IMPROVEMENTS IN RECIPROCATING SHUTTLE SEWING MACHINES
Year: 1882

page_text: LETTERS PATENT to Arthur Greenwood of Leeds in the County of York,
Machine Maker for an invention of "IMPROVEMENTS IN RECIPROCATING
SHUTTLE SEWING MACHINES
"
PROVISIONAL SPECIFICATION left by the said Arthur Greenwood at the
Office of the Commissioners of Patents on the 23rd May 1882.
ARTHUR GREENWOOD of Leeds in the County of York, Machine Maker,
"IMPROVEMENTS IN RECIPROCATING SHUTTLE SEWING MACHINES."
The object of this Invention is to enable lock stitch sewing machines, such for
example as those of the Howe or the Singer type, to sew leather work with hard
waxed threads.
Hitherto great difficulty has been experienced in passing the shuttle through
the loop of hard waxed thread although such loop was opened for the admission
of the nose of the shuttle by the descent and dwell of the eye pointed needle. This
difficulty it has been proposed to remedy by lubricating the nose of the shuttle at
the risk of destroying the adhesive character of the wax, and a composition
immitating wax only in appearance has been used as a substitute for what is known
as shoe-makers wax. To enable me to use hard waxed thread in these kinds of
machines I provide a means for retaining the open loop while the shuttle is passing
through it, and I apply heat to the framing of the machine by a lamp or gas jets
as in the well known Crispin Machines.
The shuttle which will be of the ordinary form I propose to groove on its back
from near the nose to the heel in order that it may receive the point of the loop
retaining device. This device may be a rocking finger which may also be termed
a loop spreader. This loop spreader I pivot to the rear end of the shuttle race,
and I fit it with a pin or bowle near its forward end which enters a cam-shaped
groove at the back of the shuttle carrier This groove I so form that as the
shuttle advances to enter the open loop the point of the finger will advance and
come in front of the loop; it will then enter the groove in the shuttle and retain
the loop while the shuttle is passing forward to the end of its race.

page_text: On the return traverse of the shuttle the finger will return to its quiescent position,
ready for advancing to assist in the formation of the next stitch. To provide for the
spreading of the loop so that the shuttle may freely pass through it, it will be
necessary to slacken the needle thread at the proper moment. This I do by means
of a positive "take up," which in its descent supplies the needle with the requisite
amount of thread from the bobbin, and on moving outwards draws the loop off the
heel of the shuttle and tightens the stitch in the work. This positive take up
consists of a reciprocating arm mounted on the head of the machine and actuated
by a cam on the cam shaft. This arm carries at its extremity a guide pulley for
the waxed thread which is laid under and over similar guide pulleys mounted on
the head of the machine. By rocking this arm towards and from the stationary
guide pullies the waxed thread will be delivered to the needle or drawn to tension
as required. The tightening up of the stitch should be so timed that it will be
completed before the feed takes place for the next succeeding stitch, and the rise of
the needle out of the work should take place simultaneously with this movement.
By this arrangement of stitch-tightener I reduce the friction on the needle thread
to a minimum.
To ensure the proper action of the take up, the needle thread bobbin must have
put upon it an amount of friction sufficient to enable it to resist the pull of the
reciprocating arm when tightening the stitch. For this purpose any suitable
arrangement of adjustable spring pressure may be applied to the bobbin.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur Greenwood in the Great Seal Patent Office on the
23rd November 1882.
ARTHUR GREENWOOD of Leeds in the County of York Machine Maker
"IMPROVEMENTS IN RECIPROCATING SHUTTLE SEWING MACHINES"
The object of this Invention is to enable lock stitch sewing machines, such for
example as those of the Howe or the Singer type, to sew leather work with hard
waxed threads.-Hitherto great difficulty has been experienced in passing the
shuttle through the top of hard waxed thread, although such loop was opened for
the admission of the nose of the shuttle by the descent and dwell of the eye-
pointed needle.
This difficulty it has been proposed to remedy by lubricating the nose of the
shuttle at the risk of destroying the adhesive character of the wax, and a com-
position imitating wax, only in appearance, has been used as a substitute for what
is known as shoe-makers' wax.-To enable me to use hard waxed thread in these
kinds of machines-I provide a means for retaining the open loop while the shuttle
is passing through it, and I apply heat to the framing of the machine by a lamp or
gas jets as in the well-known Crispin Machines.
I also adapt to the machine a positive take-up motion, so timed that it will
tighten the stitch last formed before the next succeeding feed motion takes place.
In the accompanying drawing fig: 1 shews in side elevation partly in section, so
much of a sewing machine of the ordinary type with my improvements applied
thereto, as will serve to explain the manner of working with thread saturated with
hard wax according to my Invention. Fig: 2 is a partial plan view of the same,
shewing the shuttle in place in its race, with its driver and loop spreader; and
Fig: 3 is a cross section of the same on the line 1. 2 of Fig: 2.-Fig: 4 is a front
view of the upper part of the machine.
In these figures A is the shuttle of the ordinary type, but grooved on its back
rearwards from near the nose, as at a. for the purpose to be presently explained.―
B is the race in which the shuttle lies and C is the shuttle driver.-This shuttle
driver receives its motion from a reciprocating connecting rod C¹, furnished with a
cam slot into which a crank pin projecting from a vertical rotating shaft C² enters
for the purpose of actuating the same. The shuttle driver C is formed with a
horizontal extension in which a cam groove c is cut for the reception of a pin
projecting downwards from the loop spreader D.-This loop spreader consists of a
rocking cranked arm which has its fulcrum on the rear end of the shuttle race, and
it terminates at its opposite end in a finger d which finger is intended to dip into
the longitudinal groove a in the back of the shuttle, and hold the loop of the needle
thread while the shuttle is passing through the loop to lay its locking thread
therein-The cam slot c of the driver C is so cut as to ensure the finger d advancing
in front of the loop so soon as the nose of the shuttle has entered it, and of
receding at a rate exactly proportioned to the increase in the height or thickness
of the shuttle as the shuttle advances under the finger to enter and pass through
the loop. Thus the extremity of the finger & following the contour of the shuttle
as the latter advances, will remain in the groove a so long as that groove is
presented to the finger, and it will thereby offer an effectual bar to the escape of
the loop otherwise than at the rear of the shuttle.-By this means the missing of
stitches will be avoided, the loop so soon as entered by the nose of the shuttle
being secured by the loop spreader D.
On the return traverse of the shuttle the finger will retire to its quiescent
position ready for advancing to assist in the formation of the next stitch.-To

page_text: >>
provide for the spreading of the loop so that the shuttle may freely pass through it,
it will be necessary to slacken at the proper moment the thread of the vertical
eye-pointed needle E, the bar of which slides in guides in the head of the
machine. This slackening of the thread I effect by means of a positive "take up'
which in its descent supplies the needle with the requisite amount of thread from
the bobbin E¹ and on moving outwards draws the loop off the heel of the shuttle
and tightens the stitch in the work. This positive take up consists of a recipro-
cating arm F pivotted on the head of the machine, and carrying a bowle F which
enters the groove cut in the face of a disc F1 keyed to the horizontal shaft F2
which has its bearings in the hollow bracket arm G.-A crank pin f¹ on this disc
engaging with a cam plate E2 carried by the needle bar E³, serves to actuate the
needle in the well known manner.- -The rocking arm F carries at its extremity &
guide pulley f for the waxed thread, which is laid under and over similar guide
pulleys mounted on the head of the machine. The thread from the bobbin E¹
passes to a pulley g mounted on the top of the bracket arm G. From this pulley
it passes to a pulley e carried by the needle bar E3, and thence to pulley g¹ on
the head of the machine.-From this pulley the waxed thread passes to the
pulley of the stitch tightening lever F, thence to the pulley g² mounted on the
head of the machine, and then to the eye of the needle and so into the work.
By rocking the arm F towards and from the stationary guide pulleys g¹ g², the
waxed thread will be delivered to the needle, or drawn to tension as required The
tightening up of the stitch should be so timed that it will be completed before the
fred takes place for the next succeeding stitch, and the rise of the needle out of the
work should take place simultaneously with this movement..
This result will be obtained by arranging the groove of the cam F¹ and the
crank pin f' with its cam plate E2, as shewn at fig: 4
By this arrangement of stitch tightener I reduce the friction on the needle thread
to a minimum.
To ensure the proper action of the take up, the needle thread bobbin must have
put upon it an amount of friction sufficient to enable it to resist the pull of the
reciprocating arm when tightening the stitch-For this purpose any suitable
arrangement of adjustable spring pressure may be applied to the bobbin.
In the drawings I have shewn a coiled spring interposed between a nut e¹ and
the bobbin E¹, the nut being fitted to the threaded end of a vertical pin e² on
which the bobbin rotates. The tightening up therefore of this nut will increase
the elastic pressure on the bobbin to any extent required.
His the combined feed and presser bar which will be worked in the manner
common to the Crispin machines.
Having now set forth the nature of my Invention of "Improvements in recipro-
cating shuttle sewing machines" 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 reciprocating shuttle sewing machines which have their
shuttle below the work, of the means above described for ensuring the passage of
the shuttle through the loop of the thread of the eye-pointed needle when that
thread is charged with shoe maker's wax, and for tightening the stitch, as and for
the purpose above explained.
In witness whereof I the said Arthur. Greenwood have hereunto set my hand
and seal the twenty first day of November in the year of our Lord One
thousand eight hundred and eighty two.