for adequacy of grease lubricant. To prepare the overhead trolley for inspection:

　　1. Unbolt the trolley and remove it from the chain

　　2. Remove the grease fitting from the bracket

　　3. Place a 3/16” diameter punch through the grease fitting hole

　　4. Strike the punch with a hammer to remove the welsh plug

　　(See the Figure below.)

　　5. Examine the balls and raceways for presence of grease

　　l Save the fasteners and grease fitting for reuse. Discard the welsh plug - it must be replaced. If the following conditions are observed, the overhead trolley can be put back into service:

　　1.All of the balls are coated with grease

　　2.Grease is present in the openings between the balls

　　3.The raceways are coated with grease

　　4.There is grease on the lands adjacent to the raceways

　　l If the following conditions are observed, replace the overhead trolley:

　　1.Metallic chips, slivers or other such debris

　　2.Damaged or broken shields, seals or other components

　　3.Radial play greater than 1/8”; end play or rock greater than 1/4”

　　l If the following conditions are observed, add grease and return the overhead trolley to service:

　　1.Dry balls and raceways, devoid of grease

　　2.Dirt and other foreign material, caked or mixed with grease

　　3.Corrosion, pitting or other damage to the balls and raceways

　　4.Water or other fluids

　　How to return the overhead trolley to service:

　　1. Replace the grease fitting and set the overhead trolley in the welsh plug fixture

　　2. Press a new welsh plug into the outer ring

　　3. Install the trolley to the track and chain; tighten the fasteners

　　4. Add grease if needed, run the chain and wipe off any purged grease

　　The welsh plug fixture must provide good containment for the outer ring and ample clearance for the shields and bracket. Position the fixture on the press to align the wheel with the centerline of the ram. The top plate (punch) should have a 0.030” step for 6” wheels and a 0.010” step for 4” wheels. This ensures the welsh plug will be fully flattened when the plate contacts the outer ring.

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