1 ==
Needle
bar
frame
2 =
Needle
bar
3 =
Work
clamp
4 = Clamp foot lifting lever
5 = Thread wiper wire
6 = Feed plote
7 = Work clomp feet
8 =
Presser
bar
9 — Presser bar lifting bracket
Fig. 2 Feed
plate
and
work
clamp
While the last
stitch
is being
formed,
the stop
motion
is released so that
the
machine
stops
exactly
in the predetermined
position
after
completing
the
last
stitch.
When the left treadle is depressed, the needle
and
bobbin threads
are
trim
med and the work clomp raised for easy removal of the work.
Electromagnetic Control
On machines fitted with electromagnetic control, various operations that
used to be performed by hand or foot
previously,
such
as
raising
the work
clomp and starting the
machine,
are controlled by solenoids. On the
Pfoff
3334,
the
solenoids
ore
activated
by
depressing
push-button
switch
FS
(Fig.
4)
on
the
foot
rest.
When
this
button
is
pressed
down
to the
first
switch
position,
the
work
clamp
is
lowered
onto the
goods.
At
this
stage, the
work
clamp
may
be
raised
or
lowered
indefinitely
by
depressing
or
releasing
the
push
button,
as
may
be
required to odjust the position of the work under the clamp. Depressing the
button to the first switch position will not start the machine.
Only
when
the
button
is depressed to the second
switch
position
will
the
machine be storted by a second solenoid
(Fig.
4).
10