WaferTransportSolutionManual - 第20页
HEAVY PALLET RAILS MECHANICAL DETAIL 1.12 Wafer Transport Solutio n Chapter Issue 1 August 11 Pneumatic Snugger Mechanism The rear rail has two pneumatically operated bello ws assemblies, located between the beam lif t c…
HEAVY PALLET RAILS
MECHANICAL DETAIL
Chapter Issue 1 August 11 Wafer Transport Solution 1.11
Snugger Rail Snugger plates are fitted to the front and rear rails; the rear snugger provides
the pallet holding action.
With the pallet in position, the transport beam drops allowing the pallet overhang
edge to rest on the pallet support blocks. For extra support, and to prevent the
pallet from moving out of position, a pneumatic snugger mechanism on the rear
rail assembly, actuates, pushing the rear rail snugger plate toward the front rail.
Figure 1-5 Rear Rail Snugger Operation
Rear Rail Front Rail
Pneumatic Snugger Mechanism
(Rail removed for clarity)
Snugger
View on Left End of Rear Transport Rail
Snugger Off, Pallet Free
Snugger On, Securing Pallet
Snugger Plate
Top Plate
Pallet Overhang Edge
Pallet
Beam
Support Block
HEAVY PALLET RAILS
MECHANICAL DETAIL
1.12 Wafer Transport Solution Chapter Issue 1 August 11
Pneumatic Snugger
Mechanism
The rear rail has two pneumatically operated bellows assemblies, located
between the beam lift cylinders and the rail legs, on both ends of the rail.
The bellows provide the motive force to push the rear snugger plate, which
clamps the pallet to the front snugger plate. A rail width collar locks the fixed
plate whilst the other side of the belows is free to move the snugger plate.
Rail Width Collar
Lower BellowsFixed Plate
Bellows Mounting Plate
Upper Bellows
Leg
Beam Lift Cylinder
View on Left Hand End of the Rear Rail
HEAVY PALLET RAILS
MECHANICAL DETAIL
Chapter Issue 1 August 11 Wafer Transport Solution 1.13
The pneumatically operated bellows act against a pair of fixed plates (only the
l.h.s shown in the diagram). The bellows are secured to the moveable bellows
mounting plates which are in-turn mounted to the snugger via a leg leaf spring
and a horizontal tie.
In operation, the left hand and the right hand bellows sets work together. They
move the snugger toward the front of the printer, clamping the pallet. The
system air pressure is applied causing all four bellows to expand, pushing the
snugger forward.
At the end of the print operation the pallet is released. Air pressure in each of
the bellows is exhausted, allowing the return spring assemblies to return the
moving plate back to the start location. The return spring assemblies are held
in place by a shoulder bolt which screws into the fixed plate.
Fixed Plate
Upper Bellows
Snugger
Lower Bellows
Bellows Mounting Plate
Leg Leaf Spring
Shoulder Bolt (2)
Return Spring (2)
Partially Exploded View (l.h.s. bellows) of the Snugger Mechanism
Horizontal Tie