DE4400005C1 - Warp yarn tensioner for circular weaving machine - Google Patents

Abstract

Each warp yarn (1) on a circular weaving machine is taken through an eyelet (21) of a spring wire tensioner before going to the shed (15). The tensioner is supported on a bearing (23) and at least one stop (41) limits the tensioner motion. The tensioner is formed as a loop (22) which, together with the support bearing (23), is below the path of the eyelet (21) movement. A guide section (25) is placed below and approximately parallel to the path of the eyelet (21).

Description

The invention relates to a device for Tensioning the warp threads in front of the round shed loom, individually assigned to each warp thread thread tensioner made of spring wire with a frame stes camp is assigned, the free end with a thread eyelet for the warp thread is provided and which guide means below the trajectory the thread eyelet are assigned.

A device of this type is, among other things, by EP-PS 109 387 became known. A long, out an elongated, springy wire Thread tensioner is at a low point fixed to the frame on the machine. On his he wears a thread eyelet through which the Warp thread is drawn in the form of a loop.

With the help of a height-adjustable connection ges for the thread tensioner can the spring characteristics stik, starting at a certain deflection, see above be changed that the thread with a higher Tension can be woven.

In this way, the temporarily higher ones Forces caused by any resistance in the Thread feed arise, better overcome and the thread tension can be reduced again.  

If the thread tension continues to increase, it will stop insurmountable resistance in the thread feed which makes it necessary to start the machine hold and fix the error manually.

The thread tensioner reaches here, at next increased thread tension, a contact rail, whose impulse triggers the machine to stop.

If a thread is broken, the thread chip moves ner in his almost relaxed position, reached there a second contact rail, whose pulse also the machine stops.

Such a device is in many ways disadvantageous. It requires a very large height, because on the one hand the thread length difference due to the Specialist education is relatively large and secondly same during each phase of subject training a permanently low thread tension is desirable.

The spring of the thread tensioner must therefore be very soft be a flat feather over a long way possess characteristic.

It must also be ensured that the spring forces of adjacent thread tensioners as possible are the same. If not, it is streaky goods unavoidable.

Especially when the thread tension to Purpose of overcoming resistance by the then effective stops becomes very high the material and dimensional tolerances particularly negative on the tissue image.

Frequently occurring warp thread breaks are wide re disadvantageous consequence of this arrangement.  

Another crucial one The disadvantage is that the rod-shaped, long springs of the thread tensioner at under different loads deflect. They collide with each other and influence each other.

The attachment of well-known leadership advisers prepares for the thread tensioners on the one hand considerable Problems replacing tired or broken ones ner thread tensioner, on the other hand increase this Füh rungsriete not only the cost of the machine itself, but also the cost of changing the Warp density.

With the aim of reducing the overall height of the thread spanners and reducing the risk of collision of the operator with the thread tensioners one proposed earlier, the thread tensioner to be designed as a double-armed swivel lever (DE-PS 34 08 565).

The lower end of the swivel lever is marked by a usual spring element, a coil spring loaded. After reaching a first stop on lower lever arm is the load on the warp thread only thanks to the elastic double lever with its own spring characteristic accomplishes.

Another, even closer to the thread eyelet The stroke changes the spring characteristics times, in the limit case, the machine by one Contact is turned off.

This device also has considerable disadvantages. Usually processed on circular looms ten thread materials with their abrasion Turns of the spiral springs very quickly and prevent the proper functioning of the Spring element.  

After a short runtime of the machine only works the resilient swivel lever as a spring element. A high warp thread tension with strong fluctuation gen is a logical consequence of such a design Thread tensioners.

They helped themselves with the appropriate cladding the feather. This actually extended the duration of the Functionality, the problem itself was solved but not.

The effort to ensure the functionality speed is still considerable. Through the Productive downtimes decrease frequently machine.

With the aim of keeping the thread tension in the range of Reduce thread feed from the bobbin, and thereby the feather of the task of the overwin freeing of resistance in the thread path, was already proposed by DD-PS 1 36 861 in front of the thread tensioner to balance the cycli differences in thread length during thread processing device to arrange at least one conveyor roller.

This conveyor roller was a separate thread tensioner subordinate, which always took effect when the thread tension in the thread feeder increased for some reason.

The out of this thread tensioner when thread needs released stress on the thread at the exit of the conveyor roller caused the rope friction on the Conveyor roller was effective.

The conveyor roller conveyed the thread with a high Tractive force from the spool and can be large overcome stands in the thread course.

Then the thread tension decreased by conveying Thread so that this separate thread tensioner or the thread he loaded on a stop  or got stuck, the funding was interrupted again by the conveyor roller. The thread tension at the exit of the conveyor roller was so equal to or close to zero.

With such a device it is possible in Area of thread processing, here in the weaving zone, with a downstream thread brake one exactly to achieve defined thread tension.

These are used on circular looms Device however some crucial things opposite.

Driven conveyor rollers are acceptable Install only along a straight axis bar.

The delivery of the threads from one or more Gate to a round shed does not allow the conveyor rollers described immediately before Use shed.

An effective interplay of conveyor rollers and the thread tensioner, which is immediately in front of the shed is arranged and with a stop in the area of his greatest deflection is not on circular looms accessible with reasonable effort.

The aim of the invention is to address the shortcomings of the described to avoid these devices.

The object of the invention is a Propose thread tensioner, which with a small overall height hey a flat spring characteristic enables its Bias is adjustable, which is overcome by Resistance in the thread path supports one safe guidance of the arm carrying the thread eyelet guaranteed and which is variable within limits of warp thread numbers.  

In principle, this object is achieved by the method described in claim 1 resolved named features of the device. Due to the loop shape of the thread tensioner on the one hand, the overall height is significantly reduced. Ande on the other hand, part of the loop of the thread chip effective as a guide section.

The inevitable bearings of the thread tensioner are thus bearings for the guide means at the same time.

With the assignment of a support bearing and the Ver adjustability of one of the bearings, not only the setting of the tension of the thread tensioner realize.

The embodiment according to claim 3 allow a stable and easy to use arrangement of the thread spanners with maximum use of its spring length.

The arrangement according to claim 4 is especially then useful if the conveyor rollers are very close to the Thread tensioners can be arranged.

With the embodiment according to claim 5 it becomes possible Resistance in the thread feed also through the To overcome spring action of the thread tensioner.

The arrangement of the stops according to claim 6 Applies in connection with the adjustment option one of the bearings of the thread tensioner the preselection of the effective stop first.

The design of the fixed bearing according to An Proverbs 7 and 8 ensure stable guidance every thread tensioner. At the same time it is possible additional thread tensioners on the guide shaft to arrange or remove them from there.  

The design of the thread tensioner according to claim 9 supports the achievement of a high warp thread density.

With the assignment of driven conveyor rollers and Thread guide elements with low friction between Conveyor roller and thread tensioner will overcome further optimized by resistance in the thread run.

Taking the effort of installing one additional thread tensioners immediately after the Conveyor rollers in purchase, you can choose the resistors the warp thread feeder already at the entrance of the Overcome machine and a very low Reach warp thread tension (claim 12).

The thread tensioner in front of the entrance to the shed do not need stops to change the spring characteristic can be assigned. Developed regularly only in the area of its soft spring characteristic line and only equalizes the thread length differences that occur cyclically during the technical training.

The invention is in some embodiments tion examples are explained in more detail. In the show associated drawings,

Fig. 1 is a schematic overall view of a machine Kettfadenzuführung Rundweb,

Fig. 2 shows an embodiment of the yarn tensioner,

Fig. 3 shows a cross section through the frame fixed bearings of some thread tensioners and

Fig. 4 shows some variants illustrated schematically to 7 of the yarn tensioner with different bearing arrangements and strokes.

On circular looms according to the embodiment example, the warp threads 1 are fed from two gates 10 arranged on both sides of the loom.

The threads 1 individually drawn from the bobbins 11 are fed to the conveyor rollers 12 via the usual tensioning devices.

Additional thread tensioners 121 can be arranged downstream of the conveyor rollers 12 . This, designed as a load bracket thread tensioner 121 lie with reduced thread consumption on the stops 122 , clamp the thread and ensure that the thread tension at the output of the conveyor rollers 12 is zero. The promotion is interrupted according to the laws of rope friction.

If thread 1 is consumed, the thread tensioner 121 rises and tensions the thread at the outlet of the conveyor rollers 12 . These can now promote thread 1 according to the laws of rope friction.

The thread tension forces occurring at the entrance of the conveyor rollers 12 are significantly higher than those at the exit of the conveyor rollers 12 .

These conveyor rollers are ideal for this to overcome high resistances in the thread feed the without being in the processing zone of the thread high thread tensile forces occur.

The thread is now guided by the thread tensioner 121 , 122 , under the operating aisle, approximately to below the circular outer boundary of the shed 15 . There, preferably rotatably mounted thread guide elements 13 deflect the warp threads 1 individually or in groups upwards.

Close below the shed 15 , the warp threads 1 , based on the round weaving unit, are guided radially outward via the thread guide element 14 to the thread tensioners 2 . From there, the warp threads 1 go directly to the shed 15 .

The wavy shed formation created by the partial shafts leads to different thread lengths between the closed and open shed. Picking up this thread length difference is the primary task of the thread tensioner 2 .

The design of this yarn tensioner 2, its location tion and measures to influence the spring characteristics are first with reference to FIGS. 2 and Fig. Are described. 3

The thread tensioner 2 essentially has a triangular basic shape. It consists of a loop-shaped spring wire.

At its upper end it carries the thread eyelet 21 through which the warp threads 1 are drawn.

From here, the leg 221 , which carries the thread eyelet 21 , extends downward. From the lower bend, the leg 222 leads upward again at an acute angle and merges into the guide section 25 after a further bend.

At the end of the guide section 25 there is the bearing 23 fixed to the frame.

This frame-fixed bearing 23 can either be a bar in which the spring wire of the thread tensioner 2 is clamped, or a pivotable bearing 23 , consisting of a bush 3 and a shaft 43 , as shown in FIG. 2.

If you use a pivotable bearing 23 ; 3 , 43 , then an additional support bearing 24 and on one of these bearings 23 , 24 a lateral guide for the thread tensioner 2 is required.

In the example, this lateral guidance of the thread tensioner 2 is formed by the side walls of the annular groove 32 of the bush 3 .

It slides and rotates with its bore 31 on the shaft 43 with little play.

In the annular groove 32 of the wire of the yarn tensioner 2 is provided with an elastically biased bearing lug engaged. From there, it can be solved and used again with little effort.

The shaft 43 is composed of a plurality of individual segment-like sections on the circumference of the circular weaving machine, which can be removed by individually detachable bearings.

You can add or remove bushings 3 and thread tensioner 2 at any point on the circumference.

The support bearing 24 has the task of defining the position of the thread tensioner when the warp thread 1 is drawn in.

To adjust the pretension of the spring of the thread tensioner 2 , one of the bearings 23 or 24 is made adjustable relative to the other and relative to the basic position of the thread eyelet 21 .

If the bearing 231 is adjusted upward, the spring tensions so that the angle between the guide section and the leg 222 is larger.

The leg 222 bears against the support bearing 24 from the right.

Only leg 221 and the lower apex of the bend now act as an effective spring arm. The spring is relatively stiff.

If you set the bearing 23 so that the bearing 24 rests on the left, the spring is only effective with the leg 221 .

If the thread tension increases, the leg 221 bears against the stop 41 . The effective spring arm now extends from the stop 41 to Fa denöse 21st

Occurs in the thread feeder such a large resistance that the thread tensioner reaches the contact rail 51 , the machine is switched off.

If the thread breaks, the thread tensioner 2 jumps to the contact rail 52 and also triggers a stop signal.

The guide section 25 of the thread tensioner 2 is aligned essentially transversely to the leg 221 which carries the thread eyelet. In the relaxed state, the leg 221 slides on the side of the guide section 25 with slight pretension. The friction occurring there dampens the vibrations of the thread tensioner 2 .

FIGS. 4 through 7 illustrate different forms of the yarn tensioner 2 which are used depending on the used thread material of the warp threads 1 and the intended use of the fabric.

The choice of one of these variants also depends on whether and to what extent the thread tension peaks can be reduced by the conveyor roller pair 12 .

The embodiment according to FIG. 4 will be chosen if a low warp thread tension is to be used in the shed and the tension differences in the feed are relatively small.

In the position shown, the support bearing 24 first determines the effective spring arm. If the load increases through the thread 1 , the leg 222 first contacts the stop 42 , then the leg 221 to the stop 41 and finally to the contact rail 51 .

With an adjustment of the bearing 23 upwards, one starts with the abutment 42 . If, on the other hand, the bearing 23 , 3 is placed downward, the stop 41 becomes effective in the starting position.

The embodiment of FIG. 5 should be selected when the conveying rollers 12 along with their thread tensioners 121, 122 are so effective that the warp yarn 1 reaches the thread tensioners 2 with a very low and uniform thread tension.

Here, the entire loop 22 is regularly effective as a spring arm.

Similar to the yarn tensioner of Fig. 5 behaves also the one according to FIG. 6. Here, only different bearing elements were used.

For the frame-fixed bearing 23 , a clamping piece for the wire of the thread tensioner 2 was used here, which has a bore for receiving on the shaft 43 .

If the conveyor rollers 12 are very effective in the sense described, the effective spring arm of the thread tensioner 2 can be reduced to the absolutely necessary mini mum. In such a case, one can also do without the stops 41 , 42 and only work with the contact rails 51 and 52 .

Reference list

1 warp thread, thread
10 gates
11 coils
12 conveyor rollers
121 - thread tensioner, additional
122 - stop
13 thread guide elements, below
14 thread guide elements, top
15 shed
2 thread tensioners
21 thread eyelet
22 loop
221 legs - with thread eyelet
222 legs
23 bearings, fixed to the frame
24 support bearings
25 guide section
3 rifle
31 - bore
32 - ring groove
41 stops - on the leg 221
42 stops - on leg 222
43 wave
51 contact rail, overvoltage
52 contact rail, thread break
6 service aisle, pedestal.

Claims (13)

1. Device for tensioning the warp threads ( 1 ) in front of the shed ( 15 ) of a circular loom, with each warp thread ( 1 ) individually assigned thread tensioner ( 2 ) made of spring wire,

• - To which a frame-fixed bearing ( 23 ) is assigned,
• - The free end is provided with a thread eyelet ( 21 ) for the warp thread ( 1 ),
• - Which near the thread eyelets ( 21 ) is assigned at least one stop ( 41 ) in an end position of the thread tensioner ( 2 ) and
• - Which guide means are assigned below the path of movement of the thread eyelet ( 21 ),

characterized,
that the thread tensioner ( 2 ) below the movement path of the thread eyelet ( 21 ) is bent as a loop ( 22 ),
that the frame-fixed bearing ( 23 ) of the thread tensioner ( 2 ) is arranged near and below the path of movement of the thread eyelet ( 21 ) and
that the guiding means is formed by a guide section ( 25 ) of the thread tensioner ( 2 ) which is arranged and aligned close below and approximately parallel to the path of movement of the thread eyelet ( 21 ). 2. Device according to claim 1, characterized in that
that the frame-fixed bearing ( 23 ) is designed as a pivot bearing ( 3 , 43 ),
that an additional support bearing ( 24 ) for the loop-shaped thread tensioner ( 2 ) is provided at a distance from the frame-fixed bearing ( 23 ) and
that one of these bearings ( 23 , 24 ) relative to the other bearing ( 24 , 23 ) and relative to the thread eyelet ( 21 ) is adjustable. 3. Apparatus according to claim 1 to 2, characterized in that the frame-fixed bearing ( 23 ) behind the thread eyelet ( 21 ) supporting leg ( 221 ) of the thread tensioner ( 2 ) in its relaxed position and the additional support bearing ( 24 ) in front of Thread eyelet ( 21 ) is arranged in its tensioned position. 4. Apparatus according to claim 1 to 3, characterized in that the additional support bearing ( 24 ) is arranged on the lower vertex of the loop ( 22 ) of the thread tensioner ( 2 ). 5. Apparatus according to claim 1 to 4, characterized in that within the loop ( 22 ) of the thread tensioner ( 2 ) at least one stop ( 41 , 42 ) for limiting the deflection of the thread tensioner ( 2 ) is arranged. 6. The device according to claim 1 to 5, characterized in that in the region of both legs ( 221 , 222 ) of the loop ( 22 ) of the thread tensioner ( 2 ) each has a stop ( 41 ; 42 ) is provided. 7. The device according to claim 1 to 6, characterized in that
that the frame-fixed bearing ( 23 ) of the thread tensioner ( 2 ) is arranged on an annular shaft ( 33 ) arranged coaxially to the shed ( 15 ) of the circular weaving machine,
that each thread tensioner ( 2 ) for storage on this shaft ( 33 ) is assigned a bushing ( 30 ) with a central bore ( 31 ) which has an annular groove ( 32 ) on its outer circumference for releasable fastening of the bent wire of the thread tensioner ( 2nd ) has. 8. The device according to claim 1 to 7, characterized in that the shaft ( 33 ) of the frame-fixed bearing ( 23 ) is divided several times and the sections are individually releasably mounted on the frame of the machine. 9. The device according to claim 1 to 8, characterized in that the free legs ( 221 ) of the thread tensioner ( 2 ) in the region of the guide portion ( 25 ) are reduced in cross section. 10. The device according to claim 1 to 9, characterized in that the thread tensioners ( 2 ) in the thread running conveyor rollers ( 12 ) are arranged, the peripheral speed is greater than the processing speed of the warp threads ( 1 ). 11. The device according to claim 10, characterized in that freely rotating thread guide elements ( 13 , 14 ) are provided in the thread path between the thread tensioners ( 2 ) and the conveyor rollers ( 12 ). 12. The apparatus according to claim 1 to 11, characterized in that the conveyor rollers ( 12 ) for each warp thread ( 1 ) additional, the thread up to a stop ( 122 ) deflecting thread tensioner ( 121 ) are arranged immediately after the thread.