Improvements in Machinery and Appliances for the Manufacture of Twist Lace and Bobbin Net.
Year: 1889

page_text: PROVISIONAL SPECIFICATION.
Improvements in Machinery and Appliances for the Manufacture of
Twist Lace and Bobbin Net.
We, Joux CROPPER, and HENRY SMITH CROPPER, Engineers, both of Great
Alfred Street, and WILLIAM BIRKS, Lace Manufacturer, all of the Town and County
of the Town of Nottingham, do hereby declare the nature of this invention to be as
follows:-
Our invention has for its object the manufacture of plain bobbin nets, lace curtains,
and other descriptions of plain or figured laces, on twist lace machines of a much
simpler construction and capable of working at much higher speed, than any twist lace
or bobbin net machines now known to be in operation.
Our invention is an improvement upon an invention which was patented in the
year 1854 by James Redgate and others, the Specification of which is numbered 2630.
That invention was used only for the manufacture of a twist lace known as Mechlin
net, and not for any description of fancy or figured lace. Nor was the invention
practical for the production of nets of fine gauges. In consequence of the partial
impracticability of the invention of Redgate and others here referred to; the invention
was abandoned about thirty years ago. In all twist lace machines, with the exception
of that of Redgate and others already referred to, it is necessary to take up the
twist and the meshes as they are formed by means of bars of back and front points
operating at alternate motions in a manner quite familiar to all lace-makers. The
movements of these two bars of points require much carefully fitted mechanical
apparatus, such as revolving shafts with their requisite gearing, point-bar cams, dipping
cams, knocking out cams, links, levers &c. Amongst other disadvantages pertaining
to the use of points is the difficulty of driving all this apparatus at a high speed
without imparting a tremulous movement to the points and thereby reducing their
efficiency.
By our invention we are able to dispense with the use of points and all their
attendant mechanism, which not only simplifies the machine but enables us to run it
at a greatly increased speed. The method by which we accomplish this is to use a
carriage differing in form from any now in use.
The carriage we use is triangular and in working its apex is as near the centre-line
of the machine as is practicable without running a risk of coming into contact with
the lower edge of the facing bar. The essential difference between this carriage
and that used by Redgate and others in the invention previously referred to is that
whereas the breast of their carriage was made in a straight line from base to apex we
make ours slightly concave, the effect of which is that in the passage of the carriages
through the warp threads the concavity of the breast of the carriage causes the twist
to run up as safely and effectively as if bars of points were being used.
In order to bring the bobbin thread to the centre of the carriage, or as nearly to
the centre as may be necessary, we adopt one or two methods; we either pierce the
thread hole vertically through the apex of the carriage, or through the carriage flat-
wise as near the apex as is convenient. In this latter case we cut a narrow threadgate
sufficiently deep or chamfer the surface of the carriage above the thread hole so as
to make the bobbin thread stand in the centre of the carriage. Instead of feather-
edging the carriages alike on each edge as is usually done we make a broad flat
chamfer on one edge of one side of the carriage and on the opposite edge on the
other side of the carriage, in such a manner as that when a carriage stands in the
combs the front edge will be chamfered on the right hand side of the carriage and
the back edge on the left, or vice versa as the case may be.
By this form and arrangement of carriage the warp threads readily slide up the
breasts of the carriages without check or hindrance taking up the twists. fining or

page_text: other weaving to the spot where the formation of the complete mesh is perfected
namely immediately above the apex of the carriage.
The guide bars are operated by any of the well known methods already in general
use. When the guides have been traversed to throw the threads which they operate
over one, two or more carriages as required by the mesh or pattern the movement
of the carriages from back to front or from front to back causes the carriages to
take up such threads to the spot where the weaving is completed without the aid
and use of points or similar apparatus.
.6
"
By means of the improvements already described we are able to drive machines
made according to our invention at 300 or 400 or more motions per minute which
is a far higher speed than has hitherto been attained in the production of ornamental
twist-lace.
It will be obvious to those who are familiar with the working of a twist lace
machine that a different arrangement of Jacquard apparatus than that ordinarily
employed would be required to keep pace with the increased speed attained by our
invention. We accomplish the desired object by using two Jacquards where one
is now used, which Jacquards are brought into action alternately.
One Jacquard operates the selectors at the first and second movements of the
carriages, and the other at their third and fourth movements and so on in regular
succession, thus having four motions for the required selection of threads instead of
two motions as would be the case were one Jacquard only used. We use two strings
to each selector, one string being attached to the proper hook or needle in one
Jacquard, and the second string to the corresponding hook of the other Jacquard.
This arrangement does not necessitate the use of additional cards.
We divide the pack of cards required for any given pattern into two parts putting
those numbered with the odd numbers on one Jacquard and those with the even
numbers on the other.
It will be seen from this description that by using two Jacquards instead of one
and in the manner indicated we are able to operate the pickers or selectors at a speed
equal to the speed of the lace producing machine.
In making nets and laces of fine gauges. bottom bars and stump bars may be used
in the place of selectors, the operation of the Jacquard being distributed over four
motions in the manner already described, either by means of a Jacquard with double
cylinders or by what is known as a double-lift Jacquard.
Dated December 17th 1880
COMPLETE SPECIFICATION.
Improvements in Machinery and Appliances for the Manufacture of
Twist Lace and Bobbin Net.
We, JoHN CROPPER and HENRY SMITH CROPPER, Engineers, both of Great Alfred
Street, and WILLIAM BIRKS, Lace Manufacturer, all of the Town and County of the
Town of Nottingham, 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:-
Our invention has for its object the manufacture of plain bobbin nets, lace curtains,
and other descriptions of plain or figured laces on twist lace machines of a much
simpler construction and capable of working at much higher speed than any twist
lace or bobbin net machines now known to be in operation.
It has before been proposed to dispense with the points and point bars together with
the mechanism for operating the same as usually employed for taking up and

page_text: completing the work, and to complete the work by the aid of a specially constructed
carriage, and our invention is an improvement on such proposed construction of
machine.
In all twist lace machines with the exception of that already referred to, it is
necessary to take up the twist and the meshes as they are formed by means of bars
of back and front points operating at alternate motions in a manner quite familiar to
all lace makers. The movements of these two bars of points require much carefully
fitted mechanical apparatus, such as revolving shafts with their requisite gearing,
point bar cams, dipping cams, knocking out cams, links, levers, &c.
Amongst otherdisadvantages pertainingto the use ofpoints is thedifficulty of driving
all this apparatus at a high speed without imparting a tremulous movement to the
points and thereby reducing their efficiency.
By our invention we are able to dispense with the use of points and all their
attendant mechanism, which not only simplifies the machine but enables us to run it
at a greatly increased speed.
Figure 1 is a sectional end view of a lace machine and its connected Jacquard
apparatus as arranged for carrying our invention into effect.
Figure 2 is a face view and Figure is a cross section on the line 1, 1, of Figure 2
of one of the improved carriages.
Figure is a face view of the feeding cam, that is to say, the cam which draws the
yarn from the spools.
Figure 5 is a face view of the cam for operating the selector working bar.
Figure is a face view of the lifting cam, or cam which operates the Jacquard
grid, and
Figure 7 is a face view of the Jacquard cylinder cam, that is to say, the cam which
presses the Jacquard cylinder up to the needles and thereby selects those which the
pattern requires.
is the end standard or frame of the lace machine, is a crank fixed on the driving
shaft and which imparts motion by the link to the elbow lever 2 which by the
links and levers operates the rocking shafts 6, and these latter by the levers 6
and links communicate the desired motions to the catch bars c, which latter by acting
upon the nibs of the carriages d, give motion to the latter. e is a carriage bobbin,
ff, are the combs of the circle, gare guide bar guides, h, h, represent the selectors,
i is the axle for carrying the selector working bar which swings the selectors into
and out of the threads. is the warp beam. is the facing bar, m, m¹ are work
receiving rollers or net beams. n is the shaft which carries the four cams shown at
Figures 4, 5, 6 and 7; is a standard to carry the Jacquards, is a Jacquard
machine, 4, 7, are spool boards, r. r, are strings connecting the selectors / with the
Jacquards.
The method by which we carry our invention into effect is to use a carriage d
differing in form from any now in use. The carriage we use is triangular and in
working its apex is as near the centre line of the machine as is practicable without
running a risk of coming into contact with the lower edge of the facing bar 7. The
essential difference between this carriage and that used in the invention previously
referred to, is that whereas the breast of the former carriage was made in a straight
line from base to apex, we make ours slightly concave as shown at Figure 2, the effect
of which is that in the passage of the carriages & through the warp threads, the
concavity of the breast of the carriage causes the twist to run up as safely and
effectively as if bars of points were being used.
In order to bring the bobbin thread to the centre of motion of the carriage, or as
nearly to the centre as may be necessary, we adopt one of two methods; we either
pierce the thread hole vertically through the apex of the carriage, or through the
carriage flat-wise, as shown at Figure 2. as near the apex as is convenient..
In this latter case we cut a narrow thread gate d³ sufficiently deep, or chamfer the
surface of the carriage above the thread hole, so as to make the bobbin thread stand
in the centre of the carriage.

page_text: Instead of feather edging the carriages alike on each edge as is usually done, we
make a broad flat chamfer d' on one edge of one side of the carriage and on the
opposite edge of the other side of the carriage, as shown at Figures 2 and 3, in such
a manner as that when a carriage stands in the combs, the front edge will be chamfered
on the right hand side of the carriage and the back edge on the left or vice versa as
the case may be. By this form and arrangement of carriage, the warp threads readily
slide up the breasts of the carriages without check or hindrance, taking up the twist,
fining, or other weaving, to the spot where the formation of the complete mesh is
perfected, namely immediately above the apex of the carriage.
The guide bars are operated by any of the well known methods already in general
use. When the guides have been traversed to throw the threads which they operate
over one, two, or more carriages as required by the mesh or pattern, the movement
of the carriages d from back to front or from front to back causes the carriages to
take up" such threads to the spot where the weaving is completed without the aid
and use of points or similar apparatus.
By means of the improvements already described we are able to drive machines
made according to our invention at 300 or 400 or more motions per minute, which is
a far higher speed than has hitherto been attained in the production of ornamental
twist lace. It will be obvious to those who are familiar with the working of a twist
lace machine that a different arrangement of Jacquard apparatus than that ordinarily
employed would be required to keep pace safely with the increased speed altained by
our invention. We accomplish the desired object by using two Jacquards where one
is now used, which Jacquards are brought into action alternately. The shaft which
operates them revolves once while the carriages make four motions, whereas on the
old system it revolves once for every two motions of the carriages. One Jacquard
operates the selectors at the first and second movements of the carriages and the other
at their third and fourth movements, and so on in regular succession, thus having
four motions for the required selection of threads instead of two motions as would be
the case were one Jacquard only used. We use two strings to each selector, one string
being attached to the proper hook or needle in one Jacquard, and the second string
to the corresponding hook of the other Jacquard, by which arrangement each Jacquard
makes half the necessary selections and the second Jacquard alternates with the first.
This arrangement does not necessitate the use of additional cards. We divide the
pack of cards required for any given pattern, and which are punched and numbered
in the usual way, into two parts, putting those numbered with the odd numbers on
one Jacquard, and those with the even numbers on the other. It will be scen
from this description that by using two Jacquards instead of one, and in the manner
indicated, we are able to operate the pickers or selectors at a speed equal to the
speed of the lace producing machine, while the Jacquards are operated at a perfectly
safe speed. the operations thereof being performed so leisurely as to ensure that
exactitude and accuracy without which the increased speed of "our improved lave
machine would be of little or no value.
In making nets and laces of fine gauges, bottom bars and stump bars may be used
in the place of selectors, the operation of the Jacquard being distributed over four
motions in the manner already described. either by means of a Jacquard with double
cylinders or by what is known as a double lift Jacquard.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. In machinery and appliances for the manufacture of twist lace and bobbin net,
the novel construction of triangular carriages, in which the breasts are slightly concave
and are chamfered on one edge of one side and on the opposite edge of the other
side, substantially as herein shown and described and for the purpose stated.
2. In machinery and appliances for the manufacture of twist lare and bobbin net,
the employment of triangular carriages constructed and operating as herein described,

page_text: in combination with two Jacquards, or with a double lift Jacquard, one of which
operates the selectors at the first and second movements of the carriages and the
other at their third and fourth movements, and so on, substantially as herein described
and for the purpose stated.
Dated this 26th day of August 1890.
JOHN CROPPER.
H. S. CROPPER.
WM. BIRKS.
By Harris & Mills,
23, Southampton Buildings, London, Agents.