3M 3M-Matic Dual S-867 II, Instructions And Parts List

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11
Theory of Operation
This section contains general information about the
S-867, a pneumatic schematic, detailed operational
explanation and a pneumatic components list.
General Information
The S-867 is a pneumatically powered machine
containing eleven pneumatic valves and six pneumatic
cylinders. These components are all listed at the end
of this section with a brief description of their function.
The machine consists of four primary assemblies
listed below.
• Knife assembly – cuts the section of tape to be
applied.
• Buff assembly – applies the section of tape to the
box corner.
• Feed assembly – advances the tape between
applications.
• Jaw assembly – retains the free end of the tape
between applications.
Operational Explanation
REST POSITION, AIR OFF
When the machine is in rest position with the air off, a
spring-actuated air cylinder extends to hold up the
feed assembly. See Figure 3-1. This is necesssary
because the air cylinder is in the fully extended
position. Without the spring-actuated air cylinder, the
weight of the feed assembly could cause the air
cylinder to retract and damage the section of tape
ready for application.
REST POSITION, AIR ON
When air is applied to the machine, it is routed
through the On/Off control valve V-1, through line 2,
through safety valve V-9, and into the manifold through
line 28. See Figure 7-1.
The manifold then routes the air to seven locations.
Four of the routes from the manifold direct air to valves
that are closed when the machine is in the rest
position. These "blocked" air routes are:
• Through line 3 to valve V-2
• Through line 25 to valve V-3
• Through line 24 to valve V-4
• Through line 18 to valve V-6
The remaining three routes direct air to actuate the air
cylinders and prepare the machine for the application
cycle.
• Air is directed through line 29 to retract the spring-
loaded safety cylinder that retains the feed
mechanism.
• Air is directed through line 27 to the pilot valve
P-1. The air exits the pilot valve and is branched to
retract the buff and cut cylinders. The pilot valve
directs air through line 9, the buff cylinder retract
flow control valve, and line 21 to the rod end of the
buff cylinder to retract the cylinder, and through
line 8 to the rod end of the cut cylinder and
retracts it also.
• Air is also directed through line 7 to pilot valve
P-2. The air exits the pilot valve P-2 and is
branched to extend the feed and jaw cylinders. Air
travels from the pilot valve through line 14, valve V-
5, and line 26 to the head end of the jaw cylinder
and extends the cylinder. Air is also directed
through line 15, valve V-7, line 19, the feed cylinder
extend flow control valve, and line 22 to the head-
end of the feed cylinder and extends the feed
cylinder.
Figure 3-1 – Rest Position