WO1996024714A1

WO1996024714A1 - Weaving loom

Info

Publication number: WO1996024714A1
Application number: PCT/EP1996/000313
Authority: WO
Inventors: Henry Shaw
Original assignee: Picanol N.V.
Priority date: 1995-02-07
Filing date: 1996-01-26
Publication date: 1996-08-15
Also published as: BE1009096A3

Abstract

A frame (1) of a weaving loom is supported by air dampers (34, 35) which are used as power-operated lifting and lowering elements controlled by a control unit (45) for tilting the frame of the weaving loom.

Description

Weaving loom

The invention concerns a weaving loom.

In weaving looms the produced fabric is on the front, while the warp yarns are located at the rear. The warp yarns are guided from a warp beam via a back beam to the so-called "surface" of the warp, which surface extends between the back beam and a fell of the cloth. The height of the weaving loom is determined by the height of the above-mentioned surface of the warp. This surface of the warp is preferably almost hori¬ zontal, since this allows the shedding devices to be moved up and down almost vertically. Since the diameter of the warp beam is usually greater than the diameter of the cloth beam, the height of the surface of the warp is determined by the diameter of the warp beam. This has the disadvantage that with warp beams with a large diameter, the height of the wea¬ ving loom can be considerable, so that an operator's access to the weaving loom is made more difficult.

Weaving looms are usually supported on four to six support elements, one half of these support elements being at the front of the loom, the other half of these support elements being at the rear of the loom. It is known (EP-A 0 139 773) to provide between these supports and the floor air dampers for the purpose of damping the vibrations of the weaving loom in relation to the floor. These air dampers can be provided at each support. The providing of air dampers between the supports and the floor usually has the disadvantage that a weaving loom provided with air dampers will stand higher abo¬ ve the floor than a weaving loom directly fixed to the floor.

In order to reduce this disadvantage, the air dampers can be integrated in each of the supports, so that the air dampers no longer influence the height of the loom (EP-A 379 679) . Further, the height of these air dampers (EP-A 379 679) is controlled for keeping the distance between the weaving loom and a Jacquard mechanism at a constant value.

The object of the present invention is to improve acess at the front of the weaving loom. This object is achieved by the invention claimed in claim 1.

The invention offers the advantage that the height of the weaving loom in tilted position, at the side towards which it is tilted, can be reduced. This allows the height especially at the front of the weaving loom to be reduced, and this vir¬ tually independently of the diameter of the warp beam.

The invention is further explained below by means of drawings showing different embodiments in which:

Fig. 1 shows a schematic diagram of a weaving loom provi¬ ded with air dampers according to the invention;

Fig. 2 shows a simplified cross-section along the line II- II of figure 1;

Fig. 3 shows the weaving loom of figure 1 in another posi¬ tion; Fig . 4 and 5 show an embodiment in the two positions according to figures 1 and 3;

Fig. 6 shows a further embodiment similar to figure 5.

In figures 1 and 2 a weaving loom is shown according to the invention. This weaving loom has a frame which consists of two lateral parts 1 which are interconnected by means of cross beams 2. At the rear 3 of the weaving loom, there is a rotatably mounted warp beam 4, a back beam 5, and a warp stop motion 6. At the front 7 there is a sand roller 8 and a rota¬ tably mounted cloth beam 9. The warp yarns 10 are guided from the warp beam 4 via the back beam 5 to the surface 11 of the warp, which surface 11 extends between the back beam 5 and the fell 12 of the cloth 13. The cloth 13 is guided via a guide 14, and the sand roller 8, and the guides 15, to the cloth beam 9.

In the centre 16 of the weaving loom, there are in addition shedding devices 17 in the form of heald frames which are controlled by a shed drive unit 18, such as a dobby or cam box. Between the shedding devices 17 and the sand roller 8 a slay 19 is mounted with a reed 20 which is driven by a dri¬ ving mechanism 21. The reed 20 beats the weft yarns against the fell 12, in such a manner that a cloth 13 is produced with the weft yarns and warp yarns 10.

The slay 19, the driving mechanism 21, the sand roller 8, the guides 14 and 15, the cloth beam 9 and the shed drive unit 18 are all mounted on the lateral parts 1 of the frame of the loom. A second frame rests on the lateral parts l of the fra¬ me and consists of two lateral sections 22 which are inter¬ connected by cross beams 23. On each of the lateral sections 22 a warp beam shaft 24 of the warp beam 4 is rotatably moun¬ ted by means of a bearing not shown in detail. In additon, two supports 25 are adjustably in height fixed to each late- ral section 22. The back beam 5 and the warp stop motion 6 are fixed to these two supports 25. Each shaft end 26 of the back beam 5 is arranged in a lever 27 which is held at one end by a rotary shaft 28 and at the other end by a spring 29 on the supports 25. Each lateral section 22 is in addition provided with an arm 30 on which heald frame guides 31 are arranged. The lateral sections 22 are fastened onto the late¬ ral parts 1 of the frame by means of bolts 32 and 33.

At the rear 3 of the loom two air dampers 34 are provided at each lateral part 1 of the frame. At the front 7 of the loom a further two air dampers 35 are provided at each lateral part 1 of the frame. These air dampers 34 and 35 support the loom in relation to the floor 36. These air dampers 35 and 35 are partly integrated in the lateral parts 1 of the frame of the loom. In the example shown, two air dampers 34 and 35 are provided at each lateral part 1 of the frame, which means that the loom is supported in relation to the floor 36 by four air dampers. These air dampers 34 and 35 permit the re¬ duction of transmission of vibrations of the loom into the floor 36. The air dampers 34 and 35 consist for example of a bellows in which compressed air can be fed and contained.

It is clear that in the event that between the lateral parts 1 of the frame another intermediate frame or several interme¬ diate frames are provided which are not shown in the figures, air dampers can also be provided at these intermediate fra¬ mes. By this means the loom can be supported by six or more air dampers.

In looms the warp beam 4 is usually mounted in such a manner that the warp beam 4 is just above the floor 36. If the air dampers 34, 35 are integrated in the lateral parts 1 of the frame, the lateral parts 1 will be just above the floor 36. The surface 11 of the warp lies above the warp beam 4 and is preferably almost horizontal. The position of the slay 19 with the reed 20 and guide 14 for the cloth 13 are then de- termined by the position of the surface 11 of the warp. Since the cloth beam 9 usually has a relatively small diameter, the cloth beam 9 can be mounted at any position between the sand roller 8 and the floor 36.

In figure 2 a simplified insertion system 37 for an air jet loom is shown, consisting of a bobbin 38, a weft preparing device 39, a main blower 40 fixed to the slay 19, a valve 41, a compressed-air source 42 and a reed 20. The insertion sy¬ stem 37 can also contain additional blowers and a stretch blower, which are not yet shown, along the reed 20. In addi¬ tion are shown a weft thread detector 43 which is positioned after the bobbin 38, and a weft thread detector 44 which is positioned after the reed 20. The control unit 45 of the loom controls the weft preparing device 39 and the valve 41 and receives signals 46 from the weft thread detectors 43 and 44. The bobbin 38 and the weft preparing device 39 are provided with a support 47 which is fixed to a lateral part 1 of the frame. The control unit 45 is also fixed to a lateral part 1 of the frame. The bobbin 38 and the weft preparing device 39 can also be fixed, as a variant, to a separate frame.

As is shown in figure 1, the air dampers 34 and 35 are fed with compressed air via three-three valves, for example from the compressed air source 42. In this example the two air dampers 34 at the rear 3 are fed with compressed ar via the valve 48, while the two air dampers 35 at the front 7 are fed with compressed air via the valve 49. The valves 48 and 49 contain a plunger, two release springs and two electroma¬ gnets. The release springs force the plunger into a central position and each electromagnet is capable of forcing the plunger into the respective extreme position.

The electromagnets of the valves 48 and 49 are activated by the control unit 45. In a first extreme position of the val¬ ves 48, 49, a first electromagnet 66 is activated, and com¬ pressed air is fed to the air dampers. In a second extreme position the second electromagnet 67 is activated and the compressed air can escape from the air dampers 34, 35. The control unit 45 contains devices which prevent both electro¬ magnets 66 and 67 from being activated simultaneously. In the central position neither of the electromagnets is activated and the compressed air present in the air dampers is shut in. In this way the compressed air remains in the air dampers when neither of the electromagnets is activated. This ensures that the air dampers 34, 35 continue to support the loom in the event of electrical power supply failure.

The pressure of the compressed air present in the air dampers is at a maximum equal to the pressure of the compressed-air source 42, and is generally determined by the length of time that compressed air from the compressed-air source 42 is fed to the air dampers 34 and 35. This means that the prevailing pressure in the air dampers 34 and 35 is usually lower than the pressure of the compressed-air source 42. The height of the loom is determined by the pressure of the compressed air in the air dampers 34 and 35 and by the weight exerted by the loom on the air dampers 34 and 35.

In order to ensure that the compressed air in the air dampers 34 and 35 is at the appropriate pressure, the control unit 45 contains switching devices 50, 51, for the appropriate acti¬ vating of the valves 48, 49.

These switching devices 50 and 51* work together with the height sensors 52 and 53, respectively, which, for example, from the moment that the height of the loom falls below a first present value, let through or send a first positive electric signal to the switching devices 50, 51, and from the moment that this height exceeds a second present value, let through or send a second negative electric signal. Clearly, the first value will be preset at a slightly lower value than the second value. If a negative signal is fed to the switching devices 50, 51, the electromagnet 66 of the respective vale 48, 49 will be activated by the switching devices 50, 51 in such a manner that the valve 48, 49 will be forced into a first extreme po¬ sition and compressed air will be supplied. If a positive si¬ gnal is fed to the switching devices 50, 51, the electroma¬ gnet 67 will be activated in such a manner that the valve 48, 49 will be forced into a second extreme position and compres¬ sed air will be allowed to escape from the air dampers. This permits the setting of the weaving loom at an appropriate height. This is important since the weight exerted by the weaving loom on the air dampers 34 and 35 changes during wea¬ ving. In particular, the weight exerted on the air dampers 34 decreases, and the weight exerted on the air dampers 35 in¬ creases, since the warp yarns 10 are used up to produce the cloth 13.

Although these height sensors 52 and 53 are shown in figure 1 at a certain distance from the air dampers 34 and 35, in practice these should preferably be located close to the air dampers.

The loom according to the invention contains air dampers 34 and 35, a control unit 45 and devices in the form of valves 48, and 49 which permit the tilting of the loom.

According to a first alternative, the control unit 45 of the weaving loom is provided with selection devices 54 which per¬ mit, on the basis of, for example, a signal 46 indicating thread breakage originating from a weft thread detector 43, 44, the stopping of the weaving loom, and in the case of a machine standstill, the escaping of compressed air from the air dampers 35 at the front 7, and/or from the air dampers 34 at the rear 3. For this purpose an electromagnet 67 of a val¬ ve 48 or 49 is activated via the selection devices 54 of the control unit 45, in such a manner that the valve is forced into the second position, as mentioned above, and compressed - 8 -

air is allowed to escape from the respective air damper 34 or 35. By this means the weaving loom is tilted.

The loom preferably contains a control unit 45 with selection devices 54 and devices such as valves 49 which permit the tilting of the power loom towards the front 7. This is, be¬ cause the majority of operations to be carried out by the operator, such as the repairing of a broken weft thread, must be carried out from the front 7, and because the size of the cloth beam 9 usually permits the tilting of the weaving loom towards the front 7. When a signal 46, as mentioned above, is fed to the control unit 45, the switching devices 51 will ge¬ nerate a signal which activates the electromagent 67 of the valve 49 in such a manner that the compressed air is allowed to escape from the air dampers 35 at the front 7.

According to a second alternative, the weaving loom contains devices in the form of abuting elements 55 and 56 at the front 7 or at the rear 3 of the two lateral frames 1, re¬ spectively. The abuting elements 55 and 56 are so positioned that when the loom is not supported by the air dampers 34 and 35, the loom is in a position as is shown in figure 3 which is tilted in relation to the position as is shown in figure 1 in which position the loom is supported by the air dampers.

In this case, when a signal 46 is fed to the control unit 45, a signal will be generated by the selection devices 54 which causes the valves 48 and 49 to be activated in such a manner that the compressed air is allowed to escape from the air dampers 34 and 35. When the compressed air escapes, first the abuting elements 56 at the rear 3 of the lateral fram 1 will make contact with the floor 36. When further compressed air escapes, the power loom will tilt round the abuting elements 56 mentioned above. When still further compressed air esca¬ pes, the abuting elements 55 at the front 7 will also make contact with the floor 36, and the loom will be in the tilted position. According to yet another alternative, the control unit 45, just as in the first alternative mentioned above, can allow compressed air to escape only from the air dampers 35 at the front 7, in such a manner that the loom can be tilted round the air dampers 34 at the rear 3. In this case, after til¬ ting, the loom will be supported by the air dampers 34 and the abuting elements 55.

The control unit 45 can of course analogously allow compres¬ sed air to escape only from the air dampers 34 in such a man¬ ner that the power loom can tilt round the air dampers 35, to finally come to rest on the air dampers 35 and the abuting elements 56. In view of the dimensions of the warp beam 4, the height of the loom will only be capable of being reduced by a small amount at the rear 3, unless a warp beam is provi¬ ded the dimensions of which are smaller than the one for which the loom was designed.

Although in the examples shown the signals 46 which were fed to tilt the loom each time originated from a weft thread de¬ tector 43, the signals 46 could also originate from the warp stop motion 6 which detects a broken warp yarn. The signals 46 could also of course originate from a pushbutton 57 which is operated by the operator. This pushbutton 57 could also be the one which is used, for example, for stopping the loom.

It is obvious that the abuting elements 55 and 56 can also be mounted in such a manner that these can be adjusted in rela¬ tion to the lateral parts 1 of the frame. This permits, sub¬ ject to the dimensions of the warp beam or the cloth beam, the tilting of the machine as appropriate.

Since according to the invention it is possible to bring the front 7 of the weaving loom to a lower position, this is hig¬ hly advantageous because it permits the operator to carry out certain operations. The invention permits this to be done without it being necessary to incline the surface 11 of the warp to any great extent. In addition, the invention permits the use of warp beams with a larger diameter, without this having an adverse effect on the height of the front 7 of the loom.

At each air damper 34, 35, a manometer 58 can be provided, in order to measure the value of the air pressure. This makes it possible to detect a defective air damper. If the air pressu¬ re in an air damper suddenly falls, for example due to a fracture in the air damper itself, the signal from the mano¬ meter 58 which is fed to the control unit 45 can cause the control unit 45 to stop the loom.

When, after a machine stop, compressed air is reintroduced into the air dampers 34 or 35, the loom, after a starting si¬ gnal has been given, will be automatically started only after a certain length of time, so that the desired pressure of the compressed air in the air dampers is achieved before the loom is started.

The shed drive unit 18, the bobbins 38, the weft preparing devices 39 or the control unit 45 are mounted on the lateral parts 1 of the frame which leads to the advantage that these components do not change position in relation to one another when the loom is tilted.

The components which do not tilt with the loom and/or do change position when the loom is tilted, must contain means which permit such tilting and/or changing of position. To this end the connections for compressed air or electric power to the loom must be such that these connections permit the turning and/or changing position of the loom. The loom accor¬ ding to the invention can also use a Jacquard mechanism as shedding mechanism. In this case the Jacquard mechanism can be attached in a fixed arrangement, since the arcade yarns between the Jacquard mechanism and the weaving loom permit a tilting and/or changing position of the weaving loom.

In figure 1 locking devices 59 are shown which prevent the loom from tilting in the event of a compressed-air supply failure, for example due to a defect in the compressed-air source. These locking devices 59 can be provided at each air damper 34, 35. The locking devices 59 can consist of a sup¬ porting arm 60 which permits the supporting of the loom. This supporting arm 60 is continually held by a spring 61 under the lateral part of the frame of the loom, and can be retracted from under the lateral part 1 by a pneumatic cylin¬ der 62. This cylinder 62 is connected, for example, to the outlet of a valve 63 which is activated by the selection de¬ vices 54 when it is desired to tilt the loom, and which valve is connected, for example, to the compressed-air source 42. If the valve 63 is not activated, the compressed air is allo¬ wed to escape from the cylinder 62 under the influence of the spring 61.

The locking devices 59 are of course not restricted to the example as shown, and may, for example, also consist of rods activated by a motor which prevent the loom from being tilted when these rods are in the extended position.

In figures 4 and 5 a different embodiment is shown, in which the loom is provided with air dampers 35 only at the front 7. The lateral parts 1 of the frame can be rotated around a ho¬ rizontal shaft 64 which is located close to the warp beam shaft 24. The shaft 64 is held by a frame 65 which is fixed to the floor 36. The operation is analogous to the function shown in figures 1 to 3. When it is desired to tilt the loom or when a signal 46 indicating thread breakage is generated, the electromagnet 67 of the valve 49 is activated by the con¬ trol unit 45 in such a manner that the compressed air is al¬ lowed to escape from the air dampers 35 and the loom will tilt around the horizontal shaft 64 until the abuting ele- ments 55 make contact with the floor 36. As the shaft 64 is located close to the warp beam shaft 24, the warp beam 4 will change position only slightly when the loom is tilted.

In figure 6 a further embodiment is shown in which the hori¬ zontal shaft 64 is located in line with the longitudinal axis of the warp beam shaft 24, so that when the loom is tilted, the warp beam 4 does not change position. This permits the positioning of the warp beam very close to the floor. To this end a plate 68 is fixed to the lateral parts 1 of the frame which plate extends to the height of the warp beam shaft 24 and in which the rotary shaft 64 is mounted.

The tilted position of the loom before starting can be an ad¬ vantage when the loom is started when cold. This is particu¬ larly the case when a lubricating oil reservoir is located at the front 7 of the loom and therefore in the lowest position before starting, since this improves the return of the oil to the reservoir.

According to an other embodiment not shown, the rotary shafts 64 can be located at the front 7, in which case the loom is supported at the rear 3 by air dampers 34 and can be tilted around the rotary shafts 64 by allowing the compressed air to escape from the air dampers 34.

The invention is now restricted to air jet looms as shown, but can also be used in rapier looms, water jet looms, shuttle looms, projectile looms or any other type of loom.

The loom according to the invention need not necessarily con¬ tain a cloth beam 9. In a variant, the cloth beam may also be formed by an independent winding unit which is positioned in front of the loom. The loom can of course also contain two cloth beams placed one above the other, which is usually the case in the weaving of so-called terry towelling.

The loom according to the invention is of course not re¬ stricted to the design as described by way of example and as shown in the figures, but can be varied within the scope of the invention to different embodiments. For example, the bea¬ rings for the shafts 64 of the embodiment of figures 5 or 6 maybe fixed to the frames 65 by power-operated lifting and lowering elements. Also, the frames 65 may be lifted and lo¬ wered by power-operated elements.

In the embodiments of figures 1 to 6 air dampers 34, 35 are used as power operated lifting and lowering elements for til¬ ting a weaving loom by which maintenance operations are faci¬ litated. However, in case no dampening effect is required, other power-operated lifting and lowering elements may be use'd as support elements, for example motor-driven spindles or hydraulic cylinders.

Claims

1. Weaving loom having a frame (1) and support elements (34, 35, 64, 64) for supporting the frame on a floor (36), cha¬ racterized in that the support elements (34, 35,) at the rear (3) and/or at the front (7) are power-operated lifting and lowering elements which, by means of a control unit (45) , are operable for tilting the frame (1) .

2. Weaving loom according to claim 1, further characterized in that the control unit (45) operates the support elements (34, 35) for tilting the frame (1) towards the front (7) .

3. Weaving loom according claim 1 or 2 and further characte¬ rized in that the control unit (45) is connected to a weft breakage detector (43, 44) and/or to warp breakage detector (6) and/or to a manually operable switching element (57) .

4. Weaving loom according to one of claims 1 to 3, and further characterized in that the support elements are air dampers (34, 35) which are connected to a source (42) of com¬ pressed air by means of valves (48, 49) which valves are con¬ trolled by the control unit (45) .

5. Weaving loom according to anyone of claims 1 to 4, and further characterized in that sensors (52, 53) sensing the distance between the frame (1) and the floor (36) are con¬ nected to the control unit (45) .

6. Weaving loom according to anyone of claims 1 to 5, and further characterized in that the frame (1) is provided with abuting elements (55, 56) for supporting the frame (1) in its tilted position.

7. Weaving loom according to anyone of claims 1 to 6, and further characterized by releasable locking means (59) for locking the frame (1) in its untilted position.

8. Weaving loom according to anyone of claims 1 to 7, and further characterized in that the frame (1) at one end is ro¬ tatably supported by a horizontal shaft (64) and at the other end is supported by power-operated lifting and lowering ele¬ ments (35) .

9. Weaving loom according to claim 8, and further characte¬ rized in that the horizontal shaft (64) is arranged close to or in line with the axis of the shaft (24) of the warp beam (4) .

10. Weaving loom according to claim 8 or 9, and further cha¬ racterized in that the horizontal shaft (64) is held by a support frame (65) fixed to the floor (36) .