Patent Publication Number: US-2007101560-A1

Title: Needling machine and a method for the operation thereof

Description:
RELATED APPLICATIONS  
      This application claims priority from European Application Nos. 05026263.3, filed Dec. 1, 2005, and 05028603.8, filed Dec. 28, 2005, the disclosures of each of which are hereby incorporated herein in their entireties.  
     FIELD OF THE INVENTION  
      The invention relates to a needling machine and to a method of operating a needling machine.  
     BACKGROUND OF THE INVENTION  
      Needling machines of the kind in question here are known and are used in the field of needled non-woven bonding, such needling machines also being used, for example, in the production of paper-maker&#39;s felts. The needling machines have needle boards with special needle spacings that have specific repeats. A common feature of the needle spacings is, that there are specific forward feed regions which are revealed in millimetres forward feed of the felt per needle board stroke and which produce marks, generally undesirable marks, on the felt surface, which are unacceptable for demanding applications of the felt, such as, for example, on a paper-making machine.  
      Furthermore, during needling, visible repeats are formed on the felt surface which are caused by a natural contraction in width during needling.  
      Such repeats produce unattractive patterns or artefacts on the treated felts which are undesirable and, when the felts are used in paper-making machines, show up in the paper produced.  
      That disadvantage is inherent to conventional needling machines and it is extremely difficult, if not impossible, to obtain a textile surface appearance that is uniform over the entire felt. In the past, in the attempt to impart a uniform surface appearance to the felt produced, recourse has been taken to an irregular distribution of the needles on the surface of the needle board, but such a non-uniform distribution always constitutes a compromise and gives a result that is still unsatisfactory for many applications.  
      Conversely, with the needling machines customary hitherto, it is also not possible, however, deliberately to produce a specific repeat, a certain pattern or a certain structuring in a felt, because in that case too the repeats inherently produced by a needling machine are troublesome.  
     SUMMARY OF THE INVENTION  
      The aim of the invention is to solve the problems described above and to provide a needling machine by means of which it is possible to produce a felt without repeats or with desired repeats on the surface of a textile and/or on the surface of a felt.  
      The aim is achieved, especially, by a needling machine, especially for use in the production of paper-maker&#39;s felts, the needling machine having at least one roller, configured as a traversing roller, which is movable, preferably back and forth, in the axial direction during operation, by means of which roller the product being needled is movable transversely with respect to the needling direction, that is to say in the axial direction, in accordance with the movement of the traversing roller.  
      Furthermore, the aim is achieved by a needling machine, especially for use in the production of paper-maker&#39;s felts, the needling machine having at least one spreading device which is movable back and forth in the axial direction and by means of which the product being needled is movable transversely with respect to the needling direction, that is to say in the axial direction, in accordance with the movement of the spreading device.  
      An important aspect of the invention is that by virtue of a specific lateral displacement of the needle insertion points, in a felt or some other textile fabric, the distribution of the insertions can be rendered uniform. That effect is independent of any needle spacing used. Accordingly, in accordance with the invention it is possible, by means of a roller that is moved back and forth, to avoid unintentional repeats or, by means of specifically controlled axial displacement of one or more rollers in the needling machine, specifically to produce repeats, patterns or irregularities in the textile fabric being processed, such as, for example, a felt.  
      It is also possible by means of this technology to prevent or, as desired, specifically to increase the formation of “needling alleys”, namely repeat-like marks on the needled textile surface.  
      According to the invention, at least one driven or co-running roller is moved back and forth, that is to say in a traversing movement, transversely with respect to the forward feed movement, that is to say in the axial direction of the roller in question.  
      According to how many and which rollers of a needling machine are moved, it is possible to obtain different results in respect of a repeat or pattern. It should be stressed at this point that in the case of a plurality of traversing rollers, their movement can be in the same direction or in opposite directions. Furthermore, the stroke and the stroke frequency can be adjusted, preferably steplessly, individually for each roller.  
      In accordance with an embodiment of the invention, the stroke of the traversing roller and/or the spreading device is from 0 mm to 15 mm, preferably from 0 mm to 12 mm and especially from 0 mm to 10 mm. A larger stroke of up to three times the indicated value as well as an especially small stroke range of 1.5 mm is conceivable, depending upon the use and the pattern to be achieved.  
      Furthermore, the stroke of the traversing roller and/or spreading device is steplessly adjustable and can optionally be altered during operation.  
      According to the invention, the stroke frequency is in the region of from 1 to 120 strokes per minute, it being stressed that the movement of the traversing roller and/or spreading device proceeds continuously in the axial direction. In the same way as the stroke length of the traversing roller and/or spreading device, the stroke frequency thereof is also steplessly adjustable.  
      The drive for a stroke movement of the at least one traversing roller and/or spreading device is effected, alternatively or in combination, mechanically, hydraulically, electrically, magnetically and/or pneumatically, it being stressed that, depending on the stroke frequency and stroke length as well as the size and weight of the roller and/or spreading device, different driving can be provided. It should be stressed at this point that the spreading device can be in the form of a roller or in the form of a roller combination, especially of 3 to 5 rollers.  
      It is also possible to implement a traversing movement of the textile fabric with the aid of an additional roller pair between the needling machine and a tensioning carriage on a felt-inlet and/or felt-outlet side. It is furthermore possible for the spreader used in the needling machine, i.e. the above-mentioned spreading device, to be configured as a traversing unit transverse to the direction of travel of the felt. It should be stressed at this point that in the context of this invention a roller can also be implemented as a region that is movable back and forth, over which the textile fabric being processed; merely slides, without that region performing a rotational movement.  
      In respect of possible drive methods for the stroke movement of a roller, a roller pair or a spreader, transverse to the direction of travel of the felt, the possible methods mentioned below are provided in accordance with the invention. A mechanical drive by means of a drive rod, such as, for example, a crank drive, an eccentric drive, a cam plate or swash plate or like mechanical drives. Hydraulic drives, for example by means of hydraulic cylinders or a hydraulic motor, are also provided. Moreover, the stroke movement can be provided electrically by means of an electric motor with gears or with a spindle. The same applies to a pneumatic drive with the aid of a pneumatic cylinder or motor with the aid of a gear or a spindle.  
      The aim of the invention is also achieved by a method of operating a needling machine, especially for the production of paper-maker&#39;s felts, wherein at least one roller of the needling machine is moved in the axial direction, preferably back and forth, during operation. The movement of the roller is effected according to the invention with a stroke of from 0 mm to 15 mm, preferably from 0 mm to 12 mm, and especially from 0 mm to 10 mm, the stroke of the roller, especially in operation, being steplessly adjusted and/or re-adjusted. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
      The invention is described below on the basis of an exemplary embodiment which is explained in greater detail with reference to the Figures.  
       FIG. 1  is a diagrammatic view of a needling machine;  
       FIG. 2  is a diagrammatic view of a traversing roller with a drive unit for a stroke movement;  
       FIG. 3  is a diagrammatic view of a detail of the traversing roller with a drive unit from  FIG. 2 . 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION  
      The present invention will now be described more fully hereinafter, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements throughout. Thicknesses and dimensions of some components may be exaggerated for clarity.  
      Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.  
      The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein the expression “and/or” includes any and all combinations of one or more of the associated listed items.  
      In addition, spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.  
      Well-known functions or constructions may not be described in detail for brevity and/or clarity.  
       FIG. 1  shows a diagrammatic view of a needling machine, wherein the roller indicated by reference letter A is the drive roller of the system. The rollers indicated by reference letter D are guide rollers by means of which the textile fabric being transported and needled is moved on the one hand and held taut on the other hand. The devices indicated by reference letter Z are the respective needling zones of the needling machine, a spreader for the textile fabric, indicated by reference letter B, being shown diagrammatically in the upper region of the Figure. In the lower region of the Figure there is an external traversing unit indicated by reference letter C. The textile fabric, especially a felt, is supplied from the rolls shown, their material being moved anti-clockwise in a needling machine. According to the invention, it is possible to operate one or more of the rollers A, B, C and D in traversing mode.  
       FIG. 2  shows a traversing roller, the stroke of which in the axial direction is indicated by a double-headed arrow and labelled with 0-X, with 0-X being the stroke length of the traversing roller.  
      As shown on an enlarged scale in  FIG. 3 , the traversing roller is moved in a traversing movement from left to right and back again by means of a crank drive.  
      It should be pointed out here that all the above-described parts, alone and in any combination, especially the details shown in the drawings, are claimed as being important to the invention. Modifications thereof will be known to the person skilled in the art.