IMPROVEMENTS IN THE MANUFACTURE OF BOBBIN NET OR TWIST LACE
Year: 1883

page_text: LETTERS PATENT to William Birks Junior of the Town and County of
the Town of Nottingham for an Invention of IMPROVEMENTS IN THE
MANUFACTURE OF BOBBIN NET OR TWIST LACE.
PROVISIONAL SPECIFICATION left by the said William Birks, Junior, at
the Office of the Commissioners of Patents on the 1st November 1883.
WILLIAM BIRKS Junior of the Town and County of the Town of Nottingham
IMPROVEMENTS IN THE MANUFACTURE OF BOBBIN NET OR TWIST LACE
My Invention consists of a method of manufacturing by means of bottom bars
and stump bars a fabric which has never, hitherto, been made with bottom
bars and stump bars in connection with bobbin net or twist lace machines.
Hitherto when twist lace has been mado by bottom bars only one, or at the most
two, warp threads have been used to each bobbin thread.
In the production of lace according to my improvements I employ three, four, five
or more warp threads to each bobbin thread, whereby I am enabled to produce a very
fine and close weaving or fining by passing each of the said warp threads under
and over the particular bobbin thread which is for the time working with the
aforesaid warp threads. A certain number of these warp threads are operated by
bottom bars in such a manner as to enable me to produce an extensive pattern and
a lace of great width with a variety of nets and openworks in connection with the
before mentioned fine and close weaving.
The advantage gained in machines of coarse gauge or working half-gauge by my
improvements is obvious. For instance on a machine of five point gauge working
with three warp threads to each bobbin thread I produce a fifteen point weaving.
With four threads to each bobbin thread a five point machine would. produce
twenty point weaving, thus showing a gain of five points in gaugo for each
additional warp thread. Another advantage of my improvements is that by using
a machine of coarse gauge for carrying out my Invention I am able to embroider
the fine and close weaving with a very thick thread or cord thus producing a lace
closely resembling that which has hitherto been embroidered by hand or by a
sewing machine and I produce such lace at a much cheaper rate.

page_text: To attain these results I employ two or more perforated stump bars or their
equivalents each perforation being one gait in length. These stump bars or their
equivalents are operated by the top bar Jacquard which I cause to act twice only
in every four motions of the machine instead of at each motion as is usual in
making ordinary laco.
I cause the bottom Jacquard to act once only in every four motions of the
machine. By this arrangement (or action) I am enabled to dispense with half of
the cards for the Top bar Jacquard and three fourths of the cards of the bottom
bar Jacquard.
I will now describe the action of the various parts which produce the fine and
close weaving or fining. I take the case of three warp threads to each bobbin
thread as the simplest illustration of my process.
Two thirds of the number of these threads are put upon one warp beam and are
threaded through two top bars one thread to each gait and half of the threads
through each of the two bars. These two full bars aro connected with two levers
which are operated by two cams fixed on the shaft of tho Botton bar Jacquard.
I place the remaining one third of the threads on another beam and these threads
are passed through independent bottom bars and then through the perforations of
the before mentioned two one-gait stump bars. These threads when passed through
the stump-bars, constitute a single warp, or one warp thread to each bobbin thread.
The threads on this beam requiro greater tension than those on the first mentioned
beam, because they have to draw sufficient material from the bobbins to form tho
weft for the weaving of the other threads. The two full bars above mentioned
are placed behind the stump bars.
At the first motion of the machine the carriages being in the front combs, the
two stump bars move one gait to the right hand during which motion all the
bottom bars are stationary at tho left hand. At the second motion of the machino
the stump-bars remain in the position just described, and the bottom bars are
moved to the right hand, thus placing those threads which are passed through the
stump-bars up two gaits to the right, cách thread having passed under the first
bobbin thread and over the second.
At this second motion the first full bar (counting from the back) is moved one
gait to the right by means of a cam (N° 1) which is fixed on the shaft of the
bottom bar Jacquard.
At the third motion of the machine the bottom bars return to their position on
the left of the machine. The stump bars remain as last described, and the full
bar N° 1 moves one gait to the left. The full bar N° 2 is simultaneously moved
one gait to the right by the cam N° 2 which is fixed on the shaft of the bottom
Jacquard
At the fourth motion of the machine the stump-bars fall one gait to the left,
and the full bar N° 2 also falls one gait to the left, thus placing all the bars and
the threads in a position to repeat the movements described above, and by such
repeated movements are produced the fine and close weaving or fining before
mentioned.
When it is desired to produce the fine and close weaving in pattern on a light
net or ground-work a larger number of warp threads are operated by the bottom
bars in such a manner as to cause the threads to be loose or to float on the surface
of the fabric when they are not required for the weaving and such loose warp
threads are cut away when the lace is "finished," that is to say whon it is prepared
for sale which operation is performed after the removal of the lace from the
machine.
Certain portions of these threads can be acted upon for making a lighter
character of weaving or fining to give variety or light and shade to the
pattern.
In this case the bottom bar Jacquard acts at every motion
Pickers may be used if desired for floating theso threads instead of actuating
extra threads by the bottom bars,

page_text: When working with four warp threads to each bobbin thread, I use three full
top bars, that is bars pierced at every gait, in combination with the stump bars.
The first and third of these three bars are operated and made to operate in the
same manner.
When working with five warp threads to each bobbin thread I use four full top
bars in combination with the stump bars, the first and third working alike, and the
second and. fourth working alike.
If I use half-bars (that is bars perforated every alternate gait) instead of full
bars I require double the quantity of bars.
I would here remark that the above description of lace can bo produced by the '
aid of top bars but not so advantageously as by the incans above described, and
I would also remark that the movements of the bars can be varied without
departing from the peculiar character of my Invention. In applying my invention
to the curtain machine I operato the threads by means of top bars only. When
working three warp threads to each bobbin thread I use three full bars.
At the first motion of the machine the front bar moves one gait to the right
hand. At the second motion this bar moves one more gait to the right, and at
this motion the back bar moves one gait to the right. At the third motion the
back and front bars fall one gait to the left, whilst the centre bar of the three rises
one gait to the right. At the fourth motion the front bar falls one more gait to the
left and the centre bar also falls one gait to the left.
At the second motion of the machine such of the Jacks or Pickers as are selected
are brought through the threads and are kept in that position during the third
motion when they are taken back again.
The four motions just described are the means I adopt in carrying out my
invention when I desire to float the threads.
When it is not required to float the threads the bars are operated in the following
manner: At the first motion of the machine, when the carriages are in the front,
the back bar is moved one gait to the left and the centre bar is moved one gait to
the left. At the second motion of the machine, the back bar is moved one gait
to the right. At the third motion of the machine the back bar rises one more gait
to tho right, whilst at the same time the front bar rises ono gait to the right. At
the fourth motion of the machine, the back and front bars both fall ono gait to tho
left and the centre bar rises one gait to the right.
The pickers are selected and brought forward for the third motion and are taken
out again after the completion of the fourth motion.
In this case the pickers are made to act on the threads in the back bar only.
In case I require to float certain threads and to uso others in the weaving for the
purpose of producing certain effects of light and shade I select certain Jacks or
Pickers as required by the design and bring them far enough forward to hold the
threads in the front bar and thereby produce the desired effect.

page_text: SPECIFICATION in pursuance of the conditions of the Lettera Patent filed
by the said William Birks, Junior, in the Patent Office on the 1st May 1884.
WILLIAM BIRKS Junior of the Town and County of the Town of Nottingham
"IMPROVEMENTS IN THE MANUFACTURE OF BOBBIN NET OR TWIST LACE
"
My Invention consists of a method of manufacturing by means of bottom bars
and stump bars a fabric which has never, hitherto, been made with bottom bars
and stump bars in connection with bobbin-net or twist-lace machines.
Hitherto when twist lace has been made by bottom bars only one, or at the most
two, warp threads have been used to each bobbin thread. In the production of
lace according to my improvements I employ three, four, fivo or more warp threads
to each bobbin thread, whereby I am enabled to produce a very fine and close
weaving or fining by passing each of the said warp threads under and over tho
particular bobbin thread which is for the time working with the aforesaid warp
threads. A certain number of these warp threads are operated by bottom bars in
such a manner as to enable me to produce an extensive pattern and a lace of great
width with a variety of nets and openworks in connection with the before
mentioned fine and close weaving.
The advantage gained in machines of coarse gauge or working half-gauge by
my improvements is obvious. For instance on a machine of five point gauge
working with three warp threads to each bobbin thread I produce a fifteen point
weaving. With four threads to each bobbin thread a five point machine, would
produce twenty point weaving, thus showing a gain of five points in gauge for
each additional warp thread. Another advantage of my improvements is that by
using a machine of coarse gauge for carrying out my Invention I am able to
embroider the fine and close weaving with a very thick thread or cord thus
producing a lace closely resembling that which has hitherto been embroidered by
hand or by a sewing-machine and I produce such lace at a much cheaper rate.
To attain these results I employ two or more perforated stump-bars or their
equivalents each perforation being one gait in length. These stump bars or their
equivalents are operated by the top-bar Jacquard which I cause to act twice only
in every four motions of the machine instead of at each motion as is usual in
making ordinary lace. I cause the bottom Jacquard to act once only in every four
motions of the machine. By this arrangement (or action) I am enabled to dispense
with half of the cards for the top bar Jacquard and three fourths of the cards of
the bottom bar Jacquard.
AVI
I will now describe the action of the various parts which produce the fine and
close weaving or fining. I take the case of threo warp threads to each bobbin
thread as the simplest illustration of my process. Two-thirds of the number of
these threads are put upon one warp beam and are threaded through two top-bars
one thread to each gait and half of the threads through each of the two bars.
These two full-bars are connected with two levers which are operated by two cams
fixed on the shaft of the bottom bar Jacquard. I place the remaining one-third of
the threads on another beam and these threads are passed through independont
bottom bars and then through the perforations of the before mentioned two one-gait
stump bars. These threads, when passed through the stump-bars constitute a
single warp or one warp thread to each bobbin thread. The threads on this beam
require greater tension than those on the first mentioned beam because they have
to draw sufficient material from the bobbins to form the weft for the weaving of
the other threads. The two full-bars above mentioned are placed behind the
stump-bars.

page_text: By the way motion of the machine, the carriages being in the front combs, the
two stump bars move one gait to the right hand during which motion all the
bottom bars are stationary at the left hand. At the second motion of the machine
the stump-bars remain in the position just described and the bottom bars are
moved to the right hand thus placing those threads which are passed through the
stump-bars up two gaits to the right, each thread baving passed under the first
bobbin thread and over the second. At this second motion the first full-bar
(counting from the back) is moved ono gait to the right by means of a cam (N° 1)
which is fixed on the shaft of the bottom-bar Jacquard.
At the third motion of the machine the bottom bars return to their position on
the left of the machine. The stump-bars remain as last described and the full
bar No 1 moves one gait to the left. The full bar N° 2 is simultaneously moved
one gait to the right by the cam N° 2 which is fixed on the shaft of the bottom
Jacquards.
At the fourth motion of the machine the stump-bars fall ono gait to the left and
the full bar No 2 also falls one gait to the left, thus placing all the bars and the
threads in a position to repeat the movements described above and by such repeated
movements are produced the fine and close weaving or fining before mentioned.
When it is desired to produce the fine and close weaving in pattern on a light
net or groundwork a larger number of warp threads are operated by the bottom
bars in such a manner as to cause the threads to be loose or to float on the surface
of the fabric when they are not required for the weaving and such loose warp
threads are cut away when the lace is "finished," that is to say when it is prepared
for sale which operation is performed after the removal of the lace from the
machine.
Certain portions of these threads can be acted upon for making a lighter
character of weaving or fining to give variety or light and shade to the pattern.
In this case the bottom bar Jacquard acts at every motion.
Pickers may be used if desired for floating these threads instead of actuating
extra threads by the bottom bars.
When working with four warp threads to each bobbin thread I use three full
top bars, that is bars pierced at every gait, in combination with the stump bars.
The first and third of these three bars are operated and made to operate in the
same manner.
When working with five warp threads to each bobbin thread I use four full top
bars in combination with the stump bars, the first and third working alike and the
second and fourth working alike.
If I use half bars (that is, bars perforated every alternate gait) instead of full
bars I require double the quantity of bars.
I would here remark that the above description of lace can be produced by tho
aid of top bars but not so advantageously as by the means above described and
I would also remark that the movements of the bars can be varied without
departing from the peculiar character of my Invention. In applying my invention
to the curtain machine I operate the threads by means of top bars only. When
working three warp threads to each bobbin thread I use three full bars.
At the first motion of the machine the front bar moves ono gait to the right
hand. At the second motion this bar moves one more gait to the right and at this
motion the back bar moves one gait to the right. At the third motion the back
and front bars fall one gait to the left whilst the centre bar of the three rises one
gait to the right. At the fourth motion the front bar falls one more gait to the
left and the centre bar also falls one gait to the left.
At the second motion of the machine such of the jacks or pickers as are selected
are brought through the threads and are kept in that position during the third
notion when they are taken back again. The four motions just described are tho
means I adopt in carrying out my invention when I desire to float tho threads.
In floating the threads I use a double-lift Jacquard by means of which I bring

page_text: the selected pickers through the threads in the first, second or third bars as may
be desired.
When it is not required to float the threads the bars are operated in the following
manner at the first motion of the machine when the carriages are in the front
the back bar is moved one gait to the left and the centre bar is moved one gait to
the left. At tho second motion of the machine the back bar is moved one gait to
the right. At the third motion of the machine the back bar rises one moro gait
to the right whilst at the same time the front bar rises one gait to the right. At
the fourth motion of the machine the back and front bars both fall one gait to the
left and the centro bar rises one gait to the right.
The pickers are selected and brought forward for the third motion and are taken
out again after the completion of the fourth motion. In this case the pickers are
mado to act on the threads in the back bar only.
In case I requiro to float certain threads and to use others in the weaving for the
purpose of producing certain effects of light and shade I select certain jacks or
pickers as required by the design and bring them far enough forward to hold the
threads in the front bar and thereby produce the desired effect.
Having thus described the nature of the said Invention and the mode in which
the same is carried into effect I would have it understood that what I claim is the
improvements in the manufacture of bobbin net or twist lace substantially as herein
described.
In witness whereof I the said William Birks Junior have hereunto set my hand
and seal this Thirtieth day of April in the year of our Lord One thousand eight
hundred and eighty four.