IMPROVED MACHINERY FOR SEWING STRAW PLAIT
Year: 1885

page_text: I OWEN ROBINSON of the Champion Sewing Machine Works, Victoria Street,
Kettering in the County of Northampton Manufacturer do hereby declare the
nature of my invention for "IMPROVED MACHINERY FOR SEWING STRAW PLAIT,"
to be as follows:-
The object of this invention is to simplify the construction of machinery for
sewing straw plait.
To this end I combine an eye pointed needle' with a hooked needle and so'
arrange them below the work that after every feed they shall rise through the
work, the eye pointed needle taking the thread up through the work and the
hooked needle drawing a loop of thread down through the work and thereby
producing a series of chain stitches. The needles are set at an inclination to one
another and cross each other at a short distance above the face of the work.
Between these needles and immediately below the throat plate, which supports the
work, stands a conical loop opener the use of which will be presently explained.
The throat plate is carried by an arm pivotted to the main framing and resting at
its forward end upon an elastic support the throat plate being held down to its
required level by means of an adjusting screw passed through the arm and into the
main framing. Upon this throat plate arm is mounted the presser and also the
guides for the work. An under feed which traverses the work by equal step by
step motions works on a stud carried by the main framing. This underfeed is
adjustable vertically upon its stud to allow of the points with which it is fitted
penetrating more or less into the work. An adjustable arm carried by the feed bar
is acted upon by cams which impart a to and fro as well as an up and down
motion to the feed bar. The eye pointed needle drawing its thread from a spool
below the work receives an up and down motion in its inclined guides from
excentrics whereby it is caused to penetrate the work and leave a loop of thread in
the hook of the hooked needle. This needle receives a like up and down motion
penetrating the work slightly later than the eye pointed needle and striking into
the loop of the eye pointed needle secures the loop under its hook. The two
needles then descend the eye pointed needle still in advance and the hook needle
pulls the loop down through the work. Immediately the hook needle is clear of
the work it commences an axial movement by reason of a twist in its stem, equal
to a half turn, working through one of its fixed guides. As this half turn of the

page_text: hooked needle is proceding the feed motion takes place and the hook which at
the time the loop was taken from the eye pointed needle, faced that needle above
the work, now again faces that needle on the underside of the work leaving the
loop free to slide off the hooked needle when that needle commences another
ascent. As the work is fed forward the loop is drawn at tension over the conical
loop opener and the loop being thereby opened out the eye pointed needle will pass
through it as it rises to pierce the work and present a fresh loop to the hooked
needle. In doing this it lays the locking thread in the last formed loop under the
work and at the next descent of the needles the hooked needle will draw the
interlocked loop to tension and complete a stitch.
By means of this machine the stitch on the face of the work termed the "con-
cealed" stitch will be formed of two threads extending across the space measured by
the puncture of the two needles and the stitch below the work will consist of one
thread for about 3rds the length of one stitch and of three threads for that part
of the stitch that underlies the concealed stitch. The tension of the thread is so
arranged that the supply thread will be gripped and held firmly at the moment the
hooked needle is drawing up or tightening the stitch after which it will be left free
to answer to the requirements of the eye pointed needle.

page_text: Improved Machinery for Sewing Straw Plait.
I OWEN ROBINSON of the Champion Sewing Machine Works, Victoria Street,
Kettering in the County of Northampton, Manufacturer do hereby declare the
nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
The object of this Invention is to simplify the construction of machinery for
sewing straw plait. To this end I combine an eye-pointed needle with a hooked
needle, and so arrange them below the work, that after every feed they shall rise
through the work, the eye-pointed needle taking the thread up through the work
and presenting its thread to the hooked needle, in such manner that the hooked
needle, in descending, will draw a loop of thread therefrom down through the
work. The eye-pointed needle, in repeating its ascent, will pass through this loop,
and by a repetition of these motions, the loops of thread will be made to interlock;
thereby producing a series of chain stitches.
In the accompanying drawings, Fig. 1 is a side view of the machine complete-
Fig. 2 is a front end view of the same, and Fig. 3 is a partial plan. of the machine,
showing the clamp for holding and guiding the work. Fig. 4 is a face view of the
eye pointed needle cam.-
-Fig. 5 is an end view of the presser lifting cam-Fig. 6
is an end view of the cam for releasing the pressure of the tension discs on the
thread.
Figures 7 to 12, and 7* to 10*, are diagrams illustrating the formation of the
stitch, Figures 7 to 12 being front views of the positions of the instruments, and
Figures 7 to 10* enlarged side views of the eye-pointed needle and hooked needle,
showing the mode of transference of the loop of thread from one needle to the
other.
Referring now to the general views Figures 1, 2, and 3, A is the base frame,
which carries, in suitable bearings, the horizontal cam shaft B.-C is the eye-
pointed needle, and D the hooked needle which slide in inclined guides formed
in the front end of the framing.-Hinged to the top of the base frame is a
cover E, which overlies a rectangular opening in the base frame, and serves to carry
a spring clamp F and a spring presser G.-It is between the clamp F and presser G
that the needles C and D rise through the work, which is held by means of the
spring clamp F over the throat plate e attached to the under face, and close to the
end of the binged cover E.
The needles (see Fig. 2) are set at an inclination to one another, and cross each
other at a short distance above the face of the work.-Between these needles, and
immediately below the throat plate which supports the work, stands a looper H,
the use of which will be presently explained.
I is the under feed bar, which traverses the work by equal step by step motions.
I have said that the needles C and D incline towards each other, and that after
piercing the work, they cross each other a little above the work. To enable them
to do this, they are set so as to move in different, but closely adjacent vertical

page_text: planes, and the distance apart at which their points strike the work, determines
the length of the stitch, which is visible on the face of the work.-The eye-pointed
needle C receives its motion from a grooved cam c*, cut in 'the band pulley b of
the cam shaft B, and shewn detached at Fig. 4.-A bowl carried by an arm c on a
rock shaft C¹, having its bearings in the main framing, transmits, from the rotation
of the cam c*, a rocking motion to the shaft C¹.-An arm c¹, at the opposite end
of this shaft, is connected by a pivot pin to the stem of the needle C. Thus, the
rocking motion of the shaft C₁ is made to impart the requisite reciprocating motion
to the needle C.-For providing the like motion for the needle D, its stem is fitted
loosely to a long sleeve d, which slides in the needle guides, and is embraced by
collars d d made fast to the needle stem.
Pivotted to the sleeve d is a metal strap piece d³, which surrounds an excentric d*
on the cam shaft B.-The rotation, therefore, of this shaft, imparts a reciprocating
motion to the needle D, as well as to the needle C.-Besides this reciprocating
motion, the needle D receives an axial motion for the purpose of presenting its
hook to the needle C, to take a loop therefrom, and for delivering that loop, when
it has retired below the work, to the looper H.-This movement, which amounts to
a quarter turn, is obtained by the play, in a helical groove formed in the needle
The hinged
stem guide, of a pin or a bowl d³, carried by the stem of the needle.
cover E carrying the throat plate e may be considered as the table for carrying the
work. It is hinged to allow for its vertical adjustment, and to facilitate access to
the parts below. This hinged cover is fitted with a screwed pin e¹, which bears
upon the framing A, and thereby supports the front end of the cover clear of the
framing. By turning this screwed pin, the cover E, which, as I have already said,
serves to support the work, may be raised or lowered with respect to the point from
and when the needles cross each other, and thus the distance apart of the points
when the needles may be regulated and the length of the stitch on the face of the
work determined.-The hinged cover, when it is adjusted vertically of the screw_c¹,
is locked in position by means of a finger piece e², pivotted to the frame.-For
locking the cover, it is only necessary to move this finger piece into contact with
the hinge portion of the cover, when it will act as a stop to the movement of the
cover on its hinge.
The spring clamp F, and the spring presser G, which hold the work down on
the throat plate e, are secured at their rear ends to the hinged cover, which carries
them, by binding screws.-The clamp is formed with a vertical flange standing
transversely of the machine, to form a guide for the work.-Underlying the clamp
and the presser is a transverse pin carried by a finger piece e³, pivotted to the
cover E. By tipping this finger piece e³, its cross pin will lift the spring clamp F,
and presser G; clear of the work. As, however, it is requisite that the presser G
should rise automatically immediately before the feed takes place, the following
provision is made:-9* is a cam on the cam shaft B, and shown detached at Fig. 5.—
Overlying this cam is an arm g carried by a rock shaft G₁ mounted in suitable
bearings in the main framing.-g' is a second arm of this rock shaft, which under-
lies a stud g pendent from the elastic presser G.-As, therefore, the cam shaft B
rotates, it will rock the shaft G¹, and cause the rise of the presser G immediately
before the feed takes place.-I have said that the feed bar I traverses the work
through the machine. This it does, not, as heretofore, in straw plait sewing
machines, by alternate short and long steps, but by successive steps of equal
length, the length of the visible stitch on the face of the work being determined
by adjusting the level of the work with respect to the point at which the inclined
needles cross each other.
The feed bar I is serrated at its upper end, and is pivotted at its lower end to a
rocking arm I, which is jointed to a link rod 13 pivotted to the framing A. Fitted
to this rod is a screw i, which bears upon the base of the framing, and is intended
to adjust the height of the fulcrum of the arm 1', and thereby regulate the bite
of the feed bar on the work. The forward end of the arm I¹ has pivotted to it a

page_text: bar I formed with a slot for the reception of a cam i* on the cam shaft B,
the rotation of which cam not only raises and depresses the bar I, but also gives to
it a lateral reciprocating motion, and thereby provides the requisite four motions
for the feed bar.
A cam projection on the side of the bar Is bears against an arm I which stands
between it and the feed bar. This arm is provided with a cam shaped projection
which bears against the feed bar I, and through it transmits a variable length of
feed (derived from the lateral motion of the bar I³) to the feed bar I, a helical
spring Is, connected at its opposite ends to the feed bar I, and to the pivotted
arın I, serving to hold the bar I in contact with the arm I', and that arm in
contact with the bar I³. The arm I is pivotted adjustably to the framing, a
clamping screw 2, which forms its fulcrum, working in a vertical slot in the
framing. By raising or lowering this screw, the amount of reciprocating motion
of the feed bar may be adjusted to suit the requirements of the work, and thus a
fine or coarse feed may be obtained at pleasure. The rise of the bar 13 under the
action of the cam i*, lifts the arm I, and consequently raises the feed bar into
contact with the work on the throat plate e.-A further rotation of the cam will
then give the bar 13 a lateral motion, and thus ensure the traverse of the work.
Above the opening in the bar I in which the cam i* works, is a cam shaped slot h,
which receives a pin or bowl projecting from the squared stem of the looper H,
which stem slides in a guide lying parallel with, and in a plane close adjacent to
that of the hooked needle D.
This looper H, it will be seen, is a rectangular piece of metal, tapered off to a
point, and adjustably attached to a rectangular bar. Its duty is to enter the loop
carried by the hooked needle D, to open the same for the entrance of the needle C,
and to receive the loop from the needle D, prior to the tightening of the loop by
the descent of the hooked needle.
As the needle D descends with the loop of thread which it has drawn from the
needle C, the looper will, through the reciprocating motion of the bar 1³, rise and
enter the loop, and receive the loop from the hook needle, that needle meanwhile
turning axially in its descent, to clear its hook from the loop.
Before entering more minutely into the action of the sewing instruments, it may
be well to direct attention to the tension apparatus K, by which the loop, trans-
ferred from the needle C to the needle D, is prevented from escaping therefrom,
until the loop opener is ready to receive it. The thread passing from the bobbin
enters between a pair of tension discs, from which it passes through fixed guides
on the framing, to the needle C. A coiled spring k surrounding the rod on which
the tension discs are strung, presses on one of the discs, and causes the thread to
be held firmly between the discs until they are relieved from the pressure of the
spring. Interposed between the disc and the spring is the slotted end of the bell
crauk lever, which is pivotted to the framing, and bears upon a cam k* keyed to
the cam shaft B, and shewn detached at Fig. 6.
Tension is put upon the thread at the time the needle C commences its descent,
and at about the time it is disappearing through the work, the tension is released
by the cam k tipping the bell crank lever I', which forces back the spring k, and
releases the discs from pressure. This release from pressure is maintained until
the needle C has again risen through the work, and is about to commence its
descent.
Referring now to the diagrams, Figs. 7 to 12, it will be seen that the progress of
the stitch, from its commencement to its completion, is fully illustrated, and that
the position of the needles relatively to each other during the greater part of this
operation, is shewn on an enlarged scale at Figures 7* to 10*.-The straw plait is
introduced to the machine face upwards, and the needle C having first entered the
opened loop held by the loop opener H, passes up through the work, carrying
with it the thread which it has taken from the bobbin. When it has risen to its
full height, it returns, opening out a loop (see the front view Fig. 7 and side

page_text: Fig. 7). The needle D rising a little later than the needle C, pierces the plait a
short distance in advance of that needle (this being the length of the stitch, which
will show on the face of the work), and rising as the needle C descends, it
enters the loop of the needle thread as shewn at Figures 8 and 8*.-While rising
to pierce the work, the needle D turns axially, and the barb of the hook, as it
reaches its highest position, faces towards the front of the machine. The point of
the ascending needle D, in passing the needle C, enters between the stem of
that needle and the thread, a recess being made in the stem to facilitate its
entrance.
Figures 9 and 9* shew the needle D at its highest position, and the needle C
descending. At this time.the tension spring k will be free to act, and clamp the
thread on its way from the bobbin; thereby ensuring the tightening of the loop on
the stem of the needle D by the descent of the needle Č (see also Figures 10
and 10*).
Fig. 11 shews the needle D withdrawn from the plait and the loop lying under
its hook. In this descending movement, the hooked needle D reverses its axial
motion until the hook faces the loop opener H, and at this time the tension on the
thread is removed to give the requisite slack to the thread.
As the needle finishes its descent, the loop opener rises, and the feed taking
place at this time, draws the loop held by the hoop of the needle onto the loop
opener H, which opens it, and retains it open for the entrance of the needle C.-
The rise of this needle secures the loop by carrying through it a new loop, as
represented at Fig. 12, and the needle D recommencing its upward movement,
releases the loop from its hook. The needle C then pierces the plait for a new
stitch, and in making this upward movement, draws the last formed loop off the
loop opener.
The point at which the needle C now pierces the work, is at a
distance from the last perforation of the needle C, determined by the amount of
the feed motion, this being the length of the longest stitch on the underside of the
plait.
During the next descent of the needle C, the needle D will take the new loop
from the needle C, as before, and in drawing it down through the work, will pull
the previous loop tight up to the underside of the plait, as it slips off the point of
the descending needle C, thus completing the stitch shewn by the enlarged views
figures 13 and 14, which represent respectively the stitch as seen on the upper and
under side of the work.
In sewing straw plait, which requires turning in curves of small radius, to avoid
injury to the delicate fabric, it may be necessary to use a feeding device which
moves clear of the work, immediately on the completion of the feed.—To secure
this result, I propose to modify the feeding device above described, in the manner
shewn in side elevation at fig. 15, and in front view at fig. 16.-In these figures
the feed bar I is formed in two parts I and I*, the latter, which carries the pro-
pelling teeth, being pivotted to the upper end of the bar I, which bar is, in this
case, pivotted at its lower end to the framing. A rod I** connects the bar I to the
bar I³, which transmits, through that rod, the longitudinal reciprocating motion to
the toothed bar I*.-This bar rests on a strut I*** pivotted to the rocking arm I¹,
and a pivotted guide, or equivalent contrivance, serves to keep this strut in
position. When the bar Is is depressed by its cam, as before explained and the
arm 1 is thereby rocked, the strut 1*** will be caused to lift and hold the feed bar
in contact with the work. So soon, however, as the feed is completed, the strut
and the feed bar will drop, leaving the work free to be manipulated as desired.-
When this arrangement is employed, the loop opener H is actuated by a cam
h*
mounted on the cam shaft, and embraced by projections carried by the looper.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
1st The arrangement of machinery above describel for sewing straw plait.

page_text: 2ndly In a straw plait sewing machine provided with a looper, the use of an eye
pointed needle and a hooked needle set at an incline to each other, and crossing
each other above the work, to effect the transfer of the loop from one needle to the
other, in combination with a device for giving an uniform feed to the work.
3rd The arrangement of adjustable hinged cover for carrying the work, and
providing for the regulation of the length of the stitch on the face of the work.