Singer 51W
51W25
51W28
51W29
51W30
51W45
51W54
51W55
The following is from brochure:
HIGH SPEED
SINGER MACHINES 51w56 AND 51w57
POST BED EQUIPPED WITH OBLIQUE UNDER-EDGE TRIMMER FOR
Stitching the Edges and Under-Trimming the Linings
of Shoes, Sandals, Slippers, Etc., at One Operation
 Machines 51w56 and 51w57
have a "post" bed and are designed for simultaneously stitching the edges and
under-trimming the linings of shoes, sandals, slippers, etc. As these machines will
accomplish the combined stitching and trimming operation at the high speed of 2200
stitches per minute, a greatly increased output of excellent quality work is assured by
their use, making them the foremost "post" bed machines for this class of work.
Machine 51w56 is equipped with an oblique under-edge trimmer which trims back of the
needle. The distance from the trimmed edge to the line of stitching may be .015, .025,
.035 or .050 inch, as desired, and orders for the machine should specify the trimming
margin required. Unless otherwise ordered, this machine will be fitted for making the
trimming margin .015 inch.
Machine 51w57 is the same as Machine 51w56 with the exception that the trimmer trims
abreast of the needle and the distance from the trimmed edge to the line of stitching may
be .050, .060 or .075 inch, as desired. Orders for the machine should state the trimming
margin required. Unless otherwise ordered, this machine will be fitted for making the
trimming margin .050 inch.
Advantages of the "Post" Bed
The "post" bed of these machines is particularly suited for shoe work and
other work which is difficult to handle on a flat bed or a cylinder bed machine. The
"post" is 7 inches high and it has a very small top surface, 1 and 7/8 inch by 2
inches--which permits an operator to handle a shoe upper conveniently while fitting the
lining, without twisting the upper out of shape. Operators are thus aided in turning out a
good grade of work. There is a clear space of 7~ inches at the right of the needle.
Oblique Under-edge Trimmer
The trimming is perfectly done by means of the oblique under-edge trimmer with which
the machines are equipped. The oblique trimming knife automatically trims the lining from
under the edge of the shoe upper while it is being stitched, so that none of the lining is
visible from the outside of the work when the stitching and trimming is finished.
As the trimming knife can be instantly thrown out of action; the machines can also be
used for plain stitching when desired.
Oblique Edge Guide
To protect the edge of the shoe upper from the trimming knife while the stitching and
trimming is in progress, an oblique edge guide, which keeps the edge of the shoe upper out
of range of the knife, is fitted to the arm of the machines. This is an especially
valuable feature when stitching and trimming the edges of the inside curves in ladies' and
children's sandals.
The distance from the line of stitching to the edge of the work is instantly adjusted
by the oblique guide.
Different thicknesses of work can also be readily accommodated by a simple adjustment
of the oblique guide.
Roller Presser and Drop Feed
The machines are fitted with a ball bearing roller presser and drop feed which are very
efficient in their use on shoe work, etc., the freely turning roller presser permitting
short and sharp turns to be easily made, while the drop feed makes the feeding of the work
positive, ensuring uniform length lock stitches. Another advantage is afforded by the
locating of the feed in a convenient position at the extreme outer edge of the
"post."
Mechanical Opener
Uniformity in stitching is further assured by the adoption in the machines of the
mechanical opener, the opening lever of which slightly turns the bobbin case at every
stitch to permit the free taking up of the needle thread.
Belt Driven Rotary Hook
The machines have a rotary hook which is belt driven and they are therefore smooth
running and quiet in operation.
Foot Lifter
A foot lifter for raising the roller presser is provided with each machine, and
operators find this a great convenience as it enables them to handle a large output of
work with ease and dispatch.
(NOTE: Original document copyright 1920 and 1925)
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