close

Вход

Забыли?

вход по аккаунту

?

код для вставки
J. J. SCHILTHUIS EI’AL.
2,4}15/764
TENSION CONTROL
Filed Oct. 7, 1942
3 Sheets-Sheet 1
‘@3310 ‘M, YMMV.
J. J. SCHILTHUHS ETAL
TENSION CONTROL
Filed 06%. 7, 1942
a $0
4r
‘AW/73 04' TIME
100
@949
6'0
0
5
3 Sheets-Sheet 3
§atented Feb. ll, 19’?
was“! also.
2,415,764
TENSIGN (JONTROL
Jan J. Schilthuis, Enka, and Arthur L. Jackson,
West Asheville, N. (3., assignors to American
Enka Corporation, Enka, N. 0., a corporation of
Delaware
Application October 7, 1942, Serial No. 461,162
I 5 Claims.
1
((31. 242-45)
.
2
This invention relates to the manufacture of
threads of synthetic origin and is more particu
larly concerned with the bobbin spinning of rayon
marily to the fact that the increases in diameter
thread of superior quality,
In the bobbin spinning of rayon, the customary
procedure is to collect the freshly formed thread
thread or spinning time. Moreover, the rate of
on a rotating bobbin after its issuance from the
spin bath, one or more godets being interposed
in the path of the thread to impart to the thread
such stretch as may be desired. Then, at (the
end of the spinning period, the wound body of
thread on the bobbin is subjected to such after
treatment as may be necessary or desirable in
any particular instance.
of the package being wound on the bobbin are
not proportional to the increases in volume of
change of speed of a commercial variable speed
unit is different from the change of diameter of
the thread package and is therefore not a sim
ple function thereof. This means that a decel
eration of the rotational bobbin speed which is
uniform with time produces a non-uniform wind
ing speed and that conversely a uniform wind
ing speed can only be obtained by a predeter
mined non-uniform deceleration of the rota
tional speed. One very common type of variable
During the spinning period the thread is with-
speed apparatus used for this purpose is the
drawn from the spin’ bath by a driven godet and
led either directly to the collecting bobbin or to
another godet propelled at a greater speed. than
» Reeves drive involving pairs of cones connected
the ?rst so as to cause stretching of the thread.
one end of the transmission toward one another
by a belt, the variable delivery speed being pro
duced by gradually moving the pair of cones ‘in
The denier of the thread is controlled by corre 20 and in the other end away from each other so
lation of the spinning pump speed and the take
that the cone diameters contacted by the belt
up speed of the bobbin package. The last godet
result in a change in delivery speed. Usually the
in the path of thread travel between the spin
cones are shifted by rotation of a screw and un
bath and the collecting bobbin serves to regulate
der such circumstances, for every unit of time
closely the tension applied to the thread as it 26 there will be a proportionate displacement of the
is delivered to the bobbin, and for that reason,
cones resulting in a reduction in rotary speed of
is generally propelled at a constant speed. How
the bobbin.
‘
ever, during the spinning operation the package
In winding packages of freshly spun thread, it
increases in thickness so that the peripheral or
has been customary to drive the bobbin at a
take-up speed thereof would normally increase.
Since the spinneret delivery and the speed of the
godet from which the thread is drawn onto the ~
bobbin are substantially constant, this increase
in the peripheral speed of the bobbin package
would have the effect of progressively decreasing 35
uniformly, or substantially uniformly decelerat
ing rotational speed. Such conventional pack
ages were, for all practical purposes, wound at a
sufficiently constant peripheral speed. However,
the peripheral speeds and therefore the tensions
during the winding period were not properly
the denier of the thread and at the same time
increasing winding tension throughout the wind- .
controlled and were not constant to the extent
now and has long been customary to gradually
reduce the rotational speed of the bobbin 1
throughout the winding period so that the wind
ing speeds at the beginning and the end thereof
immediately apparent that in winding such pack.
of following a straight line when plotted against
ing period, if no compensation were introduced.
units of time. (Unexpectedly, as a more uniform‘
It has long been recognized that this condition,
deceleration is imparted to the bobbin, a more
if permit-ted, would be exceedingly harmful to 40 variable peripheral speed is imparted to the
the thread as denier variations would result and
thread package.) In the interest of economy, the
might even effect tensions of su?icient magnitude
rayon industry has commenced the production of
to cause ?lament breakage. Accordingly, it is
thick packages, e. g., packages having a diameter
are approximately the same.
of more than 150% of the empty bobbin. It was
ages of increased thread length, the variations
in peripheral or winding speeds became so pro~
nounced that prohibitive tensions were created
Although the beginning and end speeds of the
in the packages, thereby limiting the amount
bobbins have been controllable, the intermediate 50 of thread that could be feasibly wound on the
speeds have followed the characteristics of the
bobbins. Incidentally, such wide variations in
particular variable speed unit employed. These
peripheral speeds were not predictable because
characteristics are not such that the peripheral
the deceleration of a bobbin driven by the con
speeds of the package will remain constant
ventional speed change mechanisms was of the
throughout the winding period. This is due pri- 55 same order or just as constant for packages hav
2,415,764
4
3
ing a diameter greater than 150% of the empty
bobbin, as conventional packages of smaller di
ameters.
Therefore, although it has been found that ap
paratus of the type described may be used with
the winding period by apparatus constructed ac
a fair degree of success where the ultimately
wound thread package is of a diameter less than
tion;
as well as the general pattern of the cross wind.
of our invention to employ any type of traverse
operating mechanism, the one shown has been
cording to this invention;
_
Figure 2 is a graph in which the rotational
speeds of a bobbin are plotted against units of
time to illustrate various rates of speed reduc
Figure 3 is a graph in which the peripheral
speeds of a bobbin package are plotted against
150% of the diameter of the empty bobbin, it is
evident that the reduction of bobbin speed in
units of time, the illustration serving to afford a
substantially equal decrements per'unit of time,
basis for comparing different types of rotational
even for conventional packages, is not entirely
speed control mechanisms; and
_
Figure 4 is a graph in which bobbin package
satisfactory. As stated before, this is particularly
evident in the winding of packages of increased
diameters are plotted against units of time to il
size, thickness and weight, which practice has
lustrate the effect of the speed control arrange
been made possible by recent developments. In 15 ment constituting a part of this invention in the
preparation of right cylindrical packages and cy
winding these heavier, thicker and la rger
lindrical packages having frusto conical ends.
packages with conventional speed and tension
Referring now to Figure 1, it can be seen that
control it has been found that soft and tight por
a portion of a bobbin spinning machine is there
tions occur in the package, the former being
squeezed out to distort the ends of the package 20 in illustrated. Although it is within the purview
This occurs more particularly with packages built
with square ends. This tendency has resulted in
the production of an acid yarn package of poor
found to be particularly suitable. As illustrated,
both the bobbins and the traverse mechanism are
permeability and non-uniform washability and
driven from a shaft 10 which is propelled through.
has tended in some measure to nullify the effects
gear I i from the variable side of a variable speed
of improved methods and apparatus for pattern
transmission generally indicated at I2. At spaced
points along the length of shaft Ill gears i3 are
control. It has also been found that the physical
properties of the thread have been detrimentally
provided, corresponding in number to the num
influenced by variations in stretch applied during 30 ber of bobbins with which the apparatus is
equipped. In the interest of convenience of ii
the winding resulting in variations in tensile
strength. Variations in winding speed have also
lustration, only a single bobbin is shown in Fig
ure 1. This bobbin is designated by the numeral
resulted in undesirable variations in dye rate and
denier.
'
14 and is mounted on a bobbin holder of conven
It is therefore an object of this invention to 35 tional form which is attached to a drive shaft 15
overcome the difficulties heretofore encountered
which shaft carries also a gear I6 meshing with
and driven by gear l3. Since it is contemplated
that all of the gears l3—i6 be respectively of the
rayon onto a collecting bobbin under accurately
controlled tension regardless of the thickness or
same size, it is evident that all of the bobbins 14
con?guration of the package formed, the duration 40 with which the machine is equipped will be driven
throughout the winding period at a speed direct
of the winding-on period, or the degree of stretch
ly proportional to the speed of shaft ID. Shaft
to which the thread may be subjected before
H1, in addition to gears l3, carries a gear I‘! which
collection.
Another object of this invention is to provide
meshes with gear 18 which, in turn, drives a gear
a control means for a variable speed drive which
19 keyed to a shaft 20. Shaft 20, at its extremity
will cause the rotational speed of the bobbins to
remote from gear i9, carries an additional gear
and to provide for the winding of freshly spun
decrease at a rate which is a simple function of
2| which meshes with and drives a gear 22 thus
substantially a simple function of the rate of in
imparting rotation to a shaft 23. Mounted on
crease of package build~up on the bobbins where
shaft 23 "is av cam 24 provided with a peripheral
by the thread constituting the package is free 50 groove adapted to receive a follower. This fol
from variations in denier and dye rate and is of
lower extends inwardly from a bar 25 and is suit
uniform tensile strength throughout its length.
ably supported or guided so that reciprocation
.-It is a further object of this invention to pro
of the latter is brought about by rotation of cam
vide a method and apparatus for controlling the
24, the characteristics of said cam determining
tension under which freshly spun rayon may be 55 the amplitude of displacement of bar 25 per de
wound so that packages, of a diameter in excess
gree of angular displacement of shaft 23. Bar
of 150% of the bobbin diameter, in frusto conical
25, at its end remote from the cam follower, is
or right cylindrical form may be prepared having I pivotally connected to an arm 26 attached to and
a better and morestable con?guration.
depending from a rock shaft 21. It can thus be
It is further contemplated according to this in 60 seen that rotation of shaft. 10, through the vari
vention that a predetermined winding pattern be
ous gears, brings about rotation of cam 24 which,
better reproduced to result in larger wound
through bar 25 and arm 26, causes oscillation of
packages more readily susceptible to uniform
rock shaft 21'. Depending from rock shaft 21 and
after-treatment‘, and if the rayon is collected un
attached'thereto
is an arm 28. The free end of
der reduced tension, the tension is maintained at 65
arm 28 is pivotally connected to horizontal bar
a substantially constant valve to prevent ?lament
29, the other end of which is pivotally connected
breakage in :the stretching zone.
'
to a depending arm 36 attached at its opposite
_Other objects and advantages of this invention
end to another rock shaft 3|. Depending from
will be apparent upon consideration of the follow
ing detailed description when considered in con 70 bar 29 is a bracket 32 which supports a traverse
bar 33 upon which thread guides 34 are mounted
junction with the annexed drawings wherein
at spaced points to direct the laying up of thread
Figure 1 is, a schematic perspective view of a
on the various bobbins 14. Although not illus
single unit of a bobbin spinning machine
trated, it is contemplated that another bracket
the traverse and bobbin are driven in smear-91:;
similar to bracket 32 may be mounted at the op
nism at a speed progressively reduced-throughout
5
2,415,764
6
posite end of bar 29 to serve another traverse be
shafts 41 and 42 so that the diameter of the driv
on the opposite side of the machine.
‘ ~
' ing and driven periphery cont-acted by the belt
The apparatus described thus far may be used
may be varied to produce different driving speeds
in conjunction with any of the well-known spin
on the part of shaft 41. The variable speed unit
- Illng schemes wherein the thread is ultimately 5
l2, as thus far described, is conventional in form
collected on a bobbin I4. In one spinning scheme
and has, in the past, only properly controlled the
such as that shown in Fig. 1, a spinning solution
beginning and end speeds of the bobbins.
is extruded through a spinneret 35 into a spin
It is customary to shift the levers 49 and 50 i
bath indicated at 36, the rate of delivery of the‘
by operation of a screw propelled from a con
solution being controlled'by a gear pump oper 10 stant speed source. Such a screw will displace
ated at a constant speed throughout the spin
ning period from a power source, not shown.
From spinneret 35 the thread may be led around
a driven‘ godet 31, also propelled at a constant
speed throughout the winding period. From this
‘godet it is passed to and around a freely rotat
able roller 38. From the godet and roller the
thread is drawn by rotating bobbin vl4 and is
;wound thereon according to a pattern predeter
the levers a constant distance per unit of an
gular displacement of itself and the speeds effec
tive at shaft 41 will follow an improper curve
when plotted against units of time.v It has been.
hereinbefore
undesirable variations
explained that
in thread
this results
tension
in in'the.vv
highly}
path between godet 3s and bobbin l4. Thus, as‘
an important part of this invention, levers 49
and 50 are operated by a cam .53. Cam 53 is pro
mined by the movement of traverse bar 33. It 20 vided with two faces of identical curvature 180°
' will be understood that godet 31 is merely illus
trative in nature and that any number or ar
rangement of godets may be-provided depending
upon the thread characteristics sought. It is evi
apart, each face acting on one of the levers
49-50. Cam 53 is propelled at a constant speed
throughout the spinning period through a shaft
54 to which it is keyed.
Shaft 54 has mounted 1
dent, however, that the last godet in the path of 25 thereon a worm gear 55 drivenby a, worm 56.
the thread before it reaches bobbin l4 will have
Worm 56 is mounted on a shaft 51 which also
a substantially constant peripheral speed
carries a sprocket 58. Sprocket 58 is connected
throughout the winding period and that the
by a chain 59 to another sprocket 60, mounted
stretch of the yarn between the last godet and
in a box generally designated by the numeral
the bobbin will therefore depend upon the take '30 6|. The reduction system in box BI is propelled
up speed of the-latter..
by a sprocket 62_connected by a chain 63 with
If a spinning scheme, is employed involving
another sprocket, not shown, keyed tolshaft 42.
two'or more godets such as described in applic-ae
It can now be seen that cam 53 will be caused
tion Serial No. 339,974 ?led June 11, 1940, now
to turn very slowly throughout the winding pe
Patent No. 2,302,971, the above problems are fur 35 riod and that the displacement of pairs of cones
ther magnified for in that process the thread
39 and 40 per unit of time will-depend upon the
passes from the spinneret, through the coagulat
curvature of its faces.
ing bath, over a godet, and into a stretching zone,
It has been found by experimentation that, if
where a high degree of stretch and tension are
'a screw is used to'displace levers 49 and 59, or
‘7 applied thereto. Then, usually, there is in the 40 if cam 53 were to be one of straight line char
‘path of thread travel a tension release godet over ,
acteristics, the rotational bobbin speed when
plotted against units of time would follow the
path of line l—a of Figure 2, but that, under
the same conditions, the peripheralv speed of
bobbin. The yarn tension in the latter zone is. >
the bobbin would follow the line l-b of Figure 3.
an indicative factor of the yarn tension in the
Upon reference to line [-1) it will be seen that
zone of higher stretch. The latter may be about
there is a precipitate rise in peripheral speed at
ten times as high as the former. Thus, com
the beginning of the winding period which is
paratively small tension ?uctuations in the ten
?nally reduced at the end thereof to approxi
sion release zone give occasion to high tension 50
mately the same value as at the beginning of the
in the stretch zone, perhaps so high that ?la~
winding. These variations in take-up speed of
ment breakage results or that the dye rate may
the bobbin result in marked variations in thread
be decreased. This, of course, is detrimental to
tension during the winding on period. From the
yarn quality.
Regardless of the spinning scheme employed, 55 curves I--a and l-b, it is most evident that the
effect of the normal reduction in rotational speed
according to this invention the take-up speed of
of the bobbin per unit of time is unsatisfactory
bobbin I4 is maintained at the desired value by
from the point of view of the rayon manufacturer
the operation of changespeed mechanism l2.
since the thread tensions between the godet and
Change speed mechanism l2 consists essentially
of two pairs of cones 39 and 40 connected by a 60 the bobbin under such conditions vary within very
wide limits.
belt 4!. Cones 40 are mounted on a shaft 42
As distinguished from the foregoing, if cam 53
driven through» a sprocket 43 by a chain ‘44, in
is used and the rotational speed of bobbin l4 L3
turn propelled by a sprocket 45 mounted on the
thereby. properly controlled to follow line 2—-a
rotor shaft of a constant speed electric motor of
suitable characteristics designated by numeral 65 of Figure 2, the peripheral speed of the bobbin
will follow line 2-—b of Figure 3. It will be noted
46. Thus, as power is delivered by motor 46, it
that line 2-1) is a straight one and that there is
is transmitted through chain 44 to shaft 42 which,
no variation in peripheral speed throughout the
in turn, brings about the rotation of cones 49.
winding period so that there is no-variation in
The sloping faces of cones 49 engage belt 4| and
tension brought about by relative speed changes
through it propel cones 39. The latter are mount
70 between bobbin l4 and godet 31. Under these
ed on a shaft 41 which carries a gear 48 mesh
conditions the bobbin diameter increases as illus~
ing with main drive gear ll on shaft l0. Levers
trated in line 2-0 of Figure 4. 49 and 50, pivoted respectively at 5| and 52, serve
The description of Figuresz, 3, and 4 insofar
to slide the pairs of cones 39 and 40 toward and
as lines l-a, l-b, 2—-a, 2->b, and 2—c are
away from one another along their respective 75 involved, is concerned with the ‘winding of a
which the yarn runs with some measure of glid
ging friction or slippage. Finally, the yarn is
wound under reduced tension onto the spinning
2,415,764
bobbin of cylindrical form having frusto conical
ends. In the preparation of packages of right
cylindrical con?guration, i. e., packages with ends
lying wholly in a plane normal to the. bobbin
axis, it has been found that the package may be
satisfactorily built without distortion, particu
larly squeezing out at the ends, where‘the periph
are de?ned in the speci?cation and claims as
“thick” packages.
.
What is claimed is:
1. In a method of manufacturing thread of
synthetic origin wherein a thread is freshly spun
and collected in package form on a rotating bob
bin which is gradually decelerated in rotational
speed to effect approximately the same surface
eral speed follows line 3-—b of Figure 3 brought
speed of the thread on the package at the begin
about by a rotational speed following line 3-a
of Figure 2. Under these conditions it will be 10 ning and end of the winding period, the improve
ment which comprises positively driving the bob
noted that at the beginning of the winding period
bin directly from a motivating source at a de~
there is a slight increase in tension of insufficient
celerating rotational speed, which deceleration
magnitude to detrimentally affect thread denier
is continuously varied throughout the winding
but sufficient to maintain package con?guration.
period independent of the size of the package and
In this case, however, the line 3-—b is substan
in timed relation to the rotation of the bobbin so
tially straight after the initial slight increase in
that at any instant of time during the winding
tension. As distinguished from the peripheral
_ period the change in the R. P. M. of the bobbin
speeds of line 3-—b attention is directed to line
does not depart substantially from the R. P. M.
4-?) which designates the peripheral speed
changes during the winding of a right cylindrical 20 change typi?ed between curves 2a and 5a of Fig
ure 2.
package where the rotational speed of the bobbin
is controlled by a conventional means to follow
line l--a of Figure 2. In Figure 4 line 3-0
illustrates the rate of diameter increase of the
_ 2. In a method of manufacturing thread of
synthetic origin whereina thread is freshly spun
and collected in package form on a rotating bob
right cylindrical package where the peripheral 25 bin which is gradually decelerated in rotational
speed to effect approximateiy the same surface
speed thereof is in accordance with line 3—b of
speed of the thread on the package at the begin
Figure 3.
ning and end of the winding period, the improve
In the event a constant peripheral speed is
ment which comprises positively driving the bob
desired during the winding of a right cylindrical
package, the curvature of cam 53 may be de 30 bin directly from a motivating source at a decel
erating rotational speed, which deceleration is
signed to produce variations in the rotational
continuously varied throughout the winding pe
speed of the bobbin following, upon development,
riod independently of the size of the package and
line 5-a of Figure 2. Under these conditions
in timed relation to the rotation of the bobbin so
the peripheral speed of the bobbin throughout the
entire winding period will follow line 2--b of 35 that during the winding period the change in the
R. P. M. of the bobbin generally follows a curve
Figure 3.
typi?ed by 2a of Figure 2.
Although the above described mechanism shows
3. In a method of manufacturing thread of
a cam designed for imparting a‘ particular pre
synthetic origin wherein a thread is'freshly spun.
determined non-uniform reduction in bobbin R.
P. M.’s for a given period so that the take-up 40 and collected in package form on a rotating bob
bin which is gradually decelerated in rotational
speed of the thread is maintained substantially
speed to effect approximately the same surface
constant throughout the winding period, it is
speed of the thread on the package at the begin
' the predetermined control of the winding ten
sion for the complete period that is broadly novel
ning and end of the winding period, the improve
produced by plotting bobbin package peripheral
bin directly from a motivating source at a decel
ment which comprises positively driving the bob
in our present concept. Such control may be
bin directly from a motivating source at.a decel
effected through various types of speed change
erating rotational speed, which deceleration is
mechanisms either by a specially designed cam
continuously varied throughout the winding pe
to control the transmission of the rate of speed
riod independently of the size of the package and
variation, or by the design of the speed change
in timed relation to the rotation of the bobbin so
50
mechanism per se. As the peripheral speed equals
that during the winding period the change in
11- times the diameter times the R. P. M., if the
the R. P. M. of the bobbin generally follows a
' peripheral speed is to be maintained constant,
curve typi?ed by 30. of Figure 2.
then the deceleration of the bobbin is a simple
4. In a method of manufacturing thread of
function of the increase in diameter. Therefore,
synthetic origin wherein a thread is freshly spun
it is'only necessary to ?rst determine the desired .
and collected in Package form on a rotating bob
peripheral speed, e. g., a constant one for conical
bin which is gradually decelerated in rotational
packages, for a given period; determine the rate
speed to effect approximately the same surface
of increase in diameter of the package per unit
speed of the thread on the package at the begin
of time, and then adjust the rate of change of
ning and end of the winding period, the improve
the speed change mechanism so that the curve 60 ment which comprises positively driving the bob
speed against time will be a straight line. In the
case of'spinning right cylindrical packages it is
erating rotational speed, which deceleration is
continuously varied throughout the winding pe
desirable to slightly increase the peripheral speed
riod independently of the size of the packageand
65
of the package at the beginning of the spinning
in timed relation to the rotation of the bobbin
period and then gradually decrease the periph
so that during the winding period the change in
eral speed until at the end of the winding period
the R. P. M. of the bobbin generally follows a
the tension is slightly greater than at the be
curve typi?ed by 5a of Figure 2.
ginning thereof. However in this method also,
5. In a method of manufacturing thread of
it is only necessary to adjust the speed change "
synthetic origin wherein a thread is freshly spun
mechanism so that the effect when plotting the
and collected in package form on a rotating bob
peripheral speed of the package against time, is
bin which is gradually decelerated in rotational
a line similar to 3-12.
speed to effect approximately the same surface
Rayon packages having a diameter greater
speed of the thread on the package at the begin
‘than 150% of the diameter of the empty bobbins 75
9
2,415,764
10
REFERENCES CITED
ning and end of the winding period, the improve
ment which comprises positively driving the bob
bin directly from a, motivating source at a decel
erating rotational speed, which deceleration is ‘
continuously varied throughout the winding pe
»
riod independently of the size of the package and
' in timed relation to the rotation of the bobbin so
that after the initial winding period, the periph
eral speed of the thread varies less than 2.0% '
_7 The following references are of record in the
?le of this patent:
6
UNITED STATES PATENTS
Number
2,147,514 '
2,207,866
and follows a ‘straight line as typi?ed by 2b and 10 3,312,240
31) of Figure 3.
2,028,821
JAN J. SCHILTHUIS.
AR'I‘I-IUR L. JACKSON.
1)
Name
Date
Barnes ___________ __ Feb. 14, 1939
Krick ____ __,.- _____ __ July 16, ‘1940
Kline ______ _'_ ____ __'Dec. 29, 1942
Brenzinger _-_ _____ __ Jan. 28, 1936
Документ
Категория
Без категории
Просмотров
1
Размер файла
948 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа