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Патент USA US3084510

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April 9, 1963
Filed May 16, 1962
:32:5 =:3352:;
/Véq M’ W
Edited grates vlistens
Patented Apr. 9, 1953
.l'ohn Wesley Harvey, .liu, Richmond, Va, assignor to E. 1.
du Pont de Nemours and Company, Wilmington, Deb,
a corporation of Delaware
Filed May 16, 1962, Ser. No. 195,178
7 Claims. (ill. 57-81)
imposition of additional tension to the yarn due to such
erratic operation.
Further objectives of this invention are to provide this
novel device in a relatively simple economical yet reliable
form which performs effectively to handle the problems
of initial tensioning, centrifugal forces, changed thread
weights, engaging tension, variable multiplicity of yarn
lines, thread de?ection, oscillation of sensing means, speed
of response, and others.
This invention relates generally to new and useful imp
The objects of the invention are accomplished by the
provements in devices for detecting yarn or thread breaks 10
improved thread break detector of this invention which
in textile yarn processing apparatus and, as illustrated
is comprised generally of a slightly unbalanced pair of
herein, relates more particularly to an improved electrical
counterbalanced thread-engaging detection means mounted
switch actuating device of wide utility in the textile in
on a pivotal member, ‘an electrical switch means actuated
dustry but especially useful under conditions of low yarn
tension, as for example with textile downtwister machines. 15 by the detection means, these components and cooperat
ing structure constructed and arranged to limit tension
Various devices for detecting yarn or thread breaks,
applied by the detection means to the engaged thread
with corresponding signalling or stop motion devices, are
solely to the ditference in opposing torques applied by
well known in the prior art. In processing yarn or thread
the slightly unbalanced detection means.
from one textile machine position to another, it has been
Other objects and advantages will appear from a con
found highly desirable to quickly ascertain the presence
sideration of the following speci?cation, claims, and ac
of a break or serious loss of tension in the running yarn
companying drawing in which:
or thread. Such ascertainment, or detection has been
FIGURE 1 is a side elevational view of the supporting
accomplished by various means and forms of complex de
contain mechanical or electrical means for actuating a
structures (partly in section) with stationary thread
guides mounted thereon, the improved thread break de
machine stop motion device or signalling the need of cor
tector unit, and a thread line engaged therewith and
tecting mechanisms. Generally, these detecting devices
FIGURE 2 is an extended cross-sectional view taken
rective action. The single thread contacting elements of
along line 2—-2 of FIGURE 1 showing an aligned group
many of these devices have been of the gravity operated
of seven detection devices on units.
“drop-wire” type, and there have been those of the adjust
able “?y-wire” type where the “?y-wire” is operated by 3O Referring now to the drawing in which like characters
of reference designate similar parts in the respective views,
spring tension.
FIGURE 1 shows the position of the thread break detec
While such prior art devices generally have operated
tor component parts with respect to a running thread line
fairly satisfactorily, they have not provided satisfactory
40 with the thread break detector device in its locked or
detecting means that, in and of itself, imposes very little
tension on a yarn ‘which itself is under little tension in 35 “string up” position. In the drawing the supporting struc
ture of the thread break detector comprises two metal
angle frame pieces 21 mounted on two L-beam structures
39 by means of four sets of clamp shoes 19 and socket
certain arrangements for the plying together of several
head cap screws 20 with lockwashers. Bracing pieces
yarns into a single thread such as is performed on a down
twister machine. The imposition of appreciable variation 40 22 are welded to the steel angle frame pieces 21 to pro
vide bracing therefor. Stationary thread guides 4 are
in tension on the yarns by conventional “drop-wire” de
mounted on the L-beam structures 39‘ by means of eyelet
viws results in the formation of undesirable loops in the
straps 41. A pair of outer supporting members 17 are
twisted thread. This frequently can be caused by momen
moving from one textile machine position to another.
Also, such prior art devices are not desirable for use in
‘adjustably mounted on the metal angle frame pieces 21 by
tary retardation and appreciable tensioning of at least
one yarn line at its unwind package which is caused by 45 means of socket head cap screws 23 with corresponding
nuts and lockwashers. A pivot bar 10‘ is secured in bush
a. slight imperfection in the winding of the particular un
ings mounted in a pair of steel bosses 30 mounted in outer
wind package. The effect of this variation in tension can
cause erratic movement of a single yarn sensing element
and imposition of additional tension on the yarn line
which are undesirable results.
It is an object of this invention to provide an improved
yarn or thread break detector that will impose very little
supporting members 17. The supporting structure is elec
trically grounded by a ground line to the pivot bar 10
or to screw 16 mounted in the outer supporting member
The detection means of the thread break detector device
comprises beam member 1 pivotally mounted by means
tension on yarns being plied together, thus preventing un
of bearing elements 3 (shown in ‘FIGURE 2) on the pivot
desirable loops later on in the twisted thread.
Another object of this invention is to provide this de 55 bar 10. Thread guiding members 121 and 122 mounted
in eyelet straps 24 are attached to opposite extremities
vice in such ‘form that it will be useful wherever it is
of the beam member 1 by rivets 25 generally adjacent
desirable to impose very little tension on a yarn when
stationary thread guides 4. Adjustable weights 5 are slide<
detecting yarn breaks.
A further objective of this invention is to provide this
ably mounted on the upper arms of the beam member’s
device with adjustment means for predetermining and 60 opposed extremities for varying the sensing force applied
concurrently controlling, in variable manner, the amount
to an engaged yarn line.
of tension imposed by the thread break detector upon the
The electrical switch means which is actuated by the
yarn or yarns, thus providing re?nement of the detecting
thread break detector device comprises a ?rst rod mem
her 7 mounted in the outer supporting members 17 by
Yet another object of this invention is the provision 65 means of a pair of electrically insulated bushings 12 com
of an improved yarn break detector in which the yarn is
pressively ?tted around the ?rst rod member 7 by means
engaged at two longitudinally spaced positions in a man
of socket head set screws 34 in threaded engagement with
ner so that yarn tension and variations in yarn tension at
shoulder members 35 welded on the outer supporting
these positions tend to act in opposition to each other to
members 17. The screws 3'4 are provided at each end of
substantially cancel each other out in a differential action 70 the ?rst rod member 7 for adjusting the angular position
as far ‘as operation of the detector device is concerned,
of rod member 7. An elongated contact element 6 is
and to avoid erratic operation of the detector and the
adjustably mounted on the ?rst rod member 7 by means
of screws ‘11. The contacting element 6 is located slightly
9 and rod member “13 thus serve to limit movement of
below the lower surface of one extremity of beam mem
the beam member 1 during string up and initial tensioning
ber '1, the contact element 6 is electrically connected to
the high voltage side of a suitable relay system by means
of the yarn.
The thread line 49, which is to be processed on a suc
of a voltage line connected at one of screws 11.
ceeding machine, is sequentially passed through a ?rst
stationary thread guide 4, the thread guiding member 123i
ously this element may be grounded and the other por
tions of the structure suitably connected to a high voltage
The locking means which facilitates initial string up is
mounted on the ?rst portion of the beam member 1, the
thread guiding member 122 mounted on the second por
tion of the beam member \1, the second stationary thread
comprised of a spring-urged second rod member 13 mov 10 guide 4, and on to the succeeding machine (such as a
ably mounted in the outer supporting members 17‘ by
means of a pair of bearings 33. A lever-arm assembly
consisting of a contact collar 29 and arm 14 locked in the
contact collar 29 by screw 36 is attached to one end of
textile downtwister) for further processing. After the
threading operation is completed, the locking means is
released by rotating the second rod member 13 down
wardly out of contact With the bottom surface of the
the second rod member 13> by means of screw 37. Ten 15 beam member 1. The member 122 of the beam member
1 is then free to engage the running thread line 40 under
sion spring 8 which is under tension in the locked condi
the in?uence of the unbalanced weight and to be sup
tion of the thread break detector is mounted at one of
ported thereby until such time as there is a break or sig
its two ends in a hole drilled in the second rod member
ni?cant loss of tension in the running thread line. Adjust
13 and at its other end by shoulder screw 38 mounted in
20 ing screws ‘23 are provided to vertically adjust the entire
one of the outer supporting members 17 .
thread break detector so as to vary the tension imposed
A resilient limit-stop means for the pivoted member 1
on the yarn line and magnitude of the balanced forces on
comprises a pair of pivot arms 27 pivotally mounted on
members 1211 and 122 and also to counteract any tendency
the outer supporting members 17 by means of shoulder
by the beam member 1 to vibrate during operation of the
screws 26; and, limited as to descending movement by
adjusting screws 32 with corresponding lockwashers, and 25 thread break detector.
If a break in the running thread line 48 should occur,
limited as to upward movement by tension spring 23.
the member 122 of the beam member 1 descends until
‘Stop bar 9 is mounted at both of its ends in pivot arms
physical metal-to-metal contact is made between the lower
27 by means of screws, and is urged in the clockwise
edge of member 1 and contacting element 6. Since, as
direction as shown in FIGURE 1 by tension spring 28.
previously described herein, the beam member 1 is elec
The other end of spring 23 is attached to screw 15 in one
trically grounded and the contacting element 6 is con
of the outer supporting members 17.
nected to the high voltage side of a suitable relay system
In the preferred embodiment of the improved thread
or stop motion device; the electrical contacting of the
break detector of this invention, multiple beam members
beam member 1 and the contacting element 6 actuates
1 are used as shown in FIGURE 2. In such embodiment,
plural electrical insulating pieces 18 consisting of essen 35 the alarm or stopsthe thread processing device. The elec
trical system may include a “time delay mechanism” to
tially C-shaped pieces of polyethylene or other good elec
preclude actuation of the relay system due to momentary,
trical insulation or material are siideably ?tted around
accidental contact by the beam member 1 with the con
the contacting element 6, and are movable or slideable
tacting element 6.
along the length of the contacting element 6.
The adjustable resilient limit-stop means provided in
In the operation of the described thread break detector 40
the thread break detector device reduces undesirable oscil
starting'with the initial threading of the device, the piv
lation of he beam member 1 which occurs at times when
otedbeam member 1 is slightly unbalanced by positioning
the apparatus is started up.
of the weights 5 toward its portion of member it under
In the preferred use of his thread break detector, which
which the contacting element 6 is positioned. The degree
of unbalance between the beam member’s opposing ex
is in combination with a textile downtwister machine, a
plurality of detection devices are employed as shown in
tremities will determine the thread tension sensing force
FIGURE 2. In such preferred use it has been found
to be imposed on the running thread line 49' by thread
desirable to provide a plurality of electrical insulating
guiding member ‘122. The member 122 will apply the
pieces 18 to insulate one or more of the beam members
sensing force due to the unbalanced Weight downward
upon the running thread line 46, and the other member 50 1 in a given bank of detection devices from the contacting
element 6 when said beam member (or members) is not
121 will apply a force upward on the running thread line.
It will be seen in FIGURE 1 that the con?guration of
beam member 1 is such that guides 121 and 122 are dis
placed laterally from the straight line connecting the
guides 4.
This causes the running yarn line to bear
against the top of guides 1121 and 122, and results in im
position of a slight tension in the yarn line and opposing
forces F1 and F2 on member 1 exerted at members 121
being used to engage a running thread line. When any
beam member 1 is to be inactivated, an insulating piece
18 is slideably positioned under the beam member to be
inactivated, thus permitting normal operation of the re
maining activated detection means.
The thread break detector of this invention is partic
ularly useful where the imposition of considerable tension
on the yarn by the detector is undesirable. It has been
and 122. These forces are substantially balanced in the
operating position or" the member 1 so that variations in 60 found particularly useful in the plying together of several
the tension of the yarn line from causes other than the
unbalanced sensing force essentially do not cause false
strands of synthetic yarn to form a single thread.
ventional “drop-wire” devices have caused loops in the
?nal thread due to over-stretching of at least one strand
signalling during operation or disturb the position of
of the yarn when an imperfection in at least one yarn
member ll. However, upon breakage of the yarn the
sensing force due to the unbalanced weights will cause 65 package caused a momentary increase in tension. The
detector of this invention may be used in any application
the member 1 to move into contact with contact element
Where a sensitive thread break detector is desired. The
6 to signal the break and/ or shut off the yarn handling
instantaneous tension imposed from sources external to
apparatus with which the detector device is connected.
the detector device on the running thread line may be
In order to string up the device the beam member is
varied within limits without aiiecting the operation of
locked in a generally horizontal position by rotating the
the device. Appropriate adjustments of the adjustable
spring-urged second rod member 13 by rotating arm 14
weights on the beam member’s ?rst and second portions
counterclockwise (as viewed in FIGURE 1), to position
very accurately control the sensing force.
the second rod member v1?) against a lower surface section
It can be seen that applicant has provided a novel im
of the ‘beam member 1. ‘The rod member ‘13 is held in
proved thread break detector. Various modi?cations
this position by means of tension spring 8. The stop bar
within the spirit of this invention will occur to those
skilled in the art and it is intended that all .such are to
be included within the scope of the following claims.
I claim:
slideably mounted on the beam member so as to over
1. An improved thread break detector comprising, in
combination, a supporting structure, an unbalanced ?rst
to contact a tensioned thread in opposed engagement.
balance said second portion, and two thread guiding mem
bers mounted on the beam member each near the ex
tremity of said ?rst and said second portions and adapted
5. The device of claim 4 in which said electrically in
sulated assembly comprises a ?rst rod member mounted
in the supporting structure and electrically insulated
therefrom by a pair of non-conducting bushings, and a
spaced opposed positions along said tensioned thread, a
second means mounted on said structure and positioned to 10 contacting element adjustably mounted on the ?rst rod
means pivotally mounted on said supporting structure
adapted to engage a tensioned thread at two longitudinally
member and positioned to engage a ?rst surface section
of said beam member’s second portion when said ten
sioned thread loses tension to convert said loss of tension
sive to a signi?cant drop in tension of said tensioned
to actuation of an electrical circuit.
thread, said ?rst and second means being further con
‘6. The device of claim 5 in which said locking means
structed and arranged to have an electrical voltage differ 15
comprises a spring-loaded second rod member movably
ential maintained therebetween while said ?rst means’
mounted in the supporting structure and adapted to co
overbalanced extremity is supported by tension in said
operate with a second surface section of said beam mem
thread, a third means movably mounted in the support
engage a ?rst portion of an overbalanced extremity of
said ?rst means upon movement of said ?rst means respon
ing structure for locking the ?rst means in a given posi
tion during initial engagement by said ?rst means with
ber’s second portion, and a lever-arm assembly mounted
said tensioned thread, and a fourth pivotal means ad
on a ?rst extremity of said second rod member and con
structed and arranged to move the second rod member in-
justably mounted in the supporting structure for resiliently
to engagement against the beam member during initial
tensioning of said tensioned thread and then remove said
limiting said ?rst means’ movement in one direction.
second rod member from engagement With the beam
2. The device of claim 1 in which said unbalanced ?rst
means comprises a sensing member having two opposed 25 member to permit the beam member’s second portion to
operatively engage the tensioned thread.
unbalanced extremities constructed and arranged to exert
7. An improved thread break detector for a textile
a very small magnitude sensing force by said overbalanced
downtwister machine comprising, in combination, a sup
extremity on the tensioned thread proportional to the
porting structure, a plurality of detection means electrical
degree of unbalance between extremities, and to sub
stantially isolate the member from the action of sudden 30 ly grounded and pivotally mounted on the supporting
structure with each detection means having an under
increases in thread tension and cause engagement of said
balanced ?rst portion and an overbalanced second portion
overbalanced extremity and said second means only in
both constructed to contact generally parallel tensioned
response to drops in thread tension below a given pre
threads in opposed engagement, an electrically insulated
determined minimum value.
3. An improved thread break detector comprising, in 35 assembly mounted in the supporting structure and posi
tioned to engage a surface section of each of said plural
combination, a supporting structure, a detection means
detection means’ overbalanced second portions in the
electrically grounded and pivotally mounted on the sup
event a tensioned thread engaged with one of said detec
porting structure with an underbalanced ?rst portion and
tion means loses tension to converting said loss of thread
an opposed overbalanced second portion both portions
constructed and arranged to contact a tensioned thread in 40 tension to actuation of an electrical circuit, a locking
means movably mounted in said supporting structure in
opposed engagement, an electrically insulated assembly
cooperation with each of said plural detection means to
adapted to be connected to a source of high voltage and
prevent engagement by any one of the plural detection
mounted in the supporting structure and positioned to
means with said actuating assembly during initial tension
engage said grounded detection means upon movement of
said detection means in response to signi?cant drop in 45 ing of said tensioned threads, a resilient limit-stop means
adjustably mounted in said supporting structure in co
tension of said tensioned thread, a locking means movably
operation with said plural detection means and said lock—
mounted in said supporting structure in cooperation with
ing means for positively limiting movement of said plural
said detection means to prevent engagement of the assem
detection means when said locking means is actuated,
bly by the detection means during initial tensioning of
plural electrical insulating pieces slideably mounted on
said tensioned thread, and a resilient limit-stop means ad
the actuating assembly and adapted to be so movably po
justably mounted in said supporting structure in coopera
sitioned as to selectively prevent actuation of said elec
tion with said detection means and said locking means
trical circuit by one or more predetermined detection
for limiting movement of said detection means When said
locking means is actuated.
4. The device of claim 3 in which said detection means
References Cited in the ?le of this patent
comprises a beam member pivotally mounted on said sup
porting structure, said beam member having a ?rst por
tion and a second portion each constructed and arranged
to contact a tensioned thread in opposed engagement, a
plurality of adjustable weights of which at least one is 60
Great Britain ________ __ Jan. 10, 1962
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