DEVICE AND METHOD FOR PRODUCING KNITTED FABRIC

Abstract

A device and a corresponding method produce a knitted fabric with a knitting machine and a roving drawing and strengthening unit. The device has a roving supply unit with a roving, a stretching unit linked to the roving supply unit, and a spinning nozzle device provided downstream from the stretching unit in a roving conveying direction of the device forming a fiber strengthening segment by applying compressed air. An end thread gripping roller pair rotatable in opposite directions is provided downstream from the spinning nozzle device in the roving conveying direction delimiting the fiber strengthening segment. The device has a blow-off device for blowing off the spinning nozzle device and/or the stretching unit and a suction device for suctioning off loose fibers from the spinning nozzle device and/or the stretching unit. The suction device and the blow-off device are interconnected in a blow-off and suction system.

Claims

1-12. (canceled)

13. A device for producing knitted fabric, comprising: a knitting machine; a roving drawing and strengthening unit having a roving supply unit with at least one roving, a stretching unit coupled with said roving supply unit, a spinning nozzle device disposed downstream from said stretching unit in a roving conveying direction of the device forming a fiber strengthening segment by applying compressed air, and an end thread gripping roller pair rotatable in opposite directions and disposed downstream from said spinning nozzle device in the roving conveying direction and delimiting said fiber strengthening segment; at least one blow-off device for blowing off said spinning nozzle device and/or said stretching unit; at least one suction device for suctioning off loose fibers from said spinning nozzle device and/or said stretching unit; a blow-off and suction system, said suction device and said blow-off device are interconnected in said blow-off and suction system; at least one air channel running along over said end thread gripping roller pair; said suction device having a suction air cleaning device with at least one ventilation device, said suction air cleaning device having at least one exhaust air outlet connected to said at least one air channel; and said at least one air channel having at least one channel opening aligned on or along said spinning nozzle device and/or on or along said stretching unit.

14. The device according to claim 13, further comprising a lint filter assembly having a perforated drum with at least one lint filter layer disposed around said perforated drum, said perforated drum disposed on an underpressure side of said ventilation device.

15. The device according to claim 14, further comprising: a hole-free panel disposed in an inner circumference of said perforated drum; and a wiping device disposed on an outer side of said perforated drum opposite said hole-free panel.

16. The device according to claim 15, further comprising a gear ring disposed around said inner circumference of said perforated drum for adjusting a position of said perforated drum in relation to said wiping device.

17. The device according to claim 13, further comprising an auxiliary thread supply through which at least one auxiliary thread can be supplied to said stretching unit; and wherein said at least one air channel at least partially also runs along over said auxiliary thread supply and contains said at least one channel opening, which is aligned on or along said auxiliary thread supply.

18. The device according to claim 1, wherein: said suction device has a plurality of suction channels; and said suction air cleaning device is a collective suction air cleaning device into which all said suction channels lead.

19. The method according to claim 13, further comprising a suction collection channel formed in a conical fashion in its length expansion, extending parallel to said air channel and is disposed between said suction air cleaning device and at least one suction channel of said suction device.

20. A method for producing a knitted fabric, which comprises the steps of: supplying at least one roving to a stretching unit by a roving supply unit; applying compressed air to a drawn roving exiting the stretching unit by a spinning nozzle device in a fiber strengthening segment, being thus strengthened, wherein the fiber strengthening segment is delimited by an end thread gripping roller pair rotating in opposite directions through which a drawn, strengthened roving is led in clamped fashion and an end thread exiting the end thread gripping roller pair is supplied to a knitting machine; blowing off the spinning nozzle device and/or the stretching unit via at least one blow-off device; suctioning off exhaust air by means of at least one suction device on the spinning nozzle device and/or the stretching unit; leading suction air to a suction air cleaning device, in the suction air cleaning device an underpressure is generated by means of at least one ventilation device, through the suction air cleaning device loose fibers are led out of the suction air; and putting cleaned exhaust air gained from the exhaust air under excess pressure, the cleaned exhaust air being under excess pressure is led, starting from the suction air cleaning device, in at least one air channel running along over the end thread gripping roller pair and through at least one channel opening of the air channel by forming at least one air curtain aligned to or along the spinning nozzle device and/or on or along the stretching unit.

21. The method according to claim 20, which further comprises leading the suction air through at least one lint filter device connected to an underpressure side of the at least one ventilation device, the lint filter device having a perforated drum with at least one lint filter layer provided around the perforated drum, wherein loose fibers contained in the suction air are collected by the lint filter device.

22. The method according to claim 21, which further comprises: providing a hole-free panel in an inner circumference of the perforated drum; providing a wiping device on an outer side of the perforated drum opposite the lint filter layer; and providing a gear ring on the inner circumference of the perforated drum, wherein a position of the perforated drum is adjusted in relation to the wiping device by means of the gear ring in temporal intervals.

23. The method according to claim 20, wherein the at least one air channel also runs along over an auxiliary thread supply and at least one air curtain is aligned on or along the auxiliary thread supply by means of the at least one channel opening of the air channel.

24. The method according to claim 20, which further comprises leading the suction air suctioned off on the device collectively to the suction air cleaning device, whose cleaned exhaust air is led over the spinning nozzle device.

Description

[0056] Preferred embodiments of the present invention, including their structure, function and advantages are explained in more detail in the following using figures, wherein

[0057] FIG. 1 schematically shows details of an embodiment of a device according to the invention in a side view;

[0058] FIG. 2 schematically shows the details of the device from FIG. 1 in a frontal view;

[0059] FIG. 3 schematically shows an embodiment of a perforated drum usable on a device according to the invention in a perspective view; and

[0060] FIG. 4 schematically shows the perforated drum from FIG. 3 in a frontal view.

[0061] The figures schematically show details of an embodiment of the device according to the invention for producing knitted fabric. For the sake of clarity, a multitude of further machine details, which for example relate to the housing of the device, the media supply, the device control and so on are left out of the figures. Concerning such details, it is hereby fully referred to the explanations relating to the document DE 10 2011 053 396 B3, which describes the basic structure of the device according to the invention, wherein the device according to the invention comprises a blow-off and suction system 1 changed over the document DE 10 2011 053 396 B3, whose elements are primarily depicted in the subsequently described figures.

[0062] FIG. 1 shows a part of the device according to the invention in a side view, while FIG. 2 shows the part of the device according to the invention shown in FIG. 1 in a side view.

[0063] The device according to the invention comprises a knitting machine not depicted in the figures as well as a roving drawing and strengthening unit 10 supplying drawn, strengthened roving to the knitting machine. The roving drawing and strengthening unit 10 comprises a roving supply unit also not depicted in the figures, on which at least one roving is for example stocked on at least one supply spool.

[0064] The roving drawing and strengthening unit 10 furthermore comprises a stretching unit 5 for drawing the roving supplied to the stretching unit 5 by the roving supply unit. The roving not depicted in the figures traverses the stretching unit 5 in a roving conveying direction A, that is vertically from bottom to top in the depicted embodiment.

[0065] The stretching unit 5 used in the embodiment of the FIGS. 1 and 2 comprises three fixed, continuous lower rollers 511, 521, 531, which are faced by rolls 512, 522, 532 rotatable when operating the device and pressable against the lower rollers 511, 521, 531 by means of a lever arm 50 by forming corresponding roller pairs 51, 52, 53 indicated in FIG. 2. The rolls 512, 522, 532 can for example be rubber rolls.

[0066] The roving drawing and strengthening unit 10 furthermore comprises a spinning nozzle device 6 provided downstream from the stretching unit 5 in the roving conveying direction A. When operating the device, compressed air is being applied to a drawn roving exiting the stretching unit 5 in a fiber strengthening segment by means of the spinning nozzle device 6, said roving being thus strengthened. In the depicted embodiment, the spinning nozzle device 6 is comprised of two spinning nozzles 61, 62 automatically conveying the drawn roving in a roving conveying direction A.

[0067] The device according to the invention furthermore comprises a suction device 11. In the embodiment depicted in FIGS. 1 and 2, the suction device 11 comprises four suction channels 3a, 3b, 3c, 3d by means of whose loose fibers and/or loose particles can be sucked off on different spots of the roving drawing and strengthening unit 10.

[0068] A first suction channel 3a is therein aligned towards the lower roller 531 of the outlet gripping roller pair 53 of the stretching unit 5. In the depicted embodiment, the suction channel 3a is aligned with the lower roller 531 at approximately a right angle to the roving conveying direction A.

[0069] A second suction channel 3b is aligned with an area between the spinning nozzles 61, 62 of the spinning nozzle device 6 in order to remove loose fibers and/or loose particles from the spinning nozzles 61, 62. The suction channel 3b is aligned to the spinning nozzle device 6 at approximately a right angle to the roving conveying direction A.

[0070] A third suction channel 3c is provided downstream from the spinning nozzle device 6 in a roving conveying direction A.

[0071] A fourth suction channel 3d runs along over the spinning nozzle device 6, is bent over the spinning nozzle device 6 and is aligned at an angle from above with the outlet roller pair 53 of the stretching unit 5.

[0072] The suction channels 3a, 3b, 3c, 3d lead to a shared suction air channel 30 in which the suction air is conducted in the suction flow direction B and which leads to a suction air cleaning device 4 of the device. The suction air cleaning device 4 is enclosed by a housing 41, in which a lint filter device is provided. In the depicted embodiment, the lint filter device comprises a perforated drum 7, that is a cylindrical drum that is hollow on the inside, in whose cylinder jacket through holes are provided. A possible embodiment of the perforated drum 7 is depicted in a perspective view in FIG. 3 and in a frontal view in FIG. 4. The perforated drum 7 can for example be formed of steel.

[0073] A lint filter layer 70 is provided around the cylinder jacket of the perforated drum 7. The lint filter layer 70 comprises a multitude of passage openings, whose diameter is smaller than the diameter of the holes of the perforated drum 7. Thus, the fiber lint contained in the suction air is collected on the lint filter layer 70 and only the suction air cleaned from the fiber lint reaches the inside of the perforated drum 7. The lint filter layer 71 can for example be formed as a cylindrical, knotted or knit grid, whose loop widths are so small that the loose fibers and/or other loose particles that are generated during the roving processing on the device according to the invention, are prevented from permeating the grid to the inside of the perforated drum 7. The lint filter layer 71 can be for example formed of a filter wire mesh.

[0074] Furthermore, a panel 71 is arranged within the perforated drum 7. In the depicted embodiment, the panel 71 is on the bottom of the perforated drum 7. Outside on the perforated drum 7, opposite the panel 71, a wiping device 72 is provided on the cylinder jacket of the perforated drum 7.

[0075] For sucking off the air contaminated with loose fibers and/or loose particles on the roving drawing and strengthening unit 10, a ventilation device 8 is subsequently provided on an opening of a housing wall 411 of the housing 41. An underpressure side of the ventilation device 8 is thereby linked to the inside of the perforated drum 7, whose open drum bottom 73 leads to the opening of the housing wall 411 opposite the ventilation device 8. Accordingly, an underpressure is generated inside the perforated drum 7 and also inside the housing 41, resulting in a suction effect in the suction channels 30, 3a, 3b, 3c, 3d connected to the housing 41. The excess pressure side of the ventilation device 8 is situated outside the housing 41 so that an excess pressure arises outside the housing 41, wherein the pressure difference between the inside of the housing 41 and the area outside the housing results in an air flow towards the blow-off device 9, as shown by the arrow C.

[0076] In the embodiment depicted in the figures, the underpressure side of the ventilation device 8 closes flush around the open drum bottom 73 with the housing wall 411, however, it can also overtop it or to a certain extent can protrude inside the suction air cleaning device 4 respectively the perforated drum 7. However, the open drum bottom 73 can comprise a larger diameter than the underpressure side of the ventilation device 8.

[0077] Due to the rotational movement of at least one ventilation blade 81 of the ventilation device 8, an underpressure is generated, which causes the air to be sucked from the suction air channel 30 and thus from the suction channels 3a, 3b, 3c, 3d towards the ventilation device 8.

[0078] Due to the suction effect, the suction air sucked off from the roving drawing and strengthening unit 10 initially flows along the suction air channel 30 tapering in the suction flow direction B and reaches, coming from this suction air channel 30 via an exhaust air inlet 42, the suction air cleaning device 4. In order to be able to ensure a constant suction speed across the entire length of the suction air channel 30, the suction air channel 30 leads in a suction collection channel 43 inside the suction air cleaning device 4, which is formed conical in its length expansion running parallel to the length expansion of the air channel 9 and/or parallel to the length expansion of the rollers of the stretching unit 5.

[0079] The suction collection channel 43 is opened towards the inside of the housing 41. Within the suction air cleaning device 4, the sucked air moves towards the ventilation device 8 arranged on the housing wall 411, wherein the sucked air hereby flows through the cylinder jacket of the perforated drum 7 into the inside of the perforated drum 7. Thereby, the suction air passes the lint filter layer 70 provided around the perforated drum 7. When the contaminated air flows through the lint filter layer 70, the loose fibers and/or other particles contained in the sucked air are taken in by the lint filter layer 70 filtered from the exhaust air so that only exhaust air cleaned from fiber lint and particles flows inside the perforated drum 7 and thence to the ventilation device 8.

[0080] Due to the rotational movement of the ventilation blades 81, an excess pressure is generated outside the suction air cleaning device 4, which causes the cleaned air to flow from the inside of the perforated drum 7 through at least one exhaust air outlet of the suction air cleaning device 4 in the flowing direction C into the air channel 90. As depicted in FIG. 1, at least one channel opening 91 of the air channel 90, which is preferably a single, continuous channel opening running parallel to the rollers of the stretching unit 5, is thereby aligned with the spinning nozzle device 6 and/or the stretching unit 5 so that the cleaned exhaust air can be used for blowing off loose fibers and/or other particles of the stretching unit 5 and/or the spinning nozzle device 6. Afterwards, the blow-off-suction-circle of the present invention is completed by sucking away the loose fibers and/or particles blown off from the stretching unit 5 and/or the spinning nozzle device 6 by means of the suction channels 3a, 3b, 3c, 3d.

[0081] By processing the sucked air and using the cleaned air for blowing off the stretching unit 5 and/or the spinning nozzle device 6 in the present invention, an energetically cost-effective device and a corresponding method are provided, by means of which the stretching unit 5 and/or the spinning nozzle device 6 can be easily and efficiently freed of loose fibers and/or other particles.

[0082] To ensure a continuous air flow of cleaned air in the air channel 90 and thus out of the channel opening 91, a wiping device 72, for example in form of a wiper lip, is provided on the cylinder wall of the perforated drum 7, adjoining the lint filter layer 71 for wiping a lint fleece accumulating on the lint filter layer 72. The regular wiping of the loose fibers and/or other particles accumulated on the lint filter layer 71 prevents a blocking of the passage openings of the lint filter layer 71 formed as a grid and thus ensures a continuous air flow in the air channel 90.

[0083] As can be discerned from FIG. 1, the wiping device 72 touches the lint filter layer 71 at least during the cleaning process, in order to be able to wipe off the loose fibers and/or particles accumulated on the outer side of the lint filter layer 71. Since the fibers and/or particles are sucked tightly to the lint filter layer 71 due to the underpressure generated by the ventilation device 8 and thus their wiping by means of the wiping device 72 is hindered due to the underpressure, a hole-free panel 71 is arranged inside the perforated drum opposite the wiping device 72. Due to the panel 71, no underpressure forms on its opposing side of the perforated drum 7, whereby the loose fibers and/or particles accumulated in this area can be easily wiped off from the lint filter layer 71. A rotating movement of the perforated drum 7 with the lint filter layer 71 situated on it in relation to the wiping device is 72 helpful for wiping off the lint layer from the lint filter layer 71.

[0084] In order to enable an easy turning of the perforated drum 7 with the lint filter device 71, the perforated drum 7 comprises a gear ring in the area of the open drum bottom 73 in the embodiment depicted in FIG. 3. By an intervention of a slide formed corresponding to the gear ring 74 or another correcting actuator not depicted here into the gear ring 74, the perforated drum 7 alongside the lint filter layer 71 provided on it can be turned around the drum axis, that is the position of the perforated drum 7 can be changed in relation to the wiping device 72 for an eased wiping of the lint fleece from the lint filter layer 71.

[0085] In a simple embodiment of the suction air cleaning device 4, the panel 71 can just be placed in the perforated drum 7 and thus automatically lies in a lower area of the perforated drum 7 due to the gravity. The wiping device 72 is hereby provided below the perforated drum 7. In other embodiments of the present invention, however, the panel 71 can also be firmly fixed in the suction air cleaning device 4. Insofar the panel 71 is provided fixed in the suction air cleaning device 4, it can also be provided on any other position of the circumference of the perforated drum 7, the only important thing being that the wiping device 72 is arranged opposite the panel 71.