IBM 727, Руководство по инструкции

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5. Remove these colla rs.
6. Remove the screws entering the rear of the shafts.
70 Remove the rear plate, which is held by six screws and four dowels.
8. The clutch and shaft assem blies may now be removed from the fram e. Note
carefully the position of any shims; do not interchange the two assem blies.
Assem ble in reverse order. After assembly, check the brushes for good tension
and square contact.
15. 5.3 Adjustments on Drive Clutch Unit
The commutator brushes are positioned to make contact squarely and in the cen­
ter of the commutator rings. Loosen brush mounting screws to do this. Form ten­
sion strap for a strong wipe to insure no arcing at the brushes. Excessive carbon
deposits have been found on the commutator rings. They produce contact resistance
affecting the operation appreciably and, therefore, should be removed.
The take-up spindle block is positioned vertically with the mounting screw s in
elongated holes to bring the chain gear level with the chain gear on the left stop-
clutch drive-shaft. Position the stop-clutch drive-shaft bearing blocks so that the
worm teeth are fully meshed with the teeth on the stop-clutch gears and the shafts
are free from binds. The forward and reverse m otors are positioned vertically to
provide normal V belt tension— about one inch free play at the center of the longest
belt span.
15.6 VACUUM UNIT
1 5.6 .1 Removal and Adjustment of the Vacuum Columns (Figure 22)
Two methods are used to fasten the vacuum columns to the lower main plate.
On earlier machines, two mounting screws are used per column; on current machines,
four mounting screws are used. The removal and adjustment of both types is ex­
plained.
The right column can be removed in the following manner. Remove the lower
clean-out cover, the lucite cover angle clamps and the lucite cover. Remove the
four screws (from rear) holding the lower end of the column to the manifold. Remove
the screws securing the column to the lower main plate. Remove the column, being
careful not to damage the flutter valve operating arm. Reassem ble in reverse order,
making sure the neoprene tubes to the vacuum column switches are in place.
When necessary to rem ove the left vacuum column, it is quicker to rem ove both
columns and the manifold as an assembly, and then rem ove the left column. To do
this, disconnect the vacuum hose from the manifold and the leads from the flapper
valve microswitcheso Loosen the two screws holding the manifold to the machine
base. Remove the lower clean-out covers, the lucite cover angle clamps, the lucite
covers, and the screws securing both columns to the lower main plate.
When reassem bling the lucite covers, make sure they are tight against the vacuum
chamber covers (C) and the lower clean-out covers to prevent air leakage. Be very
careful when handling the angle clamps and the vacuum columns because they are
manufactured with a very close tolerance on straightness.
Do not tighten the holding
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