Abstract:
The invention relates to a device for needling a fibrous web having at least one needle bar. The needle bar carries a needle board on the bottom thereof having a plurality of needles, the needle bar being guided by means of a moveably mounted bar carrier. The bar carrier is driven by a vertical drive in an oscillating manner in up and down movements. For straight guidance of the bar carrier, a guiding device is provided, which has at least one rocker held at the end by a rotary bearing of a machine frame. In order to obtain the straightest possible guide path in the bar carrier, according to the invention the opposite end of the rocker and the bar carrier are connected by a plurality of members of a coupling kinematic mechanism.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 12/669,763, filed Jun. 10, 2010, which is a national phase application of International Patent Application PCT/EP2008/059291, filed Jul. 16, 2008, which claims priority to German Patent Application DE 10 2007 036 897.8, filed Aug. 4, 2007, each of which is incorporated herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a device for needling a fibrous web. 
     2. Description of Related Art 
     For consolidating and structuring laid fibrous webs, it is known from the prior art to pierce the fibrous webs with a plurality of needles, which are guided in an oscillating upward and downward movement. Since the needles are not smooth but provided with barbed hooks that are open in the piercing direction, individual fibers of the fibrous web are caught and realigned within the fibrous web when the needles pierce the latter. This results in the desired fiber-mingling and bonding effects within the fibrous web. For guiding the plurality of needles, devices are used in which the needles are disposed on a lower side of a needle beam. The needle beam is held with the aid of a movable beam carrier, which is driven by means of a vertical drive for an oscillating vertical movement. In order to enable the straightest possible insertion of the needles into the fibrous web during the vertical movement, it is further known from the prior art to use a guiding device, which acts on the beam carrier and which guides the vertical movement of the beam carrier. 
     A device for needling a fibrous web is thus disclosed in DE 44 31 055 A1, in which device the guiding device is formed by a rocker, one end of which is held on a machine frame with the aid of a rotary bearing and the opposite free end of which is coupled to the beam carrier via a swivel joint. The beam carrier is thus guided on a guideway predetermined by the rocker. The guideway of the beam carrier is shaped like a circular arc. In order to still produce defined punctures with the help of the needles, curved needles are used that are adapted to the guideway of the beam carrier. 
     U.S. Pat. No. 4,241,479 discloses another device for needling a fibrous web, in which device the guiding device for the straight guidance of the beam carrier is formed by two rockers that are held in supporting bearings in relation to a machine frame. The supporting bearings each comprise at least one tooth gap, in which that end of the rocker that is formed as a tooth engages. The device disclosed thus requires more space in order to be able to guide the outwardly protruding rockers in the machine frame. Furthermore, the lubrication and sealing of the teeth disposed between the rockers and the supporting bearings pose problems, in particular. 
     EP 0 364 105 A1 discloses another device for needling a fibrous web, in which device the guiding device comprises at least one guiding rod that is guided in a guide bushing held on a machine frame. One free end of the guiding rod is connected to the beam carrier so that the beam carrier maintains a guideway predetermined by the guiding rod and the guide bushing during the vertical movement. The device disclosed is also based on a tribological pairing of two parts for guiding the beam carrier, and the lubrication and sealing of these parts pose problems, in particular, and require a large amount of equipment. 
     Moreover, the guiding devices for the straight guidance of the beam carrier known from the prior art only allow the needle beam to be driven in the vertical direction. Retrofits of the known devices for carrying out a horizontal movement of the beam carrier are either not feasible or are associated with considerable expenditure. 
     SUMMARY OF VARIOUS EMBODIMENTS 
     It is now the object of the present invention to design a device for needling a fibrous web of the generic kind, which device comprises a guiding device, which enables a straight guidance of the beam carrier in the longitudinal direction by means of a compact and simple coupling kinematic mechanism. 
     Another aim of the invention is to design a flexible and reliable guiding device for the straight guidance of the beam carrier in the device of the invention. 
     This object is achieved according to the invention by a device for needling a fibrous web, which device has the features of the various embodiments. 
     Preferred developments of the invention are defined by the features and combinations of features of the various embodiments. 
     One particular advantage of the invention is that the linkage of the beam carrier in relation to the machine frame with the aid of a rocker guided in the rotary bearing is retained. The guideway predetermined by the rocker can be converted advantageously by interposing a coupling kinematic mechanism and can be adapted to match the requirements of the needling process. According to the invention, the opposite end of the rocker is connected to the beam carrier with the aid of a plurality of members of a coupling kinematic mechanism. The guideway that is effective on the beam carrier for the straight guidance of the needle beam can thus be determined by the cooperation of the rocker and the coupling kinematic mechanism. 
     In a preferred development of the invention, the members of the coupling kinematic mechanism are formed by a steering rod and a frame lever, the steering rod being connected to the beam carrier with the aid of a swivel joint, and the frame lever being held on the machine frame with the aid of a rotary bearing. The vertical movement of the beam carrier can thus be received and guided exclusively by pivoted levers of the guiding devices. The rotational movements of the lever means can be enabled advantageously by the rotary bearings or swivel joints so that the entire guiding device has a simple tribology. Both the rotary bearings and the swivel joints can easily be sealed in relation to the ambience so that a stable and secure guidance of the beam carrier is ensured. 
     Depending on the design of the frame lever within the coupling kinematic mechanism, it is possible to implement different guideways for the straight guidance of the beam carrier. In a first variant, the frame lever is formed as a tilting lever comprising the rotary bearing in a central portion thereof. One end of the tilting lever is connected to the steering rod with the aid of a swivel joint and the opposite end is connected to the rocker by means of a second swivel joint. The guideway effected by the steering rod on the beam carrier can be formed such that it is approximately straight depending on the coordination of the lengths of the steering rod and the tilting lever. 
     In order to produce a straight guideway of the beam carrier in a narrow space as far as possible, the frame lever is formed as a second rocker according to a preferred development of the invention, the first rocker and the second rocker being each connected to the steering rod with the aid of a swivel joint. The selection of the positions of the rotary bearings and the lengths of the rockers enables an almost straight pivot point between the steering rod and the beam carrier over a maximum vertical stroke. This variant of the invention is particularly suitable to carry out high-quality needling processes on fibrous webs. The plurality of needles can be guided on the needle beam precisely in a vertical upward and downward movement for needling the fibrous web so that a very uniform needling structure can be produced within the fibrous web. 
     The selection of the rocker arrangement is user-definable depending on the machine type, the installation options and the desired guiding properties. Thus, for example, the swivel joints of the rockers can be formed on the steering rod at a distance from each other, the swivel joint between the beam carrier and the steering rod being formed at a free end of the steering rod or in a central portion of the steering rod. 
     This variant of the invention can be developed in such a way to particular advantage that one of the rotary bearings of the rockers is formed as an eccentric bearing at the circumference of an eccentric shaft, which eccentric shaft can be optionally driven or locked into position by means of a kinetic facility. This provides the possibility of producing a constant horizontal stroke on the beam carrier. For this purpose, the eccentric shaft can be driven by means of the kinetic facility. Alternately, the eccentric shaft is locked into position by the kinetic facility, if required, so that only the straight guidance produced by the steering rod is effective on the beam carrier. 
     Depending on the design of the steering rod and the linkage of the swivel joints of the rockers, the two rotary bearings of the rockers are preferably disposed at a distance from each other above the beam carrier. Particularly compact and space-saving guiding devices can thus be achieved. 
     In order to improve the guiding stability of the beam carrier, the two rotary bearings of the rockers are disposed symmetrically in relation to the center of the beam carrier according to a preferred development of the invention. 
     For this purpose, the swivel joint is preferably disposed at the center of the beam carrier for the linkage of the steering rod. The vertical movement of the beam carrier can thus be transmitted securely and with stability onto the steering rod for straight guidance. 
     A particularly high degree of flexibility is ensured for the use of the device of the invention by that development of the invention in which the rotary bearing of the rocker is formed as an eccentric bearing on the circumference of an eccentric shaft, which eccentric shaft can be optionally driven or locked into position by means of a kinetic facility. Thus, optionally a superimposed horizontal stroke can be carried out on the beam carrier so that, depending on requirements, the fibrous web can be needled either with a horizontal stroke with a movable eccentric shaft or without a horizontal stroke with an eccentric shaft that is locked into position. 
     In order to achieve a high-quality needling of the non-woven web, the vertical drive is preferably formed in such a way according to a development of the invention that two connecting rods driven by separate eccentric drives are connected to the beam carrier. For this purpose, the eccentric drives each comprise a crankshaft which is connected to the connecting rod with the aid of a connecting-rod big end. The small ends of the connecting rods are connected to the beam carrier with the aid of swivel joints. Such a vertical drive provides a high degree of flexibility in adjusting and guiding the needle beam in order to needle different fibrous webs having different fibers in a manner that is specific to the product. 
     When designing such a vertical drive, the rocker and the coupling kinematic mechanism of the guiding device are preferably disposed between the connecting rods of the vertical drive in order to achieve very narrow thread spacing. However, it is alternately also possible to arrange the rocker and the coupling kinematic mechanism next to the connecting rods of the vertical drive in order to enable a lateral arrangement of the guiding device, for example. 
     The device of the invention is designed advantageously for implementing large working widths with appropriately long needle boards even with several vertical drives which are strung together in a machine and which jointly act on a beam carrier. In doing so, a straight guidance is assigned to each of the vertical drives, the rockers of which are each connected to the beam carrier with the aid of a coupling kinematic mechanism. 
     A superimposed horizontal movement of the needle beam can also be implemented advantageously by a development of the invention, in which the vertical drive comprises a phase-adjusting device for the phase adjustment of the two crankshafts. In this case, the crankshafts can be driven such that they are offset by a phase angle so that the beam carrier carries out a tilting movement which also results in a horizontal movement in addition to the vertical movement due to the vertical distance from the needles. This development of the invention is particularly advantageous in order to carry out small, infinitely adjustable horizontal strokes on the needle beam. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Some exemplary embodiments of the invention will be described below for explaining the invention in more detail with reference to the attached Figures, in which: 
         FIG. 1  schematically shows a side view of a first exemplary embodiment of the device of the invention 
         FIG. 2  schematically shows a side view of another exemplary embodiment of the device of the invention 
         FIG. 3  schematically shows a side view of another exemplary embodiment of the device of the invention 
         FIG. 4  schematically shows a side view of another exemplary embodiment of the device of the invention 
         FIG. 5  schematically shows a side view of another exemplary embodiment of the device of the invention 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a first exemplary embodiment of the device of the invention for needling a fibrous web. The exemplary embodiment of the device of the invention shown in  FIG. 1  shows a beam carrier  2 , which holds a needle beam  1  on the lower side thereof. The lower side of the needle beam  1  comprises a needle board  3  having a plurality of needles  4 . A bedplate  29  and a stripper  28  are assigned to the needle board  3  comprising the needles  4 , a fibrous web  30  being guided at a substantially constant feed rate between the bedplate  29  and the stripper  28 . An arrow indicates the direction of movement of the fibrous web  30 . 
     A vertical drive  5  acts on the beam carrier  2 . The vertical drive  5  drives the beam carrier  2  in the vertical direction in an oscillating manner so that the needle beam  1  comprising the needle board  3  carries out upward and downward movements. The vertical drive  5  is formed by two eccentric drives  6 . 1  and  6 . 2  disposed parallel to each other in this exemplary embodiment. The eccentric drives  6 . 1  and  6 . 2  comprise two crankshafts  9 . 1  and  9 . 2  respectively, which are disposed parallel to each other above the beam carrier  2 . The crankshafts  9 . 1  and  9 . 2  each comprise at least one eccentric portion for receiving at least one connecting rod.  FIG. 1  shows the connecting rods  7 . 1  and  7 . 2 , which are disposed on the beam carrier  2  and the connecting-rod big ends  10 . 1  and  10 . 2  are held on the crankshafts  9 . 1  and  9 . 2  respectively. The opposing small ends  11 . 1  and  11 . 2  of the connecting rods  7 . 1  and  7 . 2  are connected to the beam carrier  2  with the aid of two connecting swivel joints  8 . 1  and  8 . 2  respectively. The crankshaft  9 . 1  together with the connecting rod  7 . 1  and the crankshaft  9 . 2  together with the connecting rod  7 . 2  form the eccentric drives  6 . 1  and  6 . 2  respectively in order to guide the beam carrier  2  in an upward and downward movement. The crankshafts  9 . 1  and  9 . 2  are driven synchronously in the same or opposite direction so that the beam carrier  2  is guided in an at least approximately parallel manner. 
     For effecting the vertical movement of the beam carrier  2 , a guiding device  12  is provided, which in this exemplary embodiment comprises a rocker  13 , which is connected to a machine frame  15  via a rotary bearing  14 . The free end of the rocker  13  is connected to the beam carrier  2  with the aid of a coupling kinematic mechanism  16 . In this exemplary embodiment, the coupling kinematic mechanism  16  is formed by a steering rod  17  and a second rocker  22 . The second rocker  22  is held in a pivoting manner on the machine frame  15  at a distance from the first rocker  13  with the aid of a second rotary bearing  23 . The free end of the first rocker  13  and the free end of the second rocker  22  are coupled to the steering rod  17  at a distance from each other by means of swivel joints  24 . 1  and  24 . 2  respectively. The swivel joints  24 . 1  and  24 . 2  are formed at an end section of the steering rod  17 . The opposite end section of the steering rod  17  is connected to the beam carrier  2  with the aid of a swivel joint  20 . The swivel joint  20  is formed at the center of the beam carrier  2 . 
     The rocker  13  and the members of the coupling kinematic mechanism  16  are disposed above the beam carrier  2 . For this purpose, the rotary bearings  14  and  23  are disposed on the machine frame  15  between the connecting rods  7 . 1  and  7 . 2  of the vertical drive  5 . This arrangement results in a very compact and narrow design. The vertical drive  5  and the guiding device  12  thus form a compact unit above the beam carrier  2 . 
     The positions of the rotary bearings  14  and  23  and the lengths of the first rocker  13  and the second rocker  22  are selected such that the steering rod  17  carries out a straight guidance of the beam carrier  2  on the pivot point of the beam carrier  2 , which pivot point is determined by the swivel joint  20 , in the vertical direction over the entire stroke of the vertical drive  5 . The straight guidance of the beam carrier  2  is advantageously implemented in relation to the machine frame  15  exclusively with the aid of rotational movements of the parts of the guiding device  12 . The rotary bearings  14  and  23  and the swivel joints  24 . 1 ,  24 . 2  and  20  can be implemented in a low-friction manner so that an overall low-friction straight guidance of the beam carrier  2  is achieved, which does not require any additional torque by way of the vertical drive  5 . An additional advantage of the use of the rotary bearings  14  and  23  and swivel joints  20 ,  24 . 1 ,  24 . 2  is that commercially available lubrication systems can be used that have a sealing effect in relation to the ambience to prevent any lubricant residue from escaping into the ambience. 
     During operation, the crankshafts  9 . 1  and  9 . 2  of the vertical drive  5  are preferably driven in opposite directions of rotation and at equal rotational speeds. By means of the connecting rods  7 . 1  and  7 . 2 , the movement of the crankshafts  9 . 1  and  9 . 2  is transmitted to the beam carrier  2 , which carries out an upward and downward movement. The vertical movement of the beam carrier  2  is received by the steering rod  17  of the guiding device  12  and transmitted to the rockers  13  and  22 . The rockers  13  and  22  held in place on the rotary bearings  14  and  23  carry out a rotational movement. The kinematics of the rocker  13 , the rocker  22  and the steering rod  17  is selected such that the free end of the steering rod  17  comprising the swivel joint  20  is moved on a plumb line. The beam carrier  2  is thus held on a straight guideway during the entire stroke of the vertical drive  5 . 
     In the exemplary embodiment shown in  FIG. 1 , the members of the coupling kinematic mechanism  16  for linking the rocker  13  to the beam carrier  2  are formed as a steering rod and a second rocker by way of example. In principle, the members of the coupling kinematic mechanism  16  can be implemented using different lever geometries. 
     The exemplary embodiment of the device of the invention shown in  FIG. 2  merely represents one additional possibility of connecting the rocker, which is locked into position on the machine frame by the rotary bearing, to the beam carrier with the aid of a coupling kinematic mechanism for the straight guidance of the beam carrier. 
     The exemplary embodiment shown in  FIG. 2  is identical to the one cited above in terms of construction and design of the vertical drive  5 , the beam carrier  2  and the devices held by the beam carrier  2  so that reference is made to the above description. As opposed to the exemplary embodiment shown in  FIG. 1 , the guiding device  12  in the exemplary embodiment illustrated in  FIG. 2  is disposed substantially next to the connecting rods  7 . 1  and  7 . 2 . For this purpose, the guiding device  12  comprises a rocker  13  which is locked into position on a rotary bearing  14  in relation to a machine frame  15 . The rocker  13  is pivoted in the rotary bearing  14 . 
     The coupling kinematic mechanism  16  is formed by a rocker arm  18  and a steering rod  17  for linking the rocker  13  to the beam carrier  2 . The rocker arm  18  is held laterally above the beam carrier  2  on a rotary bearing  19  in the machine frame  15 . The rocker arm  18  is articulated on the rotary bearing  19  so that a free upper end and a free lower end can be pivoted relative to the rotary bearing  19 . The free upper end of the rocker arm  18  is pin-jointed with the free end of the rocker  13  with the aid of a swivel joint  21 . 2 . The lower end of the rocker arm  18  is pin-jointed with the steering rod  17  with the aid of the swivel joint  21 . 1 . The free end of the steering rod  17  protrudes up to the center of the beam carrier  2  and is pin-jointed there with the beam carrier  2  with the aid of the swivel joint  20 . 
     The vertical movement of the beam carrier  2 , which is driven by the vertical drive  5 , is maintained by means of the steering rod  17  in a guideway determined by the kinematics of the guiding device  12 . The beam carrier  2  can be guided on an approximately straight guideway depending on the length of the steering rod  17 . Here too, the translatory motion of the beam carrier  2  is guided solely by rotational movements of the parts of the guiding device  12 . 
     The exemplary embodiment of the device of the invention shown in  FIG. 2  is particularly suitable for optionally driving the beam carrier with a superimposed horizontal stroke. For this purpose, the rotary bearing  14  of the rocker  13  is replaced with an eccentric bearing and an eccentric shaft which is driven by means of a kinetic facility for transmitting a horizontal stroke into the rocker  13 . The straight guidance can thus be utilized for the transmission of a horizontal stroke. If the beam carrier is intended to be driven only in an oscillating vertical movement, the eccentric shaft is locked into position so that the eccentric bearing exclusively acts as the rotary bearing of the rocker. Thus, no more horizontal movement is transmitted into the rocker. 
       FIG. 3  schematically shows the side view of another exemplary embodiment of the device of the invention. The exemplary embodiment shown in  FIG. 3  is essentially identical to the one shown in  FIG. 1  so that only the differences will be explained at this point and reference is made to the above description in all other respects. 
     In the exemplary embodiment shown in  FIG. 3 , two needle beams  1 . 1  and  1 . 2 , each of which carries a needle board  3  and a plurality of needles  4  on the lower side thereof, are held on the beam carrier  2 . The beam carrier  2  is coupled to a vertical drive  5  which is designed identically to the one in the exemplary embodiment described above. For the straight guidance of the beam carrier  2 , a guiding device  12  is provided, which consists of a first rocker  13  and a second rocker  22 . The first rocker  13  is locked into position on the machine frame  15  with the aid of the rotary bearing  14 . For this purpose, the rotary bearing  14  is disposed laterally next to the beam carrier  2 . The second rocker  22  is held on a rotary bearing  23 , which is disposed on the machine frame  15  on the opposite side of the beam carrier  2 . The first rocker  13  and the second rocker  22  protrude on opposite sides up to the center of the beam carrier  2 . In the central portion of the beam carrier  2 , a steering rod  17  is provided, the central portion of which is connected to the beam carrier  2  via a swivel joint  20 . The free ends of the steering rod  17  are coupled to the first rocker  13  and the second rocker  22  with the aid of the swivel joints  24 . 1  and  24 . 2  respectively. 
     In the guiding device  12  shown in  FIG. 3 , the rockers  13  and  22  have equal length. In order to achieve a guideway at the pivot point of the steering rod  17  in relation to the beam carrier  2 , which guideway results from the rotational movements of the rockers  13  and  22 , the rockers  13  and  22  are disposed at varying angular positions relative to the beam carrier  2 . During the vertical movement of the beam carrier  2 , an approximately straight guideway can therefore be produced at the pivot point of the steering rod  17  that is determined by the swivel joint  20 . 
     A very stable guidance of the beam carrier  2  is achieved as a result of the symmetrical arrangement of the guiding device  12  and the bilateral linkage to the machine frame  15  with the aid of the rotary bearings  14  and  23 . 
     The aforementioned exemplary embodiments of the devices of the invention are suitable for needling a fibrous web, in which the needles are guided in a vertical upward and downward movement. The straight guidance of the beam carrier is due to the fact that the needles carry out the most precise vertical movement possible. 
     If the needles for needling the fibrous web have to carry out a superimposed horizontal movement in addition to a pure vertical movement, the guiding device  12  can be upgraded advantageously in such a way that the beam carrier  2  optionally carries out a reciprocating motion in addition to the upward and downward movement.  FIG. 4  schematically shows a side view of an exemplary embodiment of the device of the invention. The exemplary embodiment is identical to the one shown in  FIG. 1  so that reference is made to the above description and only the differences will be explained below. 
     As opposed to the exemplary embodiment shown in  FIG. 1 , the rotary bearing of the second rocker  22  is replaced with an eccentric bearing  25  within the guiding device  12  in the exemplary embodiment shown in  FIG. 4 . The eccentric bearing  25  is formed on an eccentric shaft  26  that drives the rocker  22  when rotated. The eccentric shaft  26  is coupled to a kinetic facility  27  by means of which the eccentric shaft  26  can optionally be locked into position or driven. 
     In the case of an eccentric shaft  26  that is locked into position, the rocker  22  is locked into position by means of the eccentric bearing  25  and can be guided around the eccentric bearing  25  only in a rotational movement. In this situation, the steering rod  17  acts in relation to the beam carrier  2  exclusively for guiding the vertical movement of the beam carrier. For this purpose, the free end of the steering rod  17  in the swivel joint  20  is preferably guided on a plumb line so that the beam carrier  2  achieves a straight guidance during the vertical stroke. 
     If the kinetic facility  27  drives the eccentric shaft  26 , the beam carrier  2  is driven in a constant horizontal stroke that it is superimposed in relation to the vertical movement. The steering rod  17  acts as a push rod and guides the beam carrier  2  with the aid of the swivel joint  20  in a superimposed horizontal movement. The beam carrier  2  and thus the needle beam  1  carry out an elliptical movement. The rotational speed of the eccentric shaft  26  and that of the crankshafts  9 . 1  and  9 . 2  of the vertical drive  5  are equal in this case so that a horizontal stroke of the needle beam  1  can be adjusted depending on the eccentricity of the eccentric shaft  26 . 
     In the exemplary embodiment shown in  FIG. 4 , the rotary bearing  14  of the rocker  13  could alternately also be formed by an eccentric bearing on an eccentric shaft for implementing a superimposed horizontal movement on the beam carrier  2  so that a horizontal component motion is introduced via the rocker  13  when the eccentric shaft is driven. The second rocker  22  would be guided on a rotary bearing on the machine frame. However, it would also be possible for both the rockers to be held on eccentric shafts, which would then be selectively driven or locked into position by a kinetic facility. 
     The device of the invention for needling a fibrous web thus offers a high degree of flexibility for guiding and driving a needle beam. In particular, purely vertical needling processes can be achieved for producing high-quality fiber products having uniform fiber structure. 
       FIG. 5  schematically shows a side view of another exemplary embodiment of the device of the invention. The exemplary embodiment shown in  FIG. 5  is identical to the one shown in  FIG. 1  except for the vertical drive  5  so that only the differing features of the vertical drive will be explained at this point and reference is made to the above description in all other respects. 
     In the exemplary embodiment shown in  FIG. 5 , a phase-adjusting device  31  is assigned to the vertical drive  5 . The phase-adjusting device  31  comprises two actuators  33 . 1  and  33 . 2  that are assigned to the crankshafts  9 . 1  and  9 . 2 . The actuators  33 . 1  and  33 . 2  are connected to a control device  32 . The actuators  33 . 1  and  33 . 2  can be activated with the aid of the control device  32  independently of each other in order to rotate the crankshafts  9 . 1  and  9 . 2  in their bearings. A phase position between the crankshafts  9 . 1  and  9 . 2  can thus be adjusted in any desired manner. In addition to the purely vertical upward and downward movement of the needle beam  1 , a superimposed horizontal movement can thus also be effected on the beam carrier  2 . Therefore, an approximately vertical upward and downward movement is carried out in the case of a phase balance of the crankshafts  9 . 1  and  9 . 2  and a synchronous drive of both the crankshafts. In the case of an offset in the phase positions of the crankshafts  9 . 1  and  9 . 2 , an oblique positioning of the beam carrier  2  is effected by the connecting rods  7 . 1  and  7 . 2 . In the case of an advancing movement, this oblique positioning of the beam carrier generates a component motion that is directed in the movement direction of the fibrous web  30 . The magnitude of the phase adjustment between the crankshafts  9 . 1  and  9 . 2  is directly proportional to the stroke length of the horizontal movement. The stroke of the horizontal movement can therefore be adjusted infinitely via the angle of phase difference of the crankshafts  9 . 1  and  9 . 2 . 
     The phase-adjusting device  31  could alternately also be formed by an actuator and an adjustment mechanism acting on the crankshafts  9 . 1  and  9 . 2 . In this case, it is essential to drive the crankshafts  9 . 1  and  9 . 2  such that they are offset in relation to each other by a phase angle in order to enable a horizontal movement for needling the fibrous web in addition to the vertical movement. 
     In this case also, the guiding movement of the beam carrier is carried out with the aid of the guiding device  12 , which takes place as in the exemplary embodiment shown in  FIG. 1 , by means of the rocker  13  and the coupling kinematic mechanism  16  consisting of a steering rod  17  and the second rocker  22 . 
     The exemplary embodiments of the device of the invention for needling a fibrous web shown in the  FIGS. 1 to 4  serve as examples of the design and construction of the guiding device for the straight guidance of the beam carrier. In principle, the coupling kinematic mechanism can also comprise more than two members in order to couple the rocker with the beam carrier. Likewise, a plurality of vertical drives can act on one beam carrier at the same time. In doing so, one of several straight guidances can be assigned to each of the vertical drives or a group of vertical drives.