Note: Descriptions are shown in the official language in which they were submitted.
~)43C~69
The present invention relates to a self-aligning
type weighting arm for use with a top-roller holding and
pressing device which can be used for forming a nip for dra~t
operation in textile machines including drawing frames, flyer
frames and spinning frames.
The following description will refer to the
accompanying drawings, whereinO
Figure 1 is a side view of a Gonventional adjusting
type guide arm;
Figure 2 is a plan view of said arm;
Figure 3 (sheet 2) is a graph showing deviated
- conditions according to a self-aligning device utilizing the
guide arm shown in Figures 1 and 2;
Figure 4 (sheet 1) A and B, which appear on the same
sheet as Figures 1 and 2, show a conventional pendulum type
guide arm;
Figure S is a graph showing the frequency dis-
tribution of parallelism of back top rollers in a conventional
device;
: 20 Figure 6 is a graph showing the frequency dis-
tribution of parallelism of front top rollers;
FigurP 7, A and B, which appear on the third sheet
of drawings, show a conventional fixed type guide arm;
Figures 8, 9 and 10 show a conventional adjustable
type guide arm,
Figures 11 and 12 (sheet 3~ show concrete examples
of the adjustable type;
Figure 13, A and B, (sheet 4) which appear on the
same sheet as Figures 8 and 9, are views ex~lanatory of
self-aligning action;
Figure 14 (sheet 4) i~ a view explanatory of the
main point o~ dynamical consideration of said action;
-- 1 --
B
3q~
Figure 15, A and B~ is an imaginary view of a convention-
al weighting arm assembly;
Figure 16, A, B and C, is a view explanatory of operating
difficulties;
Figure 17, A9 B and C, and Figure 18, A and B, show
embodLments incorporating the basic nature of the present in-
vention;
Figures 19 through 24 are views showing other examples of
the pre ent invention; and
Figure ?5 is a table showing Lmprovement percentages
under various items.
In general, a pendulum arm type weighting arm having a
self-aligning action which is in wide use3 as shown in Figures
1 and 2~ comprises a weighting arm A, a guide arm case B, a
guide arm pin C, a driving body D(having a curved or a plane
surface), driven rollers RJ a driven roller shaft G, and a press
body SO
Usually9 the draft section of a textile machine comprises
: two or more pairs of parallel-disposed assemblies described above3
and in each such pair the driven top roller R is xotated as
pressed against the driving bottom roller D while maintaining
a cyli~drical contact relation therewith and forming a pressure
nip which may have various forms~ including point~ line and
surface contact~ clepending upon the quality of p~rallelism of
the axes o the top and bottom rollersO For the textile machine
draft section, highly stabilized surface contact is an essential
prerequisite for Improved yarn quality~ More particularly, if
the parallelism between the axes of the top and bottom rollers
~ and D i~ LmpairedJ this causes an unstable change in their
~436~6~
condition of contact, bringing them into a point or line contact
condition, which means that a stable pressure nip cannot by main-
tained and hence it is difficult to obtain a smooth and skable
draft ac~ion, with the result that there is a direct adverse
effect on the quality of the product. 'rherefore, maintaining
the parallelism of the axes of the bottom and top rollers D and R
has been an indispensable condition for the draft section of
textile machines. Conventionally9 the measures taken to achieve
this condition have been to maximize the degree of accuracy of
the guide arm A and weighting arm, to make adjustments during
assembly, or to resort to self-alignmentO It is under always-
parallel conditions that the rollers continue to form a roller
nip with a uniform pressure distribution over the entire area
of contact while executing pr~ssure contact rotationO This de-
vice has a tendency to produce an unstable condition as it is
~ubjected to the influence of a complex motion such as yawing,
rolling and pitching due to the arrangement of the weighting anm
Ao
Particularly in the ca~e of Figure 1 wherein the driven
roller R and the driving roller D contact each other along a
cylindrical surface, depending upon the quality of parallelism
of their axes, their contact condition presents various forms,
producing a very unstable nip in connection with pressingO
In brief, the draft section requires a stable and secure
nipO Further, it is important to maintain a strong nip condition
uniformly distributed over the entire width of the contact regionO
More particularly, if the parallelism between the axe~ of the
top and bottom rollers R and D is impaired, this produces an un-
stable change in the nip condition o~ the rollers, w.ith the
-- 3 --
~43~6~31
pres~ure contact condition changing its linear form into one re~
sembling a point, thereby making it difficult to obtain a unformly
pressed nip condition stabilized widthwise of the rollersO
Figure 3 shows deviated conditions associated with a self-aligning
mechanism corresponding to Figure 1~ wherein a designates a
- normal condition and b and c designate abnormal conditions de--
viated to either side. When measured at a job site, it is ~ound
that in most cases either a or b predominates. The maintenance
of the parallelism of the axes of the driven roller and the driv-
ing bsdy is a subject of utmost importanceO No sufficient approachto meet this condition has been establishedO Heretofore, there
has been no choice but to maxLmize the degree of accuracy of the
components of the guide arm and the weighting arm, to repair or
adjust them during assembly while taking much time, or to resort
to a ~el~-aligning mechanism o~ the convention~l type though this
is not very satisfactoryO These approaches, however, have their
lLmitationsO In order to meet the needs of the market, it is
necessary to no longer rely on the con~entional ~systems which
are at a deadlock and instead to invent a novel weighting arm con-
struction of high sensitivityO Such demand has led to varioustypes of weighting constructionsO
The weighting anms actually employed at job sites may be
classified into the following three typesO
SELF-CE~TERING TYPE ~PE~DULUM TYPE)
This type, as shown in Figures 4A and 4B, is based on the
principle of employing a pivot construction with the axis of the
swing motion of a conventional pendulum type guide arm 3 located
at a pin 6, whereby the guide arm is supported for rotation in the
vertical and horizontal direction or yawing directionJ wherein a
-- 4 --
~ 43~9
top roller 2 is rotated by a bo~tom roller 1, ther~by automatical-
ly adj usting the parallelism of the top roller 2 with resp~ct to
the bottom roller 20 The numeral 4 designates a spring; 5, a
guide arm case; and 7 designates the support for the arm. Thus,
this ype is based on the principle ~f the pendulum found in the
centrally directed restoration action of two freely rotatable
wheels in the case where said wheels are symmetrically arranged
while a pendulum arm holding their shaft at its midpoint is dis-
posed at right angles with the shaft and has its fulcrum located
on an extension thereof The restoration action is based on the
production o thrust due to alignment, but the influences of
cumulative error due to various factors connected with manufac-
ture including deviations in the spring, deviations in the guide
arm case, deviations in the arm body, and errors in the holding
part are noticeableO Particularly, the recent demand for in-
creased weighting ha~ a marked tendency to amplify the effect of
these sources of deviation because of the nature of the surface
of contact between the top and bottom rollers. It is the second
back roller and the following roller having a lower rpm that are
particularly greatly subjected to said sources of errors. ~n
these parts, the restoration force (a thrust force) is so small
that it is insuEficient to accommodate said cumulative error.
Therefore, under these circumstances, when the part having the
lower rpm has been remodelled into a pendulum form, this has
resulted in interfering with the maintenance of the parallelism
of the top roller relative to the bottom rollerO Further, in
order to improve the draft performance of the draft section~ as
is currently demanded~ it is indispensable to incraase the
nip pressure. ~owever, the increase in the pressure on the top
~ 5 ~
1~L31369
roller in the cylinder-on-cylinder arrangement aggravates the
errors in parallelism of the bottom and top rollersO Therefore,
there is a limit to the increasedl pressure that can be applied
with the arrangement using self-alignment based on the pendulum
principle, and at present it is used beyond its limitO Parti-
cularly in the second roller and the following roller having
lower rpmO there is the drawback that this tendency toward de
viation is pronouncedO (See Figures 5 and 6.) It has been proved
that the adverse effect of relying on self-alignment on recent
10 flyer frames using low rpm and high weighting pressure leads to
a lowering of the performance of the fiber draft section and
that self-alignment has xeached its limit in improving quality~
As a countermeasure thereagain~t, a method is sometLmes employed
in which a guide piece ~not shown) is attached to the guide arm
for correction purposes, but it is practically impossible to
maintain the required accuracy.
FIXED TYPE
This method is shown in Figures 7, A and Bo Figure 7, A~
shows a system not relying on self-alignmentJ wherein the part
for holding the arbor of the top rollers pressed by a pressure is
directly held at a right angle by a guide arm 3 in such a manner
as to be capabl~e of two motions, yawing and rollingO In this
system, the guide arm 3 itself is fixed to the arm body 90 De-
9 ignated at 11 is a set screw and 12 is a spring-anchoring pinO
The arrangement shown in Figure 7, ~, resembles that shown in
Figure 7J A. In order to prevent conc~mit~nt lowering of the
pressure on the top roller due to frictional resistance at the
part for holding the top roller to the guide arm, which is the
drawback cf the type of arrangement of Figure 7, A, a guide arm
-- 6 --
~ 3~i69
pin 10 is provided. As described above~ the fixed type is the
type of guide arm used in heavy weighting systems when it has
been attempted to eliminate the drawbacks of the pendulum system~
and in recent years there has been an increased tendency to use
arrangements belonging to this type. It is impossibla to obtain
satisfactory results unless the arm body is at a true right angle
with the bottom roller and unless all the components of the guide
arm have very high manufacturing accuracyO As in the pendulum
system, cumulative error is produced, widening the range of
scatter more than would be expected. In this case also, the
cumulative error is not very different from that in the case of
: the above-described pendulum systemO Though it is theoretically
possible, as in the pendulum system, to maintain the parallelism
of the top and bottom rollers, in practice it is very difficult.
Both the pendulum arm type and the fixed type have serious draw-
backs with respect to self-alignment performance9 as described
aboveO
This is fully endorsed by the following investigation
results obtained at job sites. Thus, Figure 5 shows the degree
of deviation of the back top roller in the pendulum arm system
and in the fixed system~ and similarly Figure 6 shows the degree
of deviation of the front top roller in said two s~stemsO In
ea~h case, the data was obtained at large firms on the basis of
a strict sasnpling methodO Considering this data, it is clearly
seen that although the self-aligning type weighting arm is a little
more advantageous, the deviation scatters over a wide range be-
yond the allowable limits (range irrelevant to the occurrence of
yarn unevenness)O For f irms which manage a very large number of
groups~ it is no easy task to maintain the top roller in an
7 -
~43~
allowable conditionO
As a result, it can be said that basic investigation for a
high sensitivity sel~-aligning construction having a maintenance-
free capability is an urgent necessityO
The structural drawbacks of the weighting arm cannot ~e
easily elLminated~ as described above, but this doeq not necessari-
ly mean that there is no perfect arrangement. ~he adjustment type
to be described below provides an improvement.
ADJUSTMEN~ TYPE
. 10 According to the adjustment type disclosed in Japanese
Patent Application NoO 117330/72 (Patent Opening No. 72422/74), it
is po~sible to elLminate the direct drawbacksO Figures 8-10 show
an ex2mple of the adjustment system. According to this adjustment
~ystem9 in the draft section of a textile machinQ~ the top roller
is fLxedly held by one end of the waighting anm (guide anm), the
other end being supported in a pivot fashion to constitute the
pendulum system, while separately from the guide anm, the guide
arm ca-ee, or a separately fixed deviation-adjusting spherical
element, is brought into spherical surface contact with a portion
of the guide arm in a ~ree condition with respect to the guide arm
so a~ to allow the yawing motion of the top roller to be adjusted
and controlled, thereby maintaining the axis of the top roller
parallel with the axis of the bottom roller and at the same time
allowing the pitching motion and the rolling motion of the top
roller to follow the bottom roller, thus ensuring that the bottom
and top rollers will move in close and inseparable relation to
one another. Thu~, this arrangement follows the principle of the
pendulum system in that in the case where one end is supported in
a pivot fashion in the guide arm, the top roller held by the holding
part at the other end is free with respect to the three spatial
coordinate axes, namely, in the X~ Y and Z axis directions, so that
-- 8 --
3~D69
the top roller held hy the guide arm i~ pressed against the
bottom roller in a complex relation of point~ line and sur~ce
contact and in a manner which allows yawing, rolling and pitching
motions thereof.
In this case~ the main factor in maintaining the paral-
lelism of the top roller with respect to the bottom roller is the
yawing motion of the top rollerO If the yawing moti~n of the top
roller perfectly follows the bottom roller, all the conditions are
balanced and the maintenance of parallelism of their axes is
established, so that a stable surface contact nip can be obtained.
~n the contraxyJ if it is not able to ~ollow the bottom roller,
all the other conditions lose their balance, making it impossible
to achieve the intended objectO
If, therefore, a method is employed in which with the ro-
tative axis of the top roller is held parallel to a reference axis
based on the rota~ive axis of the ~ottom roller, then only he
yawing motion of the guide arm is strictly controlled while allow-
ing it to freely follow in the other directions, namely, with re-
spect to the pitching and rolling motions and it then follows that
the various conditions needed for the top roller weighking condition
are satisfied, as described aboveO As long as this condition iæ
maintained, the condition of the nip for fleece having a given
width becomes satisfactory and is stable for any heavy load. This
relation holds perfectly for the pitching motion, but or the
rolling motion3 t:heoretically it ~lightly in~luences the yawing
motiona Howeverv its displacement is practically negligible with
respect to a very small displacement of the order of bottom-roller
deflection and it hardly becomes such a displacement as will have
sufficient influence on the yawing motion to upset the parallelismO
_ g _
~3~U69
The reason therefor iq shown in Figure 10~ Supposing a
spherical surface accentricity-ad~uster to have a radius R (the
amount of deviation ~), the amount: of displacement ~ in the
yawing directio~ with respect to t:h~ angle e of the rolling motion
at the point of contact between the spherical surface and the
guide arm is expressed as follows:
~ = R (1 - cos ~ )
It is seen that ~ is nearly equal to zero for a infinitesimal
di~placement of ~r
In the adjustme~t system, various methods may be con-
templated and in this connection Figures 8 and 9 show an example
of the eccentric type and Figures 11 and 12 show examples of the
adjusting pin type. Figure 11 shows the adjustment type using a
lock nut No~ while Figure 121 A a~d Bs shuws a clamp type using
a plate spring nl or nl', C shows the type using crLmping n3, D
shows a type u~ing an elastic body n2 such as rubber, and E shows
the use of a ~ube n4 of a relativaly soft metal such as lead or
copper combined with means for deforming the same to fix an ad-
justing pin ~ at the middleO F shows one way for fixing the ad-
justing pin, using an adhesive agent or solder n5~ Each type has
been developed so that it allows adjustment when necessary. Thus,
a suitable j ig is prepared for each type and is used when ~eces-
sary to make adjustments, thereby eliminating difficulties due to
the deviation of the top rollerO However, this system require~
skill and time in making adjustmants, ~o that it is difficult to
put into practiceO Therefore, it is used by makers when a
statistical method is applied to the weighting arm assembling
operation to correct errorsO
At any rate~ these systems are based on a concept which
-- 10 --
1~3~
almost ignores the self-aligning function of the pendulum arm,
ignoring natural laws which could be advantageously utilized, and
in practice they are not always convenient9 as described a~ve.
Thus, they cannot be called carefully thought-out measures.
However, su~ficient rnarits can be obtained by applying them to a
wide gauge top roller or to very slowly rotating top rollers in-
cluding the second top roller and the ~ollowing roller which are
heavily loaded and whose rpm is very 14wo Further, thare has
been an example in which a control system similar thereto is
applied in the form of a guide arm control clip to the weighting
arm in a flyer frame. ~ut this is nothi~g more than a makeshift
means which is somewhat different in category from the above-
described ad~ustment sys,tem. At any rate, compared with the
weighting anm arrangements now in use~ this type of adjustment
system provided an e~fective measure as considered from the point
of view of manufacturing errors in the current mass-production
system. Further~ a system which is based on the fixed type con-
c~pt premises that the arm body is set always correctly as de-
signed, as or example in the.saddle system prsduced by some leading
firms, and this i9 far from satisfactory as evidenced by many
actual examples thereof and by the actual results of maintenance
thereof ~or yeaxs, and further by the fact that under present
circumstances it form~ a source o noticeable complaints as to
its qualityO
As is evident from the above, as along the weighting anm
of the conventional system is employed, it is a task of extreme
difficulty to maintain or control the parallelism of a vast
number of top rollers which are operating in textile millsO
However, judging from the fact that the parallelism of the top
-- 11 --
3~
roller R contributes much to lmproving the quality~ production
efficiency and operational stabil:ity in the various subsequent
proce~ses, it should be of vital :~portance to create a new
technical arrangement which is capable of making effective use
of the self aligning performance.
The description given so far has clarified the present
condition concerning the circumstances and drawbacks of the
weighting arms in the weighting arm units now in useO In particu-
lar, the pendulum type arm which, though based on an ingenious
idea, has not had its self-aligning performance fully developed
because of its structural drawbacks, has been described by citing
concrete examples. Now, the principle of the self-aligning per-
formance of tbe pendulum anm will be considered by going back to
its starting point.
Figure 13 is a view explanatory of the self-aligning actionO
As shown in Figure 13, the basic principle of the pendulum arm
system is represented by Figures 13A and 13B~ When a driving
surface D' is continuously moving in the direction of arrow YY',
the press arm A is supported by a small-diameter pin I at a
fulcrum 0 in a pivot fashion, and orthogonally holds the rotary
shaft XX' of the driven roller R and is pressed ~ubstantially
perpendicularly at a fixed point P on the guide arm by press meansO
In this arrangement, the press a~m A continues to maintain strict-
ly the relation of JoJo ~XoXo under the condition of YY'l XX'.
This relationship is preserved irrespective of how many rollers
as shown in Figure 13~ A and B are used, and remains unchanged as
long a~ there is no disturbance from the outside.
The main points of a dynamic consideration of the rea~on
thereor will now be de~cribed with reference to Figure 14. With
- 12
1~3(~6~
the driving surface D' continuously moving in the direction of
the arrc~w (parallel with the ~' axis), consideration will be
given to three basic attitudes a, b and c of the driven body R
with respect to its holding axis xx ' . For the movement of the
driving surface D in the direction of the arrow parallel to the
travel direction s~atum axis YY', the attituda a of the driven
roller R show a condition in which it is at its datum axis
original position where the relation YY'lxoxo'll B' holds;
attitude b shows a condition in which the roller is rightwardly
10 upwardly inclined at an angle e to the reference axis Xo~o', and
attitude c shows a condition in which it is leftwardly upwardly
inclined at an angle e to the datum axis XoXo ' O Therefore, in
attitude a, the midpoint Q on the roller R is always positioned
on the datum axis YY' extending through the pivot-like support
point O and no angular displacement thereof takes place on ~he
driving surface D'. On the other hand, the path described by
the midpoint Q2 on the roller R2 is as shown by a straight line
Y~ ~' while that for the roller Rl in c is represented by a
straigh~ line yryx'. Since the roller R make~ line or sur:eace
contact with the driving surface widthwise of the ro~l~r, it
describes paths on the J~ 3~ and JR ~urface~, respectively.
That i~, in b and c, as shown in Figure 149 these paths are de-
f ined by an angle of inclination e of the driven roller R to
the datwll axis nr' ~ and in the pvsitional relation shown in
Figure 14, both a and b follow path~ approaching the datu~ axi~
YY'O The speed s thereof expressed as follows:
. s = V sin e . O . . . O O (1)
~ ynamically, this relation can be directly replaced by
a vector value having the direction of orce F~
- 13 -
~3(~69
As shown in Figure 15, A and BJ suppose a weighting anm
construction wherein a support ann OQ having a length 1 and occupy-
ing a fulcrum 0 on the datum axie YY' holds the roller shaft xx'0
AS long as the normal datwm positional relation
xx'¦l XoXo~YY' is retained and thl- driving surface D' travels
in the direction YY', the normal position is maintained per-
manently since no vector is produced in the direction which dis-
plac~s the axial direction XoXo'0
In Figure 159 A and BJ where the driving roller R is in
the conditions of Rland R2, i~ is ~een that in the condition of
Rl, a component vector Tl corresponding to the drive vector V is
produced in the direction Gf axis X1X1 ' of the roller Rl. As a
result of this thrust, a torque M in the restoration directio~
equal to Tl 1 with a center at the fulcrum 0 of the swing arm is
produced to bring the weighting arm back in the directional con-
forming to the datum axis YY' since the roll Rl is orthogonally
supported by the swing arm of length 1.
M -- Tl lo o ~ o o o ~ o (2)
At this time, the vector corresponding to the component force in
the rotative axis direction xlxl' of the driven roller R1, iOe.
the thrust Tl produced in Rl is expressed as follows,
Tl - V sin e 00...(3)
Thus 9 it becomes evident that the thrust is a function of the
angle of inclination ~ formed with the datum axis direction
xOxO' of the driven roller Rl-
From the equations (2) and (3~,
M - 1 V sin ~ 00..00...00..0(4)
From this equation it is seen that unless the angle of inclina-
tion between the rotative axis direction xx' of the driven roller
- 14 _
~ ,i , , ,
~ ~L3~
R and the datum axis direction XoXo' o~ the driven body with
respect to the travel axis YY' of the driving body D' is stabiliz-
ed such that e = o, the restoration torque M will not disappear.
Thus, if e = o, then M = o and the swing arm is stabilized at
that position. In the case whPre the driven roll~r takes the
disposition of R2, ~ only takes a minus sign and the various
relations remain unrhangedO
The theory described above is applied to the pendulwm
arm type weighting armO
Therefore, in this form, the swing support part 0 forming
a fulcrum for the pendulum actio~ of a conventional weighting
arm is in the form of a characteristic pivot-like support system
and at the other end it correctly orthogonally holds the driven
roller Ro Further, the means for presqing the weighting arm
usually comprises a spring, e~g. a compression spring (coil
spring of volute spring) or a plate spring of special shapeO The
system shown in Figure l is a typical example of thi O In rare
cases~ said means comprising a pres~ing device uses gas or llquid
pressure, such as pneumatic or hydraulic pressure. Whiche~er
system may be utilized, the present condition is thak it i3
arranged to act on the upper surface of the weighting arm or on
a spring receiving part integral therewith,
As long as a system corresponding to or similar to this
kind of arrang~ment is employed, similar dr~wbacks invariably
exist therein. Particularly in the typical example shown in
Figure 1 using a spring, it can hardly be expected that a pressure
vector or pressure distribution in the pressure contact region
produced by the compression of the spring will be the theoretical,
normal uniform distribution in the datum normal position of the
~3(~
weighting arm.
As described above, the existing pressing system~ whether
a compression spring (coil spring or volute spring) or plate
spring, actually have individually considerably scattered in-
trinsic deviations~ and the direction of the spring pressure also
tends to be scattered in a wide range with respect to the axial
direction of the springO Thus, a technique for directing the
direction of such spring correctly to the direction of the spring
axis has not been establishedO Moreover, the tendency t~ward in-
creasing the pressure in the weighting arm unit in accordancewith advances in ~extile technology including the rise of synthetic
fiber blend spinning in addition to the increase of draft ratio
and of productivity on the basis of operating stability and the
guality-first precept5 has resulted in increasing the drawbacks
of the existing weighting arm unitsO
Even if these deviations in spring pressure, etc. remain
in a very small range, the secondary, balance-destroying action
influenced by the buckling phenomenon found in compression springs,
. and by the deviation of the axis of the pressing spring accompany-
20 ing the angular displacement of the weighting arm A, continues tointerfere with the function peculiar to the pendulum arm of ad-
justing the axis of the driven roller R to make i~ parallel with
the rotative axis on the driving sideO This phenomenon may be
considered to be shown in Figures 5 and 6 in terms of measured
valuesO Figure 169 A, B and C, explains this interfering
phenomenonO Thus~ as shown in a front view A in Figure 16, the
pressing construction of a conventional weighting arm i~ such
that a compression coil spring 23 is supported at its upper end
surace by a spring position controlling projection 25 on the
- 16 -
~3~9
ceiling of a guide anm case 21 while it~ lower end surface issupportsd under pressure by a spring position controlling pro-
je~tion 26 provided on the outer ceiling surface of a weighting
arm 22. Dri~en rollers 24, 24' orthogonally supported at its
middle by the weighting arm 22 are opposed to a driving body
in the illustrated relation. ~herefore, the horizontalne~s of
tha pressure contact surface of the pressing spring 23 posi~ioned
on the outer ceiling surface of he weighting arm is governed by
the manner of contact between the driving surface D and the driven
rollers 24, 24'. ~he weighting arm construction is subjected
directly to various influences from factors including the hori-
zontalness of the pressing surface of the pressing 23 and the
intrinsic deviation of the pressing spring 23 during operation
of the waighting arm 22 and the angle of deviation es of ~he
center axis of the compression spring 23 due to the displacement
of the pressing center P of the guide arm 22 with respect to
the longitudinal datum axis ZZ' extending through the weighting
point P of the weighting arm construction, with the result that
an overall vector Pl acts on the weighting armO
The overall vector Pl has an angle of deviation ~0s with
respect to the datum vertical axis Z2' of the weighting arm con-
structionO From this relation, the driven rollers 247 24' have
a thrust E produced in the direction of their rotative axis xx'
which is a component thrust in the anti-restoration direction of
the guide arm~
The siæe of the thrust E, as seen in a vector diagram
shown in Figure 16, B~ is express~d as follows~
E = Pl sin ~es~oooo-00(5)
Therefore, the deviation torque ~s which is a moment in the
- 17 -
~3~g
deviation direction acting on the point P of the guide arm 22
and produced by a pressure a~ting on the guide arm 22 is expre~sed
by the following equationO
Ms = s P sin ~osO~oooo(6)
On the other handJ as shown in a plan view C in Figure 16, the
guide arm 22, under the influence of the deviating actio~, is
positioned displaced by S e relative to ths datum axis YY' in the
weighting arm construction extending through the center of swing
motion o of the arm 220 Thusg from the equation (4) the restora-
10 tion torque Mr produced at the center point Q of the drivenrollers 24, 24 ' is expressed by the ~ollowing equationO
~ r = 2 1 Vo sin~eOO0.00(7)
The two kinds of moments, namely9 the deviation torque Ms and re-
storation torque Mr having different directions described above
sLmultaneously act on the weighting arm Ql at points P and Q.
Therefore, the guide arm OQ continues to remain at a position
where the ~wo torques are balanced.
Ms = MrO0Ø0..0(8~
As shown in a plan view in Figure 16, C, with the weighting arm
constructed to have rotatable rolls on opposite sides of the
holding shaft oiE the guide arm, equal thrusts Tl and T2 are pro-
duced on opposite sidesO Therefore, the equation (8) is developed
as follows~
- 2 1 V sin S~ = S Pl sin ~5
sin ~e = S Pl sin 5
2 1 V
e = 1 sin~l~s Pl sin ~ 0O.OOOO(9)
2 ~ 1 V
It is evident from t~e ~quation (9) that it is necessary and
sufficient condition for O = O that l~s - OO That is, unless
- 18 -
~3~
the pressing vector line coincides with the weighting datum axis
ZZ' in the front view in Figure 16, A, it will not return to the
origin Q. The condition ~6s = 0 theoretically is at the weight-
ing arm original position where XX' 11 xx' 11 ~Y', and this condition
is no more than the absolute parallelism of the rotative axis
xx' of the driven rollers with respect to the right-angle axis
XX' of the bottom driving surface Do This proves the fact that
the self-aligning property of the top rollers with respect to the
driving roller D of the pendulum type weighting arm is very
imperfectç In ordar to achieve higher aligning performance here-
tofore demanded at job sites, iOe. the allowable deviation range
within 003 mm indicatRd in Figure~ 5 and 6~ it is required in an
aspect of basic design to minimize or eliminate the pressing
deviation characteristics of the individual pressing bodies or
pressing assemblies. ~owever, it is evident also from investi~
tated data that it is impossible even by the exi~ting technique
to include the limit of management of tens of thou~ands or
hundreds of thousands of lots in the above r~nge. In this con-
nection, Figures 5 and 6 prove that even the typical weighting
arm which is produced with the highest level of technique and
according to the best principle has been still in~ufficient to
improve quality and op~ration in practice~ Weighting arms used
especially in textile mills are the key to forming a roller nip
which governs the quality of spun yarn and operating efficiency~
ThereforeJ it is an important subject to improve the parallelism
of the driven rollers R with respect to the driving bottom roller
D in that case~
~ he present invention has been developed in view of the
above and relates to a construction wherein on the assumption
-- 19 --
~3~;g
that the pressing deviation charactexstics peculiar to a pressing
body or assembly which are the main cause of troubles are allowed
to eXist at substantially the pre,sent level, a rolling-contact
bearing element or rolling assembly i9 interposed between it and
a guide arm to isolate them from ~each other, the function of the
rolling element being utilized to elL~inate the deviation vPctor
while transmitting only the necessary pressing vector directed
in the direction of the vertical datum axis ZZ', thereby making
fullest use of the self-aligning principle and function of the
known pendulum arm systemO
Weighting arm assemblies according to the prssent invention
may be arranged in a plurality of row~ inside the weighting arm
body, whereby they can serve as a weighting arm device capable
of performi~g the necessary and sufficient weighting arm function
for the respective lines in ~he draft sectionO Therefore, the
invention has high rationality in that it has the versatility to
adapt for the production of many kinds of types or standards of
weighting arm and has as well the capability of being applied as
a ~tandard form so as to provide for mass-productionO In parti-
cular, the significance o~ its capability in opening the way Eorhigh rationali~ation of manuacturing facilitie~ is higher than
expected~
As regards the effects of the invention on the performance
of the weighting arm used in a spinning frame, a great Lmprovement
can be obtained in the parallelism of the axes of the bottom and
top rollers D and R, and this is highly advantageou~ in improving
the quality of yarn material~ The improvement of the quality of
yarn material not only contributes to an improvement of the
quality of the textile end products but also increases the
- 20 -
~3~g
operating efficiency and productivity o~ spinning proce~se~ andat the same time minimizes the occurrence of defects in the yarn
and has marked effects on the production efficiency and on the
productivity of secondary processes and those that follow. For
example, when a yarn material providing about 0o5-1~ increase in
~ of 40s combed yarn is used, there is for example an ex-
pectedly high percentage improvement in the quality and efficiency
of tht3 weaving and o~ the weaving proces~ 9 as shown in the table
of Figure 250 This is why the requirements ~or the quality of
10 yarn material are becoming increasingly severe in proportion to
advances in the proce~sing facilitie~ and in the ~ubsequent pro-
cesses, and in the diversification of productsO These conditions
can hardly be satisfied with the present level of paralleli~m
found in the existing weighting armsO (See Fi~ures 5 and 60)
~hus~ the requirement~ for the weighting arms in the spinning
frame are high. That is, the problems of, ~or example, firstly
increasing the pressure, secondly stabilizing the quality,
thirdly, convenience of operation, and fourthly freedom from
maintenance are all difficult to solve. Even the mo~t modern
weighting arm uni~., iX frankly criticized from the standpoint
o~ an expert, ha~ many problerns including tho~e described above
which are yet to be solved. That is, whereas great merits are
provided by the. weighting arm unit, the Lmportant aspect of
~tability i~ sacrificed to convenienceO
Among other things, it is pointed out that it is in the
parallelism of the top roller that the greatest drawback is
exposedO Needless to say, the parallelism oE the top roller
directly govern~ the performance of the draft section, f~rming a
main factor affecting the quality of yarnO The improvement
-- 2 1 --
3~
thereof will result in rais ing the level of textile technologyO
In brief~ the present invention is arranged to enable all the
top rollers associated with the spindles in a 3pinning Prame to
be confined within the allowable range of deviation of the
paralleliQm of top rollers (where no yarn unevenness takes place)0
Thus 9 the invention i~ significant.
In addition, the invention provides a self-aligning type
weighting arm construction which is ucable not only with textile
machine~but al80 with other similar machines using a parallel-
10 hold type ro atable press roll assembly.
Figures 17 and 18 show embodiments incorporating thebasic nature of the present invention, and the structural concept
hereoP will now be described~.
(1) The ~onstruction of a support point 0 for the
swing motion of a guide arm A in the rear is by the pivot-wise
support methodO
(2) A rolling element i8 received in the lower end
surface of a pre sing spring SO There is pxovided a bottom cap
HB of the illustrated shapeO For exam~le, in the case of a
compression coil spring9 an inverted U-section cap is provided
and this cap H.B receives a rolling element3 for example a ball
K or a cylindrical roller or a shaft-equipped rollerO The upper
inner surace X3X3' of the bottom cap i~ arranged so that with
respect to the upper surface X5X5' of the guide arm ca~e it is
maintained in the relation X3x3'l1 X5X5' during operation.
~ 3) At a predetermined position on the upper surface
oP the guida arm oppo~ed to a pressing body or pxe~sing a3sembly9
a rolling contact flat ~urface portion X2X2' is formed to provide
a small guide surfaceO
- 22
~43(D~;~
(4) Even if (2) and (3) are reversely installed, the
resulting arrangement will be exactly same in function with some
exceptions.
(5) The pressing ~pring S is usually in the form of a
compression coil spring. The 90-~degree anyularity of the
opposite end surfaces of the spring S wi~h respect to its longi-
tudinal axis, and the parallelism of said opposite end surfaces
are strictly controlled according to JIS (~apanese Industrial
Standard)~ Although some ~catter i5 produced, if it i~ within
the range specif ied by JIS~ experiments have proved that such
scatter does not matter. In in~talling the spring S, its upper
surface is vertically fitted on a projection 25 formed at a pre-
determined po~ition on the upper end of the guid~ arm case. The
inner surface X3X3' of the bottom cap HB mounted on the lower
surface of the pressing spring S in this condition could retain
a nearly horizontal condition but ~is can hardly be said to be
sufficient~ In the present invention, therefore, the bottom cap
HB i~ combined with the pressing spring S in such a manner that
the clearance with respect to the diameter of said epring ~whether
~he inner or outer diameter) is minimized and a~ the same time it
i~ combined with tha guide arm case B ( in some ca~es, the arm
body) in such a manner that the clearance between the diameter
(or width) d of the b~ttom cap B and the widthwise in~ide di-
men ion w of the guide arm case is similarly minimized. As a
result of this design, the vertical axis of the pressing spring
S approximately coincides with the datum axis ~' of the width
of the ca3e. Thus, this arrangement assures that the pres~ing
spring S will be maintained upright at the predetermined position
on the end surface X5X5' of the guide arm ca~e BJ while minimizing
~ 23 -
3~)~9
the sources of deviation such as the buckling phenomenon, so thatthe axis of the spring substantially coincides with the central
axis of the width of the guide arm case B and hence the pressure
exerted by the spring acts vextically. In response thereto, the
ceiling surface X3X3' of the bottom cap HB maintain~ the altitude
x5x5~ 11 X3X3' o that through the pressing structure using the ball
or other rolling element K contained in the bottom cap ~, the
pressure of the spring S is transmitted to the end surface X2X2'
of the guide arm B in the correct direction, that is, only the
required correct pressure obtained by elLminating the intrin~ ic
deviativity of the pressing spring S is transmitted.
(6) On the other hand, the self-aligning function of the
driven roller ~ provided by the driving of the driving body D
acts in accordance with the principle described a~ove, producing
a self-aligning swing motion of the weighting arm A around the
fulcrum 0. As a result, the resistance to the rolling of the
rolling element K at points of contact 27~ 28 between the end
surface X2X2' and the end surface X3X3' of the bottom cap HB i9
minLmized almost to zero~ Thus, an ideal pendulum type weighting
arm con~truction allowing the guide arm A to swing independently
of the pressuxe and without any substantial resistance can be
obtained. As for the parallelism of the upper and lower races
XX' and X2X2' between which the rolling element is interposed~
some amount of tilt relative to each other away from paralleli~m
cannot be avoided in practiceO However~ in the present system in-
corporating compensating means as described above~ the relative
tilt remains withln a very small range and no slippage on the
races occurs since the pressure being transmitted act~ to increa~e
the res i~tance. In brief, the most characteristic feature of
the present invention cons ist~ in the fact that the 2~rrangemerlt
-- 24 --
~43~i~9
comprising a rolling element interposed between the bottom
surface X3X3' of the pressing body and the upper ~urface X2X2' of
the weighting arm on the pressed side provides three different
functions, namely, a rolling function, a pressure transmitting
function and a ~unction of elLminating the deviative pressure
vector component:of the pressing body between the races defined
by the upper and lower parallel surfaces between which the rolling
element is held~ That is, the invent.ion has opened a new way
for maintalning the resistance to the sel~-aligning swing motion
of the weighting arm alway~ at zero even under high pressure and
fully developing the pendulum performance. As a result, a
rolling support type prsssing construction i5 formed which re-
sponds to the restoration torque automatically produced on the
weighting arm side with very high sensitivity even under heavy
load, whereby the pure pre~sure which does not interfere with
the pendulum function of the wei~hting arm ~ is accurately trans-
mitted to the top roller R~
(7) In the draft aection of the textile machine, the
angle of ~wing of excessi~ely large amplitude found in the exist-
ing pendulum arm i~ unnecessary and moreover, in most ca~e~,superfluous swing is harmful. Particul~xly in the large-sized
heavy-load weighting arm demanded in recent years, the exce~sive-
ness of the angle of swing has close correlation with the de-
gradation of the parallelism of the top roller Ro
- The present invention has investiaged the principle of the
self-aligning function of the pendulum ~ystem heretofore sought
after as the ideal arrangement for the weighting arm and has
opened a new way for most reasonably making efficient use of it.
Further, the invention has investigated the causes of the
- 25 -
~3Q~9
degradation of the parallelism found in the conventional sy~tem~
and has as one of its features the fact that in order to in-
cre~se the stability necessary for advantageously U9 ing the
intrinsic features of the conventi.onal systems, a particularly
limited range is set for the angle of 3wing of the weighting arm
A and the limit value of the effective amplitude thereof is
a~sociated with the range of cumulakive error produced during
manufacture of weighting arms 50 as to limit the amplitude to
an allowable minimum by special means. Thus, the invention has
successfully provided a construction having a perfect self-
restoration function by applying a unique idea based on the
above descxibed various concepts and experiments to make rea~on-
able use of the principle of the self-alignment of the pendulum
system.
As is evident from the above~ in the present invention~
the long experience and information concerning the characteri-
stics of the xi~ting typical weighting arm have been sy~temati-
cally arran~ed to investigate and grasp the merits and demerits
of ~aid weighting arm~ The conclusion is that the principle of
the ~elf-alignment of the known pendulum 4ystem i~ theoretically
quite correct and~ if correctly applied, will provide ~.uperior
stable functiolls most suitable for the weighting arm. The rea30n
why the parallelism of the top roller R is disturbed i~ that the
defects of the weighting m~ans for the weighting arm impede the
performance of the top roller, as described a~oveO Thus, the
conclusion i~ t:hat even if the pre~ing means or pre-~ing device
has its intrin~ic dire~tionality, the correct self aligning
function peculiar to the pendulum type arm can be derived if
~ome measure i~ taken to eliminate the influence of said
-- 26 --
3~69
directionality. In the pr~sent inventionJ therefore, a method
is employed which denies the se].f-alignme~t of the conventional
weighting axm construction and lncorporates a rolling element
or device between the weighting anm A and the pre~sing body or
pres~ing assembly SO
Th~ arrangement of the invention will now be described
in more detail wi~h refs~ence to Figures 19 through 24.
Figures 19, 20 and 21 show the relation betwe~n the bottom
~ cap HB holding the rolling element K and the guide arm case B
and also 9hOW various attitude~ at points of contact 27, 28 be-
tween the rolLing elemant K and the bottom cap HB and guide
arm Ao
In Figure 19~ Figure A shows a front view of the weighting
arm davice and Figure B ~hows a s ide view thereof . In Figure A,
a recesg M is formed at a regio~ of the guide arm A where the
rolling body K is pressed thereagainst. The configuration of
the recess is ~uch that when viewed in the side view B, it is an
arcuate groove having a radius R' ~omewhat greater than the
radius R of the ball K and that when viewed in Figure A it hag
a radius R e~ual to the radius R of the ball K with its center
displaced by a di3tance ~ so as to form a f lat surface over the
distance ~ ~ . Since the ball K rolls within thi3 recess M, the
h~rizontal swirlg of the guide arm A i~ performed in the range
of aid flat surface a ~, thereby making it po~sible to control
the swing angle of the weighting arm Ao The portion of the ball
K greater than its radiu~ is received in the inside pocket of
the bottom cap HB with some clearance therebetween so ~hat there
is no interference with the rolling of the ball K. FurtherJ in
the side view BD the de~ign of the cross-section of the groove M
- 27 -
~43~69
does not allow the horizontal di~placement of the ball K, thu~
maintaining the contact point 27 on the datum axis ZZ'.
On the othex hand7 the bottom cap ~B is fitted in the
guide arm case B with a minimum clearancs therebetween and, if
nece~sary, it occupies a height h. As a result, there is obtained
the function of compensating for the influence of the deviation
tendency or buckling phenomenon peculiar to the pre~ing
-pring S.
Although the control of horizontal displacement of the
bottom cap ~B as viewed in Figure B is omitted in this 3ystem~
there will be no difficulty in practice ~ince the ball K is con-
trolled by the race groove M in the guide arm A.
Figure 20 shows a sy tem in which ths ceiling plate of
the guide arm A is formed with a rectangular race groove M for
use as a race for the ba~l Ko In this case, th~ amount of
rolling di-~placement of the ball K is controlled by the dimension
o~ the longer side a of the rectangle, as shown in the front
view Ao Furtherl as seen in the side view B, since th~ race for
the ball K ha~ a groove width b, the ball K contacts he race
at two edges 27 and 27', whereby the same operating condition
as in Figura A i~ established. In Figure A, although the bottom
cap HB is loo~ely fitted in the guide aLm case B only by mean~
of its plate thicknes~, this i~ sufficient if the accuracy of
the pre3sing spring S is good.
Figure 21 show~ a system }:elonging:: to the most typioal
o the embodiments of the invention. As shown in the front
view A, swing control projectivns 29, 29' are provided at parti-
cular po~itions on opposite outer surfaces of the guide arm A.
This idea is ~imilar to that of using the previously describsd
- 28 -
~ ~3(~6~
control pin (see Figures 11 and 12) and there is lef~ a swing
clearance ~ relative to the ins:ide dimension of the guide arm
case Ao This relation correspond~ to the plane distance ~
shown in Figure 19, Ao Instead~ it becomes unnecessary to form
a reces~ in the upper surface of the guide arm Ao The other
conditions are the same as those sf the system shown in Figure
19. ~owever, a construction is added wherein guide projections
30, 30', 31, 31' disposed on opposite inner surfaces of the
guide aLm ca~e B to surround the outer periphery of the bottom
- 10 cap HB, as shown in the plan view C in Figure 21, control the
movement of the bottom cap HB so that it moves only in the correct
spring pressing direction, i~eO in the direction of the pressing
axis of the pressing spring without deviating in any other
direction~. This construction can ba applied, without any
change, to the embodiments shown in Figures 19 and 20. Figure
22 shows another embodLnent coneerning the rolling intermediary.
As shown, thi~ embodiment belongs to the type Nsing a roller K
having a shaft.
Figure 22, A, shows a front view and B shsws a 9 ide viewO
20 ~igure C is a par~pective explanatory view. Figure D show~ a
weighting arm construction us ing ~ plate spring S ' as the pre~-
ing spring S and also using a roller K having a shaft.
~ he system shown in Figure 23 is same as that shown in
Figure 22 in that it uses a roller K, but the way the shaft o~
ths roller is assembled is different. Thus, as contrasted with
the system of Figure 22 having the sha~t attached to the bott~m
~ap HB, the syqtem of Yigure 23 has the shaft attached to the
upper plate portion of the guide arm Ao At any rate9 the systems
shown in Figures 22 and 23 have the advantage that the rolling
element K, which is an intermediary, can be stabilized by ths
- 29 -
~436~69
setting of the ~haft and hence the swing action of the guidearm A is further stabilized. However, in some cases~ such con-
struction tends to become complicated and, on the other hand,
sLmplification involve~ some cau~e of ~lippage. Some amount of
slippage does not matter so much and this sy~tem is convenient
in ca~es where priority should be given to stabilization.
The embodLment shown in Figure 24 is an example of the
so-called universal type weighting arm construction appl~ able
to the various lines (front roller, 2nd.roller, 3rd roller, etcO)
in the draft section of a textile machine,
In Figure 24, the swing axis O for the weighting arm
for supporting one end of the weighting arm A i~ locatsd at the
lower end of the guide arm case B. The other end of the weight-
ing arm A is provided with a stay kn~b 43 which is received on
the lower edge of a rectangular opening 14 formed in the guide
arm caseO The arbor G of the top roller R i5 securely held at
right angles by a central lower inverted U-shaped gxoove in the
guide arm A. The opposite ends of a pressing coil spring S are
provided with a top cap 32 and a bottom cap 31 to form parallel
surface at right angles with the central axis of the æpring S
: extending along said opposite end urfaces.
The upper surface of the guide arm is formed with a race
for the ball K,. Usually, in the race for the roller arrangement,
the center of the roller K is located on the datum axis XX' of
the weightiny arm construction so that the roller will not dis-
place forwardly or rearwardly of the guide arm A, while a
particular limit range is provided in the direction of swingO
Thus the arrangement is s imilar to those shown in Figures 19-21~
More than the upper half of the ball K is received in the bottom
- 30 -
16~43~DG9I
cap 31 and its top i~ in contact with the end surface thereof
under pressureO
The bottom cap 31 and top cap 32 are fitted in the inner
diameter of the pressing spring S with a minLmum clearance there-
between and their outer ~urfaces are fitted likewise in the
guide arm case B with a minimwm clearance therebetween, ~o thak
they are slidable only in the pressing directionO The upper
assembly 36 of the guide arm case B forms an attaching base part
for selectively fixing the weighting arm assembly at a predeter-
- lO mined position an the weighting arm main body 42 and also serves
a. a base for adjusting a screw 35 which adjusts the pressure of
ths press ing ~pring S .
As for the spring pre~sure adjustment, this embodiment
shows a basic system using a screw and gauge plate 41, but this
is an example only9 since many methods may be used, including
one using a stepwise adjustable top-shaped cam and one using a
combination of a lever device and a c~n devicaO Therefore, the
invention is not l~nited to the screw adju~tment type. Further,
pins 38, 38' illustrated are an example of means ~or uniting the
upper and lower assem~lies 36 and 37 of the guide arm case B.
It is also po~sible to form them integrally with the guide arm
case B,
While there have be~n describ~d herein what are at pre~ent
considered preferred embodiments of the several features of the
invention, it will be obvious to those skilled in the art that
modifications and changes may be made without departing from the
essence of the ~vention.
It i~ thQrefore to be unders tood that the exemplary embvdi-
ments thereof are illustrative and not restrictive of the
- 31 ;
~L~43~
invention, the ~cope of which is defined in the appended claim~
and that all modif ication~ that come within tha meaning and
range of equivalency of the cla~ras are intended to be included
the rein.
32
