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two screws. A single escapement pawl is mounted on the
escapement pawl bracket by a shoulder rivet passing through
an elongated hole- in the pawl. An escapement 'pawl spring
pulls the escapement pawl tip to the right and into the escape-
ment rack. The escapement pawl spacer cont$lins a larger
elongated hole and is ~ounted ,on the same sholllder rivet as
the escapement pawl. A short pawl spacer spring loads the
spacer toward the right and
to
the rear. Also mounted to the
pawl bracket with another shoulder rivet is the escapement trip
lever.
The escapement rack is secured ot the underside of the car-
riage with dowel pins and screWs. It contains a number of
teeth per inch corresponding to the pitch of the typewriter.
(Operation)
The escapement is
a
single pawl type operated each time a
type bar moves to the platen, or whenever the space ,bar mech-
an ism is activated.
As the type bar moves toward the platen, it contacts the uni-
versal bar and pushes it toward the rear. An adjusting plate
mounted on the universal bar transfers the universal bar motion
to the escapement trip I ink. Motion of the trip link toward the
rear rotates the escapement trip lever, on its shoulder moLint-
ing rivet, so that the top of the trip lever moves toward the
front of the machine. The top of the trip lever contacts an
upright lug on the escapement pawl sP<;lcer, part of which is
behind the tail of the escapement pawl, and rotates the left
erid of the escapement pawl spacertoward the front of the type-
writer.
As
the upright lug moves forward, it carries the tail of
the escapement pawl forware. The escapement pawl pivots
abaut its shoulder mounting rivet, and the pawl tip is removed
from the escapement rack (Fig. 19).
Elongated Mounting Hole
Carriage held
by
escapement pawl
~:;::
Pawl spacer trips pawl from rack
__
J\J\.!\IIJ\I\JV __
Pawl spacer still forward
Carriage must overcome inertia
before
it
moves.
After escapement paWl
resh?res
to
next
tooth
of
rack, corriege starts
~.
move
Carriage completes movement
under mainspring tension
Figure 19. Escapement Pawl Operation
8
After clearing the rack tooth, the escapement pawl snaps to
the right under tension of the pawl spring and immediately
contacts the next rack tooth. The type bar continues on toward
the platen and prints, causing the pawl spacer to continue its
forward travel. A portion ofthe escapement pawl bracket
serves as an overthrow stop and prevents the spacer from get-
ting in front of the pawl tait., As the type bar reverses its
direction, the pawl spacer spring restQres the spacer to the
rear, clear of the escapement pawl tai I (Fig. 19).' Because
of its relatively heavy mass and inertia, the carriage does not
move until all of these actions have taken place.
As
the car-
riage moves to the left under tension of the main spring, the
escapeme,nt pawl is pushed to the left unti I the edge of its
elongated mounting hole contacts the mounting rivet. This
stops and holds the carriage. The tai I of the escapement pawl
is again in front ofthe escapement pawl spacer lug (Fig. 19).
Thus, the escapement mechanism completes one operation and
is in position for the next.
The motion described above occurs under power operation
only; if a type bar is raised to the platen by hand, the car-
riage and escapement pawl wi II move before the escapement
pawl spacer restores. The elongated slot in the escapemen't
pawl spacer a I lows the spacer to be moved to the left past
0
the tail of the escapemerit pawl and prevents either damage to
parts or jamming of the carriage.
As
the type bar moves away
from the platen the spacer wi" restore to its norma I rest po-
sition.
Maximum escapement speed is obtained by keeping the escape-
ment pawl spacer overthrow to a minimum after the tripping
point has been reached. This permits the spacer to restore as
rapidly as possible.
Each time the escapement pawl is operated, main spring tension
is allowed to move the carriage one space to the
left~
Mounted
tq
the power frame casting is the main spring and holder as-
sembly containing the main spring (Fig. 20). The main spring
drum rotates about a mounting stud which passes through the
center of the main sp,ring and into the power frame. Tension
is appl ied to the main spring drum by the main spring and
transferred to the carriage by, the tension tape. A loop on the
end of the tension tape is attached to the carriage by one of
Lug of main spring drum
Figure 20. Main Spring and Holder Assembly
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