US3762141A

US3762141A - Machines for producing synthetic yarn

Info

Publication number: US3762141A
Application number: US00091792A
Authority: US
Inventors: I Slack; P Slack
Original assignee: Plasticisers Ltd
Current assignee: Plasticisers Ltd
Priority date: 1968-02-20
Filing date: 1970-11-23
Publication date: 1973-10-02
Anticipated expiration: 1990-10-02
Also published as: GB1261891A

Abstract

This invention provides a single machine for use particularly in the production of twisted synthetic yarn from continuously produced synthetic filament material. By employing the particular physical arrangement of the various stages of the process proposed by the invention a particularly compact machine is produced which can handle a large number of separate filaments simultaneously. The machine comprisea a ring twister device of novel design mounted at the output end of a yarn path, the input end of which is fed with synthetic tape, the yarn path extending through or over heating means located between said input and a yarn stretching means and fibrillator means is located between said yarn stretching means and yarn tensioning means, the latter serving to supply fibrillated material to the ring twister device. The separate stages are conveniently mounted vertically one above the other.

Description

United States Patent Slack et al. I 1 Oct. 2, 1973 15 1 MACHINES FOR PRODUCING SYNTHETIC 3,460,416 8/1969 Gllhlil'l 214/1 FUX YARN 3,503,106 3/1970 Port et a1 1 28/1 F UX 3,214,899 11/1965 Winninger c1211.. .57/157 s ux [75] Inventors: lan David Slack; Philip Trevor Slack, 3,439 435 4 19 9 L|Oyd 57/34 H5 both of Drighlington, near Bradford, 2,511,928 6/1950 Mansfield 57/34.5 England 3,474,611 lO/1969 Suzuki et al. 57/31 2,572,138 10/1951 Griset 57/34.5 X [73] Assignee: Plasticisers Limited, Drighlington,

England Primary Examiner-Donald E. Watkins 22 Filed; 23, 1970 Attorney-Scrivener, Parker, Scrivener & Clarke [21] App]. No.: 91,792 [57] ABSTRACT Related Appllcafim Dam This invention provides a single machine for use partic- [63] Continuation-impart of Ser. No. 738,479, June 20, ularly in the production of twisted synthetic yarn from 1968, abandofledcontinuously produced synthetic filament material. By employing the particular physical arrangement of the 1 1 Foreign pp Priority Data various stages of the process proposed by the invention Feb. 20, 1968 Great Britain 8,097/68 a particularly compact machine is produced which can handle a large number of separate filaments simulta- [52] US. Cl 57/31, 57/75, 57/34 R, neously. The machine comprises a ring twister device 57/34 HS, 57/157 S, 57/157 R of novel design mounted at the output end of a yarn [51 I Int. Cl D02g 3/06, B261" 1/24 path, the input end of which is fed with synthetic tape, [58] Field of Search 57/1, 31, 34 R, 34 HS, the yarn path extending through or over heating means 57/34.5, 75, 93, 98, 100, 106, 110, 139, 140, located between said input and a yarn stretching means 156, 157 S, 157 TS, 157 MS, 167; 28/] F, 1 and fibrillator means is located between said yarn B; 225/3, 97 stretching means and yarn tensioning means, the latter serving to supply fibrillated material to the ring twister [56] References Cited device. The separate stages are conveniently mounted UNITED STATES PATENTS vertically one above the other.

3,293,844 12/1966 Winninger et a1, 57/157 R 21 Claims, 20 Drawing Figures United States Patent 1 l l 3,762,141

Slack et al. 1 Oct. 2, I973 PATENTEDUBT'ZW 3.762.141

SHEET 1B? 9 (Mum-1:

Pmemanw 317-82141 SHEET 2 OF 9 PArEmmncfz m 3.182.141

SHEET 7 [IF 9 MACHINES FOR PRODUCING SYNTHETIC YARN This is a continuation-in-part of application Ser. No. 738,479 filed June 20, 1968.

This invention concerns synthetic yarn production and in particular relates to a machine by which synthetic tapes can be drawn, fibrillated, twisted to form a yarn and wound in a package.

It has been proposed to provide separate machines for performing the various operations involved in the production of synthetic yarn. This type of arrangement is not suited to continuous or high speed production of yarn and it is an object of the present invention to provide a single machine which will perform all the above mentioned operations simultaneously on a large number of synthetic tapes.

The machine employs a ring twister device for twisting and winding yarn into a package.

One such ring twister comprises a spindle carrying the wound package of twisted material, a flyer carried on a ring surrounding the spindle, the ring being arranged to traverse the spindle during winding, traverse drive means and drive means to rotate the spindle at a substantially cnstant speed during winding, the driving torque of the spindle drive means is reducible at least during threading-up of the device to allow the twister to follow any reduction in the speed of delivery of material to the twister during threading-up without increasing the tension in the material beyond its breaking point.

Preferably spindle drive control means is provided having three positions corresponding to no drive to the spindle, drive with reduced torque and drive with full torque, respectively.

The drive for the spindle may comprise an electric motor and the drive control means, a three position switch and current limiting means associated with one position of the switch to limit the current to the motor in that switch position.

Alternatively the drive may comprise a constant speed drive and a friction or magnetic clutch may be provided between the constant speed drive and the spindle. The drive control means would in this case comprise a clutch control device to disengage the clutch OFF), allow clutch slip REDUCED TORQUE) and fully engage the clutch FULL TORQUE).

Preferably the traverse drive means may be uncoupled from the ring during threading-up, so that the ring remains at one end of its travel until the drive is reinstated.

A ring twister embodying the two preferred features may be threaded-up according to the following steps of, driving the spindle with reduced torque, uncoupling the traverse drive from the ring, causing the material to become wrapped around an empty package former (spool) carried by the spindle, at the end of the former adjacent the stationary ring, looping the material under the flyer on the ring, increasing the spindle drive to full torque and reinstating the traverse drive to the ring.

To facilitate wrapping the material around the package former, the material is first passed around a smooth stationary abutment or peg on the machine substantially in line with the stationary position of the ring. The flyer may then be moved around the ring to embrace the material passing over the ring, after which the loop of material can be slipped off the abutment or peg to allow the flyer to circulate around the ring and introduce the twist into the material.

A suction waste disposal tube may be provided either temporarily or permanently at or near the input to the ring twister into which the leading end of continuously produced material may be deflected during threadingup.

An alternative ring twister employs a hollow spindle to receive the leading end of the tape at least during threading-up of the machine and a draught of air is induced through the hollow spindle to gather the leading end and convey it into and through the spindle.

According to the present invention a single machine for producing synthetic yarn from tape comprises an input which is fed with synthetic tape, tape orientating means, including heating and stretching means, tensioning means, fibrillator means, located between the orientating means and tensioning means and a ring twister device supplied with fibrillated material from the tensioning means.

It has been found necessary to control the temperature of the tape during the orientating stage to within close limits, so as to provide yarn having consistent temperature shrink resistance and one of the objects of the present invention to provide an improved orientating means for the machine of the invention.

Preferably the separate parts of the machine are mounted vertically one above the other with the input at the top and the ring twister at the bottom. in this arrangement the yarn tensioning means is located vertically above the spindle of the ring twister, the fibrillator is mounted vertically above the yarn tensioning means and the yarn stretching means is located vertically above the fibrillator. The input includes nip rollers one of which is driven. The driven roller (around which the tape passes) is a heated roller and constitutes the heating means. According to the present invention said roller is hollow and is associated with heat exchange means for heating a heat transfer fluid, such as oil, means connecting the heat exchange means to the hollow roller, means for circulating heated fluid from the heat exchange means to the hollow roller and returning the fluid thereto, turb ulance generating means in the roller, and temperature regulator control means for controlling the supply of heat to the fluid to maintain the fluid at a substantially constant temperature.

The above described vertical arrangement occupies only a narrow space and a large number of such vertical arrays can be accommodated, side-by-side, to form a multiple machine for handling a large number of tapes simultaneously. The tapes may be produced from extruded film which is slit at regular intervals across its width. Guide means such as rollers or upstanding smooth pegs may be disposed adjacent the input nip rollers to guide each tape separately.

The fibrillator comprises a rotary drum having upstanding teeth or cutting elements which engage in the tape as it passes the drum and causes it to become fibrillated. Tape guides such as smooth pegs mounted parallel to the axis of rotation of the fibrillator drum and spaced apart one above and one below the axis, are preferably provided. In order to facilitate threading-up of the machine, the pegs are preferably mounted on a slidable plate member for movement towards and away from the fibrillator drum.

Stop means, preferably adjustable is provided in each fibrillator stage to determine the horizontal distance between the tape guides (pegs) and the axis of the fibrillator drum, during operation. This distance will determine the arc of contact of the tape with the fibrillator drum. Since the fibrillator stage in each machine section is in horizontal alignment with the fibrillator stages in all the other vertical machine sections, a mechanical coupling can be provided between all the fibrillator stage to effect simultaneous adjustment of the stop means in all the fibrillator stages. It will be appreciated that the arc of contact is an important factor, which for a given yarn speed and drum speed, largely determines whether or not correct fibrillation will occur.

The drive for each fibrillator drum is preferably provided from a single rotating shaft mounted to the rear of the vertical machine sections. The drive may be transmitted between this shaft and the fibrillator drums by band means and according to a preferred feature of the machine, each driving band is oversize and is tensioned by a tensioning roller which is movable out of engagement with the band. A braking device is preferably associated with the fibrillator drum, the brake moving into a braking condition when the tensioning roller is moved into its non-engaging position. In this way positive braking of the fibrillator drum is effected as soon as the drive to the fibrillator is released.

In order to facilitate threading-up of the machine the stretching means and tensioning means each comprise one or more rollers associated with a nip roller which is rapidly displaceable preferably by a snap action from a tensioning or nipping position to a release position. Likewise one of the input nip rollers is also rapidly displaceable from one position to another. Each such nip roller is preferably moveable by means of a lever arm or the like which extends clear of the tape path of the front of the machine.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a side view of one vertical machine section constructed in accordance with the invention,

FIG. 2 is a side view of the fibrillator carriage of the machine in FIG. 1 on an enlarged scale,

FIG. 3 is a reverse view on the tibrillator carriage assembly shown in FIG. 2,

FIGS. 4, 5, 6 and 7 illustrate one type of ring twister and the steps involved in threading-up, where:

FIG. 4 illustrates the first stage of threading-up,

FIG. 5 the second stage,

FIG. 6 the machine when threaded and operating, and

FIG. 7 the machine with a fully wound package, at the end of winding,

FIG. 8 is an end view of an N type fibrillator partly in section,

FIG. 9 is a plan view of a portion of the cylindrical surface of the N" type fibrillator of FIG. 7 unrolled to form a flat plain surface,

FIG. 10 is an end view ofa part ofa P" type fibrillator.

FIG. 1 1A is a view of one end of a GT" type fibrillator,

FIG. "B is a view similar to FIG. 10 of an alternative GT" type fibrillator,

FIG. 12 is a plan view of a segmented disc for use in an 58" type fibrillator,

FIG. 13 contains two sectional details on the radial lines A and B of FIG. 12 and illustrates the way in which alternate cutting elements are ground in opposite directions,

FIG. 14 is a side view of a number of segmented blades sandwiched to form a fibrillator,

FIG. 15, FIG. 16 and FIG. 17 are three similar views of an alternative ring twister and illustrate three stages in the threading-up operation of the machine.

FIG. 18 is a schematic view showing means for heating the roller in accordance with the invention.

FIG. 1 is a side view of one vertical section of a multiple section machine. The vertical side (or frame) of the machine 10 carries a ring twister device at its lower end comprising a hollow spindle l2 and parallel slides (only one of which is shown) 14 on which the ring assembly 16 is slideably guided. A suction device 18 is mounted below the hollow tube 12 to induce a down-flow of air through the hollow spindle to thereby gather into the upper end of the hollow spindle a free leading yarn end. The construction of the ring twister device is not shown in detail in FIGS. 1, 2 and 3 but will be described later with reference to FIGS. 4 to 7 and 15 to 17.

Tape to be processed is suppied to the upper end of the machine section and the tape path is shown in chain dotted line at 20. The vertical side frame 10 can be mounted broadside to the supply of tape, in which event the tapes merely require lateral guides to separate the tapes for feeding to the separate vertical machine sections. Preferably, however, the machine comprises two vertical side frames spaced apart but mounted back-to-back and the tapes are fed into one end of the machine between the two side frames 10. In this latter arrangement the tapes are guided to their respective machine sections by means of guides such as 22 which conveniently comprise vertical or inclined pegs or rollers.

Each tape 20 first passes over a heated roller 24, which is mounted at the upper end of the frame 10 and extends over the entire length of the frame. The roller 24 is hollow and is driven by suitable means such as the motor 23 shown in FIG. 18. The roller is mounted at each end in bearings 25 having rotating unions 27 for fluid connections to be made axially of the cylindrical roller 24. Within the hollow interior of the roller 24 is mounted a cylindrical mandrel 29 which rotates with the roller. At intervals along the length of the mandrel turbine-like blade assemblies 31 are mounted, the vanes in successive assemblies 31 being oppositely orientated. In view of the rotation of the cylinder relative to the initial fluid stream thereinto, the action of the blades or deflector vanes 31 is to set up turbulance in the oil flow so as to produce better temperature distribution along the length of the roller.

An oil feed pipe 33 is connected to the left hand union 27 and a return flow pipe 35 is connected to the right hand union. 7

In the feed pipe 33 is arranged a circulation pump 37 for forcing fluid from a heat exchanger 39 through the pipe 33, roller 24 and via the return pipe 35 to the heat exchanger 39. In order to prevent losses of fluid occurring, a reservoir 41 is provided, communicating with the heat exchanger.

Conveniently the fluid is oil although any suitable fluid heat transfer medium may be employed.

Within the heat exchanger 39 is arranged an electric heating element 43 in the form of an immersion heater,

the electrical supply to which is controlled by means of a switch 45. The switch 45 is in turn controlled by a thermostatically controlled control unit 47 including a visual indicator for indicating the temperature at any instant. The control unit 47 derives an electrical input singal proportional to the temperature of the fluid medium within the heat exchanger from a temperature sensing probe 49.

Although an electric heating element is shown any convenient form of heating may be employed such as a gas or oil burner.

In addition to the heating means comprising the heated roller 24 a local heating source such as a heating plate 36 may be provided for each machine section. In the embodiment shown in FIG. 1 such a local heater is shown at 36 which defines a vertical passage through which the tape can pass and the heater is arranged so that this passage is in alignment with the exit tangent from the roller 24.

A roller 40 is mounted vertically below the heater 36 and a quick release nip roller 42 co-operates with the roller 40. The roller 40 is keyed to a shaft 46 which extends horizontally over the entire length of the machine frame 10. The shaft 46 is driven by drive means such as the electric motor for driving the roller 24. In order to provide stretching between the roller 24 and the roller 40, the shaft 46 is rotated at a higher rotational speed than the roller 24. Typically the roller 40 is rotated so as to possess a peripheral speed equal to 7 x the peripheral speed of roller 24 linear speed of tape) so that a drafting ratio of 7:1 is obtained.

The nip roller 42 which co-operates with the roller 40 is carried at the end of a pivoted arm 48 which in turn is carried at the end of a mounting arm 50 secured to the machine frame 10. The arm 48 carries an operating lever 52 and spring means (not shown) is provided between the arm 48 and mounting arm 50 to urge the roller 42 against the roller 40. As with the nip roller 26, the spring means (not shown) is positioned so as also to retain the roller 42 and arm 48 in a stand-off position to facilitate threading of the tape through the machine. The nip roller 42 is covered with rubber or a similar non-slip material to improve the grip on the tape.

A fibrillator assembly is mounted vertically below the

roller pair

40, 42 and comprises a supporting plate 54 mounted on the machine frame which carries at its outer end a rotary fibrillator drum 56 and a slideable plate 58 which is slideable on the support plate 54 and carries two smooth pin guides 60 which extend from the plate, parallel to the axis of the drum 56. The tape is guided around the upper pin 60, around the drum 56 and finally around the lower pin 60 and as will be seen, movement of the pins towards the drum increases the arc of contact of the tape 20 with the drum 56. A lever arm 62 is pivotally mounted on the lower region of the slideable plate 58 and the inner end of the lever arm 62 is cut away at 64 to engage a stop member 66. The inner end of the lever arm is urged in an upward direction by a tension spring 68.

As shown in more detail in FIGS. 2 and 3 the slideable plate 58 is perforated to define two outer narrow parallel slots 70/72 and an inner wide slot 74. The supporting plate 54 is provided with a short parallel sided abutment 76 which is received in the upper narrow slot 70 and a longer parallel sided abutment 78 which is received in the lower narrow parallel sided slot 72 in the slideable plate 58. The upstand-ing height of the

abutments

76 and 78 above the surface of the plate 54 is commensurate with the thickness of the plate 56 which is retained in sliding contact with the plate 54 by means of washers 80 threaded on screws 82 which are screwed into the abutments 76/78. A shaft 84 is carried in a boss (not shown) to protrude axially on opposite sides of the plate 54. The fibrillator drum (shown in dotted outline only on FIG. 2 for clarity) is keyed to the shaft end which protrudes through the aperture 74 in the plate 58 while a pulley or like drive wheel 86 is keyed to the shaft end which protrudes on the other side of plate 54. Drive is transmitted to the pulley 86 by means ofa driving belt 88 which is oversize and an idler pulley 90 (see FIGS. 1 and 3) is carried by an arm 92 pivotally mounted on the plate 54 which is engageable with the belt 88 to tension the latter. To this end the arm 92 is carried on a shaft which extends through a boss (not shown) in the plate 54 having an arm 94 keyed to the protruding end on the other side of the plate 54. A spring 96 (see FIG. 1) is attached to the upper end of the arm 94 and to a lower portion of the plate 54 and the arrangement is such that when the arm 92 is lifted so that the pulley 90 is clear of the belt the spring 96 is to the right of the pivot axis (with respect to FIG. 1) to hold the pulley arm 92 and pulley 90 clear of the belt 88. It will be seen, howevr, that as soon as the pulley arm is lowered towards the belt and the spring moves to the left of the pivot axis, the spring will contract and draw the pulley into contact with the belt. In order to facilitate the movement of the pulley arm 92, a lever arm 96 is attached to the arm 92 in the region of the pivot to extend, as shown in FIG. 1, forward of the fibrillator assembly for manual operation. Lifting of the lever arm 96 will dis-engage the pulley from the belt while lowering of the lever arm 96 will cause the pulley and belt to be engaged and drive to be transmitted.

In order to restrain the fibrillator drum 56 from rotating when the drive is released, a further arm 98 extends from the arm 92 having a brake pad 100 mounted on its free end for engagement with the periphery of the pulley 86. The arm is dimensioned so that the brake pad 100 engages with the pulley 86 when the pulley 90 occupies its released or stand-off position. It will be seen that subsequent movement of the lever arm 96 to move the pulley 90 into engagement with the belt 88 simultaneously removes the brake pad 100 from the pulley 86.

The arc of contact between the tape 20 and the fibrillator drum 56 is determined by the spacing between the pins 60 and the axis of the fibrillator drum 56. Since the plate 58 is slideable relative to the plate 54 and therefore the axis of the drum (which can be thought of as the shaft 84) the arc of contact can be varied from a limiting condition in which the tape just touches the fibrillator drum 56 to a second limiting condition in which the pins 60 almost engagethe surface of the fibrillator. Preferably the length of the abutment 78 slideable in the lower slot 72 in the plate 58, is dimensioned so as to restrict the maximum displacement of the plate 58 so that the pins 60 cannot interfere with the teeth on the drum 56.

The inner end of the plate 58 abuts against a stop member 66 and as hereinbefore described the slideable plate 58 is retainable in this position by means of the lever arm 62 engaging the stop member 66. In order to provide for variation of the position into which the slideable plate 58 is retained, the stop member 66 comprises a downwardly turned lip formed along one of the non-parallel sides of a trapezoidal plate 102 whose other non-parallel side is secured to an elongate plate 104 slideable on the machine frame and retained thereon by a bolt 106. The plate 104 extends from end to end of the machine. Since the lip 66 is not parallel with the plate 104, movement of the plate 104 parallel to the machine frame 10 will present a different part of the lip surface to the plate 58 which will be either further away from the machine frame 10 or nearer thereto depending upon the direction in which the plate 104 is slid. (In FIG. 1 it will be seen that the trapezoidal plate 102 is shaped so that the lip 66 converges towards the plate 104 into the plane of the paper).

In order to maintain tension through the fibrillator stage, a tensioning device is arranged below the fibrillator stage and in the embodiment shown in FIG. 1 this comprises a similar assembly to the

roller pair

40, 42 which comprises the stretching means. The roller pair of the tensioning device comprises a roller 108 which is keyed to a shaft 112 which, like the shaft 46, extends over the entire length of the machine frame 10. The shaft 112 is conveniently driven from the same drive means as supplies drive to the shaft 46 and the roller 24. The nip roller 116 of the tensioning device is carried on a pivoted arm 118 which is pivotally joined to the end of a mounting arm 120 secured to the machine frame 10. The roller 116 is also rubber covered to improve grip on the fibrillated material. An operating lever 122 extends from the pivoted arm 118 and spring means (not shown) is provided to maintain the roller 116 in contact with the yarn in its operating position. By employing the over centre principle (as hereinbefore described), the same spring can be used to retain the roller 116 in its stand-off positon, to facilitate threading-up of the machine.

In order to maintain tension across the fibrillator stage, the roller 108 is rotated with a peripheral speed just greater than the peripheral speed of the roller 40.

FIGS. 4 to 7 of the drawings illustrate a perferred form of ring twister in which a cylindrical former 10 is carried on a vertical spindle l2 driven by an electric motor 14 and is surrounded by a ring carriage 16 around which a flyer 18 can circulate. A pigtail lappet 20 is mounted coaxially above the spindle 12 the material to be wound on the former 10 being guided through the eye in the lappet. The current supply to the electric motor 14 is controlled by a switch 22 having three positions, indicated in FIG. 1 only as OFF, REDUCED TORQUE and FULL TORQUE.

The ring carriage 16 is driven by drive means (not shown) so as to traverse the length of the former 10 during winding and thereby distribute the wound material over the available length of the bobbin. A lever 24 is provided by which the traversing drive can be disengaged and the carriage 16 arrested at one end of its traverse.

A suction discharge device comprising a tube 26 is shown in dotted outline adjacent the lappet 20. This may be permanent or fixed temporarily in place when it is required to dispose of unwanted material for example to prevent build-up during threading-up. To this end the material is deflected into the tube 26 by which it is conveyed to a waste container.

To assist threading-up, a smoother peg 28 is provided on the edge of the carriage under which the material can be looped. It will be appreciated any convenient abutment may be used as for example the shaft of the lever 24.

The first three FIGS. show the various stages of threading-up the machine which can be described as follows: 7

Initial threading-up is shown in FIG. 4. Here material 30 to be wound (shown in chain link line) is passedthrough the lappet 20, around the peg 28 and wrapped around the former 10. The traverse drive is disengaged during threading-up and the material 30 is consequently wound around the lower end only of the former 10.

Any adjustments are now made to stages of the material path preceding the lappet 20 any changes in speed of the material resulting from these adjustments being accommodated by the speed/torgue characteristics of the spindle drive motor when operated with reduced supply voltage.

As soon as the material passing through the lappet is suitable for twisting and winding the flyer 18 is moved around the ring carriage 16 to the position shown in FIG. 5. Here the material is made to pass under the flyer hook" before passing to the former.

Full torque is now applied to the spindle 12 by advancing switch 22 to the appropriate position, and the loop of material 30 slipped off the peg 28, which allows the flyer to circulate and impart twist into the material (see FIG. 6). At the same time the traverse drive is reinstated by appropriate adjustment of lever 24.

The resulting package is shown in FIG. 7. Here the material 30 is shown cut just below the lappet 20. The free leading end is gathered into the suction disposal device 26 while the trailing end 32 is shown overlying the carriage 16. It will be noted that the untwisted material is bunched around the lower end of the former and this can be removed from the end of the package for example by cutting-off that end of the package. The resulting package then only contains fully processed material (e.g. fully twisted yarn).

In FIG. 7 the switch 22 is shown in the OFF position by which the spindle is held stationary for removal of the full bobbin and positioning an empty bobbin after which the machine is threaded-up according to the previously described procedure.

The construction the fibrillator drum is shown in more detail in FIGS. 8 to 14 which illustrate a number of alternative constructions of drum.

In FIGS. 8 and 9 of the drawings an N type fibrillator is shown comprising a cylindrical body 10 mounted on an axle or shaft 12 for rotation about its axis. At regular intervals around the cylinder axially parallel slots 14 are formed in which lines of needles 16 are retained. As best seen in FIG. 9 the needles 16 are arranged close together with their points (shown diagrammatically at 18) in linear alignment with the slots 14.

In order to facilitate manufacture and replacement each line of needles is mounted on an elongate bar 20 for example by soldering or welding shown at 21, the assembly of needles and bar forming a comb-like structure. Additional soldering or welding is applied between adjacent needles as shown at 22. Each comb forms an integral structure of needles and blades which is thereby readily replaceable should damage or wear occur.

The blade assemblies are secured in their respective slots by cover plates 24 which overlie the bars 20 and are screwed or otherwise secured to the cylinder 10. In

order that the surface of the cylinder is smooth the cover plates 24 are let into recesses adjacent the slots and formed by cutting away one wall of each slot.

In order to prevent clogging or a clawing action, the needles 16 extend at an angle 4) (see FIG. 8) to the tangent to the cylinder at the line of contact of the line of needles with the cylinder. The angle is such that the needles point away from the direction of rotation of the cylinder 10 so that instead of clawing their way out of the material the needles are withdrawn with little or no relative linear movement between the needles and material. (It will be seen that by defining (it as the angle between the rear of the needle and the surface of the cylinder, the maximum value of d) is 90. In practice (1) will be considerably less than 90 and a preferred value of d) is found to be 75 this is suitable for a 3 inch diameter drum having 36 lines of cutting elements arranged in sets of six).

In order to provide staggering between adjacent lines of pins, spacers 26 are positioned at (say) the left-hand end of each slot 14. The left-hand ends of the slots 14 in FIG. 9 lie in the same radial plane and the spacers 26 are dimensioned so as to obtain the desired off-set between each successive line of needles. For example where the spacing P (see FIG. 9) is 0.012 and it is desired to divide this spacing P by a factor of 6, five such spacers are required the first 0.002 inches thick, the next 0.004 inches thick etc., the largest spacer being 0.010 inches thick. The seventh line of needles is in alignment with the first line of needles and in consequence no spacer is required for lines 1, 7 etc.

Although in the arrangement shown in the drawing only six lines of needles are shown, in practice a large number of lines of needles are used so that the speed of rotation of the fibrillator can be reduced. By arranging, for example, six sets of six lines of needles around the cylinder 10, the resulting fibrillator can be operated at one sixth the rotational speed that would be necessary for the same fibrillator having only six lines of needles.

In FIG. 10 there is shown a "P" type fibrillator which comprises a hollow cylindrical shell 30 which forms a sleeve which can be fitted over a cylindrical bobbin 32. The bobbin 32 is preferably keyed to the sleeve 30 so that drive is transmitted between the two. The cutting elements are formed by pins 34 and the region around one of these pins 34 is shown in section to illustrate how the pins are retained in position. Each pin is conical in shape and is pushed into a tapered hole 36 formed in the wall of the sleeve 30. Each hole 36 tapers towards the outer surface of the sleeve 30 so that each pin 34 can only be introduced into a hole 36 from the inside of the sleeve 30. The length of the pin 34 and the angle of the taper is arranged to be such that the base of the needle lies substantially flush with the inside surface of the sleeve 30 so that the cylindrical bobbin 32 serves to keep the needles 34 in place, when inserted into the sleeve.

In accordance with the invention the tapered holes 36 are arranged in lines at regular intervals around the sleeve 30 with the holes in each line being off-set by a pre-determined distance (equal to the inter-cut spacing) from the corresponding holes in adjacent lines.

One end of one form of GT type fibrillator is shown in FIG. 11A of the drawings. This comprises a cylindrical drum 40 having a multistart helical thread profile formed in its outer surface. Axially parallel slots 42 are formed in the surface of the drum 40 at regular intervals around the drum. The slots 42 cut right through the thread profile 44 and result in a line of cutting edges along either side of each slot 42 defined by the peaks of the thread profile. Since the thread follows a helical path the cutting edge defined by the peak of each thread profile and one slot 42 will be displaced axially from the corresponding cutting elements formed by the same thread profile peaks and the adjacent slots 42.

An alternative GT type fibrillator is shown in FIG. 118 in which the bases of the slots 42 are inclined to the surface ofthe drum. In the embodiment shown the bases of the slots extend between the peaks of one line of cutting edges to the bases of an adjacent line of cutting edges.

FIGS. 12 and 13 illustrate the component from which an SB type fibrillator is built up and FIG. 14 illustrates part of a stack of such components which together form an SB type fibrillator. As best seen in FIG. 12 each component comprises a thin annular disc 20 having six radial protrusions 52 regularly spaced apart around its periphery. Each protrusion is ground or otherwise machined to form a cutting edge (as will be hereinafter described) so that the six protrusions 52 correspond to six cutting elements according to the invention. By stacking a number of discs 50, as shown in FIG. 14, with the radial protrusions 52 in axial alignment, a fibrillator can be formed. Holes 54 are preferably formed in the discs 50 so that when assembled, the discs can be held together, for example, by means of bolts, or rods passed through the aligned holes 54 and secured at each end for example by peening over.

In order to reduce the axial spacing between adjacent cutting elements, the protrusions 52 are ground in a particular way as will be explained with reference to FIG. 13. FIG. 13A shows the protrusion immediately beyond the section line A while FIG. 138 shows the protrusion immediately beyond section line B, of FIG. 12. Referring to FIG. 13A it will be seen that this protrusion is ground so that the cutting edge 56 is off-set from the centre of the disc thickness, the edge being formed by two equally inclined ground surfaces one of which extends over three quarters of the thickness of the disc and the other of which only extends over a quarter of the thickness. On the other hand,the protrusion immediately beyond section line B (and for that matter the next prot'rusionbeyond the one shown in FIG. 13A) is ground so that the cutting edge 56 is offset towards the right-hand face of thedisc and is also formed by two equally inclined ground faces, the lefthand one of which extends over three quarters of the thickness of the disc. In this way the razor edge of each cutting element 52, is off-set in opposite directions on alternate cutting elements.

As described with reference'to the N type fibrillator, more than one set of cutting elements can be arranged around the periphery of the fibrillator drum, so that the fibrillator can be rotated at lower speeds. Thus instead of six protrusions around the

discs

50, 36 protrusions could be formed at 10 intervals, the speeds of rotation of the resulting fibrillator requiring to be only one sixth that of the fibrillator shown. The construction and operation of an alternative ring twister is shown in FIGS. 1s, 16 and 17.

Yarn to be twisted and wound passes through a guide eyelet (or lappet) 220 (not shown in FIGS. 1, 2 and 3),

which is arranged vertically above and in axial alignment with a vertical hollow spindle 240 which corresponds to spindle 12 in FIGS. 1, 2 and 3. The spindle is rotated by means of a driving band or belt which passes around a driving pulley mounted on the spindle but preferably a separate electric motor is provided to drive each shaft, independently see motor 18 in FIG. 1.

A hollow cylindrical take-up bobbin 232 is carried by the spindle 240 and the yarn after passing through the lapped 220, is guided onto the take-up bobbin 232 by a traveller 234 freely carried on a ring 236 arranged coaxially with the spindle 240. The traveller 234 is free to move around the ring 236 and at the same time, the ring 236 is arranged to traverse the length of the bobbin, reversing its direction as it reaches each end of the bobbin, so that the yarn is wound in layers on the bobbin as the latter rotates. For the sake of clarity, the traversing mechanism is not shown but the movement of the ring is merely indicated by means of the arrow 238.

By virtue of the hollow spindle 240 the yarn is conveyed axially through the twisting mechanism to emerge at the lower end of the spindle 240 where it passes between a pair of nip

rollers

242, 244 which constitute a yarn tensioning and take-up device for feeding yarn into a yarn collecting bin or other suitable container 245. To assist in the rapid threading of the leading end of a yarn into and through the hollow spindle 240, a down-draught of air through the spindle is generated by an air ejector or vacuum pump 246, located at the lower end of the hollow spindle 240. The pump is not shown in any detail and it will be appreciated that any convenient form of draught producing means may be employed.

The threading-up operation is as follows:

A spindle carrying an empty bobbin 232, with the spindle stationary, is positioned beneath the lappet 220 and the leading end of a yarn to be twisted is fed through the lappet 220. It is then drawn into the upper end of the hollow interior of the spindle 240 and drawn down the spindle, by the down-draught of air created by the air ejector or vacuum pump 246, to emerge at the lower end of the spindle 240 and pass between the pair of nip

rollers

242, 244.

While the spindle is still held stationary the yarn between the lappet 220 and the upper end of the hollow spindle 240 is drawn out in the form of a loop and this is looped around the traveller 234 on the ring 236 as shown in FIG. 16.

The spindle 240 and the bobbin 232 are then caused to rotate. The yarn catches in a groove 248 formed in the upper end of the bobbin 232 and begins to be wound around the bobbin.

in order to ensure free rotation of the spindle and bobbin it is necessary to break the yarn between the spindle and nip

rollers

242, 244. Although the continued rotation of the spindle and bobbin will eventually cause the yarn to fracture a guillotine or cutting edge is provided between the lower end of the spindle and the nip

rollers

242, 244 to cut the yarn as soon as the yarn has begun to wrap around the tube. The guillotine is not shown in detail in the drawing but this conveniently comprises a knife edge (not shown) and a hook 250 which latter moves to engage and pull the yarn against the knife edge.

The vacuum pump/air ejector 246 can be replaced to advantage by a blowing device 260 shown in dotted outline only in FIG. 15. The device comprises a discontinuous annular hollow shell of generally frusto-conical shape with its wide open end uppermost to receive the flying I leading end of yarn. The internal wall of the shell is stepped (not shown) and a plurality of downwardly directed nozzles are formed in the step to produce a converging downwardly directed air (or gas) stream which is directed into the upper end of the hollow spindle 240. The shell is discontinuous so as to enable it to be withdrawn when the yarn has passed therethrough and down the spindle and been engaged by the

nip rollers

242, 244 and to assist in its movement from one position to another the device is conveniently mounted at the end ofa flexible air line 262 for supplying compressed air thereto.

We claim:

I. In a machine for the production of twisted synthetic yarn from synthetic tape,

an input which is fed with synthetic tape,

tape orientating means, including a heated roller around which the tape passes and stretching means,

tensioning means,

fibrillator means, including a rotary drum having upstanding teeth or cutting elements to engage in the tape and fibrillate same, located between the orientating means and tensioning means,

tape guide means,

means mounting the tape guide means,

means for moving the guide mounting to an operating position in which tape is constrained to engage at least a'portion of the surface of the drum and a release position in which the tape is not urged into contact with the drum,

means for adjusting the operating position of the guide mounting relative to the drum,

brake means to arrest the drum,

clutch means to supply drive to the drum, and

ring twister means supplied with fibrillated material from the tensioning means to twist and wind same.

2. In a machine as set forth in claim 1,

- means for gathering a loose leading end of material and conveying same to waste storage means at least during threading-up.

3. In a machine as set forth in claim 2,

- suction waste disposal means mountable adjacent the ring twister means at least during threading-up to constitute said gathering and conveying means.

4. In a machine as set forth in claim 1,

means coupling the brake means with the clutch means to remove the drive to the drum during braking.

5. In a machine as set forth in claim 2, ring twister means, comprising,

a spindle for carrying the package of twisted material a ring surrounding the spindle,

a flyer slidable around the ring,

drive means to move said ring axially of the spindle to traverse same during winding,

drive means for rotating the spindle at constant speed at least during winding, and

control means to adjust the driving torque of the spindle drive means to reduce the torque at least during threading-up of the machine to allow the spindle speed to alter and follow any reduction in the speed of delivery of material to the twister.

6. In a machine as set forth in claim 5,

electric motor means to drive the spindle.

7. In a machine as set forth in claim 6, control means comprising,

switch means having three positions,

current limiting means, and

means connecting said switch means and current limiting means with the electric motor means and a source of electric current, whereby no current is supplied to the motor in one position, reduced current in a second position and full current in the third position of the switch means.

8. In a machine as set forth in claim 5,

means for uncoupling the traverse drive means from the ring at least during threading-up of the machine, to keep the ring in a given position.

9. In a machine as set forth in claim 8,

additional tape guide means substantially in line with said given position of the ring around which the tape can pass during theading-up.

10. In a machine as set forth in claim 2, ring twisting means comprising,

a spindle for carrying the package of twisted material, said spindle being hollow throughout its length,

a ring surrounding the spindle a flyer slidable around the ring,

drive means to move said ring axially of the spindle to traverse same during winding, and

means to induce a draught of air through the hollow spindle, said spindle and draught inducing means thereby constituting the gatering and conveying means for the loose leading end during threading- 1 1. In a machine as set forth in claim 1, an input comprising,

a driven roller,

a nip roller, mounted for engagement with the driven roller to trap tape therebetween, and

means to release the nip roller from the driven roller to allow threading-up.

12. In a machine as set forth in claim 11, orientating means comprising in combination with the first mentioned driven roller and nip roller,

a second driven roller spaced from the first driven roller and driven with a controlled higher peripheral speed than the first drive roller,

a second nip roller, mounted for engagement with the second driven roller to trap tape therebetween,

means to release the second nip roller from the second driven roller to allow threading-up, the tape being stretched between the two sets of rollers due to the increased peripheral speed of the second set, and

heating means for heating the tape immediately before or during stretching.

13. In a machine as set forth in claim 12, said first driven roller is heated and constitutes said heating means.

14. In a machine as set forth in claim 12, said heating means comprising,

a heating element between the first and second roller sets over which the tape passes in contact with a heated surface thereof.

15. In a machine as set forth in claim 12, said tensioning means comprising in combination with the second driven roller and nip roller,

a third driven roller beyond the fibrillator means, in the direction of tape movement and driven at a controlled higher peripheral speed than the second driven roller, a third nip roller, mounted for engagement with the third driven roller to trap tape therebetween, and means to release the third nip roller from the second driven roller to allow threading-up. 16. In the continuous production of a plurality o twisted synthetic yarns from a corresponding number of synthetic tapes,

means for producing continuously a plurality of synthetic tapes, and a machine supplied with said tapes to fibrillate and twist same to form a corresponding number of yarns and wind the yarns into packages,

said machine comprising a number of vertical machine sections, the number of machine sections being at least equal to the number of tapes and each section comprising,

an input at the upper end of the machine section and supplied with one of said synthetic tapes,

tape orientating means including a heated roller around which the tape passes and heating and stretching means,

tensioning means below said orientating means,

fibrillator means, including a rotary drum having upstanding teeth or cutting elements to engage in the tape and fibrillate same, located vertically between the orientating means and tensioning means,

tape guide means,

means mounting the tape guide means,

means for moving the guide mounting to an operating position in which tape is constrained to engage at least a portion of the surface of the drum and a release position in which the tape is not urged into contact with the drum,

brake means to arrest the drum,

clutch means to supply drive to the drum, and

17. In the continuous production of a plurality of twisted synthetic yarns from a corresponding number of synthetic tapes as set forth in claim 16, said means for continuously producing a plurality of synthetic tapes comprises,

plastics extrusion means for extruding a continuous plastics film,

shearing means for cutting the film at regular intervals across its width into continuous strips or tapes lengthwise of the film, and

guide means for guiding each tape so produced, to an input of the machine.

18. In the production of synthetic yarn as in claim 16 including thermostatic means for controlling the temperature of said heated roller to within predetermined close limits.

19. In the production of synthetic yarns as in claim 18. wherein said heated roller is hollow and said thermostatic control means comprises a heat exchanger, heating means within said exchanger, means for continuously circulating liquid from said exchanger through including turbulance producing means within said roller.

21. In the production of synthetic yarn as in claim 20 wherein said turbulance producing means comprises vane means within said hollow roller.

Claims

1. In a machine for the production of twisted synthetic yarn from synthetic tape, an input which is fed with synthetic tape, tape orientating means, including a heated roller around which the tape passes and stretching means, tensioning means, fibrillator means, including a rotary drum having upstanding teeth or cutting elements to engage in the tape and fibrillate same, located between the orientating means and tensioning means, tape guide means, means mounting the tape guide means, means for moving the guide mounting to an operating position in which tape is constrained to engage at least a portion of the surface of the drum and a release position in which the tape is not urged into contact with the drum, means for adjusting the operating position of the guide mounting relative to the drum, brake means to arrest the drum, clutch means to supply drive to the drum, and ring twister means supplied with fibrillated material from the tensioning means to twist and wind same.

2. In a machine as set forth in claim 1, - means for gathering a loose leading end of material and conveying same to waste storage means at least during threading-up.

3. In a machine as set forth in claim 2, - suction waste disposal means mountable adjacent the ring twister means at least during threading-up to constitute said gathering and conveying means.

4. In a machine as set forth in claim 1, means coupling the brake means with the clutch means to remove the drive to the drum during braking.

5. In a machine as set forth in claim 2, ring twister means, comprising, a spindle for carrying the package of twisted material a ring surrounding the spindle, a flyer slidable around the ring, drive means to move said ring axially of the spindle to traverse same during winding, drive means for rotating the spindle at constant speed at least during winding, and control means to adjust the driving torque of the spindle drive means to reduce the torque at least during threading-up of the machine to allow the spindle speed to alter and follow any reduction in the speed of delivery of material to the twister.

6. In a machine as set forth in claim 5, electric motor means to drive the spindle.

7. In a machine as set forth in claim 6, control means comprising, switch means having three positions, current limiting means, and means connecting said switch means and current limiting means with the electric motor means and a source of electric current, whereby no current is supplied to the motor in one position, reduced current in a second position and full current in the third position of the switch means.

8. In a machine as set forth in claim 5, means for uncoupling the traverse drive means from the ring at least during threading-up of the machine, to keep the ring in a given position.

9. In a machine as set forth in claim 8, additional tape guide means substantially in line with said given position of the ring around which the tape can pass during theading-up.

10. In a machine as set forth in claim 2, ring twisting means comprising, a spindle for carrying the package of twisted material, said spindle being hollow throughout its length, a ring surrounding the spindle a flyer slidable around the ring, drive means to move said ring axially of the spindle to traverse same during winding, and drive means for rotating the spindle at constant speed at least during winding, and means to induce a draught of air through the hollow spindle, said spindle and draught inducing means thereby constituting the gatering and conveying means for the loose leading end during threading-up.

11. In a machine as set forth in claim 1, an input comprising, a driven roller, a nip roller, mounted for engagement with the driven roller to trap tape therebetween, and means to release the nip roller from the driven roller to allow threading-up.

12. In a machine as set forth in claim 11, orientating means comprising in combination with the first mentioned driven roller and nip roller, a second driven roller spaced from the first driven roller and driven with a controlled higher peripheral speed than the first drive roller, a second nip roller, mounted for engagement with the second driven roller to trap tape therebetween, means to release the second nip roller from the second driven roller to allow threading-up, the tape being stretched between the two sets of rollers due to the increased peripheral speed of the second set, and heating means for heating the tape immediately before or during stretching.

14. In a machine as set forth in claim 12, said heating means comprising, a heating element between the first and second roller sets over which the tape passes in contact with a heated surface thereof.

15. In a machine as set forth in claim 12, said tensioning means comprising in combination with the second driven roller and nip roller, a third driven roller beyond the fibrillator means, in the direction of tape movement and driven at a controlled higher peripheral speed than the second driven roller, a third nip roller, mounted for engagement with the third driven roller to trap tape therebetween, and means to release the third nip roller from the second driven roller to allow threading-up.

16. In the continuous production of a plurality of twisted synthetic yarns from a corresponding number of synthetic tapes, means for producing continuously a plurality of synthetic tapes, and a machine supplied with said tapes to fibrillate and twist same to form a corresponding number of yarns and wind the yarns into packages, said machine comprising a number of vertical machine sections, the number of machine sections being at least equal to the number of tapes and each section comprising, an input at the upper end of the machine section and supplied with one of said synthetic tapes, tape orientating means including a heated roller around which the tape passes and heating and stretching means, tensioning means below said orientating means, fibrillator means, including a rotary drum having upstanding teeth or cutting elements to engage in the tape and fibrillate same, located vertically between the orientating means and tensioning means, tape guide means, means mounting the tape guide means, means for moving the guide mounting to an operating position in which tape is constrained to engage at least a portion of the surface of the drum and a release position in which the tape is not urged into contact with the drum, means for adjusting the operating position of the guide mounting relative to the drum, brake means to arrest the drum, clutch means to supply drive to the drum, and ring twister means supplied with fibrillated material from the tensioning means to twist and wind same.

17. In the continuous production of a plurality of twIsted synthetic yarns from a corresponding number of synthetic tapes as set forth in claim 16, said means for continuously producing a plurality of synthetic tapes comprises, plastics extrusion means for extruding a continuous plastics film, shearing means for cutting the film at regular intervals across its width into continuous strips or tapes lengthwise of the film, and guide means for guiding each tape so produced, to an input of the machine.

19. In the production of synthetic yarns as in claim 18 wherein said heated roller is hollow and said thermostatic control means comprises a heat exchanger, heating means within said exchanger, means for continuously circulating liquid from said exchanger through said roller and thence back to said exchanger, and a thermostat responsive to the temperature of said liquid to control the operation of said heating means so as to retain the temperature of said liquid and said roller to within said predetermined close limits.

20. In the production of synthetic yarn as in claim 19 including turbulance producing means within said roller.