IBM 727, Руководство по инструкции

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3. Unscrew the four bolts that mount the pump. Lower the pump out to the right
of the machine. Be careful that the pump inlet pipe does not strike the floor of the
machine, possibly jamming the impeller blades.
1 5.6 .6 Vacuum Column Tape Guide
The guide fits in each vacuum column and bears on the tape just before the tape
reaches the moving pulley. Any tape twist in the vacuum columns is taken out before
the tape reaches the idlers and head assembly.
The following adjustment to the tape guides should be made with vacuum on and
tape in the columns: Move the block away from the column side 1/64" to 1/32"
farther than necessary to make contact across the full width of the tape. Make sure
that the guide is not placed in a position where the tape will be against the drive cap­
stans when in stop status.
15. 7 DRIVE CAPSTAN MECHANISM
15. 7.1 Removal of a Drive Capstan
Remove the capstan belt and rem ove the elastic stop nut from the rear of the
capstan shaft while holding the shaft from turning by a pin punch inserted into the hole
in the capstan pulley. The drive capstan and shaft may be pulled out from the front
of the machine. Carefully prevent the pin punch from striking the capstan retracting
slide assembly. The needle bearings are held in a race so that there is no danger of
their falling out.
15. 7. 2 Removal of a Capstan Housing
Remove the capstan drive belt. On the retracting operating shaft, loosen the
fork operating arms and the inboard clamps; rem ove the clip holding the operating
link to the solenoid plunger link.
If the left housing is to be rem oved, move the shaft far enough to the right to clear
the housing. If the right housing is to be removed, move the shaft to the right until it
clears the left housing, disconnect the solenoid plunger, and rem ove the housing with
the shaft in it. The housing is held to the lower main plate by four Allen head screws
accessible at the front. To rem ove the one behind the vacuum column, use an
abbreviated Allen wrench. (One should be sawed or ground off for this pu rp ose.) Re­
move these screws and pull the housing from the rear.
When assembling, position the housing so that the operating shaft is free from
binds. Make and check all shaft adjustments.
15. 7.3 Capstan Retracting Mechanism
The retracting solenoid assembly may be removed by unlatching the plunger,
then removing the leads to the coil and latch magnet armature and the three mounting
screw s. The solenoid plunger is removed by removing the screw through it which
holds the two links. The dashpot may now be worked up and out to the left of the
machine.
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