SINGER 331K4 - Manual (Page 3)

DESCRIPTION MACHINE 331K4:
Machines 331K1 and 331K4 produce top quality,
single-needle, straight-line lock stitching in suits, shirts,
skirts and other clothing.
MACHINE 331K1:
Stitch Type #301.
Central bobbin.
Short beak, oscillating shuttle on horizontal axis.
Link take-up.
Thread take-up lever guard.
Drop feed.
Hinged presser foot 161066.
Feed dog 149603.
Throat plate 26606.
Length of stitch controlled by regulator thumb screw
on front of machine arm.
Maximum stitch length—5-1 /3 to the inch.
Front, intermediate and rear plain bearings.
Clamp type needle bar.
Tapped hole and seat in rear of arm provided for
mounting light fixture independently of presser bar
lifting lever hinge screw.
Needle bar stroke is 1.472 inches.
Clearance under presser foot is 5/16 inch.
Machine dimensions; Bed length 18-3/4 inches,
width 7 inches.
Belt guard 174112 available on order.
Knee lifter 139625 regularly supplied.
Similar to Machine 331K1, with the following
exceptions;
Spring-biased, quick reversible feed mechanism
permits operator to feed work backward or forward
at will.
Solid presser foot 12144.
Feed dog 149304. Throat plate 12414.
INSTALLATION
Before placing the machine in its cut-out on table,
see that the four cushioning pads are at the four cor­
ners of the cut-out. Place the machine on these pads.
SPEED
The maximum speed for these machines is 2200
stitches per minute, according to the material sewn
and the type of work being done.
It is advisable to operate these machines at a more
moderate speed the first few days, after which they
can be operated at maximum speed.
Reduce speed of machine when sewing closely
woven fabrics or treated materials.
MACHINE PULLEY
Machine pulley 139724 (solid discs, balanced) has
an outside diameter of belt groove of 2.90 inches
for 3/8 inch V-belt. Effective diameter for 5/16 inch
round leather belt is 2-5/16 inches.
When in operation, the top of the machine pulley
must always turn over toward the operator.