8
Repairs (cont.)
If the feeder still exhibits signs of spring malfunction
after the tuning spring has been checked and
replaced, check the two cylindrical elastomer springs
(see Figure 5).
1.
First, remove the spring lever arms and the
tuning spring stack.
2.
Lay the unit on its side, making sure that the gap
spacers stay in place, and use a small hammer
and flattened round bar or dowel to tap the
elastomer spring out of the body housing. Next,
support the tiebar with a small block between the
tiebar and work surface, and tap the spring out of
the tiebar.
3.
Carefully examine both springs for signs of
failure and replace if such signs are found. A
failed spring will exhibit one or more of the
following characteristics:
(a) Looseness of the spring combined with signs
of rubbing or abrasion at the outer surface of
the cylinder. Looseness of the metal sleeve.
(b) Small crack in the elastomer around the end of
the metal sleeve, possibly with small abraded
particles of the elastomer present.
(c) Tackiness of the elastomer around the metal
sleeve and at the outer surface of the
cylinder, possibly with some outward
bulging of the elastomer.
FIGURE 5
4.
In replacing the elastomer springs, lay the unit on
its side so that the chamfered ends of the spring
holes are up. After making sure that the holes
and their chamfered ends are clean and free from
obstructions, lubricate the elastomer spring with
a solution of water and 10% of liquid dishwasher
soap (never use a petroleum lubricant) and press
them partly into place with the thumbs. Then tap
the springs back into place, again using the small
supporting block between tiebar and work surface.
Make sure that the springs go in straight and
protrude equally at both ends of both spring holes.
5.
Replace the lever arms, tightening the two
fastening bolts securely.
COIL REPLACEMENT
The coil in a vibratory feeder may eventually fail due
to over-voltage or normal aging.
The following procedure should be followed in
removing and replacing the electrical assembly,
which includes the coil:
1.
Remove the locking hex nut at the back of the
unit.
2.
Remove the four bolts securing the backplate
of the electrical assembly to the body.
3.
Lift out the electrical assembly. Unscrew and
remove the adjustable plunger (see Figure 6).
FIGURE 6