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Technical Manual: Butted Seam
70 Class Machines Feeding Mechanism
FEED DOGS
1) Feed dogs are
provided with either fine cut teeth or coarse cut teeth, single row or double
row, dependent upon the work. Generally, the Feed Dogs should be set as low as
practical.
2) The length of feed
can be changed by removing the Feed Eccentric and substituting another Feed
Eccentric of different throw. Feed Eccentrics are marked to indicate
approximately the number of stitches per inch produced at the edge of the
fabric.
3) Feed Dogs and
Needle Plates must match each other.
4) The letter
D in the Style 70-D3B or 70-ABBD means it contains a differential
or gathering feed. The differential contains two separate Feed Dogs with their
separate Feed Carriers and separate Feed Eccentrics. When it is desired to
prevent the edge of the fabric from being stretched or lengthened while
seaming, the Front Feed Dog is made to travel a greater distance than the Rear
Feed Dog. In most cases, a slight difference is sufficient and the number of
each Feed Eccentric and the difference between the two is dependent upon the
number of stitches required per inch and the elasticity of the fabric
itself.
5) On certain fabrics
it may be desirable to tilt the Feed Mechanism. To make this adjustment, loosen
the Set Screw 48-5/32, slowly turn the Feed Carrier Block Pin to the desired
location and tighten this Set Screw. When the Screw Slot in the Pin is level
with the base of the machine, the Feed Dogs will be in their standard level
position. It is never necessary to remove the Stop Screw 48-5/32. This leveling
device on the Feed Mechanism permits delicate adjustment of Feed Dogs.
Y TYPE FEED MECHANISM
6) The Y
Type Feed Mechanism is used on Merrow Styles 70-YeB, 70-ABBY, 70-ABBY-1 and
70-ABBY-4. The following sections dealing with this Feed Mechanism apply only
to these styles.
DISASSEMBLY
- Remove the Work Plate Support M-29-5 by first removing
Screws (2) 52-3/16 then moving the Support to the rear. The Work Plate and
Fabric Guard may be left on the Work Plate Support. Remove Needle Plate, Lower
Looper Thread Tube and Feed Dogs.
- Remove Nut 2-3/16 from end of Lower Shaft and Feed
Eccentric 6/82-(4-5-6-7-etc.).
- Remove Machine Base A-19 Assy-2 by removing Screws
83-3/16 (2) and one Screw 103-3/16. Feed Adjusting Lever M-357-1 must be fully
depressed to expose Screw #103-3/16 and allow its removal.
- Working from the bottom of the machine unscrew Screws (2)
71-3/16 which hold Feed Link Pivot Support M-358-1 to the Machine Frame. Now,
the whole Feed Assembly may be removed from the machine by sliding it to the
left.
- The Feed Carrier may be separated by taking off Nut
2-3/16, F.C. Bolt 6-77-E and Bushing 6-79-D which connect it to the Feed
Carrier Link (rear) M-76-4.
- The Feed Carrier Links, front M-76-3 and rear M-76-4 are
removed by rotating Feed Link Pivot M-351-1 to a position where it is totally
below the mounting surface of Feed Link Pivot Support M-358-1, and sliding out
Feed Link Pivot Pin M-352-1.
- The Feed Link Pivot is removed by taking off Nut 4-3/16
and Feed Link Pivot Arm Spacer Bolt M-355-1, then Feed Link Pivot Arm Spacer
can be slipped out of the Feed Link Pivot.
- Feed Link Pivot Arm (inner) M-353-1 will now slide out of
Feed Link Pivot Support M-358-1 and Feed Link Pivot Arm (outer) M-353-2 will
slide out when Set Screw 77-3/16 is removed from Feed Link Pivot Arm Actuator
M-356-1.
ADJUSTMENT
- The Feed Stroke of the Y Mechanism is
adjustable to produce stitch length variations in ratios up to 4 or 5 to 1. The
normal stitch spacing is set by the Feed Eccentric (6-82-4, 5, 6, 7, 8, etc.).
The multiple stitch is achieved by a stroke change actuated by depressing the
Feed Adjusting Lever, M-357-1.
- The maximum and minimum positions of the Feed Adjusting
Lever are controlled for Stop Screws #105-3/16 and 106-3/16, Stop Screw
#105-3/16 protrudes from the front of the Feed Link Pivot Support M-358-1 is
used to set the Feed Adjustment Lever for the maximum number of stitches
desired at the selvages. Set Screw #106-3/16 which protrudes from the rear of
Feed Link Pivot Support M-358-1 sets the number of stitches desired in the body
of the seam. It is possible to make fewer stitches than the rating of the Feed
Eccentric.
- Tension Spring Adjustment Screw #6-3/8 is used to adjust
the spring which returns the feed adjusting lever to its normal position.
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Machines Set-Up & Operations
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ENGLAND, LE6 0GT
Tel: +44 (0)116 2321779 Fax: +44 (0)116 287 8099
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