IMPROVEMENTS IN SEWING MACHINES
Year: 1880

page_text: LETTERS PATENT to William Lawrence Bigelow, of 66, Chancery Lane, in the
County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS IN
SEWING MACHINES." A communication from abroad by John Bigelow, of
Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said William Lawrence Bigelow
at the Office of the Commissioners of Patents on the 17th December 1880.
WILLIAM LAWRENCE BIGELOW, of 66, Chancery Lane, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN SEWING MACHINES." [A communication from
abroad by John Bigelow, of Philadelphia, Pennsylvania, United States of
America.]
This Invention relates to a novel construction and arrangement of revolving
cutting blade, and to means for adapting the same to sewing machines in which
the work requires to be trimmed as the sewing progresses.
The object in view is to provide a revolving cutter, which by reason of its
excentric edge will give a drawing cut to the work to be trimmed, and for this
purpose an oval blade of thin sheet steel is formed, such oval blade being screwed
or otherwise securely fixed to the end of a shaft carried in bearings attached to the
work plate, and driven by gearing from the main driving shaft of the machine.
The shaft carrying the oval blade passes through a sleeve and collar, to which it
may be connected by a screw when required for action. By loosening this screw
the shaft carrying the oval blade may be pushed back out of work.
The end of the shaft on which the oval blade is mounted is so shaped as to allow
of the clippings passing freely under it. The work plate has a fine cut made in it,
alongside of and parallel to the line of feed, the said cut piece being only wide
enough for the revolving blade to pass through. The axis of the shaft carrying the
oval blade is set back of the line of the needle, so that the blade will cut only up
to the line of the needle, but the slot in the work plate through which the said
blade passes extends some little distance nearer to the operator, and thus a tongue
of steel is formed through a hole in which the needle passes. This tongue of steel
Price 6d1

page_text: is consequently slightly elastic, and will give slightly in the event of the work
jamming if the knife dulls, for something must give way if the blade fails to cut.
The presser foot is so shaped that one side thereof will exactly correspond to or
lie closely alongside of the knife slot in the work plate, and the blade cuts close to
this side of the presser foot. The presser foot has a hole in it for the needle to pass
through, and a fine saw cut connects such hole with the side next the revolving
blade. It is also formed with a horn projection in front of the knife. The action
of the machine is so timed that the oval blade shall give a drawing cut to the work
at the moment that the presser foot is holding it closely down to the work plate,
and it is found that a thin piece of steel having an excentric edge, when revolved
rapidly, cuts most efficiently. The revolving blade is timed to rise and fall with
the needle bar, and is thus out of the way when the work is fed forward.
A slight modification of the arrangement of the gearing will enable revolving
blades of the description above given to be adapted to all sorts of sewing machines
in which the work requires to be trimmed as the sewing progresses, whether the
main driving shaft is placed above or below the work plate, and it may also be
adapted to trimming the edges of fabrics as they are being sewn together by the
zig zag or herring bone stitch. By imparting to the revolving blade an intermittent
action its use may be extended to button hole machines.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Lawrence Bigelow in the Great Seal Patent Office on
the 17th June 1881.
WILLIAM LAWRENCE BIGELOW, of 66, Chancery Lane, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN SEWING MACHINES." A communication from
abroad by John Bigelow, of Philadelphia, Pennsylvania, United States of
America.
This Invention relates to means to be applied to sewing machines for trimming
the edges of the work as the sewing proceeds. To this end a rotating cutter is
provided in the form of an oval steel blade chamfered at its edge.
This blade cuts against a fixed edge carried by the work plate, and being so
timed in its rotation as to get clear of the work when the feed is taking place.
The Invention is applicable to various kinds of sewing machines, but the
machines to which it will be most generally adapted are those which sew most
rapidly, viz., the chain-stitch machines used in sewing hosiery goods.
In the accompanying Drawing I have shewn the Invention as applied to a
Willcox and Gibbs' single-thread chain-stitch machine. Fig. 1 is a side elevation
of the machine with the rotary cutter applied thereto; Fig. 2 is an end view of
the same, and Fig. 3 is a partial plan view, the upper parts of the machine for
working the needle and presser being removed, the better to shew the cutting
apparatus.
In these Figures A is the work table, below which is situate the main driving
shaft B; C is the curved bracket arm standing up from the bed of the machine,
and carrying at its front end the needle bar D and the presser bar E as usual.
The needle bar is worked by a rock lever E¹ mounted on the bracket arm C, and
receiving its motion from an excentric on the driving shaft B. This shaft carries
at its forward end the looper F, the action of which is well understood. G is the
feed bar underlying the table A, and worked by cams on the shaft B; H is the
rotary cutter, which is keyed to one extremity of a horizontal shaft H¹ that overlies
the table A. This shaft is mounted in a sleeve bearing H2 which stands up from
the base frame, and the further to steady this shaft its rear end enters a bearing
made for it in the bracket arm C. A collar h on this shaft, and fixed thereto by
a screw, works against the end of the sleeve bearing, and thus prevents the endway
motion of the shaft in one direction, while a spur pinion h³ keyed on the shaft at
the other side of the sleeve bearing prevents the endway motion of the shaft on
the opposite direction.
This spur pinion h¹ gears into a pinion h² of the same diameter keyed on the
driving shaft A, and hence rotary motion is imparted to the blade or cutter H.
Fitted to the table A is an inclined fixed cutter a, against the outer face of which
the cutter works. To enable the cutter to clear the table in its rotation the table
is grooved or slotted transversely in a direction parallel with the incline a, so that
the outer face of the incline may correspond with the inner face of the groove or
slot. I have said that the rotating blade H is made of an oval form; it is also
mounted excentrically, so that it makes a long draw cut for every rotation of the
driving shaft A. This cut takes place, as will be seen by the Drawing, when the
needle is in the work, but when the needle has risen clear of the work the excen-
tricity of the blade will enable it to clear the work and offer no obstruction to the
feed.
As the feed takes place the incline a will open the work in the line of the
cut and turn aside the trimmings clear of the action of the cutter.
The incline a, it will be seen, is held in place by means of set screws. This is for
the purpose of facilitating its removal when not required for use. With the same

page_text: object the shaft H' is made to slide in its bearings and draw back the cutter into
the dotted position of Fig. 3. To enable it to take up its position it is only
necessary to withdraw the tightening screw of the collar h, and the shaft H' will
be free to be slidden in its sleeve bearing. From the foregoing it will be under-
stood that the Invention by a slight modification of the driving gear may be
adapted to a large variety of sewing machines in which the work is required to be
trimmed while being sewn, whether the main shaft be situate below or above the
work.
Having now set forth the nature of the Invention of "Improvements in Sewing
Machines," as communicated to me from abroad, and explained the manner of
carrying the same into effect, I wish it to be understood that under the above in
part recited Letters Patent I claim,-
The application to the table of sewing machines of cutting apparatus as described,
whereby a draw cut is obtained for the purpose of trimming the work.
In witness whereof, I, the said William Lawrence Bigelow, have hereunto set
my hand and seal, the Fifteenth day of June, in the year of our Lord
One thousand eight hundred and eighty one.
WILLIAM LAWRENCE BIGELOW. (L.S.)