IBM 727, Руководство по инструкции

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bulb and photo cell to no tape existing). This peak voltage swing is not to be less than
ten volts using a 2 0 ,000-ohm /volt voltm eter. Physically adjust the reflector plate
by using the adjusting screw . This screw can be secured by the setscrew to lock it
into position. If m ore adjustment is necessary than can be obtained by the adjusting
screw alone, loosen the mounting screws for the reflector plate and shift the plate
itself in the oversize holes.
9. Replace head covers.
15.5 DRIVE CLUTCH ASSEMBLY
1 5 .5 .1 Removal of Drive Clutch Unit
To remove the drive clutch unit, do the following:
1. Drive the pin from the hub of each of the reels.
2. Disconnect rewind motor plug.
3. Loosen one of the two setscrew s in the rewind motor rubber coupling.
4. Remove three screws holding the rewind motor bracket, being careful not to
damage the motor coupling.
5. Remove the belts from the forward and reverse clutch pulleys. These belts
are matched in pairs, and should be reassem bled in the same order in which they
are removed.
6. Remove the clamp from the cable running to the sensing arm switch.
7. Remove the Jones plug from its socket on the clutch fram e.
8. Install hinges on upper main plate and be sure they are tight.
9. Remove upper head cover.
10. Remove 6 Allen head screw s and plated washers from the upper main plate.
11. Carefully lower the upper main plate until it hangs from its stop chains.
While doing this, rem ove the six spacers so that they do not fall into the machine.
12. Remove the four Allen head screw s and washers holding the clutch assembly
to the upper main plate.
13. Lift the clutch assembly straight up.
The small hole in each clutch surface is for manufacturing purposes. It is not
an oil hole.
Reassem ble in reverse order, with these points in mind:
1. The Jones plug socket on the clutch fram e has no locating pin, so make sure
that the plug is put back in correctly.
2. When replacing the rewind motor assem bly, align the motor shaft to the reel
shaft as accurately as possible.
1 5 .5 .2 Removal of the Drive Clutch Shaft Assem blies
The recommended procedure is that the entire clutch unit (six clutches) be r e ­
placed as an assembly. However, in em ergencies the following procedure could be
used.
1. Remove the drive clutch unit (15. 5.1 ).
2. Mark the placement of the two rear-com m utator brush-mounting bars in pencil;
rem ove the leads from the brushes; rem ove the bars.
3. Loosen the Alien head screw s, entering the rear of each shaft about three
turns.
4. Drive the pins from the front shaft retaining colla rs.
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