IBM Selectric I/O Manual Of Instruction page 30

FIGURE 60. Shift Cam and Shift Arm
Two keybuttons, one at each front corner of the keyboard,
can be used to actuate the shift mechanism (Fig. 61). A
bai I between the two keylevers causes both of them to move
together regardless of which one is depressed by the operator.
If the operator desires to keep the mechanism in the upper
case position, a shift lock is provided for this purpose. The
shift lock is attached to the left keylever and may be locked
by depressing the shift lock keybutton. The shift lock may
be released by depressing and releasing either shift keybutton.
The right hand rotate pulley is fastened to
thE~
top of the
shift arm. The arm pivots to right on "a pin at the bottom. A
strap from the shi ft arm to the pivot pin acts to stabi
Ii
ze the
shift arm to minimize front to rear movement of the pulley
{Fig. 62). In the lower case position, an adjusting screw
near the top of the arm rests against the head of a mounting
screw on the side of the powerframe.
22. 1