Singer 601 - Page 18

DESCRIPTION OF BACK TACKING OPERATION
Back tacking with the back tack device is done by means ot a built-in back tack solenoid.
When an electronic command from the control box (for automatic back tacking) and/or the push button switch is
relaved to the back tack solenoid, the solenoid causes the leed rock shaft driving frame action lever fastened to the
right end ot driving trame action shaft to rotate and push the feed rock shaft driving frame upward and hold it in
this position until back tacking is completed. While the above takes place, the feed reverse lever remains immovable
due to the slot provided on the joint portion ot the feed reverse lever hinge stud crank connecting link which is
connected to the teed rock shaft driving frame.
The teed rock shaft driving fiame stopper lever provided on the feed reverse lever hinge stud crank has been
designed to control the reverse stitch length to same stitch length as set for forward stitch with the feed regulating
dial on the feed reverse lever.
Die automatic back tack switch connected to the control box permits automatic back tacking at start and at end
of stitching independently. The number of stitches in reverse is controlled by the control box.
Back tacking can be done at any desired position during the sewing operation by depressing the push button
switch provided adjacent to the needle bar. Tire machine will continue to sew in reverse while the push button is
depressed, however, when the machine is stopped, the protective circuit automatically cuts off the current supply
to the solenoid after I 2 seconds even when the push button is continuously depressed.
SETTING AND ADJUSTING BACK TACK DEVICE
GETTING BACK TACK SOLENOID
I he back tack solenoid is correctly set in the machine before the machine leaves the factory. If, however, this
setting has been disturbed and resetting becomes necessary, reset as instructed below.
Setting (Fig. 86):
Set the back tack solenoid so that there is a clearance of about 0.7mm (.03") between the flange of its plunger
and the rotating hook shaft when plunger is pushed toward the shaft.
When assembling the back tack solenoid link to the solenoid, be sure the solenoid is correctly positioned laterally
and correctly angled so that the link can operate smoothly and without any binding in the groove provided on the
plunger.
Adjustment (Fig. 86):
Loosen the two screws holding the back tack solenoid bracket and adjust position of solenoid as required and
re-tighten the screws.
SETTING AND ADJUSTING FEED ROCK SHAFT DRIVING FRAME
Setting:
Set the feed rock shaft driving frame A so that there is a clearance of 1.5mm (.06") in 591 D machines and 0.5mm
( 02 ) in 591C and 601D machines between its left end and the boss on the bed as shown in Fig. 89.
The feed rock shaft driving frame hinge pins B. the leed and feed lifting eccentric and the feed reverse lever hinge
stud crank C must be correctly set in relation with the feed rock shaft driving frame A so that it can rotate freely
when operated manually.