US2621390A - Roll system - Google Patents

Description

Dec. 16, 1952 A. NlELD 2,621,390

ROLL SYSTEM Filed April 12, 1948 2 SPEETSSHEET 1 JNVENTOR. &RNOLD NIE-LD ATTORNEY A. NIELD ROLL SYSTEM Dec. 16, 1952 Filed April 12, 1948 2 SHEETS-SHEET 2 mm m WE vw mm MD R. w M

Patented Dec. 16, 1952 UNITED STATES ATENT OFFICE ROLL SYSTEM tion of Great Britain Application April 12, 1948, Serial No. 20,481 In Great Britain April 14, 1947 12 Claims.

This invention relates to an improved roll system which enables a filamentary material e. g. a yarn, filament, wire, cord, tape, ribbon or band to make adequate frictional contact with a moving roll surface without encircling the moving roll. More particularly it relates to an improved roll system for use in the conveying of yarns and filaments and is of particular interest in relation to roll systems where the rolls rotate at high speeds e. g. in the drawing or winding of artificial yarns and filaments.

It is necessary during the conveying of filamentary materials by means of roll systems to prevent slipping over the surface of the driving rolls. One method of doing this is to use a nip roll in conjunction with the driving roll, the filamentary material being pinched between nip and driving roll. This method has the objection that the roll surfaces undergo considerable wear owing to the friction occasioned between the driving roll and the nip roll. As soon as the surfaces of the rolls wear, inequalities in the pinching force are produced and these lead to slipping and thus to variation in the rate of movement of the filamentary material. This is particularly noticeable in the textile trade where, to prevent damage to the yarn or filament and to give adequate frictional control, the nip rolls have a soft surface e. g. rubber, and this is worn away very quickly. Another method of preventing slippage frequently used in the textile trade is to use a single idler roll the axis of which is slightly off parallel with that of the driving roll, so that a filamentary material e. g. a yarn looped a number of times round the two rolls makes a number of loops round the rolls without overlapping and thereby makes contact with the driving roll over a comparatively large arc of the circumference thereof, the total of a number of arcs of contact being often equivalent to more than one complete turn round the driving roll.

Referring particularly to the textile trade, it is common practice in the art to subject artificial yarns and filaments to a drawing process. In the commercial drawing of artificial yarns and filaments it is usual to use a battery of feed roll/draw roll systems on one supporting metal frame, all driving rolls being connected by gears to a main driving shaft. This apparatus has the disadvantage of under-going considerable vibration and as a result of this, in conjunction with the inevitable slight mechanical inaccuracies in the gearing there is a tendency for the apparatus to produce inequalities in the degree to which the yarn or filament is drawn. To overcome this difficulty it has been proposed to use one shaft, running the length of the supporting frame, carry ing all feed rolls, and a similar shaft, capable of rotating at higher speeds, carrying the same number of draw rolls. Such an apparatus needs far less gearing and undergoes less vibration than that normally used but difliculty is experienced in stringing up each driving roll and its attendant idler roll as the stringing up operation normally takes place while the rolls are in motion and the yarn or filament has to be passed into the interior portion of the machine and near the moving parts to encompass the driving roll and its idler roll, while the shaft on which the driving roll is mounted is rotating at a high speed. This stringing up operation is difficult and may be dangerous for the operator. Nip rolls have been used with such a drawing apparatus and while they may be satisfactory in conjunction with feed rolls I find that owing to the high rate of wear they are not satisfactory when used in conjunction with draw rolls.

An object of this invention is to provide an improved roll system to enable a filamentary material e. g. a yarn, filament, wire, cord, tape, ribbon or band which makes frictional contact with a moving roll surface to make adequate frictional contact without encircling the moving roll. A further object is the production of an improved roll system for use in the conveying of filamentary material which can be strung up more easily than those of the prior art. A still further object is the provision of an idler roll device for use in the drawing of artificial yarns and filaments and the winding of textile yarn and filamentary materials. Yet a still further object is the provision of an idler roll device for use in conjunction with draw frames having a series of draw rolls mounted on one continuous shaft. Further objects will appear hereinafter.

According to the present invention these objects are accomplished by the provision of a roll system comprising an idler roll and a driving roll, the axes of which are substantially parallel, characterised in that it also comprises means for ensuring that filamentary material when being transported by the roll system and encompassing said idler roll, makes arcs of contact with but does not encircle the driving roll and means for ensuring that the filamentary material makes more than one loop round the idler roll without overlapping.

The means for ensuring that filamentary material encompassing the idler roll makes arcs of contact with but does not encircle the driving roll, preferably consists of one or more additional 3 idler rolls which are all encompassed by the filamentary material in the manner illustrated in the attached drawings. It will be appreciated that one or more of these additional idler rolls may be replaced by other supporting means such as bars or guides.

In a preferred embodiment of this invention the idler roll together with any additional supporting means is so mounted that either the idler roll or the additional supporting means or both may be swung or otherwise moved away from the driving roll during stringing up. Utilising this apparatus the roll system may be strung up-very easily, the filamentary material being wound round the idler roll and other supporting means without any contact being made with the moving driving roll and brought into contact with the driving roll after the system has been strung up. A similar effect may be achieved if desired by moving the driving roll but it will be appreciated that this involves more difficulty in machine design and greatly increases the cost of the machine.

The means for ensuring that the filamentary material makes more than one loop round the idler roll may be any of the known spacing devices such as combs or a number of guides which separate the various loops of filamentary material. A preferred method of operation is to mount one of the idler rolls used, slightly 01? parallel with the other supporting means so that it acts as a skew or oblique roll. Another method of operation is the use of ridged or grooved idler rolls or supports. Both the last two methods have the advantage of combining a spacing means with a supporting means.

In the attached drawings'Figure l'is a diagram illustrating the general application of the roll system of this invention. The filamentary material l passes to, but does not encircle, the driving roll 2 and is held in contact with the roll 2 over the arc ab by causing it to follow'the path shown in the drawing round the two idler rolls 3 and 4. From the idler roll 4 the filamentary material passes to a further treating zone or normal collecting device. The filamentary material makes a number of loops round the idler rolls 3 and 4 to increase the frictional grip between the filamentary material and the roll 2, and to prevent overlapping of the various loops the axis of rotation of the roll 3 is set just off parallel with the rolls 2 and 4.

Figure 2 illustrates a preferred form of the device of this invention applied to the drawing of artificial yarn, wherein yarn licoming from the feed rolls (not shown) makes four turns round the threeidler' rolls 6, l and 8 (roll 3 is slightly off parallel to enable the yarn passing round the rolls 5, I and 8 to make a number of turns without overlapping) during which it is held against the driven draw roll 9 and finally passes from the idler roll 8 to a collecting device (not shown). The three idler rolls are mounted on stub axles which are fastened to a frame Hi which can swivel about axle ll set in the bracket l3 which is attached to the frame of the drawing apparatus. The frame it is fitted with a spring device 12 which presses against the bracket 13 and holds the frame It in the position required for the yarn to make the necessary arcs of contact with the draw roll 9.

Figure 3 shows an end view of Figure 2 in which the path of yarn roundthe rolls 6, T, 8 and 9 can be clearly seen, the yarn making contact with the draw" roll over the arc my. It will be appreciated 4 that the yarn actually makes four arcs of contact with the draw roll surface.

Figure 4 shows an end view of Figure 2 wherein the frame It has been swung away from the driven draw roll 9 about the axle H by pulling the handle it and thus releasing the spring device 12. It will be seen from this drawing how the yarn can be wrapped round the idler rolls without any contact being made with the moving draw roll which, on the preferred type of draw frame, is one of a series mounted on one continuous driven shaft. To start the drawing process, after the yarn has been wound a number of times round the idlers and passed to the collecting device, pressure is applied to the handle l4 and the frame swung into the position shown in Figure- 3 where it is held by the spring device The four arcs of contact the yarn makes with the draw roll provide an adequate frictional grip, and slip over 'the draw roll surface is reduced to a minimum. This enables the draw ratio to be exactly controlled.

While in the foregoing description, devices using two and three idler rolls are illustrated, any number of idler rolls may be used. I have found that two or three idler rolls are very satisfactory as when two or three are used it is possible to obtain large arcs of contact with simple construction. The use of more than three rolls increases manufacturing costs and the complexity of the apparatus. The idler rolls may if desired make contact with the driven roll but it is preferred that they do not do so as such contact is liable to cause excessive wear and also complicates the design of the apparatus.

When supporting means other than idler rolls are used, care must be taken to ensure that the frictional force evoked by the passage of the filamentary material over the supporting means is less than the frictional grip of the filamentary material in contact with the driving roll, otherwise slippage over the driving roll surface will occur. The frictional force at the supporting means surface will depend on the arc of contact of the filamentary material, the material of the supporting means and the filamentary material itself. It is therefore advisable that not more than one supporting means other than idler rolls should be used. A further disadvantage of nonrotating supporting means is the wear caused by the filamentary material slipping over the support surface. Such supports must therefore either be con=tructed of specially hardwearing material or replaced frequently. Both courses of action tend toincrease the cost of the machinery.

While the method used in the drawings for withdrawing the idler rolls from the driving roll 15 one preferred for use with the device of this invention, it will be appreciated that the rolls may be withdrawn by any usual means, they may for example be slid away from the driving roll along suitable guides. Furthermore it is not necessary that all the idler rolls or other supporting means should be withdrawn from the proximity of the driving roll. Any number may be withdrawn depending upon the type of mountmg used. For example two idler rolls may be mounted on arms which can be moved from the proximity of the driven roll by means of a scissors action. This type of mounting has the advantage that it can be set up so that the pull of the filamentary material holds the idler rolls in close proximity to the driving roll since the path traversed by the filamentary material while in contact with the driving roll is shorter than the path when the filamentary material is out of contact with the driving roll. The construction of the apparatus may therefore be simplified since no holding device such as the spring device illustrated in the drawings is required.

The spring device used to hold the idler roll device illustrated in the drawings in position may be replaced by any holding device which will maintain the filamentary material in contact with the driving roll e. g. a bolt, a latch or a weighted balance arm.

The path of the filamentary material round the idler rolls and other supporting means will depend upon the mounting thereof and the direction of rotation of the driving roll. The number of loops of filamentary material will depend upon the frictional grip required i. e. referring to the drawing of yarns, for heavy yarns more loops will be required than for lightweight yarns.

The amount of contact of the filamentary material with the driving roll depends to some extent on the disposition of the idler rolls or other supporting means. The greater the arc of contact the filamentary material makes with the driving roll the more efiicient is the system and it is preferred that the arc of contact should be at least 90 at each pass over the driving roll. However a smaller arc of contact may give adequate grip if the number of loops of filamentary material is increased accordingly.

While the idler roll device of this invention had been described with particular reference to roll systems used for the conveying of yarns it will be appreciated that it may be applied with equal success to all cases Where it is desirable to avoid winding any filamentary material round a driving roll i. e. to avoid using a capstan grip, while ensuring that the filamentary material does not slip over the roll surface. Such a roll system may be used for example in the textile trade for the gripping of yarns, filaments, ribbons and braids, in the rope trade for the gripping of ropes and cordage of all kinds and in the metal trade for the gripping of Wires, cables and metal bands and strips.

While in the description the driving rolls referred to all have plane surfaces this is not essential. In the conveyin of wire for example added frictional grip may be provided by the use of grooved rolls. Such grooves as well as serving to provide additional frictional grip also act as means for causing the filamentary material to make a number of loops round the idler rolls without overlapping.

The device of this invention may be constructed to any of the materials commonly used in the production of roll machinery. It will however be appreciated that th type of roll surface required is dependent on the type of filamentary material. In the textile trade good results have been obtained using steel rolls or rolls made of light weight alloys e. g. aluminium alloys having a chromium plated surface.

The following examples illustrate but do not limit the scope of my invention.

Example I idler rolls were mounted at one end of a plate, which was free to swing about its other end in a plane at right angles to the axes of rotation of the polished metal draw roll (3" diameter 6" long), and were so positioned on the plate that their axes of rotation contacted the plate at the apices of a triangle, one axis being 3 to 4 olf parallel with the other two which were parallel to the axis of rotation of the draw roll as illustrated in Figures 2, 3 and 4. This plate was held so that the idler rolls were well away from the draw roll during stringing up but was thereafter swung into a position with the idler rolls arranged round the draw roll so that yarn passing in a triangular path round. the idler rolls was forced into contact with the draw roll on one side of said triangle as illustrated in Fig. 3. The feed roll of this apparatus rotated at revs. per minute, the draw roll at 600 revs. per minute. The yarn produced had a ratio drawn length to undrawn length of 4.95:1 which indicates that there was a minimum amount of slip over the draw roll surface.

Example 2 In this example a device similar to that illustrated in Figures 2, 3 and 4 was used but the third roll I was removed so that only two idler rolls were used.

A viscose yarn was taken from a package via suitable guides and wound three times round two idler rolls, each 2 inches in diameter, and one 01' which was slightly off parallel, mounted on a movable frame as illustrated in Figures 2, 3 and 4, without making contact with the drawing roll. From the idlers the yarn passed through a lappet eye to a rin twisting spindle capable of rotating at 6000 revs. per minute. After stringing up the yarn, the spindle was set in motion and the idler roll supporting frame swung over so that the filamentary material made contact with the driving roll, rotating at a surface speed of 50 feet per minute. A twist of 10 turns per inch was imparted to the yarn which showed no tendency to slip over the driving roll which in this case acted as a feed roll.

I claim:

1. A process for forwarding artificial filamentary material by contact of said filamentary material with a driving roll which comprises looping the filamentary material round an idler roll and at least one additional support, which idler roll and support are positioned so that the filamentary material looped round them does not make contact with the drivin roll, and then changing the position of at least one of the members of the group, idler roll, additional support and driving roll so that the filamentary material looped round the idler roll and additional support is caused to make arcs of contact with the driving roll, while said idler roll and additional support are maintained in spaced relation from said driving roll throughout their axial extent.

2. A process according to claim 1 wherein the additional support is another idler roll.

3. A process according to claim 1 wherein the idler roll and the additional support can be moved as one unit in relation to the driving roll.

4. A process according to claim 1 wherein the arcs of contact made by the filamentary material do not overlap.

5. A process according to claim 1 wherein the filamentary material is an artificial yarn or filament.

6.; Aprocessgaccording toclaim- 1 wherein the driving roll isa draw-roll.

7- Aprocess. of drawing artificial iyarns and filaments wherein the yarn or filament coming from feed rolls is. loopedrround a supporting device-comprising at leastone idler roll,.th axis of which is substantially parallel to a driven drawroll, and one other idler roll skewed in relation to-the first idler; and thereafter causing the looped filamentary-material to make arcs of contact with the driving draw-roll but Without permitting contact between said' idler rolls and draw-roll by changing th'eposition of the idler-rolls relative tothe-drawrolls, and then passing theryarn or filament toa suitablecollecting device.

8,. Apparatus-{or forwarding filamentary material comprisingsa frame. a, driving. roll, a. bracket mounted upon: said; frame and movable from an inoperative to operative position with respect to said driving roll, a plurality of filament supporting elements mountedupon said bracket and extending along axes which are substantially parallel to the axis of said driving roll, eachcoi said elements including a peripheral surface adapted to be engaged by filamentary material, at least one of said elements being rotatable about its axis, said filament supporting element being positioned on said bracket so that in both operative and inoperative positions throughout their axial extent the peripheries of said elements will be spaced from the periphery of said drivin roll, and so that when the bracket is in the operative position filamentary material looped round the filament supporting element makes arcs of contact with the driving roll.

9. Apparatus according to claim 8 in which there are two filament supporting elements both of which are rotatable about their axes.

10. Apparatus for forwarding filamentary material comprising a frame, a driving roll, a bracket mounted upon said frame and movable from an inoperative to an operative position with respect to said driving roll, two filament supporting elements mounted upon said bracket, the first of said elements extending along an axis substantially parallel to the axis of the driving roll and the second of said elements extending along an axis askew to the axis of the driving roll, each of said elements including a peripheral surface adapted to be engaged by filamentary material, both said elements beingrotatable about their axes, said filament supporting elements being positioned on said bracket so that in both operative and inoperative positions throughout their axial extent the peripheries of said elements will be spaced from the periphery of said driving roll, and so that when the bracket is in the operative position filamentary material looped roundthe filament supporting elements makes arcs of contact with the driving roll.

11. Apparatus according to claim 8 wherein one of the supporting elements is a bar.

12. Apparatus according to claim 8-whereinat least one of the filament supporting elements is a guide.

ARNOLD NIELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'IEN'I' Number Name Date 483,809 Leonard Oct. 4, 1892 1,803,475 Kampf May 5, 1931 2,002,994 Hartmann et a1. May 28, 1935 2,294,871 Sellner Sept. 1, 1942 2,424,400 Kronofi July 22, 1947 2,462,043 Neidel Feb. 15, 1949 FOREIGN PATENTS p Number Country Date 219,635 Germany Mar. 2, 1910

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