Abstract:
The invention relates to a chain stitch multi-needle guilting machine with stitch-forming quilting elements and a method for creating a pattern in a guilting material. The elements of the quilting machine are comprised of at least one needle bar with attached needles and at least one looper shaft with attached loopers. Each of the needles and the loopers have a corresponding needle thread and looper thread associated therewith, form quilting element pairs, and are driven to build chain stitches in a quilting material. At least one of the needles is adjustable between two positions and participates in the quilting procedure in a first position and does not prick into the quilting material in the second position during the quilting procedure. The quilting machine can be made to have a device to knot the needle thread with the looper thread, or a device to cut the looper thread, or both.

Description:
BACKGROUND OF THE INVENTION 
     Different multi-needle quilting machines are well-known from the state of the art technology. In this connection, so-called lock stitch multi-needle quilting machines must be distinguished from chain stitch multi-needle quilting machines. For example, U.S. Pat. No. 5,005,499 shows a lock stitch multi-needle quilting machine with one or more needle bars, each provided with a multitude of stitch forming needles. In case of this pre-known lock stitch multi-needle quilting machine, single needles can be moved, dependent on the pattern to be quilted, back and forth between two positions by means of pneumatic cylinders; whereby these needles participate in a first position in the quilting procedure, and are lifted in a second position in such a way that they do not prick into the quilting material during the quilting procedure. 
     With the chain stitch or double chain stitch, a needle takes a thread to the deepest point of its movement and forms a thread loop during the following upward movement. Whereas the needle returns to its highest position after the forming of the thread loop, a looper enters the thread loop with a looper thread. During the transport of the quilting material to the next stitch in quilting direction and the next downward movement of the needle, the looper is turned back to its initial position, whereas the needle stitches into a thread triangle spread out by the thread loop and the looper thread, thus forming a chain link of the chain stitch seam. 
     Compared with the lock stitch, the chain stitch or double chain stitch has the advantage forming smooth seams and largely avoiding the so-called displacement crimping as, contrary to the lock stitch, the tangle of needle and looper thread is not dragged into the quilting material but located on the bottom of the quilting material. Moreover thinner sewing threads can be used with chain stitches or double chain stitches compared to the lock stitch. Furthermore the chain stitch or double chain stitch has the advantage in comparison with the lock stitch that the needle thread is subject to an abrasion considerably lower resulting from the fact that less thread is pulled back and forth through the needle&#39;s eye per stitch forming with the double chain stitch. Altogether the chain stitch or double chain stitch shows the larger strength compared to the lock stitch. The disadvantage with the chain stitch or double chain stitch consists that even insignificant slip stitches or a thread break in the area of the needle and/or looper thread leads to that the thread chain can easily be opened. 
     Several chain stitch multi-needle quilting machines with stitch forming quilting elements are well-known from the state of the art technology. Generally, such chain stitch multi-needle quilting machines comprise one or more needle bars with attached needles as well as looper shafts, which number corresponds to the number of needle bars with attached loopers. Needle bars and looper shafts are located on the opposite sides of a quilting material support formed as perforated plate with a tap hole for each needle provided in the quilting material support. Most different patterns can be made in a quilting material with such chain stitch multi-needle machines. In this connection, even patterns can be made having single, each identical or different pattern elements being located distantly from each other. 
     In order to create such kind of patterns in a quilting material it is well-known to move the quilting material on the quilting material support not only in the main quilting direction but also oppositely and at least in a right angle to it. The forming of chain stitches and double chain stitches requires that each stitch is performed accurately so that highest care regarding the forming of a seam is provided. If, for example, several pattern elements are arranged in a quilting material distantly from each other, the quilting material will be moved to a position where the next pattern element is to be quilted after the first pattern element is finished. The needle bar bearing the needles is in a lifted position and the looper shaft bearing the loopers in a returned position. During this procedure, the looper thread, pulled off from a bobbin, is guided along the bottom of the quilting material without being connected with the quilting material in this area. 
     It could be optionally intended with chain stitch multi-needle quilting machines that the needle thread is cut by a cutting device after one pattern element is finished and that a completely new quilting procedure is initiated at the beginning of the next pattern element. 
     SUMMARY OF THE INVENTION 
     Starting from this state of the art technique, the invention is based on the object to develop a chain stitch multi-needle quilting machine or a method to create a pattern in a quilting material in such a way that additional and/or supplementary patterns could be easily quilted into the quilting material. Furthermore, a chain stitch multi-needle quilting machine according to the invention should be adaptable to predetermined quilting tasks. 
     With type-pursuant chain stitch multi-needle quilting machines, the solution of this problem provides that at least one, preferably a multitude of needle(s) are adjustable between two positions, with the needle(s) participating in a first position in the quilting procedure, and not pricking into the quilting material in a second position during the quilting procedure, and a device to knot the needle thread with the looper thread and/or a cutting device for the needle and/or looper thread being allocated to at least one of the needles adjustable between the two positions. 
     Therefore the arrangement of liftable needles to chain stitch multi-needle quilting machines is intended according to the invention. It must be considered in this connection that the needles could be lifted during the quilting procedure with lock stitch machines, what is not possible with the forming of chain stitches as this would produce slip stitches facilitating the opening of the thread chain. Besides the possibility of adjusting the single needles between two positions, it is necessary with chain stitch multi-needle quilting machines in order to secure the chain stitch seam that a device to knot the needle thread with the looper thread is provided at least in the area of the adjustable needles to avoid the automatic opening of the thread chain in this area. Optionally or supplementary to this device a cutting device for the needle and/or looper thread can be provided facilitating at least the needle thread being cut with an appropriate length before or after knotting without the risk of the automatic opening of the thread chain or the chain stitch seam. Thus, the invention represents a combination of a chain stitch multi-needle quilting machine with liftable needles, a device to knot the needle thread and/or a cutting device for the needle and/or looper thread, with which the task described before can be solved in an unforeseeable and favourable way. 
     According to a development of the invention it is intended that the liftable needles adjustable between two positions are arranged in the peripheral and/or central area of the needle bar. It turned out that additional patterns or pattern elements are especially favourable in these areas. 
     It makes for example an additional quilting in the peripheral area possible, especially favourable with multi-layer quilting material as an improved connection of the quilting material layers lying on top of each other is achieved. 
     Alternatively, it can be intended that the liftable needles adjustable between two positions are arranged on the needle bar alternately with needles not adjustable. Of course, it is also possible that all needles of one or all needle bars are adjustable between two positions. 
     According to another characteristic of the invention it is intended that the needles adjustable between two positions are adjustable through a drive. This drive of the needles adjustable between two positions preferably comprises a pump for a hydraulic or a pneumatic pressure medium and at least one linear motor. It can also be provided that each needle is driven by an own linear motor and that single needles are adjusted through a hydraulic and/or pneumatic control. 
     An optional variant intends that the drive is built as electromechanic drive, especially consisting of a toothed rack and an electric motor driven pinion meshing with the toothed rack. 
     According to another feature of the invention it is intended that the cutting device is built as cutting blade. It proved as particularly favourable arranging the cutting device at the looper or at a spreader allocated to the quilting element pair. If the cutting device is arranged at the looper, it could be brought in contact with the appropriate thread by an additional rotating movement of the looper shaft in order to cut the thread in a sufficient length from the latest connecting point between looper thread and needle thread. 
     Preferably it is finally intended with the chain stitch multi-needle quilting machine according to the invention that the quilting material support has a quilting material transport device serving the transport of the quilting material in at least two opposite directions. The quilting material on the quilting material support is moved forward in quilting direction with the quilting material transport device before the adjustable needles are being activated whereby additional thread is taken off a thread supply in order to pull the needle thread out to a length before cutting excluding an automatic opening of the thread chain. 
     As solution of the problem described before it is intended with a type-pursuant method, that after one stitch is finished, preferably after one pattern element is finished, at least one needle is transferred from a first position participating in the quilting procedure, in particular in the stitch forming, to a second position where the needle does not participate at least in the following stitch, preferably in the following pattern element with the needle thread being connected with the looper thread in such a way that an automatic opening of the last stitch is prevented. 
     Preferably the needle thread is knotted with the looper thread before or after the needle is transferred to the second lifted position. In the simplest case the knotting is effected by needle and looper thread being pulled tightly during the last stitch and thus pulled into the quilting material, for example, by the quilting material being transported while a needle thread loop is still tied around the looper. During the further transport it is favourable to release the needle and looper thread tension since otherwise the threads could break. Thereby it is prevented that the thread seam opens automatically by outer influences. Alternatively or supplementary it can be intended that the needle thread is cut after the seam and the last stitch are finished, and is located in a second position at the beginning of another pattern element. Once the needle thread being knotted with the looper thread, it can be cut relatively short. On the other hand, without knotting the needle thread with the looper thread, or if this knotting was only insufficiently executed, the needle thread is cut with a relatively long thread end. 
     According to another characteristic of the invention it is intended that the quilting material is moved in quilting direction, preferably before the beginning of the next pattern element, in order to pull the lengthened thread off a thread supply before the needle thread is knotted with the looper thread and/or cut. In this way, a sufficient length of the needle thread is provided that is sufficient for both the knotting with the needle thread and for the cutting procedure without the risk of an automatic opening of the thread chain and that the needle thread has a sufficient length for the next quilting of a pattern element. 
     Furthermore it is intended that several needles arranged on at least one needle bar are transferred from the first to the second position at the same time. It can also be intended that all needles are transferred from the first to the second position or reverse at the same time. 
     Moreover, a further characteristic of the method according to the invention provides that the needle(s) is/are moved hydraulically, pneumatically or electromechanically. 
     Finally it is intended that the needle or needles is/are controlled by a programmable control. The programmable control preferably runs in analogy to one or more patterns. According to this, it is intended that one or more patterns, comprising preferably a multitude of pattern elements, are stored for example in a computer. The data of these patterns are transmitted to a known transport device for the quilting material and to the needles so that a fully automatic control is possible without making changings on the machine necessary during the quilting procedure. 
     The control technology can also intend that the stored patterns or pattern elements are combined with each other and used for the control of the needles. 
     Further characteristics and advantages of the invention result from the following description of the appropriate drawing showing a preferred form of a invention-pursuant chain stitch multi-needle machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawing shows: 
         FIG. 1  a chain stitch multi-needle machine in a schematically represented side view; 
         FIG. 2  the chain stitch multi-needle machine according to  FIG. 1  in a perspective view; 
         FIG. 3A  a section of a needle bar with several needles of the chain stitch multi-needle according to  FIGS. 1 and 2 , and another exemplary drive therefor; and 
         FIG. 3B  a section of a needle bar with several needles of the chain stitch multi-needle according to  FIGS. 1 and 2 , and exemplary drive therefor. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A chain stitch multi-needle machine according to  FIGS. 1 and 2  comprises a machine stand  1  with a needle bar  2  in the upper section with the single driven needles  31  are essentially being arranged side by side vertically to the focal plane. Sign  3  marks a common pressure foot,  4  a looper row according to needle row  2 . A needle plate  13  or a sewing table is located below the layers of the quilting material fitted together in the quilting area. This needle plate  13  serves as quilting material support. 
     The quilting material consists of an upper layer  6 , for example fabric, ticking or something similar and is pulled off a storage roll  5  and guided below a catwalk for the operator around deflection rollers  8 ,  9 ,  10 ,  11  and  12  into the quilting area, that is into the area between pressure foot  3  and the needle plate  13  or the quilting material support. 
     This layer  6  of the quilting material consists of inelastic material. In addition, the quilting material comprises a further layer  15  of elastic material, for example foam, which is stored on the storage roll  14 . For this elastic layer too, guiding or deflection rolls  16 ,  17 ,  18  and  19  are provided. 
     The layer  15  of elastic material is quilted in the quilting unit with the upper layer of inelastic material and another layer  21 , and is taken off the quilting unit as finished quilting material  28  in direction of arrow  29 , whereby the feeding of layer  6 ,  15 , and  21  is provided by the force acting on the finished quilting material  28 . Behind the quilting unit, the finished quilting material  28  passes a section with deflection or guiding rolls  25 ,  26  and  27  providing among others a tightening of the quilting material  28  in the exit section of the quilting unit. 
     The lower layer  21  that is pulled off a storage roll  20  is fed into the quilting unit via deflection or guiding rolls  22 ,  23  and  24 , whereby the lower layer  21  according to  FIG. 1  can also be fed together with the upper layer  6  and layer  15  of the deflection roll  12  which will be described in detail below. 
     A support  30  is arranged opposite the deflection roll  12  with the distance to the outer circumference of the deflection roll  12  and the support  30  being adjustable, that is either the deflection roll  12  is movable relative to the support  30  or that the support  30  is movable relative to the deflection roll  12 . Alternatively it can be intended that both the support  30  and the deflection roll  12  are adjustable in vertical direction. This variant serves the adjustement of the chain stitch multi-needle machine to differently strong layers  6  and  15  whereby the layer  15  consisting of elastic material is considerably stronger than the layer  6  consisting of inelastic material. 
     It is necessary that the deflection roll  12  acts on the layers  6  and  15  with a certain pressure in order to supply the necessary frictional forces. 
       FIG. 2  shows that the pressure foot  3  and the needle plate  13  or quilting material support in longitudinal direction of the machine stand  1  are not movable. On the contrary, the support  30  is movably arranged relative to the pressure foot  3  and to the needle plate  13  in longitudinal direction to the machine stand  1  so that the quilting material of which  FIG. 2  only shows layer  6  consisting of inelastic material is movable relative to the needle rows  2  in such a way that any pattern can be transferred to the quilting material. In order to clarify this, layer  6  is shown with an example for a pattern to be quilted. To move the support  30  an electro motor  35  is provided containing on its driving shaft  36  a pinion  37  that combs a rack  38  which is firmly connected with support  30  with a toothed wheel. 
     Especially  FIG. 2  shows that the needles  31  are arranged in two needle rows  2  running parallel to each other and are located behind each other in quilting direction. A looper of a looper row  4  is allocated to each needle  31 . In this connection, looper row  4  is formed by a looper shaft  33  that is oscillatorily moved by an eccentric formed drive not described precisely. This oscillating movement is transferred to the loopers mounted on the looper shaft  33  with the loopers forming double chain stitches in the quilting material  28  together with the needles  31  oscillatorily moved up and down. For this, each needle  31  brings a thread, not described precisely, to the deepest point of its way located below the quilting material  28  in an area between the pressure foot  3  and the needle plate  13  so that the looper arranged there and allocated to the needle  31  can take a thread loop left there during the upward movement of the needle  31 . While the needle  31  is being returned from its deepest position to its highest position, the looper moves into direction of the thread loop and takes a looper thread into the thread loop of the needle thread. 
     In the next step, the quilting material  28  is transported into the direction of arrow  29  before needle  31  is being moved again from its highest position to its deepest position. At this moment, the looper returns to its initial position with a thread triangle being formed of the thread loop of the needle thread and the looper thread in which the needle  31  enters. In this way a double chain stitch is formed consisting of a needle thread lying on the upper side of the quilting material and penetrating the quilting material and a looper thread lying on the lower side of the quilting material. 
     The single needles  31  of a needle row  2  are changeably fixed on a needle bar  34  so that the needle bar  34  can be fed with needles  31  according to the desired pattern  32 . The same applies for the loopers that are also changeably fixed on the looper shaft  33 . 
     In order to quilt particular patterns it is necessary that certain needles  31  are participating in the quilting procedure at times, and at times are not pricking into the quilting material  28 . For this purpose it is provided according to  FIGS. 3A and 3B  that a part of the needles  31  is provided with a drive  39 ,  139  enabling that the needles  31  can be adjusted between two positions with the needles  31  participating in the quilting procedure in a first position and not pricking into the quilting material during the quilting procedure in a second position. 
     Referring to  FIG. 3A , a pneumatic or hydraulic drive  39  preferably comprises a pump  51  for a hydraulic (non-compressible) medium or for a pneumatic pressure medium. Each needle  31  adjustable between two positions has its own such drive  39  consisting of a linear motor  40  having a pneumatically/hydraulically driven and spring-loaded piston  41  with the needle  31  inserted into an aligned bore-hole at its free end. 
     The piston  41  is provided with a spring, not described precisely, that is arranged between the lower end of drive  39  aligned to needle  31  and a piston disk; this spring holding the piston in its initial place in a position during which the needle  31  is not participating in the quilting procedure. 
     If the piston  41  is supplied with compressed air through an energy line  42 , it moves contrary to the spring force of the spring, not described more detailed, into the direction of the quilting material  28 , so that it holds, in this position, the needles in their first position where they participate in the quilting procedure. If the supply of compressed air to the piston  41  is interrupted, the spring, not described precisely, pushes the piston  41  back to its initial position described before. 
     The linear motors  40  are screwed with the needle bar  34  via L-shaped angle sheet metals  43 . The independently adjustable needles may be arranged along the needle bar to suit the particular quilting applications, such as in the peripheral and/or central area of the needle bar. For example,  FIG. 3A  shows three needles  31  adjustable in their positions between two stationary needles  31  and one stationary needle  31  which therefore constantly participate in the quilting procedure. The stationary needles  31  are detachably fixed to the needle bar  34  with a needle holder  44 . The needle holder  44  and the angle sheet metals are preferably fixed with screws detachable in an easy way. 
     In  FIG. 3B , an alternate drive  139  is built as an electromechanical drive, preferably including a toothed rack and an electric motor driven pinion, meshing with the toothed rack. 
     In addition to the adjustable needles  31 , the chain stitch multi-needle quilting machine according to the invention comprises a cutting device which is build as cutting blade  45  with each looper (or spreader) having such a cutting blade  45 . To operate the cutting blades  45 , it is intended that the looper shaft  33  executes an additional movement initiated by an eccentric drive during this movement the cutting blade  45  is brought into contact with the needle thread so that the needle thread is cut over it. It can also be provided that the cutting of the needle thread is effected by an additional movement of the quilting material  28  so that the tightened needle thread is pulled into and cut in the area of the cutting blade  45 . 
     With the chain stitch multi-needle quilting machine described before, a method to create complicated patterns in a quilting material can be carried out in an easy way. In this connection it is favourable that additional seams can be made during the quilting procedure with the adjustable needles  31  without a change of the chain stitch multi-needle machine becoming necessary that additional needles  31  must be fixed to the needle bar  34 . 
     After finishing a double chain stitch, the needle thread can be cut in the area of the needles  31  adjustable between two positions with the cutting blades  45  in a length avoiding an automatic opening of the thread chain. Alternatively or additionally, a knotting device (shown schematically at  47  (FIG.  1 )) can be provided to knot the needle thread with the looper thread during the last stitch against automatic opening. In order to prepare a sufficiently long needle thread, it is provided that the quilting material is moved into the direction of arrow  29  during a first step after the last stitch forming of a pattern element to pull additional needle thread off a bobbin, not described more detailed. Afterwards, the needle thread is cut with the cutting blade  45  in a required length. 
     A variant of the invention was described before, during which the needles  31  are movable, that means liftable between a lower position directed towards the quilting material and an upper position, away from the quilting material. Certainly, the invention is not restricted to such a form. Further variants are rather possible with which at least one, preferably a multitude of needles is/are adjustable between two positions with the needle(s) participating in the quilting procedure in a first position and not pricking into the quilting material during the quilting procedure in a second position. For example, the needles  31  can be fixed slewably around a pivot on the needle bar  34 . In this case, a linear motor touches at one end of the needle  31 ; this motor adjusts the needle  31  around a pivot relative to the needle bar from an essentially perpendicular orientation where the needle  31  participate in the quilting procedure into a turned position where the needle  31  is not participating in the quilting procedure. This turned position is taken for example by a turning of the position by 30° degrees from the vertical orientation into direction of the horizontal orientation of the needle relative to the needle bar. Of course, larger turning angles are possible as far as it is guaranteed that the needle  31  is not pricking into the quilting material in the turned position. 
     Alternative to this, a twisting of the needle  31  relative to the needle bar  34  can also be intended. In case of this variant, a rotational axis at which the needle  31  is coupled, runs parallel to the normal line of the plane of the needle bar  34  whereas the rotational axis with the alternative of the slewable needles  31  first described runs in longitudinal direction to the needle bar  34 . 
     Both alternative forms offer the possibility that the twisting or turning of the needles is carried out by the drives mentioned before, for example hydraulic or pneumatic linear motors or electromechanic drives. Furthermore it is possible with these alternatives too that several needles  31  are movable by a joint drive or each needle by an allocated drive  39 .