TWI467071B - Drawing unit for a knitting machine - Google Patents

Description

Stretching unit for knitting machines

The present invention relates to a stretching unit for a knitting machine according to the preamble of claim 1 of the patent application.

In the past, various methods have been proposed for making knitted fabrics directly from staple fibers or rovings. A knitted fabric that weaves a substantially flawless fiber tampon with approximately parallel fibers is very soft and comfortable to wear. Moreover, since the intermediate stage of the conventional spinning (forming of the yarn, winding it onto the bobbin and possibly repeating the winding) is omitted, it is very economical to produce the knitted fabric. The non-twisted fiber tampon has a certain degree of longitudinal elasticity at the same time, so that it is easier to resist the change in the direction of the yarn guiding the knitting machine and the yarn is not often broken.

For example, the document US-A-3,877,254 teaches the delivery of staple fibers to the needle of a knitting machine. In this case, a circular knitting machine is taken as an example for the description. The short fibers are arranged in a circle by a brush, taken up by a wheel having a hook, carded, and then transferred to a circular knitting machine which is formed into a knitted fabric of short fibers. The interlacing points in the grid give the knitted fabric the necessary strength. It also means that the auxiliary line of the yarn can also be woven into it.

WO 2004/079068 proposes a circular knitting machine in which the woven area is fed by a fiber tampon stretched in a previous draw frame instead of a refined yarn drawn from a bobbin distributed to each woven zone. material. The draw frame has three or more syringes with a pair of double aprons and an outlet pressure roller, i.e., a ring spinning machine for spinning as in the prior art. The roving from a drum or a The roving tube is stretched out and supplied to a draw frame that stretches it to a predetermined extent. The drawn fiber tampon can be supplied directly to the knitting needles located in the woven zone after the pair of outlet pressure rolls. This configuration is particularly useful for circular knitting machines having a small diameter syringe, for example, a long fiber can be processed thereon. For larger circular knitting machines having larger sized cylinders, for example, 48 or 96 woven zones can be provided which propose to incorporate a twisting device between the draw frame and the woven zone. For example, the twisting device includes a pneumatically operated swirling nozzle in which a false twist is provided to the drawn fiber tampon. The temporary yarn thus formed has sufficient strength to be conveyed a little further distance. The false twist is again released in the weaving zone so that the fibers are substantially parallel to each other when they are combined by the needles to form a knitted fabric.

For reasons of space, for example, the draw frame is distributed into three groups around the circumference of the cylinder of the circular knitting machine. Each set of draw frames includes a plurality of draw frames on the same line and is co-driven for the drive elements of the draw frame. The driven draw frame element includes at least one continuous barrel. In order to avoid an excessively sharp change in the direction of passage of the fibers between the set of draw frames and their associated weaving zones, the weaving zone is activated at the cylinder instead of the so-called dead zone or dead zone, where the circular knitting machine There is no weaving area or the area does not participate in weaving. Thus, on a large circular knitting machine formed in a known manner, only about half of the woven area is available. In this relationship, it is even explained in WO 2004/079068 that direct weaving of rovings can be taken according to economic advantages, which is not the most important. It is even suggested that, alternatively, the size of the barrel can be enlarged, so that the circumference of the barrel can be provided with a plurality of available woven areas.

In fact, when the processed fiber tampon is stretched in a draw frame, only a portion of the woven area on the large circular knitting machine is available, which represents a serious shortcoming of such a deep user-friendly technique. Increasing the size of the syringe is a technical step backwards, and it is impossible under any circumstances due to structural reasons and lack of space. In addition, assembling a draw frame as a group means that it is very difficult to repair them.

It is therefore an object of the present invention to provide a method of overcoming the disadvantages of the associated knitting machine, particularly the prior art circular knitting machine. A drawing unit for forming a fiber tampon from a roving is provided, which is permitted in all existing knitting zones in related knitting machines, particularly circular knitting machines of conventional construction and size. The stretching unit has a simple design, an economical structure and is particularly easy to repair.

The term roving is generally referred to hereinafter to a spun yarn and a draw frame sliver which has a flick and is usually supplied to a bobbin which is flawless and is provided in a drum.

This work is carried out by a stretching unit for a knitting machine having the features described in the characterizing portion of the first aspect of the patent application. Further modifications and/or other advantageous embodiments of the invention are the subject matter of the appended claims.

The present invention provides a stretching unit for a knitting machine for forming a roving into a fiber tampon, characterized by having a double apron guided by apron roller and a pair of outlet pressure rollers that can be driven by a motor. The pair of apron roller and outlet pressure roller pair for the double apron respectively engage a driven lower syringe, the shaft of which is coupled to the base One end and extend outward. The motor powers the lower syringe.

In contrast to the assembly of the stretching units in a circular knitting machine proposed in the prior art, which have a common drive unit, a common lower cylinder or the like, the stretching unit according to the invention is provided as an autonomous element. Each stretching unit has its own drive and tensile elements. The stretching unit has a simple structure, is easy to assemble, and is economical. If one of the stretching units needs to be repaired, the other adjacent stretching units will not be affected. It is only necessary to replace the separate individual stretching units, so that the knitting machine can be operated again continuously and unimpeded. Since the cantilever beam configuration of the driven lower needle barrel is only placed at one end and the motor is located at the same side end of the base, the structure is very simple and space-saving, and can be used for circular knitting of a syringe having a conventional size. All weaving areas on the plane.

The compact structure of the stretching unit is assisted by the electric motor, the shaft of the electric motor extending through the base and connecting the driving pinion at the rear end of the base, such that the lower outlet cylinder and the double skin The lower apron syringe of the ring can be driven. By covering the drum, the tensile and driving action of the drive is effectively distinguished and protected from contamination and wear of the fibers contained in the air.

It is appropriate to drive the lower syringe by means of a synchronized belt. Timing belts are conventional, especially when it is digitally and decelerated, which is smoother than direct drive. It reduces the pressure on the drive assembly.

In order to stretch the roving as much as possible to the desired fineness, the invention is varied to engage a pair of inlet rolls which are placed in the direction of transport of the roving prior to the double apron. The pair of inlet rollers divide the stretching unit into an initial The step stretching zone and a main stretching zone. Due to the high strength, the woollen yarn has a light twist, most of which is loosened in the preliminary stretch zone. Thus, the roving yarn can be stretched to the desired yarn fineness in the main stretch zone.

Two electric motors are sufficient to operate the stretching unit. The driving of the lower inlet cylinder and the driving of the lower apron cylinder for the double belt are provided by the same electric motor. The electric motor is preferably a synchronous electric motor. It is driven by a frequency converter. Electric motors of this type are known and can be produced economically. Operation by the frequency converter allows the electric motor to be fully synchronized in a separate stretching unit in a circular knitting machine having 48 or 96 weaving zones.

In order to have a precise conveying path for the roving supplied to the stretching unit, it is preferable to provide a wire guide at the entrance of the stretching unit in the conveying direction with respect to the roving.

For reasons of space, one stretching unit may be supplied to two weaving zones. Thus, two adjacent wire guides can be placed at the entrance of the stretching unit, each guide defining a conveying path for the roving.

Preferably, each wire guide has a passage that tapers in the direction of transport. Thus, the supplied roving will experience a certain degree of pressure before being stretched. In particular, the fibers protruding toward the ends are again incorporated into the roving. In this way, the roving can be stretched more efficiently and the fibers in the air can be reduced. This may also be suitable for separate wire guides that combine two or more adjacent channels.

In order to replace the stretching unit as quickly as possible, the base has a quick clamping device by which the base can connect the adjacent weave to the knitting Part of the structure of the machine. Thus, the time required for the knitting machine to stop due to repair or maintenance is minimized.

In order to make the stretching unit easier to install, especially on a conventionally sized circular knitting machine, it is advantageous if its height matches the length of the shaft of the lower cylinder, preferably at a height of 50 mm to 100 mm. between.

A knitting machine having a stretching unit according to the present invention allows all of the knitting zones to participate in the knitting process. The woven fibers made directly from the roving are drawn into fiber tampon. The intermediate stage of the conventional spinning (forming of the yarn, winding it onto the bobbin and possibly repeating the winding) is omitted. The knitted fabric formed here has sufficient strength and is very soft.

The stretching unit according to the present invention can be used for a flat knitting machine as well as a circular knitting machine. However, it is particularly suitable for use in a circular knitting machine having 48 or 96 knitting zones. The highly succinct structure of the stretching unit according to the present invention allows for all weaving in the circular knitting machine as compared to the combination of the circular knitting machine and the previous grouping of the draw frame around the circular knitting machine. The area can be used.

In a further implementation of the invention, two or more adjacent weave zones are assigned to each individual stretching device. This allows the stretching unit according to the invention to be used even on a circular knitting machine having a particularly compact space with a smaller syringe.

For the sake of clarity, the same reference numerals are used in the drawings.

Figure 1 shows an overview of the important components of a circular knitting machine, usually by label 1 means that it is made directly from a roving into a knitted fabric. The circular knitting machine 1 has a syringe 2, for example 48 or 96 knitting needles 3, in particular tongue-shaped needles, are arranged on the cylinder. The knitting needle 3 directly processes the draw tampon from a drum 5 or the roving provided from the roving of a roving bobbin, and places it on the bobbin of the circular knitting machine. The roving L is stretched in the stretching unit 6 and supplied to the knitting needle 3 directly or through an intermediate twisting device 4 to form the fiber tampon into a knitted fabric which is made from the roving L The stretched fiber tampon has a false twist. The stretching unit particularly includes a three-cylinder draw frame in Fig. 1 comprising a pair of inlet pressure rolls 7, a double apron 8 guided by apron rolls and a pair of outlet pressure rolls 9. This or the same type of draw frame is generally used in ring-type spinning machines. The conveying direction of the roving L or the forming direction of the fiber tampon is indicated by an arrow T in FIG.

The drawing unit 6 in Figs. 2 to 5 is a three-cylinder draw frame for stretching a so-called roving L. A roving is a roving that already has a certain twist. Thus, the spun yarn wound on the roving bobbin can be easily placed on the bobbin of a knitting machine (especially a circular knitting machine). The roving has a high strength sufficient to allow it to travel a long distance. Since the roving L is drawn into a yarn of a desired fineness, the crepe must be loosened in the preliminary stretching zone of the draw frame before the stretching reaches a predetermined extent in the main stretch zone. As shown in the three-cylinder draw frame 6, the preliminary stretch zone extends from the pair of inlet pressure rolls 7 to the apron rolls for the double aprons 8. The preliminary stretching is formed by the different peripheral speeds of the pair of rolls and the peripheral speed is about 1.2 or 1.4. The main stretch zone extends from the double apron 8 to the pair of outlet pressure rolls 9. In the main stretch zone, the roving L is stretched by a factor of between 25 and 50.

As shown in Figures 2 to 5, the entire stretching unit 6 is located on a base 60. Each pair of rollers has upper pressure rollers 71, 81, 91 and lower syringes 72, 82, 92, respectively. The pair of inlet pressure rollers 7, the apron roller for the double apron 8, and the lower cylinders 72, 82 and 92 of the pair of outlet pressure rollers 9 are located on the shaft connected to one end of the base 60 and extend outward. The inlet pressure roller 71 and the other apron roller 81 have their bearings on the respective assembly discs 78 which are coupled to a spring clip 75 of the base 60. The spring clip 75 extends between a support bearing 79 extending from the base 60 and a thrust point 77 provided on the assembly disk, and is tensioned by a clamping cam having a pivot on the base 60. . Thus, the upper inlet pressure roller 71 and the upper apron roller 81 are pressed against the lower inlet pressure cylinder 72 and the lower apron cylinder 82, respectively. This tension can be adjusted by the clamping cam 76. The upper outlet pressure roller 91 is located on a bracket 96 that is free to move about the base 60. The bracket 96 is tensioned by a leaf spring 93, one end of which is fixed to an assembly protrusion 95 of the base 60. The upper outlet pressure roller 91 is located only on the bracket 96 and can be easily moved by lifting the outlet pressure roller 91 from the lower outlet cylinder 92 against the tension of the leaf spring.

The lower syringes 72, 82, 92 are driven by electric motors 62, 63 while being secured to the base 60 and freely extending outwardly in adjacent lower syringes. The electric motors 62, 63 are preferably synchronous electric motors operated by a frequency converter.

The basic difference between the configuration according to the invention and a three-cylinder or multi-cylinder draw frame is known from the ring-type spinning machine. In view of the fact that the pressure roller of the draw frame and the associated lower needle cylinder are usually arranged in pairs and assigned to two adjacent spinning zones, the present invention proposes a completely autonomous stretching unit 6, the stretching element The piece is fixed to one end of the base 60 by a cantilever beam. In contrast to known draw frames, wherein the upper outlet pressure roller is held against a continuous lower needle barrel by a spring, each stretching unit having its respective outlet pressure roller pair. Therefore, the configuration of the adjacent stretching unit is no longer extended in a straight line in a continuous linear lower needle cylinder as a corresponding complement of a plurality of outlet pressure rollers. Instead, each stretching unit can operate autonomously independently of the adjacent stretching unit. In particular, the autonomous unit for a circular knitting machine is preferably disposed at an angle to its adjacent unit. This allows all of the knitting zones of the circular knitting machine to be supplied with the stretched roving.

As can be seen in particular in Figure 3, a guiding element 61 is located on the transport path from the pair of inlet pressure rollers 7 to the double apron 8. The double apron 8 is guided by the apron rollers 81, 82, in particular when all the fibers comprising the staple rovings are transferred to the next stretching assembly. For the introduction of the roving or roving, a wire guide 10 is provided at the entrance of the stretching unit 6. It comprises a channel 11 which tapers in the direction of transport of the roving. The inlet roller pair 7 and the upper pressure rollers 71, 81 supporting the apron roller of the double apron 8 are pressed by a spring force against the associated lower syringe 72 of the tensioning unit 75, 76, 77, 79, 82. The upper outlet pressure roller 91 is press-fixed to the base 60 by a leaf spring 93 against the lower outlet cylinder 92.

The lower syringes 72, 82, 92 are all driven by electric motors 62, 63 while the device is on the base 60 and extends outwardly. The electric motors 62, 63 are preferably synchronous electric motors operated by a frequency converter. The actual drive member of the lower syringes 72, 82, 92 is located behind the base 60 and is protected from contamination by a cover 64 (Fig. 3). The drive of the lower syringes 72, 82, 92 is shown in FIG. There are more displays. For this purpose, the shafts of the electric motors 62, 63 extend from the base 60 and are driven by the drive pinions 65, 66. The shafts of the lower cylinders 72, 82, 92 cooperate with drive gears 74, 84, 94 located at the rear of the base 60. The timing belts 67, 68 connect the drive gears 74, 84, 94 of the lower cylinder to the drive pinions 65, 66 of the electric motor. The lower needle cylinder 72 of the inlet pressure roller pair 7 and the lower apron cylinder 82 for the double apron 8 are here driven by the same drive electric motor 62. The edges of the preliminary stretch zone for the spun yarn are determined by the different diameters of the drive wheels 74, 84 such that the circumferential speeds of the two lower syringes 72, 82 are different. The diameter of the lower barrel is selected such that the initial stretch has a size of about 1.2 or 1.4. The lower outlet cylinder 92 of the pair of outlet pressure rollers 9 is driven by an electric motor 63 having a peripheral speed greater than that of the other two lower syringes. The different speeds between the double apron 8 and the outlet pressure roller 9 determine the stretch of the roving and have a stretch factor between 25 and 50. The fiber tampon stretched to a predetermined extent is outputted at the transport nip of the pair of outlet pressure rollers 9, which may be supplied directly to the needle located in the syringe or may be supplied to a rifling generating false twist. Device.

Figure 5 shows the different stretching units 6 from the perspective of the introduction of rovings in accordance with the present invention. For the sake of clarity, the elements shown have the same reference numerals as in Figures 2 to 4. As can be seen in Figure 5, the stretching unit 6 is used to stretch the two conveyed rovings or rovings to be equal to each other. For this purpose, the wire guide 10 is provided with two adjustment channels 11 for introducing rovings. The two passages are tapered in the direction of transport of the roving from the pair of inlet pressure rolls 7 to the pair of outlet pressure rolls 9. One wire guide 10 is replaced by two channels 11, and it is also possible that two wires each adjacent to each other have a channel Guide. The improved structure according to the invention allows the stretching unit to be applied to a knitting machine, in particular a circular knitting machine with a particularly tight space. The two adjacent weave zones are simultaneously provided with a stretched fiber tampon by a common stretching unit 6. It is also possible to simultaneously stretch more rovings by a suitably sized roller or lower syringe, a corresponding number of configurations of wire guides or a wire guide having a corresponding number of channels for the stretching unit.

Figure 6 shows another different stretching unit for stretching a so-called draw frame sliver. The drawbar tampon is flawless and does not require a preliminary stretch zone. Therefore the stretching unit does not have a separate inlet pressure roller pair. The lower exit syringe is located after the double apron and is designated by reference numeral 92. Since the draw frame sliver is 4 to 6 times heavier than the spun yarn, the desired yarn fineness required for the stretch is between 100 and 200. The effect of this high strength stretching is to make the stretched fiber tampon very swellable after the double apron. The expanded fiber tampon is again polymerized to have a compression zone after the stretching zone. Therefore, a guide roller 85 is provided between the upper apron roller 81 and the upper outlet pressure roller 91. Similar to the configuration of the upper inlet pressure roller and the upper apron roller of the pair of inlet pressure rollers according to the embodiment of FIG. 2, the guide roller is disposed on a separate assembly tray, and like the upper outlet pressure roller 91, Loaded by the spring support onto the lower outlet barrel 92. The lower outlet cylinder 92 has a perforated outer casing. There is a fastening element in the outer sleeve that closely abuts the inner surface of the outer casing. The element is machined with a cavity connected to a vacuum source and a groove facing the inner surface of the outer casing and extending beyond the circumferential distance of the lower outlet cylinder 92 from the guide roller 85 having the lower outlet cylinder 92. The distance from the line to the grip line of the outlet pressure roller 9. Air passes through the longitudinal fixing groove The perforations on the outer sleeve of the outlet cylinder 92 are exhausted. The expanded, stretched fiber tampon is again drawn and polymerized under the influence of this air flow. In the intended state of compression, the polymeric fiber sliver leaves the stretching unit at the line of grip of the pair of outlet pressure rolls 9.

The design of the stretching unit 6 for stretching the draw sliver of the draw frame is also suitable for a wire guide. There may be a passage for the introduced draw frame sliver, or as proposed in Figure 7, the two passages 11 are used to simultaneously stretch two adjacent fiber cottons provided to the drawing unit 6. article. In this design, the appropriate size of the pressure roller and the lower syringe, the combined configuration of the appropriate number of wire guides, or a wire guide having an appropriate number of channels, can be achieved by simultaneously stretching the plurality of stretched units. Roving.

A common feature of the stretching unit 6 shown in all of the examples is that the base 60 has a quick clamping unit 69 which allows the stretching unit 6 to be quickly exchanged. For example, the quick clamping unit 69 can be provided with a cam device through a rotating cam It can be loosened or retightened so that the locking of the stretching unit can be quickly released or clamped again. Thus, the fixing time of the knitting machine is kept to a minimum.

The present invention is described by taking a draw frame for a circular knitting machine as an example. However, in order to develop the advantages of directly processing the roving, the flat knitting machine is also suitable for use with the draw frame as described in the present invention.

1‧‧‧Round knitting machine

2‧‧‧Syringe

3‧‧‧ knitting needles

4‧‧‧捻线装置

5‧‧‧Drums

6‧‧‧Stretching unit

7‧‧‧Inlet pressure roller pair

8‧‧‧Aperture roller pair

9‧‧‧Export pressure roller pair

10‧‧‧ Silk guides

11‧‧‧ channel

60‧‧‧Base

61‧‧‧Guide elements

62,63‧‧‧Electric motor

64‧‧‧ cover

65,66‧‧‧ drive pinion

67,68‧‧‧Synchronous belt

69‧‧‧Quick clamping unit

71‧‧‧Upper inlet pressure roller

72‧‧‧Under the entrance syringe

74,84,94‧‧‧ drive gear

75‧‧‧elastic clip

76‧‧‧Tighten unit

77‧‧‧ thrust point

78‧‧‧ Assembly tray

79‧‧‧Support bearing

81‧‧‧Upper apron roll

82‧‧‧ lower apron syringe

85‧‧‧ Guide roller

91‧‧‧Upper outlet pressure roller

92‧‧‧Under the exit syringe

93‧‧‧Sheet spring

95‧‧ ‧ protrusions

96‧‧‧ bracket

Further advantages, features and variations are apparent from the above description in accordance with embodiments of the invention. As shown, it is not to scale; FIG. 1 is a schematic diagram of a circular knitting machine having a stretching unit; Figure 2 is a plan view of a first embodiment of a stretching unit for a knitting machine; Figure 3 is a perspective view of the stretching unit according to Figure 2; Figure 4 is a plan view of the rear portion of the base of the stretching unit according to Figures 2 and 3. Figure 5 is a perspective view of a stretching unit according to the variation of Figure 3; Figure 6 is a plan view of another embodiment of a stretching unit of a knitting machine for processing a draw tampon; and Figure 7 is a view according to Figure 6 A perspective view of a further varying stretching unit.

1‧‧‧Round knitting machine

2‧‧‧Syringe

3‧‧‧ knitting needles

4‧‧‧捻线装置

5‧‧‧Drums

6‧‧‧Stretching unit

7‧‧‧Inlet pressure roller pair

8‧‧‧Aperture roller pair

9‧‧‧Export pressure roller pair

Claims (12)

A stretching unit for a knitting machine for forming a roving (L) into a fiber tampon having a double apron (8) guided by apron rollers (81, 82) and a pair of outlet pressure rollers (9) Each outlet pressure roller is composed of an upper pressure roller and a lower syringe and can be electrically driven, characterized in that the lower syringe (82, 92) is driven by a motor and its shaft is coupled to the base (60). One end and extending outwardly, the drive being provided by an electric motor (62, 63), wherein the shaft of the electric motor (62, 63) extends from the base (60) and is connected to the rear of the base (60) The pinion gears (65, 66) are driven whereby the electric motor can drive the lower needle barrel (92, 82) of the pair of outlet pressure rolls (9) and the apron roll for the double apron (8). The stretching unit according to claim 1, wherein the driven lower outlet cylinder (92) and the lower apron cylinder (82) for the double apron (8) are individually separated. The timing belts (67, 68) are connected to an electric motor (63, 62). A stretching unit according to claim 1 or 2, characterized in that in the conveying direction (T) of the roving (L) before the double apron (8), a pair of upper inlet pressures are provided. Roller (71) and inlet pressure roller (7) of the lower inlet syringe (72). A stretching unit according to claim 3, characterized in that two electric motors (62, 63) are provided, the power of the lower inlet cylinder (72) and the lower apron cylinder (82) being the same The electric motor (62) is provided. A stretching unit according to claim 1 or 2, characterized in that in the conveying direction (T) of the roving (L), a thread guide The piece is provided at the inlet of the stretching unit (6). A stretching unit according to claim 5, characterized in that two adjacent wire guides are provided at the inlet, each of which defines a conveying path of a roving. The stretching unit according to claim 5, characterized in that each of the wire wires (10) has a channel (11) which is tapered in the conveying direction, or one wire guide (10) has two Adjacent channel (11). The stretching unit according to claim 1 or 2, wherein the base (60) has a quick clamping unit (69) through which a part of the knitting machine (1) can be constructed. The upper is fixed close to the weaving area. A stretching apparatus according to claim 1 or 2, characterized in that the height conforms to the upper pressure roller (71, 81, 91) and the associated lower needle cylinder (72, 82, 92) The length of the shaft is between 50mm and 100mm. A knitting machine for making a fiber tampon from a roving (V), characterized by having a stretching unit (6) according to any one of claims 1 to 9. A knitting machine according to claim 10, which is characterized in that it is a circular knitting machine. A knitting machine according to claim 10 or 11, wherein each of the stretching units (6) is assigned two or more adjacent knitting zones.