GB2147621A

GB2147621A - Apparatus for producing effect yarns

Info

Publication number: GB2147621A
Application number: GB08424139A
Authority: GB
Inventors: Atul Mehta
Original assignee: Saurer Allma GmbH
Current assignee: Saurer Allma GmbH
Priority date: 1983-10-08
Filing date: 1984-09-25
Publication date: 1985-05-15
Also published as: DE3336680C1; IT8422733A0; IT1196259B; GB2147621B; IT8422733A1; GB8424139D0

Abstract

A double drafting frame 1 has identical halves on either side of a frame member 2. The left half receives a roving V1 and the right half, a different colour roving, V2. The rovings V1 and V2 are combined and wound onto a common spindle 22 except when the delivery of one roving is interrupted and that roving is omitted from the yarn wound onto the spindle. When it is required to so omit roving V1 from a length of yarn a control member 18a is moved and wedges 13a and 14a engage feed rolls 6a and 9, 7a and 10 respectively, to interrupt delivery of V1. Roving V1 is broken above the bottom rolls 8a and 11. On retraction of the control member 18a the delivery of V1 is resumed. V1 is carried back into contact with roving V2 by an additional continuously delivered thread G1. Delivery of roving V2 can likewise be interrupted and, when resumed, additional thread 62 carries it back into contact with V1. <IMAGE>

Description

SPECIFICATION Apparatus for producing effect yarns The invention relates to an apparatus for producing effect yarns, and particularlyflame-effect yarns, from two rnvingsand, if desired, additional threads, which apparatus has a plurality of controllable drafting frames, two of which are arranged side-by-side in the direction ofthe axes ofthe bottom rolls and are combined to form a double drafting frame by their pressure rolls being connected together in pairs by means of axles which are mounted in a common support, a plurality of common bottom rolls extending in the longitudinal direction of the apparatus being provided for a plurality of adjacently located double drafting frames.

In order to be able to produce flame-effect yarns composed of two rovingsthat have been drafted in drafting frames, each of these drafting frames must be controllable. In a known apparatus ofthe kind initially referred to (DE-P5 23 21 762), two drafting frames located side-by-side in the axial direction ofthe bottom rolls are combined to form a double drafting frame, but each side of this double drafting frame has a spinning or spindle mechanism of its own associate with it. Afirst roving is fed to each of the two adjacent spindles by means of this first double drafting frame. For the treatment of a second roving, a further double drafting frame with its own bottom rolls is necessary.In the known apparatus, the control ofthe drafting frames, and hence the control ofthe different feeds of the two rovings, is obtained as a resultofthe bottom rolls being driven through clutches or being retarded by means of brakes. Since two rows of double drafting frames are necessary for operating on two rovings, a total of four bottom rolls are required for these two drafting frames, as well as a corresponding number of clutches for driving these bottom rolls or brakes for braking them. Because of this multiplicity of bottom rolls and of the clutches and brakes that are necessary for controlling them, the known apparatus is expensive to manufacture and assemble and also has correspondingly onerous servicing requirements.

With normal spinning machines which serve for the production of smooth yarn, in orderto bring the drafting frame to rest in the event of a breakage of the roving, withoutthe roving becoming broken in the region ofthe drafting framewhen the latter is stopped and reinsertion ofthe roving being required, drafting frames are also known which have a so-called roving stop motion orslubbing stop motion. Such a drafting frame is shown in German specification DE-OS3145798.Such drafting frames are likewise constructed as double drafting frames in which each pressure roll, with the exception of the pressure roll which rests upon the front bottom roll, has associated withita roving stop motion in the form of a wedge which can be inserted in the direction of travel ofthe roving between a bottom roll and the associated pressure roll. Each half of the drafting frame has its own spindle. If a yarn breakage occurs between the drafting frame and a spindle, an operating member causes the wedges to slide between the bottom rolls and the upper rolls. The upper rolls are thereby raised and the roving between the wedge and the associated upper roll is tightly clamped.After the thread breakage has been eliminated, the operating member must be returned by hand, against the pressure of a spring, to its starting position, so that the top rolls once again cometo rest on the bottom rolls and the drafting frame thus once more comes into operation. In spinning machines, these known stop motions serve exclusively, when a thread breakage occurs, for cutting outthe feed mechanism and clamping the roving between the upper roll and the wedge.

The basic object of the invention is accordingly to provide an apparatus of the kind initially referred to for the production of effect yarns, and particularly flame- effect yarns, from two rovings and, if desired addition althreads,which apparatus is of particularly simple construction, is reliable in operation and also requires very little servicing.

This is achieved according to the invention in that each pressure roll, with the exception ofthe pressure rolls which rest upon the front bottom roll, has associated with it a roving stop motion in the form of a wedge which can be inserted in the direction of travel of the roving between a bottom roll and the associated pressure rolls, that the wedges on one side of each double drafting frame are controllable jointly, but independently ofthe wedges on the other side ofthe double drafting frame by an operating member and that each double drafting frame has associated with it a common spindleforcombining the two rovings, one of the rovings being fed beneath the pressure rolls on one side ofthe common double drafting frame and the other roving being fed beneath the pressure rolls on the other side of the common double drafting frame.

The invention thus originates from the concept of using for the production of flame-effect yarns a known double drafting frame having a roving stop motion and to control the feed of the two rovings which are to be combined by controlling the wedge-operating members by means of a program control device and then conveying the two rovings, which are fed seperatelythrough a double drafting frame, to a common spindle associated with the said double drafting frame for combining them.

The apparatus is consequently substantially simpler in construction and in assembly. That is to say only the bottom rollsfora single row double drafting frames are required, namely as a ruletwo bottom rollsforthe double drafting frame itself and one further bottom roll forthefront pair of rolls. These bottom rolls may be continuously driven and need not be controllable.

Not only several bottom rolls, but also clutches and brakes are dispensed with. The new apparatus is thereby made easier to service. The drafting frames with stop motion which are produced in relatively large numbers for spinning machinesforthe production of smooth yarn, are relatively cheap. A prere quisite for the use of such known drafting frames with stop motion is of course that the operating members are drivable in such a mannerthatthey can not only be Drought into the stopping position in which the pressure rolls are raised by the wedges, but can also be moved back out of this stopping position to a normal operating position in which the wedges are out of action.

Advantageous constructions ofthe invention are specified in the sub-claims.

The invention is described below in greater detail with reference to a constructional embodiment shown in the drawings, in which: Figure lisa cross-section ofthe apparatus taken on the line l-l of Figure 2, and Figure 2 is an elevation of the apparatus as seen in the direction ofthe arrow II in Figure 1.

In the drawings only a part ofthe apparatus is shown in section in an operative position. The apparatus has in its longitudinal direction, i.e. in the axial direction ofthe bottom rolls, which will be described later in greater detail, a pluralityofdouble drafting frames 1. Each of these double drafting frames 1 is provided with a common support 2 in which the axles 3,4,5 ofthe pairs of pressure rolls 6al6b, 7a, 7b and 8a, 8b are mounted. Pressure rolls arranged on the two opposite sides of the support 2 are connected in pairs bythe axles 3-5, the pressure rolls 6a, 6b being so connected by the axle 3, the pressure rolls 7a, 7b bythe axle 4 and the pressure rolls 8a, 8b by the axle 5.Each pair of pressure rolls 6al6b, 7anb and 8al8b has associated with it a bottom roll 9,10 or 11 these bottom rolls 9-11 extending in the longitudinal direction ofthe apparatus over a plurality of adjacently disposed double drafting frames. Thread guides 12 are in addition provided on the support 2 for the delivery of base threads G1 and G2.

Each ofthe pressure rolls 6a, 6b, 7a, 7b has associated with it a wedge 13a, 13b, 14a, 14b. This does not apply in the case ofthe pressure rolls 8a and 8b which cooperate with the front bottom roll 11. The wedges 13a and 14a on one side ofthe double drafting frame are connected by means of intermediate members 15a,16ato a common operating rod 17a.

This operating rod is mounted for sliding movement in the direction of travel L ofthe roving V1 . Afirst driving shaft 18which extends parallel to the bottom rolls 9-11 is provided for jointly driving the operating rods 17a on one side ofthe drafting system composed of a plurality of double drafting frames. This driving shaft 18a has rigidly fixed to itforeach operating rod 17a a lever arm 1 9awhich is pivotally connected to the corresponding operating rod 17a. The driving shaft 1 8a may be rotated about its central axis by means of a pneumaticcylinderorthe like.

The wedges 13band 14b on the other side of the drafting frame are also connected by supporting members 15band 16bto a common operating rod 17b. A second driving shaft 1 8b is provided for driving a plurality of these operating rodsl7bwhichare associated with the other side ofthe double drafting frames, which driving shaft 1 8b extends parallel to the driving shaft 1 8a and is drivable independently ofthe latter by a pneumatic cylinder of its own. The driving shaft 18b is pivotally connected bythe lever arm 1 9bto the operating rod 17b.

A roving guide 20 may be arranged opposite each of the wedges 13a, 136, 14a and 14b.

Associated with each ofthe double drafting frames 1 isa common spindle 21 forcombiningthetwo rovings V1 and V2 which are conveyed through the double drafting frame on the two opposite sides thereof. This spindle 21 is preferably a hollowspindle on which a binding thread bobbin 22 is arranged.

One ofthe rovings V1 is advanced beneath the pressure rolls 6a and 7a as well as 8a on one side ofthe double drafting frame 1 while the other roving is advanced beneath the pressure rolls 6b, 7b, 8b on the other side of the double drafting frame 1 . In orderto provide uniform conditions, the axis ofthespindle 21 is located approximately in the longitudinal central plane E-E ofthe corresponding double drafting frame 1 which extends at right angles to the axes ofthe pressure rolls.

The pneumatic cylinders (not shown) which drive the driving shafts 18a, 18bare controlled bya program control device ofthe apparatus.

The manner in which the apparatus operates is as follows: Two rovings V1 and V2 which differfrom each other in colourand/or in the material of which they are composed, are inserted in the double drafting frame 1 so that one of these rovings V1 is fed beneath the pressure rolls 6a, 7a, 8a on one side ofthe double drafting frame and the other roving V2 is fed beneath the pressure rolls 6b, 7b, 8b on the other side of that double drafting frame. Base threads G1 and G2 may furthermore be fed through thethread guide 12 and beneath the pressure rolls 8a, 8b. The two rovings V1 and V2 and the base threads G1 and G2, come in contact with one another downstream of the front rolls 8a, 8b and 11 as shown in Figure 2.Afalsetwist is imparted by the hollow spindleto the yarn components VI, V2 as well as to the yarn components G1 and G2. The thread withdrawn from the thread bobbin 22 also passes into the hollowspindle 21 and atthe lower end ofthe latter is wound round the yarn components contained in the finished yarn G. The finished yarn is removed by drawoff rolls (not shown) and is wound on a cross coil.

In orderto produce an effectyarn, the driving shafts 18aand 18bare operated bythe program control device. If, for example, the driving shaft 1 8b is rotated in the direction of the arrow, the operating rod 17bwill be thereby displaced in the direction of travel L ofthe roving V2 and the wedges 13b and 14bill therefore enterthe regions between the bottom rolls 9 and 10 and the associated pressure rolls 6b, 7b. The pressure rolls 6b and 7bwill consequently be raised off the bottom rolls9,10,which continue rotating, andwill be broughtto rest.At the same time, the roving V2 is also clamped tightly between thewedges 13b and l4band the corresponding pressure rolls 6b and 7b. The further delivery ofthe roving is thereby interrupted.

Since, however, the front bottom roll 11 is still rotating and the corresponding pressure roll 8b has not been raised,the roving is broken apartatthe outlet end of the apron R. Consequently there is produced in the finished effectyarn a yarn portion from which the roving V2 is absent. After a predetermined length of yarn, the driving shaft 1 8b is rotated back in the direction opposite to that ofthe arrow into its starting position, so that the wedges 1 3b, 1 4b are returned to the starting positions thereof shown in Figure 1.

Thereupon the pressure rolls 6b, 7b move back into contact with their associated bottom rolls 9,10 and the delivery ofthe roving V2 is resumed. The roving V2 is carried into contactwith the roving V1 by the base thread G2.

Likewise, the feed of the roving V1 on the other side ofthe double drafting frame can be temporarily interrupted by means ofthe driving shaft 18a, as a result of which alternating "flame zones" of two different colours are produced in the finished yarn, if the two rovings V1 and V2 are of different colours. It is also possible, however, to allow one of the rovingsto pass through continuously and onlyto interruptthe feed of the other roving intermittently. With this procedure, it is also possible to dispense with one of the base threads.

The apparatus according to the invention is not only suitable for the production offlame-effectyarns in which the individual flame zones form thick parts, but also for producing other effects. Thus, it is possible to control both sides of each double drafting frame so that smooth transitions of both colours of the rovings are produced in the effect yarn without variations in thickness. It is also possible to feed two orthree different coloured rovings, instead of only one roving, through each side, ofthe drafting frame, in which case of course the supply ofthe various different coloured rovings which are fed through one side ofthe drafting frame is then controllable only jointly.

Claims

1. Apparatus for producing effectyarns, and particularly flame-effect yarns, from two rovings and, if desired, additional threads, comprising a plurality of controllable drafting frames, two of which are arranged adjacent side-by-side in the axial direction of the bottom rolls and are combined to form a double drafting frame by their pressure rolls being connected together in pairs by means of axles which are mounted in a common support, a plurality of common bottom rolls extending in the longitudinal direction of the apparatus being provided for a plurality of adjacently located double drafting frames, characterised in that each pressure roll, with the exception of the pressure rolls which rest upon the front bottom roll, has associated with it a roving stop motion in the form of a wedge which can be inserted in the direction oftravel of the roving between a bottom roll and the associated pressure roll, that the wedges on one side of each double drafting frame are controllable jointly, but independently ofthe wedges on the other side of the double drafting frame by an operating member, and that each double drafting frame has associated with it a common spindle forcombining the two rovings, one of the rovings being fed beneath the pressure roll on one side ofthe common double drafting frame and the other roving being fed beneath the pressure rolls on the other side of the common double drafting frame.

2. Apparatus according to claim 1, characterised in that the operating member is an operating rod which is arranged forsliding movement in the direction of travel ofthe rovings and which carriesthewedges.

3. Apparatus according to claim 1 or 2, characte- rised in that a first driving shaftextending parallel to the bottom rolls is provided forjointly driving the operating members or rods on one side of one drafting frame of a plurality of double drafting frames and a second driving shaft is provided for jointly driving the operating members on the other side of the drafting frame.

4. Apparatus according to claim 1, characterised in that the axis ofthe spindle is located approximately in the longitudinal central plane of the associated double drafting frame, which plane is at right angles to the axes ofthe pressure rolls.

5. Apparatus according to claim 1 or3, characte- rised in that the operating members orthe driving shafts are controllable by a program control device.

6. Apparatus according to any preceding claim including means for continuously delivering one or more additional threads for incorporation into an effect yarn such that when the delivery of a roving is interrupted and subsequently resumed that roving is carried by a base thread into contact with the other roving.

7. Apparatus substantially as hereinbefore de scribed with referencetothe accompanying drawings.

8. A method of producing effectyarns, the method being substantially as hereinbefore described with reference to the accompanying drawings.