IBM Selectric - Page 167

A new check paw I has now been re leased for use on
the SE LECTRIC I/O Printer with an improved engaging
surface. The new check pawl is easi Iy identifiable
from the old one by the deepened notch at the check-
ing area. An illustration is shown below:
Figure 15.3
This failure will usually occur at one point on the
cyc Ie shaft; the shaft wi II latch on one cyc Ie and
fai I to latch on the next cyc Ie, and it is easi Iy ob-
served. It may sti II be necessary to increase the
spring tension by either forming the spring tip down
at a 45° angle, or by winding the check pawl spring
up
one additional turn. Increasing the spring tension
wi II, however, accelerate wear of the check pawl
and ratchet.
If a problem is encountered where the cycle shaft
will not reliably detent, even after the check pawl
has been rep laced and the spri ng has been wound up,
it wi II then be necessary to replace the entire cycle
shaft assemb Iy .
The
PN 1123675 wi II remain the same!.
15.11 CYCLE CLUTCH SLIPPAGE
Slow or sluggish cycle operation may be encountered
du'e to the cycle clutch spring slipping or the sleeve
binding. This condition may be detected during re-
peated +5 ti It 3 selection. The following areas
should be checked if this occurs.
1. Excess i ve cyc Ie shaft end play - end play shou Id
be .00111 to .003".
2. Oil on spring - the proper lubrication for the
spring is #23 grease. Any oil on the spring will
allow slippage; the spring must be removed and
thoroughly cleaned with IBM cleaning fluid.
Care shou Id be taken to remove a II traces of oi I
from the cyc Ie shaft reservoi r area and a Iso the
cycle pulley hub. The whole assembly should be
relubricated thoroughly with #23 grease.
3. Incorrect adjustment of cycle clutch spring.
a. Opening of the spring too soon wi II cause
slippage.
5-23
b. The cyc Ie clutch spri ng shou Id be adj usted
left or right to
maintain .005" clearance be-
tween the spri ng and pu lIey hub. Excessive
clearance wi II not allow enoug h engagement
of the spring on the hub, causing slippage.
Too little clearance will cause the spring to
bind agai nst the pu lIey hub and overload the
clutch release train, giving rise to sluggish
keyboard reaction as well as noisy idling.
c. The cycle clutch collar should be adjusted
left or right to allow a minimum of .008" end
play of the clutch sleeve. Too little play of
the sleeve can resu It in erroneous readi ngs of
the cyc Ie shaft end p lay (where the sleeve
play substitutes for the shaft play) and cause
a direct mechanism drive connection between
cycle pulley and shaft. This latter condition
wi II prevent a comp lete closure of the cyc Ie
spring and result in slippage.
4. Worn spring (15.5).
15.12 CYCLE CLUTCH LATCH BREAKAGE
We have recei ved severa I reports of the cyc Ie clutch
latch breaking in the area of its pivot point. This
breakage is due to forming the cyc Ie clutch latch
extension which mounts the restoring roller. When a
cycle clutch latch is mounted in the SELECTRIC I/O
Pri nter, it has a tendency to mount non para lie I to
the sleeve angling to the left. This creates a problem
wherein the cycle clutch latch restore roller will con-·
tact the cycle clutch collar mounting screw. The
past fix for this prob lem was to form the cyc Ie clutch
latch extension to the right so it would track the
cam properly. This method of adjustment wi II break
the cycle clutch latch extension or wi II break the
cycle clutch latch at its pivot point since the latch is
a
hardened part. This method of adjustment a Iso fai Is
to make the cycle clutch latch parallel to the cycle
clutch sleeve.
The proper adjustment of this mechanism is as follows:
The
duckbi II pliers shou Id be i nse rted at the poi nt
where the cyc Ie clutch ·Iatch bracket mounts to the
selector bail mounting bracket. The pliers can then
easi Iy move the enti re cyc Ie clutch latch bracket to
the left or right by a twisting motion. This wi II en-
sure that the latch is parallel to the sleeve and it
wi II also ensure that the restore roller moves far e-
nough to the right so as not to contact the screw in
the cycle clutch collar.
This procedure is presently being used on the I/O
Assembly Line, with excellent results. It is very
possible, however, that there are many SELECTRIC
I/O Printers in the field whose latches were formed
using the old method. It is possible that breakage of
those cyc Ie clutch latches wi II resu It. They shou Id
be replaced using a hardened latch and the new ad-
j ustment procedure fo Ilowed .
The
cycle clutch latch assembly part number is
1135124.