3M 3M-Matic S-857, Instructions And Parts List

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12
Theory of Operation
(Continued)
APPLICATION CYCLE, CUT/BUFF SEQUENCE
When the machine is in the powered rest position and
a box is placed in the nest area, the box paddle
actuates valve V-2. This allows a pulse of air to flow
from the manifold through valve V-2, line 4, valve
V-8, and line 5 to the PA port of the pilot valve P-1.
This shifts the pilot valve P-1. Air is then directed to
the paddle cylinder, which holds the paddle to the
machine housing, which prevents the additional
actuation of paddle valve V-2 before the application
cycle is completed.
Air is then directed to the head end of the cut and buff
cylinders and causes both to extend at the same
time. At full extension, a section of tape is cut by the
knife assembly and immediately applied to the box by
the buff roller assembly.
As the buff assembly reaches full extension, it
actuates valve V-3. This directs a pulse of air to the
PB port of the pilot valve P-1 causing it to shift and
direct air to the rod end of the cut and buff cylinders.
This causes the cut and buff cylinders to retract and
return the knife and buff assemblies back to the
achine rest position. Shortly before the buff cylinder
fully retracts, it actuates valve V-4. This begins the
feed sequence.
Figure 3-3 – Cut/Buff Sequence