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Bulletin number: SB104
Category: Safety
Date issued: April 29, 2003
Machine models: TEI‰
Prefeeders manufactured prior to 1994
Subject: Unexpected retracting of the
extendo.
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To our valued customer:
This service bulletin is part of an ongoing
effort to provide quality service and support for all Alliance
Machine Systems International, LLC products. If you need assistance
or more information, please call Gary Kneale, Field Service Manager,
at 509-535-0356 and select Option two.
Description of Problem
The prefeeder extendo conveyor is used to
shingle blocks of corrugated into the finishing machine hopper. The
extendo is comprised of two, telescoping sections. The section with
the tamping system, located closest to the die cutter, is called
extendo section 2. Extendo section 2 is extended and retracted with
a power adjust mechanism.
There is a possibility that the power adjust
mechanism may fail allowing the extendo section 2 to unexpectedly
retract to the full-in position. There is a possibility that a
person may be struck by the tamper arm or the end of extendo
operator station if a failure occurs.
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There are three designs that have been
identified for review.
- TEI extendos manufactured prior to 1994
Prefeeders that originally had a
manual extension hand crank or a cable cylinder adjustment system
may have been retrofitted with a kit that contained an acme rod nut
mount with a three bolt pattern. Verify the style of bracket on
your machine and if it is the three bolt design, please do the
following:
-
Remove the three 3/8” UNC bolts and tap and replace with
three 1/2” UNC grade 5 or higher bolts. Torque the bolts to 90% of
the rated proof strength.
-
Verify a quality weld exists and correct if necessary. The
weld must be continuous around the welded acme nut mount. The weld
should not have any discontinuities and the radius of the weld
should be smooth.

Figure 1. Three
bolt mounting bracket.
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- TEI extendos with manual, hand-crank adjustment
Early Prefeeders
used a hand-crank to adjust the length of the extendo. A holding
device was initially provided with the machine. If the holding
device is not used or is used improperly, unexpected motion may
occur. If the machine matches this configuration, please do the
following:
-
It is recommended to replace the manual, hand crank
adjustment system with a powered adjustment system. A retrofit kit
is available to add an acme rod system driven by a hydraulic motor.
-
If you choose to continue to use the manual, hand-crank
adjustment system, please train all personnel using the equipment in
the proper use of the holding device. This includes using the
holding device at all times when the extendo is not being adjusted.
The gear teeth must be fully-engaged. Visually inspect the holding
device each time it is used to ensure proper use.
 |
 |
|
Holding Device Fully Engaged |
Holding Device Disengaged and Clamp
Tightened |
Figure 2. Hand Crank
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- TEI extendos with a cable cylinder adjustment system
Early Prefeeders
used a cable cylinder to adjust the length of the extendo If the
machine matches this configuration, please do the following:
- It is recommended to replace the cable cylinder adjustment
system with an alternative powered adjustment system. A retrofit
kit is available to add an acme rod system driven by a hydraulic
motor.
- If you choose to continue to use the cable cylinder
adjustment system please inspect the cable and fasteners monthly and
tighten as necessary. Replace the cable cylinder if defects are
identified.

Figure 3. Cable cylinder system.
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