The present invention relates to yarn texturing apparatus and more particularly to apparatus for converting between a medium tenacity yarn texturing machine and a high tenacity yarn texturing machine.

A filament yarn is made from one or more continuous stands called filaments which run the whole length of the yarn. Yarns which have only one filament are called mono filament yarns and multi-filament yarns can comprise as few as two or three filaments or as many as fifty or more filaments. Texturing of yarns is a process which produces bulked filament yarns. Texturing can introduce crimps, coils and loops along the length of the filaments and this gives the yarns increased volume which results in the yarns having greater air and vapour permeability.

Filament yarns are well known, as are machines for texturing the yarns. High tenacity yarns generally have high durability, strength and toughness whilst medium tenacity yarns have lesser durability, strength and toughness. Medium tenacity yarns are usually textured by friction texturing apparatus in which the yarn passes through an arrangement of overlapping friction discs which are rotated and which twist and distort the yarn during its passage through the discs. High tenacity yarns are usually produced on a pin spindle texturing unit in which the yarn passes around a transverse pin mounted in a spindle which is rotated at very high speed, typically of the order of 1 ,000,000 rpm.

Traditionally the high and medium tenacity yarn machines are completely distinct and separate. The medium tenacity machines have a single, variable speed motor for each yarn texturing unit, whereas the high tenacity machines usually have a multitude of pin spindle texturing units aligned in a row and all powered by an endless belt driven by a single high speed motor. The two types of unit are, therefore, inherently compatible with each other and it is inefficient to perform maintenance or change a yarn on one pin spindle texturing unit because this can only be achieved with the entire machine being stopped due to the single endless drive belt. Furthermore, it is often not possible to produce high tenacity yarns on a friction texturing unit because high tenacity yarns tend to have a higher oil content which is absorbed by the friction discs (usually ceramic or plastic) thereby reducing their efficiency. And of course it is not therefore possible to produce high and medium tenacity yarns on a single apparatus comprising multiple texturing units.

Hence there is a longstanding need to make the two types of texturing machine more compatible with each other in a manufacturing plant.

According to a first aspect of the present invention there is provided apparatus for converting between a medium tenacity yarn producing machine and a high tenacity yarn producing machine, the medium tenacity machine including a variable speed electric motor which is disposed within a casing and which drives a multi disc texturing unit mounted on the casing, and the high tenacity machine including a pin spindle texturing unit having a pin spindle adapted to be driven in rotation by a drive disc mounted on a drive shaft with the disc pin spindle also engaging an idler disc mounted on a rotatable idler shaft and being held against the two discs by magnetic force, said apparatus comprising:

a pulley adapted to be driven by the electric motor after removal of the multi-disc texturing unit from the casing;

a bracket adapted to be secured to the casing, the pulley being mounted to the bracket by means of a bearing unit such that the pulley is rotatable relative to the bracket, wherein the bracket incorporates one or more mounting points to which the pin spindle texturing unit can be attached in use; and

an endless drive belt for connecting the pulley to the drive shaft of the pin spindle texturing unit, the diameter of the pulley being larger than the diameter of the drive shaft and the diameter of the drive disc being larger than the diameter of the disc pin spindle.

In preferred arrangements the bracket is substantially L-shaped having a lower base and a wall upstanding therefrom. Preferably in such arrangements the bearing unit is mounted on the lower base and the pulley is disposed above the bearing unit with a shaft of the pulley being mounted in the bearing unit for engagement with an output shaft of the electric motor. Ideally, the upstanding wall provides the mounting points for the attachment of the pin spindle texturing unit.

In certain arrangements the upstanding wall has an aperture through which the endless drive belt passes. Often, there is further provided a cover for the pulley and the bearing unit, the cover incorporating an opening at one side through which the endless belt passes, wherein the opening is adjacent the aperture in the upstanding wall and wherein the cover is secured to the bracket.

A preferred feature is that the cover is provided with a number of holes about its periphery, the holes preferably being in the form of spaced slots extending axially relative to the axis of rotation of the pulley. Another preferred feature is that the pulley has axially extending teeth and the drive belt is correspondingly toothed to mesh therewith.

According to a second aspect of the present invention there is provided a method of converting from a medium tenacity yarn producing machine to a high tenacity yarn producing machine using the apparatus as described above and comprising the steps of:

removing the multi-disc texturing unit from the casing,

attaching the bracket with pulley and bearing unit to the casing, attaching the pin spindle texturing unit to the bracket,

connecting the endless belt drive to the pulley and to the drive shaft of the pin spindle texturing unit.

The invention will now be described in more detail. The description makes reference to the accompanying diagrammatic drawings in which:

Figure 1 is a side view of a friction texturing machine incorporating a number of friction texturing units;

Figure 2 is a perspective view of an illustrative friction texturing unit; Figure 3 is a schematic side view of an illustrative pin spindle texturing unit;

Figure 4 is a side view of the apparatus according to the present invention ready for use;

Figure 5 is a top plan view of the figure 4 apparatus;

Figure 6 is a front view of the figure 4 apparatus; Figure 7 is a perspective view of the apparatus of figure 4;

Figure 8 is a perspective view of a bracket component of the present invention;

Figure 9 is a perspective view of a pulley component of the present invention;

Figure 10 is a sectional view of components of the apparatus according to the present invention;

Figure 11 is a perspective view of a cover and mounting bar of the present apparatus;

Figure 12 is a sectional view of the components of the figures 8, 10 and 11 assembled together; and

Figure 13 is a perspective view of the figure 12 arrangement.

Figures 1 and 2 illustrate a known friction texturing machine 10 in which a single multi-disc texturing unit 11 is shown. This texturing unit 11 texturises a yarn 12 which may be a mono filament or a multifilament yarn which is fed from one or more bobbins 13 through a system of processes before it reaches the texturing unit 11. The constructional details of the texturing unit 1 1 are known and will not therefore be described in detail. Essentially, however, each texturing unit is driven by a variable speed motor provided in a motor housing 14. The motor drives a main shaft 15 on which are mounted a plurality of friction discs 16 which may be ceramic, plastic or other suitable material. Associated with and engaging the friction discs 16 on the main shaft 15 are other friction discs 17 mounted on secondary shafts 18, the discs 17 being rotated by frictional engagement with the directly driven discs 16. The yarn 12 passes between the discs 16, 17 and this passage causes the yarn to texturise by virtue of its convoluted path through the discs.

In a manufacturing machine, a multitude of friction texturing units 11 will be provided in a line (going into the paper when viewing figure 1) and each unit 11 will be driven by its own individual motor, typically but not exclusively at speeds up to 10,000 rpm.

Figure 3 illustrates a known pin spindle texturing unit 20 for texturizing a yarn 12. In a manufacturing machine incorporating pin spindle texturing units 20, again there will be a multitude of units 20 provided in a line, but the multitude of units 20 will all be driven by a single endless drive belt. Pin spindle texturing units 20 typically have a hollow spindle 21 through which the yarn 12 extends, the spindle 21 having a transverse pin 22 around which the yarn 12 passes. The spindle 21 is rotated about its lengthwise axis at very high speeds, typically but not exclusively up to 1 ,000,000 rpm. This is achieved in some known arrangements by the spindle 21 being magnetically held between a pair of driven discs 23 on a driven shaft 24 and a pair of idler discs 25 mounted on an idler shaft 26. Again, this is known technology and will not be discussed in detail, but the passage of the yarn through the unit 20 whilst passed around the pin 22 mounted in the rotating spindle 21 causes the yarn 12 to be texturised.

As mentioned previously, the friction texturing units 10 are suitable for medium tenacity yarns and the pin spindle texturing units 20 are suitable for high tenacity yarns, but the existing machines utilising these different texturing units are not compatible with each other. With the friction texturing units 10, maintenance and yarn change is readily possible by turning off an individual unit 10 but this is not possible with conventional pin spindle texturing units 20 because of their single drive driving a multitude of units.

Figures 4 to 13 illustrate apparatus for converting an existing friction texturing machine 10 in which there are a multitude of friction texturing units 11 so that one or more pin spindle texturing units 20 can be run on the machine 10. Normally, of course, the rotational speeds of the motors of units 11 would generally be inadequate to run the units 20 in such a way as to achieve their intended texturing action.

Figure 8 shows a bracket 30 which is used in the adaptation of the present invention. The bracket 30 is generally L-shaped and has a lower base 31 integrally formed with an upstanding wall 32. The two parts could be made separately and connected together by welding, for example, but a unitary component is preferred. The lower base 31 is shaped for compatibility/fit with the motor housing 14 of the texturing unit 11 and is provided with a central through bore 33 and a pair of spaced through bores 34. The bores 34 receive suitable bolts for attaching the bracket 30 to corresponding bolt receiving bores 35 in the motor housing 14 such that the central bore 33 is aligned with an output shaft of the motor.

The upstanding wall 32 is provided with an elongate slot 37 which is shaped and dimensioned so as to receive, in use, a drive belt 50 which is discussed later. The slot 37 tapers inwardly from the side of the wall 32 adjacent the central bore 33 to the side of the wall 32 remote from the central bore 33.

Figure 9 shows a pulley member 40 having a drive shaft 41 and a circular section pulley 42 at one end thereof. In the illustrated embodiment the pulley has upper and lower lips 43 and in use of the apparatus the drive belt 50 is received between these lips 43. The end of the drive shaft 41 is adapted to engage and be driven by the output shaft of the motor in the housing 14. In the illustrated embodiment the output shaft of the motor has an internally splined connector 44 and the drive shaft has a correspondingly outwardly splined connector 45.

Figure 10 shows a sectional view of the pulley member 40 together with this splined connector 45. The drive shaft 41 of the pulley member 40 is mounted for rotation in a bearing unit 46 provided in a hub 47. The hub 47 in the illustrated embodiment has a series of three spaced threaded bores 48 (only one shown) and a lower tubular boss 49. The boss 49 is received in the central bore 33 of the bracket 30 and retaining bolts (not shown) are provided to extend through additional bores 36 in the lower base 31 of the bracket and into the threaded bores 48, thereby securing the hub 47 to the bracket 30.

Figure 11 shows a cover assembly 60 comprising a generally cylindrical cover 61 having a top plate 62 and a partial cylindrical wall 63 depending therefrom. The wall 63 has an opening 64 at one radial side, which opening 64 is dimensioned so as to cooperate with the elongate slot 37 to enable passage of the drive belt 50 in use. The cover assembly 60 is shown as being connected to a mounting bar 65 by which the cover assembly 60 is secured to the upstanding wall 32 of the bracket 30, although other methods of fixing are readily envisaged.

Ideally, and as shown, the partial cylindrical wall 63 incorporates a number of apertures 66 surrounding the pulley 42 when the apparatus is connected together. These apertures 66 allow ventilation and figure 9 shows the preferred form of the apertures 66 as axially extending slots. The cylindrical wall 63 also has a larger slot 67, perhaps optional, which is opposite the opening 64, the larger slot 67 enabling, in this embodiment, the cover 61 to mate with a support member 70 of a yarn feed guide arm 71 of the sort known in the industry.

When a yarn texturing machine 10 is running with friction texturing units 11 , the individual units 11 are secured to individual motor housings 14. Using the above-described apparatus an individual friction texturing unit 11 can be disconnected and removed from its associated motor housing 14 whilst all other units in the machine are still running. The bracket 30 (to which the pulley member 40 and bearing unit 46 are already mounted) can then be secured to the motor housing 14 with the connectors 44, 45 mating for driving the pulley 42. A pin spindle texturing unit 20 can then be secured to the upstanding wall 32 by means of suitable bolts with the endless drive belt 60 extending around the pulley 42 through the elongate slot 37 in the upstanding wall 32 and around a drive end of the driven shaft 24 of the pin spindle texturing unit 20.

By suitable selection of the diameters of the pulley 42, the drive end of the driven shaft 24, the driven discs 23 and the spindle 21 , the motor of the friction texturing unit can produce spindle rotation speeds suitable for effecting texturing of high tenacity yarns. The diameter of the pulley 42 will be greater than that of the drive end of the driven shaft 24 and typically the diameter of the drive discs 23 will be greater than the diameter of the spindle 21. In typical arrangements, the rotational speed of the motor (and therefore the pulley 40) will be 0-10,000 rpm, the rotational speed of the driven shaft 24 (and therefore the driven discs) will be 0-50,000 rpm, and the rotational speed of the spindle 21 will be 0-1 ,000,000 rpm. The diameter of the pulley 40 may be in the range 10-100 mm, the driven shaft 5-20 mm, the driven discs 20-80 mm and the spindle 1-5 mm.

In this way a traditionally medium tenacity yarn machine can be converted to run pin spindle texturing units for high tenacity yarn. This is particularly advantageous because the medium tenacity yarn machine can swap out a chosen number of friction texturing units for pin-spindle texturing units at short notice and this is particularly beneficial for producing limited runs of high tenacity yarns whilst having a limited impact on other production.

It will be appreciated that modifications to the described embodiment will be apparent to the skilled person without departing from the scope of the attached claims. In some preferred embodiments the pulley and drive belt have correspondingly meshing teeth, as does the drive end of the driven shaft. Also, precise shapes, sizes and construction materials will be a matter of design choice and may vary depending on the actual apparatus intended for modification/reversible conversion.