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(11) | EP 0 108 205 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Thread treating nozzle |
| (57) A texturising nozzle in which thread and a fluid are passed through a texturising
chamber (44) and part of the fluid is permitted to leave the path transversely thereof
to exhaust means which include a throttle (76) for adjusting the proportion of fluid
leaving the path transversely. The throttle (76) can be selected among a plurality
of interchangeable throttles of different effective flow cross-sections. |
[0001] The present invention relates to improvements in thread texturising apparatus, particularly but not exclusively apparatus as described and claimed in co-pending United States Patent Application Serial Number 256 406 filed April 22, 1981 and its equivalent European Patent Application Number EP 81101805 published on 10 March 1982 (publication number 0039763). The full disclosure of the said co-pending patent applications (hereinafter the "prior applications") is incorporated in the present application by reference.
[0002] The prior applications describe several possibilities for adjusting the operating characteristics of the thread texturising apparatus to suit varying demands of use, for example varying thread materials, thread fineness (titer) and operating speed.
[0003] The prior applications describe and claim systems in which a thread and a treatment fluid are passed together along a thread path through a texturising chamber, a part of the fluid being permitted to leave the chamber transversely of the thread path. The prior applications are merely examples of patent literature describing this type of system, other examples being quoted in the prior applications themselves.
[0004] We have found that significant improvements in overall adaptability of such systems can be achieved if means is provided selectively to adjust the proportion of treatment fluid which leaves a given chamber transversely in relation to the fluid which leaves the chamber along the thread path. Such selective adjustment can be effected for example by selective control of the back pressure on fluid tending to leave the chamber transversely of the thread path. This latter selective control can be obtained by selective control of the effective cross sectional area for flow of treatment fluid leaving the chamber transversely, for example by means operable adjustably to-throttle an exhaust for such fluid. Adjustable throttling can be economically achieved by providing means in the exhaust to receive any selected one of a plurality of throttles of different effective flow cross sections.
[0005] By way of example, one embodiment of a texturising nozzle in accordance with the invention will now be described with reference to the accompanying drawings in which:
Figure 1 shows a section taken on a central longitudinal plane of a two-part texturising nozzle and a mounting therefor,
Figure 2 shows the faces of the two nozzle parts which engage one another at the plane II-II in Fig. 1, and
Figure 3 shows a section taken on the plane III-III in Figure 1.
[0006] The two nozzle parts are indicated with the numerals 10 and 12 respectively. Part 10 is mounted on a carrier 14 by means of a headed pin 16 on the carrier which engages in a keyhole-shaped slot 18 in the nozzle part. A locating pin 20 on the carrier engages in a receiving slot 22 in the nozzle part. An additional locator 23 will not be described in detail. Nozzle part 12 is mounted on a carrier 24 by a similar mounting, the parts 16A and 20A of which correspond with parts 16 and 20 respectively.
[0007] Part 10 comprises an elongated block, made in one piece and having a plane face 26. Part 12 comprises a similar (but not identical) block having a plane face 28 which engages the face 26 at the plane II-II in Figure 1. Where the faces 26 and 28 make contact, they form a seal against passage of treatment fluid between them.
[0008] Each block has two elongated recesses 30 extending longitudinally thereof on either side of an "island" 32 which is integral with the respective block.
[0009] Part 10 has a groove 34 in surface 26, extending from one end of the block but terminating short of the other end. Part 12 has a groove 36 in surface 28 extending from one end to the other of the block but interrupted (as further described below) by a circular section hole 38 receiving an insert 40.
[0010] When parts 10 and 12 are in their operative positions as shown in Fig. 1, grooves 34 and 36 are aligned to provide a passage extending from end to end through the nozzle and of varying cross-section therealong. The passage defines a thread path 'through the nozzle, the left hand end as seen in Figures 1 and 2 being the infeed (upstream)end. Various details of this passage are described in the prior applications and will not be given again here as they are not essential to the present invention. Briefly the passage provides a junction location 42 at which thread and treatment fluid are brought together in use, a texturising chamber 44 provided by the passage portions in and adjacent the islands 32, and a guide passage 46 between the junction location and the texturising chamber. Alignment of the blocks to form the passage is ensured by a pin 48 on part 12 engaging in a corresponding locating hole 50 in part 10.
[0011] Treatment fluid is fed to junction location 42 from a feed duct 50 in carrier 14 by way of a bore 52 in part 10 leading to a chamber 54-in the end of part 10, and thence by way of a metering tube 56 to the junction location. The internal form of the metering tube 56 and its function is fully described in the prior applications and will not be repeated here. The metering tube is mounted in a receiving bore leading from the chamber 54 to the junction location by means of a screw 58 engaging a corresponding bore in the chamber wall, and a spring 60 extending between the screw and the metering tube. Chamber 54 opens onto the end of the block, being normally closed by a closure screw 62 which can be removed to give access to the chamber for replacement of tube 56 by release of screw 58. This form of mounting for tube 56 is exemplary only. The mounting shown in the prior applications is frequently preferable, and other mountings can be devised as required.
[0012] The thread arrives at the junction location by way of the passage portion (portion of groove 36) upstream from the junction location. As best seen in Figure 2, the passage portion immediately adjacent to and upstream from the junction location is provided by a groove 36A in the insert 40. Groove 36A is choked down to hinder back flow of treatment fluid in the upstream direction. Insert 40 is located by a pin 64 in part 12 and is secured by a screw 66.
[0013] The treatment fluid is permitted to leave the texturising chamber transversely of the thread path by way of holes 68 extending through the islands 32 between the texturising chamber and the recesses 30. Slots extending longitudinally of the thread path could be provided instead of the illustrated holes. The length of the texturising chamber over which the holes 68 (or slots) extend can be chosen to suit the required operating conditions, but usually will not extend over more than half the length of the islands.
[0014] From then recesses 30, the treatment fluid leaving chamber 44 via holes 68 passes into exhaust ducts 70 in carriers 14 and 24 by way of respective outlet ports 72. As seen in each of Figures 1 and 3, each port 72 extends from the reverse face of its respective block (i.e. the face opposite the sealing face 26) to intersect the recesses 30 and receive treatment fluid.therefrom.
[0015] Each port 72 is of generally circular cross section and has a widened mouth 74 to receive a locating flange and sealing ring on a throttle 76 the externally cylindrical body of which is received in the port 72. Each throttle body is screw threaded to cooperate with screw threads in the respective part.
[0016] Each throttle 76 has a through bore provided with a central portion 78 defining a predetermined effective cross sectional area for the flow passage provided by the port. Preferably, the effective cross sectional areas of the passages through the two throttles are the same. The effective cross sectional area of either port can however be varied by removing an installed throttle and, optionally, replacing it with another externally similar throttle having a different through bore or simply omitting a throttle and allowing the treatment fluid to pass through the full section of the port.
[0017] Obviously, replacement of a throttle as described above requires cessation of texturising and demounting of parts 10 and/or 12 from their carriers. This can be avoided if a throttle adjustable from outside the unit were built into each port, but such arrangements would be costly and probably unreliable.
[0018] By controlling the effective flow passage through the port 72, each throttle effectively controls the back pressure in the recesses 30 and thus the two throttles together control the proportion of treatment fluid leaving the chamber 44 via the holes 68 in relation to the fluid leaving via the downstream end of the thread path.
[0019] The circumstances in which the throttles will be used depend greatly upon the operating requirements and must be determined empirically. In general, it is preferred to operate without the throttle. However, if the user of a particular nozzle uses that nozzle (without throttles) for texturising increasingly coarse threads of a given material, it is found eventually that an upper thread fineness limit is reached beyond which reliable texturising is no longer achieved. At this stage, the insertion of throttles to reduce the proportion of treatment fluid leaving the chamber transversely can enable the same nozzle to provide successful texturising of still coarser threads.
[0020] Accordingly, in general terms, the coarser the thread, the smaller effective cross-sectional area should be provided for flow of treatment fluid leaving the chamber transversely. However, the upper thread fineness limit (at which insertion of thottles becomes necessary) will itself be dependent upon the relation between the thread fineness and the dimensions (especially cross section) of the passage providing the thread path through the texturising chamber., and also upon the form, number and dimensions of the holes or other perforations by which fluid passes from the chamber to the recesses. Furthermore, the upper fineness limit is different for different thread types, especially different thread materials.
[0021] While no general rules can be stated in view of the large number of potential variables some of which have been outlined above, we have found that throttles with effective cross sectional bore areas of between 5 and 40 square millimetres have proved useful. It will be understood that a single port and a single throttle could be provided, the dimensions being adapted accordingly, but exhaust on both sides of the nozzle is preferred. When the throttling effect is eliminated, the effective cross sectional area of flow through the port may be so large that it has no further significant effect on flow through the holes 68, which latter therefore then alone determine the proportion of treatment fluid leaving the texturising chamber transversely.
[0022] The invention is not limited to details of the illustrated embodiments. In principle, control of back pressure in the recesses could be achieved by means other than throttling of the exhaust ports, but throttling means are relatively easily manufacturable and accurately adjustable. The block construction and the form of the thread path are not relevant to the broad inventive idea. The illustrated parts upstream of the texturising chamber simply form a means for feeding thread and treatment fluid together into the texturising chamber and other forms of such means are known from the prior art.
[0023] Different forms of texturising chamber permitting treatment fluid to leave transversely are also known. The islands -32 and their holes 68 simply provide a perforated wall for the texturising chamber, and other forms of perforation could be substituted. The recesses 30 provide a receiving region for treatment fluid adjacent the thread path, but again other forms of such region could be devised.
[0024] It will be noted that in the system described in the prior applications, the proportion of fluid leaving a given nozzle transversely to the thread path could be adjusted by replacing an insert providing the texturising chamber i.e. by changing the perforations in the texturising chamber. However, there was no provision to adjust the proportion of fluid leaving a given chamber transversely i.e. there was nothing additional to the chamber itself. In the present case, where the means defining the texturising chamber is integral with other parts of the system, replacement of the chamber itself is practically eliminated (unless the whole nozzle is replaced) and the variable flow channel feature is especially advantageous. However, the variable flow channel feature could also be used with a texturising chamber made up of one or more replaceable inserts.
1. Thread texturing apparatus comprising a texturising chamber, means for feeding
a thread and a treatment fluid together along a path through the texturising chamber,
which is such that part of the fluid is permitted to leave the chamber transversely
of the thread path, and means selectively to adjust the proportion of treatment fluid
which leaves the chamber transversely in relation to that which leaves the chamber
along the thread path.
2. Thread texturising apparatus comprising a texturising chamber, means for feeding
a thread and a treatment fluid together along a path through the texturising chamber,
which is such that part of the fluid is permitted to leave the chamber transversely
of the thread path, and means selectively to control back pressure and fluid tending
to leave the chamber transversely of the path.
3. Thread texturising apparatus comprising a texturising chamber, means for feeding
a thread and a treatment fluid together along a path through the texturising chamber,
which is such that part of the fluid is permitted to leave the chamber transversely
of the thread path to a region adjacent the path, a flow channel for exhaust of fluid
from said region and means selectively to adjust the effective cross sectional area
of said flow channel.
4. Thread texturising apparatus comprising a texturising chamber, means for feeding
a thread and a treatment fluid together along a path through the texturising chamber,
which is such that part of the fluid is permitted to leave the chamber transversely
of the thread path to a region adjacent the path, a flow channel for exhaust of fluid
from said region and means in said channel for receiving any selected one of a plurality
of throttles of different effective flow cross sections.
A method of texturising thread comprising passing thread and a treatment fluid through
a texturising chamber, which is such that part of the fluid is permitted to leave
the chamber transversely of the thread path, and selectively adjusting the proportion
of fluid permitted to leave the chamber transversely in relation to that leaving the
chamber along the path.