Thiele Streamfeeder V-710DM, Manual, Page: 30 / 73

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STEP 3:
Back Wedge
Adjustment
Keep in mind the back wedge works with
the gate assembly to provide the proper lift,
curvature of the material, and proper belt/
material contact to separate and feed one sheet
at a time.
There are a number of feeding problems which
can be solved by simply adjusting the back wedge
to different positions. Some of these problems
include double feeds, skewing, twisting, poor
singulation, ink or varnish buildup on the belts,
and jamming at the gate assembly area.
Review
The back wedge provides proper lift to the material to help keep it off
the table top and feed belts, and it creates the force necessary to push
material against the gate assembly. By adjusting it back and forth from
the gate assembly or pivoting side to side, you can create the lift and
force necessary to preshingle material against the curvature of the gate
assembly. Also, it keeps other sheets off the feed belts until proper
separation of the bottom sheet at the gate assembly has occurred.
Here are some general guidelines that should help you determine how
the back wedge should be positioned for your particular material:
•
Moving the individual wedge triangles to the outside of the back
wedge shaft will create a bow in the center. The bow will stiffen the
material to promote better singulation of thinner material.
•
Pivoting the back wedge from its perpendicular to the gate assem-
bly will increase or decrease the amount of drag or contact (trac -
tion) on the feed belts for a given side. This can also be used to
control twisting or skewing of material as it leaves the gate assem -
bly area.
•
If the back wedge is positioned too far backward
from the gate as -
sembly, the belts are driving the material before the bottom sheet
has separated and left the gate assembly area. This pushes the gate
assembly up, creating more pressure on the material, O-rings, and
feed belts. The result can be premature buildup of ink or varnish on
the belt surfaces. It can also cause more than one material at a time
to be forced under the gate assembly, creating a double feed.
By moving the back wedge forward, only the bottom material can
make contact with the belt surface. Slippage is reduced, minimizing
buildup on the belt surface. Double feeding is also reduced.
•
If the back wedge is positioned too far forward
to the gate assem -
bly, a pinch point can be created between the top surfaces of the
individual rollers and the material. Moving the back wedge even
closer toward the gate assembly can allow material to overhang the
wedge, creating too much lift of the material off the feed belts.