GB1602305A - Manufacture of fibres from an attenuable material by means of gaseous currents - Google Patents

Abstract

At least one gas jet (5) is generated and is perturbed by means of a baffle (19) inserted in its path to establish counterrotating turbulences alongside a lamina flow region towards which a lace (G) of ductile substance is brought. The baffle member (19) comprises at least one component with a surface whose sections parallel to the axis of the orifice for emitting (32) the jet and to the lace (G) of ductile substance have a convex portion placed in the flow of the jet. The device also comprises a main gas stream generator (15) for forming with the jet an interaction zone where the substance is subjected to a second drawing stage. Means of support provided with control instruments make it possible to modify the relative positions and the interactions of the various instruments of the device with a view to compensating the various fluctuations of the fibre-forming conditions. <IMAGE>

Description

(54) MANUFACTURE OF FIBERS FROM AN ATTENUABLE MATERIAL BY MEANS OF GASEOUS CURRENTS (71) We, SAINT-GOBAIN INDUSTRIES, a French Company, of 62 Boulevard Victor Hugo, Neuilly-Sur-Seine, France, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to the manufacture of fibres from various attenuable materials by attenuation by means of gaseous currents in which at least one pair of counter-rotating tornadoes is formed.

It relates more particularly to the attenuation of thermoplastic materials, especially mineral materials such as glass or similar compositions which are converted into the molten state by heating. It also applies to the formation of fibres from certain organic materials such as polystyrene, polypropylene, polycarbonates or polyamides. The apparatus described is, however, particularly interesting for the attenuation of glass and similar thermoplastic materials and the description will refer to this use by way of example.

Certain techniques using whirling currents for manufacturing fibres by attenuation of molten glass are already known. In particular, the publication of French Patent FR 2 223 318 describes the formation of pairs of counter-rotating tornadoes in a zone of interaction produced by directing a gas jet referred to as secondary jet or carrier jet to a main gas current of larger dimensions and causing said jet to penetrate said current, a stream of molten glass being delivered into this zone to be attenuated there. In the apparatus used for carrying out this process, the glass supply orifice which directs the stream of glass to the resulting zone of interaction is situated at or close to the boundary of the main current. It is also possible, however, as described in British Patent No 1521343 in the name of the Applicant, to place the glass supply orifice at some distance from the boundary of the main current and deliver the stream of glass to the said zone of interaction by gravity.

It has also been envisaged to place both the glass supply orifices and the emission orifices for the secondary jets at some distance from the boundary of the main current, the streams of glass being then introduced into the corresponding zones of interaction by the action of the jets themselves so that the streams are subjected to two stages of attenuation, one in the secondary jet and the other in the main current. This arrangement is described in particular in British Patents No 1513060 and Patent application No. 50314/77 serial no 1592683.

According to the abovementioned application No. 50314/77 serial no 1592683, in the secondary jet (or carrier jet) which delivers the glass into the zone of interaction with the main current, there is brought about the formation of a stable zone of laminar flow situated between two counter-rotating tornadoes. The stream of glass is conducted to this laminar zone and then enters the region of the tornadoes which subsequently merge downstream of the carrier jet before the latter reaches the main current. The first stage thus takes place while the stream of glass is carried into the pair of tornadoes of the carrier jet and subjected to their action whereas the second stage, which is advantageous but sometimes optional, takes place in the zone of interaction with the main current after penetration of the carrier jet and introduction of the partially attenuated stream of glass.

In application No. 50315/77, serial no 1592990 the zone of laminar flow and the tornadoes of the carrier jet associated with each fibre forming centre are produced by a disturbance of the jet which in general causes it to be deflected, this deflection of the jet contributing to the stability and regularity of operation in spite of the distance between the region where the glass is delivered into the carrier jet and the main current.

According to the invention we provide apparatus for the manufacture of fibres from an attenuable material by attenuation by means of gaseous currents, comprising at least one fibre forming centre having a gas jet emitter, a source of supply for delivering a stream of material, a deflector device arranged along the path of the jet from the emitter to modify the flow of the jet and produce a stable zone of quasilaminar flow towards which the attenuable material is directed, the source of material being located opposite the said zone, and mounting means having control devices to modify the position and/or the operation of at least one of the gas jet emitter, deflector device and the source of supply in relation to at least one other thereof.

Preferably, the apparatus includes a main current generator, the gas jet emitter producing a jet having a higher kinetic energy per unit volume than that of the main current, the jet being directed along a path which intersects the main current to penetrate the latter and produce a zone of interaction.

The deflector device is preferably interposed in the path of the jet between an emission orifice of the gas jet emitter and the stream of attenuable material, and comprises at least one element possessing a surface the sections of which parallel to the axis of the emission orifice and to the stream of attenuable material have a convex portion located within the flow of the jet, the supply orifice for attenuable material directing the stream of material towards the jet in the region of the said portion of convex surface.

The obtaining of good stability and good regularity of the supply of glass in spite of a considerable distance between the glass supply orifice and the main current or zone of interaction is also a particularly important object of the present invention.

The deflector device, placed in the path of the jet between its emission orifice and the stream of attenuable material, causes the flow to undergo a local deflection and a general deflection of its path, as will be described hereinafter. It will be noted that the device in question also guides the jet over at least part of its path but in the description it will nevertheless be referred to solely by the term "deflector device".

Although it is preferred to employ this deflector device and the resulting "jet tornadoes" as means for delivering the stream of glass into the zones of interaction formed with a main current in order to carry out attenuation in two stages, provision is also made for carrying out attenuation in a single stage, that is to say entirely in the tornadoes of the carrier jet. In the latter case there is, of course, no main current.

In certain embodiments which will be described later with reference to the figures, the deflector device comprises a circular cylindrical bar, but this may be replaced by any hollow or solid cylindrical piece in general, without departing from the scope of the invention provided it conforms to the conditions previously specified concerning the portions of surface offered to the jets. Moreover, the deflector device need not necessarily be cylindrical but may consist of a series of elements each placed opposite a jet and having, for example, a shape similar to that of a diabolo.

The apparatus according to the present invention also comprises control devices for controlling the relative positions, the operation and the interactions of the various elements used in the fibre forming centres, that is to say the main current generator, the jet emitter, the deflector device and the bushing.

Most of the controls proposed are applicable to all the forms of fibre-forming apparatus described in the Patents and/or Applications already mentioned. It will be recalled that in some of these forms of apparatus, the fibre-forming centres comprise only three basic components, (I), (II), (III), namely (I) the generator for producing the main current, (II) the jet emission device and (III) the source of supply of attenuable material delivering the stream of material into the zone of interaction of the jet with the main current. Although the various control devices or mechanisms may be used in the apparatus containing only these three basic components, some of them present a particular advantage when used in fibre forming centres which have a fourth component for disturbing the flow of the jets, as in the present application or in Patent Application No. 50314/77 serial no 1592683.

More precisely, the fibre forming apparatus comprises mounting and control devices which enable the relative positions and interactions of the various components of each fibre forming centre to be altered, particularly by an angular displacement and/or by a translation of at least one of the components in relation to the source of supply of attenuable material.

This is particularly advantageous in installations intended for the production of fibres from mineral thermoplastic materials such as glass flowing from a melting furnace.

One of the objects of the invention is also to compensate by these controls the fluctuations in the various operating conditions such as the temperature of the various components of the system, the composition and the viscosity of the attenuable material, the velocities of the gases used for the jet and the main current and the other variable operating conditions. Deformations or irregularities in the shape and size of the components may also be compensated by means of these control devices. Although some of these are in a form which requires temporary stoppage of the apparatus when it is put into operation, most of them are capable of operating during fibre formation without interrupting the process.

Since the various components of the fibre forming centres are relatively close to each other, another object of this invention is to enable certain components to be automatically withdrawn, in particular the deflector device and the device for emitting the jets, so that they can be moved further away from the source of supply of molten material in the event of failure or breakdown of the system supplying gas either to the jet emitter or to the main current. Damage to the various components of the apparatus is thereby avoided.

Figures 1 to 10b, 11 to 12b, 13 to 18, 19 to 28 illustrate five embodiments of the invention.

Figure I is a schematic overall view in longitudinal elevation of the main elements of an apparatus for the formation and collection of fibres according to the invention, with certain parts thereof shown in section.

Figure 2 is a transverse elevational view on a larger scale of the main elements of the fibre forming apparatus represented in Figure 1, taken on the right side thereof.

Figure 3 is an elevational view on a still larger scale of certain parts of the apparatus of Figure 2.

Figure 4 is a plan view of various elements of Figure 3.

Figure 5 is a vertical section through the elements of the fibre-forming apparatus of Figures 3 and 4 taken on the line V-V of Figure 3.

Figure 6 is a schematic view in perspective illustrating the operation of the apparatus represented in Figures 1 to 5.

Figure 7 is a partial and enlarged schematic cross-section through part of the apparatus of Figure 5, illustrating certain phases of the action of the jet deflector device at the time of attenuation of the glass.

Figure 8 is a schematic view of several jets and of parts of the main current represented in Figure 7, from which the glass supply and the glass fibres in the course of formation have been omitted.

Figure 9 is a schematic transverse section through three adjacent jets illustrating the sense of rotation of the counter-rotating tornadoes in the jets.

Figure 10 is a longitudinal section in elevation of the main elements of the fibre forming apparatus, illustrating in particular certain dimensions which must be taken into account to establish the operating conditions for carrying out the preferred embodiment of the present invention.

Figures lOa and lOb are detailed sectional views of two adjacent jet orifices and of a glass supply tip, respectively, again showing certain dimensions to be considered.

Figure 11 is a schematic view in perspective, similar to that of Figure 6 but representing another possible embodiment of the jet deflector device.

Figures 12 to 12b relate to the embodiment of Figure 11 and are homologous to Figures 10 to 10b respectively.

Figure 13 is an elevational view similar to that of the Figure 1 but illustrating the arrangement of elements of the third embodiment and the manner in which they are mounted, in combination with a forehearth for supplying glass.

Figure 13a is a view on an enlarged scale of part of this apparatus, representing a jet manifold box on which is mounted a deflector vane also described in our Patent Application 50314/77 serial no 1592683.

Figure 14 represents, in elevation on a smaller scale than Figure 13, a general view of an installation comprising four fibre forming stations associated with one and the same forehearth and one and the same apparatus for collecting the fibres.

Figure 15 is a partial view in elevation of part of the apparatus of Figure 13.

Figure 16 is a vertical section taken on the line 16./16. of Figure 15, showing certain parts in elevation.

Figure 17 is a schematic view of certain control devices used preferably for the apparatus represented in Figures 13 to 16.

Figure 18 is a schematic view showing various parts of an automatic control system comprising a mechanism for automatic withdrawal of certain components to move them further away from the bushing.

Figure 19 is a plan view of a group of five jet manifold boxes equipped with a deflector as in Figures 13, 13a and 18, but this figure also shows the means for mounting the manifold boxes which enables the deflector to be bent by displacement and control of the position of the said manifold boxes, thereby enabling the position of the deflector to be controlled in relation to the bushing which supplies the molten material.

Figure 20 is an elevational view taken from one end of the apparatus of Figure 19.

Figures 21 and 22 are sections taken on the lines 21./21. and 22./22. of Figure 19.

Figure 23 is a detailed sectional view taken on the line 23./23. of Figure 19.

Figure 24 is a partial view in perspective of a part of the elements for mounting a jet manifold box and Figure 25 is a perspective view showing one of the control members which fits on to these elements.

Figures 26 and 27 represent schematically the directions in which the deflector is bent and the possibilities of controlling this bending.

Figure 28 is a view similar to that of Figure 13 but showing a control system applied to fibre forming centres having only three components instead of four.

Figures I to lOb For the description of the first embodiment, reference will first be made to Figure 1 which shows a nozzle 13 for emitting a main current, which nozzle is connected to a burner or generator 14 for producing the main current 15. The latter is directed by the nozzle 13 to flow in an approximately horizontal direction below a source of glass supply indicated schematically at 16. The secondary or carrier jets are emitted by an emitter 17 equipped with nozzles whose orifices are connected to gas supply devices mounted on brackets 18.

The secondary jets are directed to the deflector device 19 which deflects them downwards so that they penetrate the main current 15 and produce zones of interaction. The separate streams of glass provided by the supply source 16 are delivered to the secondary jets and thereby led to the zone of interaction formed with the main current to be converted into fibres there. The flow resulting from the mixture of secondary jets and main current enters the inclined guide channel C' together with the attenuated fibres to deposit the fibres on the perforated surface of a receiving belt or conveyor 20. Suction chambers 21 are advantageously placed below the upper section of the conveyor belt 20, and the fibres are collected in the form of a mat B' by the action of the suction pipes connected to ventilators indicated schematically at 22 and 23, respectively.

The device for emitting the secondary jets is supported by brackets 18 connected to the support plates 24 which have apertures cooperating with bolts 25 to enable the brackets 18 to be adJusted vertically in relation to the body of the generator 14 for the main current (see also Figure 2) and consequently to control the position of the jets in relation to the main current 15 in the vertical direction.

The body of the main current generator 14 which carries the brackets 18 of the jet emitters is mounted so as to be adjustable in the vertical direction by means of screw jacks 26 connected to the supporting structure 27 of the apparatus. The main current generator and the jet emitters may therefore be conjointly displaced vertically, in particular by a movement of translation so that they can be adjusted vertically in relation to the source of supply of glass 16 and the guide channel C'. The horizontal position of this whole arrangement may also be adjusted by means of a suitable mechanism of the screw jack type indicated schematically at 28. Other possible means of controlling the elements associated with the jet emitters and with the deflector devices for the jets may also be provided, as described hereinafter with reference to some of the figures.

Referring to Figures 2,3,4 and 5 representing the fibre-forming apparatus on an enlarged scale, it will be seen that the emitters 17 for the secondary jets comprise a manifold box 17a for the jets, mounted on a collector 29 which is supported by sockets 30 attached to the brackets 18. The jet emitter 17 can thus be deflected upwards or downwards about the axis of the collector 29 and then fixed in any desired angular position, for example by means of stop screws as indicated at 31.

In addition to this upward or downward angular displacement, the mounting also allows for a lateral displacement or adjustment of the emitter 17 in a direction parallel to the axis of the collector 29. This adjustment is very important for obtaining exact and accurate alignment of the carrier jets with the glass supply orifices described hereinafter.

The manifold box 17a of the emitter 17 supplies the emission orifices 32 of each of the jets, of which there are eleven in the present example. It is clear from Figure 5 that the axes of the jet emission orifices are inclined downwards and to the right in the Figure so that they point in the direction of the surface of the deflector 19. In this embodiment, the deflector has the form of a circular cylindrical bar with its axis placed horizontally, parallel to the row of jet emission orifices. Moreover, the axes of these orifices are virtually perpendicular to the generatrices of the cylindrical bar. The bar carries mounting lugs 33 at each end, connected to the body of the manifold box 17a by bolts 34. The vertical position of the deflector bar 19 in relation to the manifold box 17a and hence to the jets may be adjusted by means of detachable chocks 45 placed between the mounting lugs 33 and the base of the manifold box 17a. The apertures in the mounting lugs 33 may be elongated so that the deflector bar can be adjusted in a horizontal direction to move it towards or away from the jet or the stream of glass.

The source of supply 16 for glass comprises a bushing 35 having a series of tips 36 each of which has a supply orifice 36a and a metering orifice 37. The glass is thereby delivered in the form of a series of bulbs G or streams to the secondary jets in which they are partially attenuated as represented at 38 in Figure 5. The partially attenuated streams of glass then enter the zone of interaction of the jets with the main current to be subjected to an additional attenuation indicated schematically at 39. Figure 3 shows nine glass supply tips 36, and it shows jet emission orifices 32 which are placed in corresponding positions except that they are greater in number, amounting to eleven so that an additional jet may be placed at the end of each row. This arrangement enables uniform fibre forming conditions to be obtained for each of the nine streams of glass used in this example.

The process of fibre formation obtained with the apparatus described above with reference to Figures 1 to 5 is represented schematically in Figures 6 to 9. It should first be noted that the cylindrical deflector bar 19 is in such a position that its axis is slightly lower than each of the secondary jets J emitted by the jet emission orifices 32. This position is shown for each of the four carrier jets J1, J2, J3 and J4. It causes a deflection of the path of the carrier jets and in addition the flow of each of the jets J is divided into an upper part and a lower part, the former curving round and adhering to the upper surface of the bar 19 by the Coanda effect while the latter curves round the lower surface. Since the axis of the bar 19 is below that of the jet emission orifices, the upper part of the flow of the jet has a larger cross-section than the lower part, a feature which is desirable for reasons given in the description.

The two parts of the secondary jet flowing over and under the bar 19 merge downstream of the bar.

Figures 6 and 8 show that the flow of the jet emitted from each orifice 32 spreads out laterally or diverges in the direction of the axis of the deflector 19 and, if the jets are suitably spaced apart, this spreading out in the lateral direction causes adjacent jets to impinge on each other while the upper and lower parts of the jets flow around the corresponding surfaces of successive elementary portions 19a, 19P, 19y of the bar 19.

This lateral impingement of adjacent jets against each other causes the development of pairs of counter-rotating tornadoes which have their apices on the surface of the bar 19. As can be seen from Figures 6 to 9, two pairs of tornadoes are produced in the flow of each jet.

Two tornadoes 40a and 40b constituting the upper pair thus form in the part of the flow which passes over the upper surface of the part of the bar 19 while a lower pair of tornadoes 41a and 41b develops in the part of the flow which passes under the lower surface.

These two pairs of tornadoes rotate in opposite senses. The movement of rotation of each tornado of the upper pair is directed downwards along their adjacent surfaces and upwards along their external surfaces, as indicated by the arrows 40c and 40d in Figure 9.

Conversely, the arrows 41c and 41d indicate that the movement of rotation of the tornadoes of the lower pair is upwards along their adjacent surfaces and downwards along their external surfaces.

Due to the position of the bar 19 in a lower horizontal position than the axes of the jets, that part of the flow which is situated above this bar is larger and more powerful.

Furthermore, this position of the bar in relation to the jets also causes a zone of substantially laminar flow which is particularly stable and powerful to develop on the upper surface, between the tornadoes 40a and 40b of the upper pair. This zone of quasilaminar flow generally has a triangular form because the tornadoes increase in size as they progress downwards until they merge. The same process also takes place in the lower pair of tornadoes.

As the flow of the jet progresses downwards, the tornadoes tend to lose their identity, as indicated schematically by the cross-section of the flow issuing from jet j3 in Figure 6. After the tornadoes have merged, the flow of each jet still has a sufficiently high kinetic energy per unit volume compared with that of the main current 15 to enable it to penetrate the main current to produce a zone of interaction of the type which has already been described in detail in the aforementioned French Patent publication FR 2 223 318. It will be recalled that this zone is characterised by the formation of a pair of counter-rotating tornadoes 42a and 42b (see Figure 6). In the region where the secondary jets penetrate the main current, the flow and velocity of each one of them remains sufficiently concentrated in the vicinity of its axis to enable each jet to act individually and form a distinct zone of interaction with the main current.

In order to be able to utilise the flow of the secondary jets J1, J2, etc. of each fibre forming centre to form fibres, the streams of attenuable material, in particular streams of glass, obtained from the bulbs of glass G formed at the outlet of the tips 36 are delivered individually into the zones of laminar flow of the jets situated between the tornadoes of the upper pairs. The characteristics of the flow above the deflector bar 19 produce a very powerful induction of air, indicated by the arrows in Figures 6 and 7 along the flow of the jet J2. The induced air promotes the attenuation of each bulb G into a stream of glass and the stable delivery of this stream into the zone of laminar flow situated between the two tornadoes of a pair formed at each fibre forming centre. The whirling currents then carry this stream away and start the process of drawing it into a fibre, as indicated at 38 in Figures 5 to 7.

The flow of the jet carrying the partially attenuated fibre progresses downwards to enter into the main current 15 and deliver this fibre into the zone of interaction between the jet and the main current where the additional counter-rotating tornadoes 42a and 42b effect an additional attenuation. The fibre may then be collected by a system such as the guide channel C' with conveyor belt 20 represented in Figure 1.

Although the attenuation which is carried out in the flow of the jet itself can be used to produce the fibres without the aid of a main current 15, it is in most cases preferred to consider the attenuation effected by the jets as only a primary attenuation and to carry out a second stage of attenuation in the zone of interaction of the jet with such a current.

The system described above is advantageous in that it separates the main elements of the fibre forming apparatus, particularly the source of supply of glass and the generator of the main attenuating current, but it also separates the latter from the jet emitters. It is easier to maintain each of the elements of the apparatus at the desired temperature when they are spaced apart from each other since the transfer of heat between them is then reduced.

However, it is important in these fibre-forming systems that the streams of attenuable material should be delivered into each of the individual zones of interaction with the main attenuating current in very precise positions. In spite of the separation of the elements, the invention provides the possibility of precise and exact delivery of attenuable material because the mode of development of the pairs of tornadoes in each carrier jet makes it possible to obtain a very stable flow. It will be noted that the apices of the tornadoes are situated on the surface of the cylindrical bar 19 and are thus "attached" to this surface in a stable position. The tornadoes are therefore themselves very much more stable than they would be if their apices were situated in free space, and consequently the delivery of attenuable material to the zones of interaction is also very stable.

Furthermore, in the event of a slight fault in lateral alignment of the bulbs of glass G in relation to the corresponding orifices 32 of the jet emission nozzles, this fault will be automatically compensated due to the currents of induced air at the level of the zone of quasilaminar flow situated between the upper tornadoes of the jet. This enables great stability in the delivery of glass into the zone of quasilaminar flow to be obtained in each jet and also results in an improvement in the stability of delivery of the glass into the zone of interaction for the second stage of attenuation.

Although the development of zones of laminar flow enables the introduction of streams of glass to be stabilised in each fibre-forming centre, certain variations in the operating conditions from time to time require a modification of the interactions, that is to say of the operating positions as regards the various components of the fibre forming centres. Various mechanisms for carrying out such modifications have been described above with reference to Figures 1 to 6, and it may be noted that some of these, for example the systems of screwjacks 26-27,28 or of sockets and screws 30-31 represented in Figure 1, may be manipulated without stopping the process of fibre-formation whereas other means of adjustment, for example the arrangement for adjusting the position of the deflector bar 19 in relation to the jet orifices by means of the parts 33-34, require temporary stoppage.

It is possible, however, to arrange all these control systems in such a manner that they can be operated while continuing the process of fibre formation. Various possible solutions are indicated in the embodiments described with reference to Figures 13 to 22.

Figure 10 is a sectional view similar to that of Figure 5 of the three main elements, the main current generator, the secondary jet emitter and the source of supply of attenuable material, as well as the cylindrical deflector bar 19. Figure 10 as well as the sections 10a and 10b contain symbols identifying certain dimensions and angles referred to in the Tables below which show the suitable ranges of variation of the dimensions and of the angles and the preferred values.

TABLE I Supply bushing and tip of attenuable material Symbol Preferred value Range (mm) dT 2 1 5 IT 1 1 5 1R 5 0 < 10 dR 2 1 - > 5 DR 5 1 o 10 TABLE II Jet Emission and Deflector Device 19 Symbol Preferred value Range (mm, degrees) dJ 2 0.5 - > 4 Ii 7 at least 1 YJ 5 3 - > 7 Di 6 6 - > 12 JD 0 +0.25 -0.5 dJ oJB 10 0 - > 45 LJD 4 3 - > 8 When the axis of the jet emission orifice is tangential to the upper surface of the bar 19, 1JD is zero and the negative values of 1JD correspond to the case of Figure 10 where this axis cuts the upper part of the bar.

TABLE III Main Current Symbol Preferred value Range (mm) 1B 10 5 - + 20 TABLE IV Relative Positions of the Various Elements Symbol Preferred value Range (mm) Zw 8 3 - + 15 Zin 17 12 - + 30 XBJ - 12 5 -12 +13 XJF 5 3 - + 8 As regards the symbol XBJ, the negative values correspond to the case represented in Figure 10 in which the outlet of the nozzle emitting the main current is situated upstream of the secondary jet emission orifice viewed in the direction of propagation of the main current.

For the embodiment represented in Figures 1 to 10h, it is provided, as indicated earlier, that the secondary jets or carrier jets should be arranged sufficiently close together to spread out and impinge on each other so as to produce pairs of tornadoes in each carrier jet.

As many fibre forming centres as desired may be created, each centre comprising a supply tip for supplying attenuable material and an associated jet, but in order that each jet may impinge on an adjacent jet on each side, their numbers should be greater by two than the number of supply tips, and two "additional" jets should therefore be arranged at the ends of each row.

The term "supply orifice" for attenuable material has a very general meaning and may denote either an isolated orifice or a slot associated with a row of jets or a plurality of orifices or of supply tips. When the tips are replaced by a slot arranged transversely to the main current, the material delivered from the slot is divided into cones and streams by the action of the jets. Here again, and for the same reasons as given earlier, two additional jets should be placed at the ends of the rows of jets.

The number of fibre forming centres may reach 150 but in an ordinary fibre forming installation for glass or similar thermoplastic material, a suitable bushing would have, for example, 70 supply tips and 72 jets.

It should also be mentioned that the operating conditions of the system according to the present invention would vary as a function of various factors such as, for example, the characteristics of the material which is to be converted into fibres.

As indicated above, the invention may be applied to a wide range of attenuable materials. In the case of glass or other inorganic thermoplastic materials, the temperature of the bushing or of the source of supply of material will, of course, vary according to the particular material which is to be converted into fibres and will generally be within a temperature range between 1400 and 1800"C. For a conventional type of glass composition, the temperature of the bushing is in the region of 1480"C.

The unit pull rate may vary from 20 to 150 kg per aperture per 24 hours, typical values being from 50 to 80 kg per aperture per 24 hours.

Certain values relating to the jet and the main current are also important, as indicated in the Tables below, in which the following symbols have been used: p = pressure T = temperature V= velocity p = density TABLE V Remission of Jet Symbol Preferred value Range PJ (bar) 2.5 1 < 4 Tj ("C) 20 10 o 1500 Vj (m/sec) 300 200 < 900 PJVJ2 (bar) 2.1 0.8 < 3.5 TABLE VI Main Current Symbol Preferred value Range PB (mbar) 95 30 < 250 TB (OC) 1450 1350 e 1800 Va (m/s) 320 200 e 550 PBVB (bar) 0.2 0.06 < 0.5 Figures 11 to 12b The representation of the embodiment illustrated in these Figures is similar to that of Figure 6 but in Figure 11, the main current 15 has been omitted and the part relating to the flow of the jets has been shortened. The main difference between this and the first embodiment is situated at the level of the deflector device. It comprises in this - case a cylindrical bar 43, preferably circular, which is provided with peripheral flanges 44 which define, along the whole length of the bar, a series of channels for the upper and lower parts of the flow of the jets. Each element 43cut, 43ss, 43y of the bar formed by these flanges defines a channel for each corresponding jet Jl, J2, J3. As can be seen from the Figures, each successive element preferably has as its plane of symmetry the plane formed by the stream of attenuable material and the axis of the jet emission orifice. The process is similar to that described above for the first example but the pairs of tornadoes are produced by the jets impinging against the side walls of the flanges 44 as they spread out and not by impingement of adjacent jets against each other. The flanges therefore help to stabilise the apices of the tornadoes, this factor being very important for the reasons already given above and particularly in order to ensure very precise delivery of the streams of attenuable material into the individual zones of interaction of the jets with the main current in spite of a considerable distance between the main elements of the fibre forming system.

Since the development of the pairs of tornadoes associated with the carrier jet does not require adjacent jets to impinge upon each other, it will be noted that the lateral space between fibre forming centres and hence between carrier jets may be greater than in the first case. This feature is advantageous for the treatment of fibre formation of various materials for which it is preferable to maintain a greater distance between the supply orifices of attenuable material.

With reference to Figures 12 to 12 b showing the dimensions and relations between the dimensions of the main elements of the fibre forming system of Figure 11, it should be noted, first, that most of the values are identical to those entered in Tables I to IV relating to the first embodiment. The diameter D1 of the bar 43 may be the same as that of bar 19 of the first example (TABLE II) while the flanges 44 may have the dimensions indicated in Table VII below.

TABLE VII Flanges Symbol Preferred value Range (mum) De 10 10 < 16 1D 2 at least 0.5 The distance YJ between the jet orifices 32 is preferably slightly greater in the second embodiment due to the presence of the flanges 44 on the deflector bar and their thickness.

Furthermore, if the flanges are suitably placed on the deflector bar, there is no upper limit to the distance between jets since the tornadoes are produced by impingement of the individual jets against the side walls of the flanges in the course of their spreading out and not by impingement of adjacent jets against each other. It is preferred, however, that the distance between jets correspond to the distance between flanges, that is to say two adjacent jets should be separated by only one, thin flange. This distance may take any value greater than about 0.5 mm.

The dimensions represented in Figures 12 to 12b are otherwise identical to those entered in Figures 10 to 10b and described above with reference to Tables I to IV.

The second embodiment is advantageous not only in cases where it is desired to have a considerable distance between adjacent fibre forming centres but also because the presence of the flanges provides for greater stability of the apex of each tornado. In fact, this apex is stabilised not only, as in the first case, in a given position on the circumference of the bar, that is to say at the level of one of the generatrices, but also in a given position along this generatrix, that is to say at the level of the side wall of the flange.

As regards the two embodiments represented, it may be noted that the position of the emission orifice 32 for the secondary jet in relation to the deflector bar (19 and 43) indicated by the distance 1JB (Figures 10 and 12, Table II) is such that the flow of the jet subdivides into two parts flowing along opposite faces of the bar. Furthermore, the bar is displaced in relation to the axis of the emission orifice for the carrier jet in order to deflect the latter from its initial path. It will also be noted, however, that the deflector bar could be arranged so that it only deflects the flow of the jet locally, thereby forming an upper part and a lower part of equal strength, which subsequently merge downstream of the bar without the resulting part of the jet being modified. In that case, the pairs of tornadoes and the zone of laminar flow would still be formed but attenuation in the jet would be less effective.

Theoretically, it is also possible to arrange each jet so that the whole flow passes over one side of the bar, but this is not the preferred form of the invention since it is desired to provide maximum stability of the angle along which the flow leaves the surface of the bar. If the whole flow passed over one side of the bar, the point at which it left the bar and consequently the angle of deflection of the jet would not be stable but would be subject to fluctuations, particularly under the influence of parasitical air currents. This would give rise to irregularities in the course of attenuation in the jet and in the course of attenuation in the zone of interaction.

The value for 1JD is therefore preferably chosen so that each jet flows on both sides of the bar but a greater proportion of the flow of the jets passes above the bar, along the surface presented to the stream of attenuable material. This inequality in the distribution of flow enables the pairs of tornadoes 40a and 40b obtained close to the supply of attenuable material to be greater and more powerful than the pairs of tornadoes 41a and 41b produced in the flow round the opposite side of the bar. This distribution is most definitely advantageous when it is desired, according to the preferred form of the invention, to favour the predominant action of the pairs of tornadoes 40a and 40b in the course of attenuation of the fibre.

Figures 13 to 18 In the embodiment represented in these Figures, the apparatus not only enables the controls obtained with the apparatus of Figures 1 to 12 to be carried out more easily but also enables other types of control to be carried out, as will appear from the description.

Reference will first be made to Figure 13, 13a and 14. A perforated conveyor of the same type as that shown in Figure 1 for collecting the fibres is represented at 20. With it are associated suction chambers 21 connected to suction pipes 22 to assist the deposition and distribution of the fibres.

A supporting structure 50 supports the forehearth 51 of a furnace which supplies a plurality of bushings 52, as can be seen from Figure 14 which shows schematically an arrangement of four fibre-forming stations A, B, C and D, one of which is represented on a larger scale in Figure 13. At each fibre forming station, the apparatus comprises various elements for producing a multiplicity of fibre forming centres. Each station comprises one bushing 52 placed perpendicularly to the plane of the Figure-and equipped with a plurality of supply tips to form bulbs or streams of molten material. It also comprises at least one generator producing a main current 15, connected to an emission nozzle 55 as in the first embodiment, and a plurality of jet manifold boxes 56 such as that represented partly in section in Figure 13a, each of these boxes having a succession of jet emission orifices 32.

The sectional view in Figure 13a also shows the form of a deflector flap 57 fixed to the jet manifold by screws 57a. The action of the flap 57 on the jet J is- indicated schematically on the same figure. The fibre 38 produced at each fibre forming centre is delivered to the channel C' at the same time as the fibres manufactured at adjacent fibre forming centres, and all the fibres then flow together through this channel to be subsequently deposited in the form of a mat of fibres B'.

The nozzle 55 of the generator, the jet manifold boxes 56 and the one or more deflectors 57 mounted on the latter are associated with each other at each fibre forming station by means of various control mechanisms and mounting arrangements described hereinafter, the whole arrangement, including the control mechanisms, forming a unit at each fibre forming station. To this end, each one of the stations has a vertical suspension rod 58 connected to the supporting structure 50 of the forehearth 51. The lower end of the suspension rod 58 (see Figures 13, 14, 15 and 16) carries a cylindrical sleeve 59 the axis of which extends transversely to the forehearth in a direction parallel to the bushing 52 of this fibre-forming station. Fitted into the sleeve 59 is a journal 60 connected to the flange 61 which in turn carries the counterflange 62 to which is fixed the support 63 designed to carry the fibre forming apparatus at each station.

On the flange 61 is a curved stop plate 64 situated between the lugs 65-65 which are integrally attached to the sleeve 59. Into it are inserted the adjustment screws 66 which are provided for the angular displacement of the support 63 about the axis of the sleeve 59 and of the journal 60. The flange 61 and counterflange 62 are locked together and fixed in the desired adjusted position by the screws 67. Although the movement of the fibre forming apparatus, main current generator 71, emission nozzle 55, manifold box 56 for the jets and collector 72 is an angular movement about the axis of the sleeve 59 and journal 60, its main effect is to displace these parts towards or away from the bushing 52 and hence the streams of glass since they are situated at a considerable distance above this axis. Due to the fact that the whole fibre forming apparatus is mounted on the support 63, all the elements 55,56 and 57 can thereby be displaced together and simultaneously towards or away from the streams of attenuable material which are delivered to the fibre forming station from the bushing 52.

Other mounting and adjustment devices are carried on the support 63 shown in Figures 13 and 15. Thus the frame 68 is mounted on this support 63, preferably by means of a slide 69 which enables it to be adjusted and displaced to the right or left of Figure 13. The frame 68 serves as a fixed point for the screw jacks 70 which are provided for the vertical adjustment of the main current generator 71. The gas collector 72 which supplies the manifold boxes 56 for the jets is mounted on the generator 71 for the main current by the devices indicated schematically at 73 which may either be fixed or carry adjustment mechanisms to adjust the position of the collector 72 and hence of the manifold boxes 56 and of the deflector 57 in relation to the main current generator 71 and other elements of the system, such as the source of glass supply 52.

The movement of the frame 68 relative to the support 63 to move the nozzle 55 of the main current, the jet manifold boxes 56 and the deflector 57 towards or away from the bushing 52 is indicated schematically in Figure 17 which also shows two systems for controlling this movement. One of these systems comprises a manual control indicated at 74 and the other a jack 75 with a cylinder and piston arrangement. These two systems 74 and 75 are connected to the frame 68 in such a manner that they can act on it independently of one another.

The piston of the jack 75 is connected to the structures provided for mounting the main current generator and the jet manifold boxes as indicated schematically by the broken line 68a in Figure 18. This Figure also shows the connection of the collector 72 to a fluid supply means 76. The cylinder of the jack 75 is provided at one of its ends with a connection 77 communicating with a distributor valve 78 which is connected to the other end of the cylinder by a connection 79. The control fluid for the jack 75 is stored in the tank 80 which is connected by the pipe 81 to the valve 78 and by the pipe 82 to the supply line 76 which supplies fluid to the jet manifold boxes. A pressure sensitive detector 83 in this line controls the multiway distributor valve 78. The detector 83, which may be equipped with a manometer, is connected to the circuit 83a comprising the control solenoid 83b for the valve 78. This detector also serves to control the circuit 84a and the solenoid 84b which is provided for closing the electromagnetic valve 84 which is situated in the pipe 82 between the tank 80 and the supply line 76. One of the positions of the distributor valve 78 is for evacuation of the fluid. In the position indicated in Figure 18, the valve is open for the supply of control fluid (for example compressed air) from the tank 80 to the pipe 79 to hold the piston in its lower position, that is to say a position in which the main current generator and the manifold boxes for the jets are placed close to the bushing. The pipe 77 connected to the lower part of the cylinder is then connected to the atmosphere by the way 78e. This arrangement is established by means of the solenoid 83b when the detector 83 registers normal pressure conditions in the line 76 supplying gas for the jets. In the event of interruption of the flow of the jets or an excessive drop in their supply pressure, the detector 83 deflects the distributor valve 78 by way of the solenoid 83b so that the pipe 79 connected to the upper part of the cylinder is in communication with the atmosphere through the evacuation way 78e. At the same time, the control fluid in the tank 80 is discharged through the pipe 81 into the connection 77 which is attached to the lower part of the cylinder, so that the piston is displaced upwards as seen in the Figure or more precisely in a direction which causes rapid withdrawal of the main current generator and jet manifold boxes to move them away from the bushing. The electromagnetic valve 84 in the supply pipe 82 of the tank 80 is also closed by means of its solenoid 84b at the moment when the detector 83 registers a pressure drop in the line 76 which supplies gas for the jets. A local reserve of control fluid is thus always available to move the main current and the jet rapidly away from the glass supply bushing whenever there is an interruption in the supply of fluid for the jet.

The object and advantages of this system will be understood if one bears in mind that at the time of fibre formation, the main current generator 55, the manifold boxes for the jets 56 and above all the deflector 57 (see Figures 13 and 17) are all placed close to the streams of molten material delivered from the supply tips 36 of the bushings 52. The presence of an evenly flowing jet ensures an adequate and stable supply of streams of attenuable material but if the jet is interrupted or its supply pressure falls to an abnormally low value, its flow will no longer maintain the streams of material in the desired position relative to the deflector 57. The molten material is then liable to fall on the deflector, the jet manifold boxes or the main current generator and possibly damage one of these elements.

Figures 19 to 27 It must first be pointed out that due to the high temperatures necessary for supplying material in the molten state, the bushings 52 become deformed after a certain time in service, and this deformation may take place either in a vertical plane or in a horizontal plane. It tends to have a deleterious effect on the precision of the interactions and relative positions of the deflector 57 and the row of glass supply tips 36. The embodiment illustrated in Figures 19 to 27 therefore provides a system of adjusting the operation or interactions and relative positions of the deflector 57 and the bushing with a view to compensafing for the deformation of the latter.

As will be seen in Figure 19, a single deflector 57 extends across the whole length of a series of five adjacent manifold boxes 56 each of which is connected to a feed conduit 111 attached to a connecting piece 112. The conduits 111 are mounted with a certain freedom of displacement in a direction towards or away from the bushing 52, for example on rollers 113. At least three manifold boxes 56 with their corresponding conduits can be displaced separately. For this purpose, each of the three central feed conduits 111 has a pin 114 directed upwards to engage in an oblique hole 115 formed in an individual plate 116 which is transversely displaceable and extends beyond the edge of the apparatus, as shown in Figure 19 and in the righthand part of Figure 21. Each plate ends in a right angled brace 117 which is perforated by a bore engaging with a threaded rod 118 which carries screw nuts for separately positioning each of the plates 116. The positions of the conduits 111 and the associated manifold boxes may thus be adjusted differently from each other in a horizontal plane, as indicated schematically in Figure 27 which shows a deformation of the bushing 52 such that the row of supply tips 36 is curved upwards and the manifold boxes are pushed into positions which cause slight bending of the deflector flap 57. It is obvious that the conditions represented in Figure 27 are grossly exaggerated and that the deflector can in fact only be bent slightly. The manifold boxes may also be displaced in the opposite sense to compensate the opposite deformation of the bushing, as represented by the broken line 52a in Figure 27.

Provision has also been made for a relative displacement of the three central manifold boxes 56 to compensate for deformation of the bushing in a vertical plane. For this purpose, each feed conduit 111 is provided with U-shaped elements 119 embracing cams 120 mounted on transverse shafts 121 which can be adjusted by rotation and then fixed by means of threaded nuts 122. The three central manifold boxes can thus be displaced slightly upwards or downwards to produce a slight bending of the deflector flap 57 and compensate for the deformation of the bushing in the vertical plane. This adjustment is illustrated schematically in Figure 26, where the amplitude of deformation of the bushing has again been exaggerated. The elements 119 and 120 are used for upward or downward relative displacements of the manifold boxes, as indicated by the solid lines and by the broken line 52b, respectively.

The elements described with reference to Figures 19 to 27 which are used for bending the jet deflector may, of course, also be incorporated in the embodiment illustrated in Figures 13 to 18.

Figure 28 In the embodiments described above with reference to Figures 1 to 28, each of the fibre forming centres has four components, namely a main current generator, a jet emitter, a device such as a deflector placed along the path of the jet to create therein a stable zone of low pressure, and a source of glass supply placed so as to deliver a stream of glass in an attenuable state into the low pressure zone of the jet, also known as the zone of laminar flow. Each of the first three components also has means for mounting it, comprising at least one adjustable device for altering the position and operation of the deflector device in relation to at least one of the other components. In other words, the various control or adjustment devices are capable of modifying the relative operating positions or the interactions of the deflector device and at least one of the other components of the fibre forming centre.

The embodiment represented in Figure 28 has no deflector device and the fibre forming centres therefore have only three components. This apparatus incorporates various control means similar to those described above to modify the position and interactions of at least one of the three components in relation to the two others. It is important to note with reference to this Figure 28 that this adjustment is effected in the plane containing the axes of the jet emission orifices and of the glass emission orifices.

Some parts of the apparatus are similar or identical to those of the embodiments described above which are represented in particular in Figures 13 to 18. Thus a vertical suspension rod 58 is connected to the supporting structure 50 which is provided to support the forehearth and the bushing 52. The suspension rod 58 carries at its lower end a sleeve 59 and a journal 60 which supports the flange 61 so as to enable the adjustment to be carried out as described above with reference to Figures 13,15 and 16. This mechanism may carry a beam or frame 90 to support the main current generator 71, the feed conduit 91 and the manifold boxes 92. These manifold boxes may be identical to those of Figures 4 or Figure 13a but they have no deflector 19 or 57, and the jet emission orifices 32a are positioned and orientated as shown in Figure 28 so that the jets are emitted downwards underneath the glass supply orifices of the bushing 52. The jets penetrate the main current, and the surrounding air or gas which is dragged with them causes the streams of glass to enter,the jets so that these streams are carried into the zones of interaction with the main current to be subjected to attenuation as described in our Patent No. 1513060 mentioned above.

Alternatively, the components of the fibre forming centre may be placed in relation to each other as described in our Patent No. 1521343 where the stream of glass directly enters the zone of interaction of the jet with the main current, instead of being carried into the latter by the jet.

A mounting plate 93 resting on the support 94 has apertures in the form of slots cooperating with screw systems 95 to lock it to the support 94. This arrangement enables the main current generator 71 to be mounted so that it can be moved towards or away from the bushing in a horizontal direction. It provides the possibility of either fixing the main current generator in a given position or leaving it free to be displaced according to the operating conditions, for example as described earlier with reference to Figure 17.

In the same way as in the embodiment illustrated in Figure 13, both manual and automatic control mechanisms such as those represented in Figures 17 and 18 are preferably incorporated in the apparatus of Figure 28 to enable the position of the manifold boxes and of the main current generator to be adjusted so as to move them towards or away from the axes of the glass supply orifices. This adjustment may be carried out manually or controlled automatically in response to a failure or anomally in the supply of gas for the jets.

Screw jacks 96 for the mounting of the main current generator 71 and the plate 93 enable the position of the main current generator to be adjusted in the vertical direction. The feed conduit 91 for the jets and the manifold boxes 92 connected to them are mounted on the main current generator 71 by means of elements 97 similar to those of Figure 13. By means of these elements, it is possible either to fix the jet emitter in a particular position in relation to the main current generator or to displace the collector 91 horizontally and/or vertically in relation to the said generator if these elements are provided with suitable adjustment means.

In the same way as in relation to the apparatus illustrated in Figures 13 to 18, it should be noted that the apparatus comprising the fibre forming centres is also mounted on the supporting structure which supports the source of supply of glass or is connected thereto.

This common support for the source of glass supply and the fibre forming

Claims (25)

**WARNING** start of CLMS field may overlap end of DESC **. incorporated in the apparatus of Figure 28 to enable the position of the manifold boxes and of the main current generator to be adjusted so as to move them towards or away from the axes of the glass supply orifices. This adjustment may be carried out manually or controlled automatically in response to a failure or anomally in the supply of gas for the jets. Screw jacks 96 for the mounting of the main current generator 71 and the plate 93 enable the position of the main current generator to be adjusted in the vertical direction. The feed conduit 91 for the jets and the manifold boxes 92 connected to them are mounted on the main current generator 71 by means of elements 97 similar to those of Figure 13. By means of these elements, it is possible either to fix the jet emitter in a particular position in relation to the main current generator or to displace the collector 91 horizontally and/or vertically in relation to the said generator if these elements are provided with suitable adjustment means. In the same way as in relation to the apparatus illustrated in Figures 13 to 18, it should be noted that the apparatus comprising the fibre forming centres is also mounted on the supporting structure which supports the source of supply of glass or is connected thereto. This common support for the source of glass supply and the fibre forming apparatus is advantageous since it facilitates positioning of the fibre forming apparatus in relation to the bushing or bushings from which the streams of glass are delivered to the fibre forming centres. It goes without saying that the particular mechanisms described in the various embodiments to carry out the various types of adjustment may be replaced by other systems performing the same functions. WHAT WE CLAIM IS:

1. Apparatus for the manufacture of fibres from an attenuable material by attenuation by means of gaseous currents, comprising at least one fibre forming centre having a gas jet emitter, a source of supply for delivering a stream of material, a deflector device arranged along the path of the jet from the emitter to modify the flow of the jet and produce a stable zone of quasilaminar flow towards which the attenuable material is directed, the source of material being located opposite the said zone, and mounting means having control devices to modify the position and/or the operation of at least one of the gas jet emitter, deflector device and the source of supply m relation to at least one other thereof.

2. Apparatus according to claim 1, and including a main current generator, the gas jet emitter producing a jet having a higher kinetic energy per unit volume than that of the main current, the jet being directed along a path which intersects the main current to penetrate the latter and produce a zone of interaction.

3. Apparatus for the manufacture of fibres according to claim 1 wherein the deflector device is interposted in the path of the jet between an emission orifice of the gas jet emitter and the stream of attenuable material, and comprises at least one element possessing a surface the sections of which parallel to the axis of the emission orifice and to the stream of attenuable material have a convex portion located within the flow of the jet, the supply orifice for attenuable material directing the stream of material towards the jet in the region of the said portion of convex surface.

4. Apparatus according to claim 3, characterised in that the supply orifice which directs the stream of material towards the carrier jet in the region of the said convex surface has its axis directed downwards, the generator of the main current producing said current at a distance from and below the source of supply.

5. Apparatus according to claims 3 or 4, characterised in that the said element which has a portion of convex surface has a position and dimensions such that it divides the flow of the jet into two parts flowing round its opposite sides.

6. Apparatus according to any preceding claim, characterised in that the deflector device is displaced from the axis of the emission orifice of the carrier jet in order to deflect the initial path of said jet.

7. Apparatus according to claim 6, characterised in that the axis of each jet is directed towards that part of the element which faces the supply orifice for attenuable material.

8. Apparatus according to any of claims 2 to 7, characterised in that the emitter has a series of emission orifices for carrier jets spaced apart from each other in the lateral direction, the distance between two adjacent emission orifices and the position of the deflector device in the paths of the jets being such that after they have spread out laterally, the adjacent jets impinge on one other and each pair of adjacent jets produces spaced-apart tornadoes, the corresponding series of supply orifices for attenuable material directing a stream of material towards each jet in a zone between the tornadoes of each pair.

9. Apparatus according to any of the claims 3 to 9, characterised in that each element is symmetrical about a plane formed by the stream of attenuable material and the axis of the emission orifice for the carrier jet.

10. Apparatus according to claim 8, characterised in that the elements have flanges

placed at intervals to define a flow channel for each carrier jet along the curvilinear part of Its path.

11. Apparatus according to any of the claims 3 to 11, characterised in that the elements are cylindrical.

12. Apparatus according to claim 11, characterised in that the generatrices of the said cylindrical elements are substantially horizontal.

13. Apparatus according to any preceding claim, characterised in that the emission orifice for the carrier jet is situated upstream of a stream of glass issuing from the orifice of the source of glass supply in a molten state.

14. Apparatus according to any of claims 2 to 13, characterised in that adjustment devices enable the relative positions of the deflector device and at least one of the gas jet emitter source of supply, and main current generator to be altered by an angular displacement in the plane containing the paths of the jet and of the main current.

15. Apparatus according to any one of the claims 2 to 14, characterised in that adjustment devices enable the relative positions of the deflector device and of at least one of the gas jet emitter, source of supply, and main current generator to be altered by a translatory displacement in the plane containing the paths of the jet and of the main current.

16. Apparatus according to any one of the claims 2 to 15, characterised in that adjustment devices enable the relative position of the source of supply and the deflector device to be altered by a translatory displacement in a direction towards or away from each other.

17. Apparatus according to any one of the claims 2 to 16, characterised in that it comprises mounting means which have elements for mounting and displacing the components gas jet emitter and deflector device together, thereby enabling both elements to be displaced simultaneously and adjusted in their position relative to the source of supply.

18. Apparatus according to any one of the claims 2 to 17, characterised in that it comprises elements for mounting and displacing the gas jet emitter and deflector device together, thereby enabling their positions relative to the main current generator to be altered simultaneously.

19. Apparatus according to any of the claims 1 to 18, characterised in that it also comprises devices which intervene automatically in the case of malfunctioning of at least one jet emitter in order to separate at least one of the gas jet emitter and the deflector device and withdraw it from the source of supply.

20. Apparatus according to any one of the claims 2 and 4 to 20, characterised in that it comprises mounting means which have elements for mounting and displacing in common the main current generator, the gas jet emitter, and the deflector device enabling their positions relative to the source of supply to be altered simultaneously, in particular by a vertical displacement.

21. Apparatus according to any one of the preceding claims, characterised in that it comprises a plurality of juxtaposed gas jet emitters and a corresponding series sources of supply so as to form a plurality of successive fibre forming centres, and in that the mounting means comprise elements for supporting and displacing the juxtaposed gas jet emitters in common, thus enabling their relative position to the corresponding series of sources of supply to be altered simultaneously by an angular displacement.

22. Apparatus according to any one of the claims 2 to 21, characterised in that the mounting means enable the relative positions of the deflector and of the gas jet emitter to be altered so as to alter the path of the jet.

23. Apparatus according to any preceding claim, characterised in that it comprises a supporting structure associated with a reservoir for molten material connected to a bushing placed at some distance from and above the main current, and a mounting mechanism supporting the main current generator and the jet emitters from the supporting framework associated with the supply of molten material.

24. Apparatus according to any preceding claim characterised in that the mounting means comprise a system of journal cooperating with a sleeve, one of which is suspended to the supporting structure for the supply of material while the other is connected to the main current generator and/or to the jet emitters to enable these to be adjusted by pivoting in relation to the bushing.

25. Apparatus according to any of the claims 2 to 24, characterised in that it comprises elements enabling the deflector to be bent in relation to the form of the source of supply, the said deflector being placed transversely to a series of consecutive gas jets and close to the streams of material.