Abstract:
A long arm quilt and lockstitch machine assembly ( 1 ) having a framework having two rail tracks, disposed orthogonally on top of one another, wherein the sewing machine ( 19 ) is disposed so as to be displaceable on the rail track lying above. The connections between the drive belt ( 33, 43 ) to which the rail track ( 9 ) lying below and the sewing machine ( 19 ) are connected by way of an electronic control system via drive motors, include overload couplings which in the case of overloading by body parts or items of clothing that are caught between the movable elements separate the movable elements from the drive belts. Advantageously, the overload coupling is simultaneously a connection element and in the case of overloading separates the connection between the elements.

Description:
INCORPORATION BY REFERENCE 
       [0001]    The following documents are incorporated herein by reference as if fully set forth: Swiss Patent Application No. 00393/16, filed Mar. 22, 2016. 
       BACKGROUND 
       [0002]    The invention is directed to a long arm quilt and lockstitch machine assembly. 
         [0003]    In order for large-area quilts to be produced, long arm quilt machines or assemblies are known nowadays. These machines or assemblies as a baseline comprise a framework having two pairs of rail tracks, disposed orthogonally on top of one another, wherein the rail track lying above is displaceable on the rail track lying below in an orthogonal direction, and a sewing machine is placed on the upper rail track so as, for its part, to be displaceable. In the case of these systems, the sewing machine may be moved either manually in the X-direction and the Y-direction, that is to say that figures may be manually generated, or if and when the upper rail track and the sewing machine that is displaceable thereon each are drivable by motive power by way of one belt, then the movements of the sewing machine may alternatively be controlled by way of a machine controller by the use of a software program. It is thus possible for quilting to be fully automatically performed. It is thus also possible to produce the quilt in a completely automatic manner. Often, the quilt patterns are generated in a largely automatic manner, and hand-made patterns are inserted therebetween. For this purpose, the connections between the sewing machine and the motive drive thereof, and between the upper rail track and the motive drive thereof, must be separated. Separating or decoupling the connections, respectively, between the drive belts and the guide tracks, or separating or decoupling, respectively, the sewing machine from the guide tracks, is known from the prior art. 
         [0004]    In the free-hand mode, that is to say in the case in which the sewing machine is completely decoupled from the travel drives, the drive belts are already stationary because decoupling is possible only in the resting state. There is no risk whatsoever to the female or male operator of the sewing machine of contacting driven rotating elements. In the case of the automatic mode in which the sewing machine is moved by two drive motors in the X-direction and the Y-direction, there is however the latent risk of the operator by way of a body part, for example a finger, a hand, the hair, or an item of clothing, to be caught by moving parts, or to be jammed between such moving parts, and to be injured. In the case of such incidents, parts of the long arm quilt and lockstitch machine assembly may also be compromised as a result of overloading. 
       SUMMARY 
       [0005]    An object of the present invention is to achieve drive connections which during the automatic operation are connected, but in the case of overloading are separable in the case in which a stoppage of the machine has not already been initiated beforehand by way of an electrical monitoring system of the drive currents of the drive motors. 
         [0006]    This object is achieved by a long arm quilt and lockstitch machine assembly according to one or more features of the invention, with advantageous design embodiments of the assembly being described below and in the claims. 
         [0007]    By way of a mechanical interruption of the connections between the drive motors and the travel-capable elements of the machine assembly, triggered by overloading, it is ensured by a coupling element that any risk of injury to the operator and/or any destruction of mechanical parts of the system are/is precluded. Not only the travel-capable elements of the drive assembly are deactivated by the coupling element on the take-off side of the drive motors, but also the drive belts that emanate from the motors and lead to these travel-capable elements. In the case of the use of coupling elements directly on the connection locations between the drive belt and the travel-capable elements of the drive assembly, the separation is performed on location, the overload being capable of being set. It is also prevented herein that parts, such as fingers or hairs, that engage in the travel path of the travel-capable elements (sewing machine and upper travel track) are damaged. 
         [0008]    It may be advantageously achieved that at the same time the mechanical connection between the travel-capable parts and the drive motor and simultaneously the overload coupling are unified in one single element by way of the coupling elements on the drive belts. The construction of these coupling elements is manufacturable in a cost-effective manner and, due to the simple construction, is also reliable in terms of the functioning thereof. Further, the arrangement of the coupling on the belt is particularly advantageous because, on account thereof, the travel-capable elements following the manual release of the coupling may be moved by hand almost without resistance, or that parts, such as hairs or items of clothing, that may have already been caught between the rollers or other elements may be immediately removed without damage. 
         [0009]    The coupling may furthermore also be manually opened, so as to be switched from the automatic mode to the manual mode in which the sewing machine is moved by hand. 
         [0010]    In the case of an arrangement of an overload coupling directly on or next to the drive motors it is advantageous for the belts to be also immediately deactivated in the case of overloading. Such a coupling may be disposed additionally to the coupling between belts and travel-capable elements, or the connection between the belts and the travel-capable elements in the connection region has likewise to be provided with a coupling in order to be able to switch from the automatic mode to the manual mode without the belts continuing to be moved, respectively. The second mentioned embodiment of the invention is thus particularly suitable for retrofitting to systems which are already in operation and are provided with an overload coupling in addition to the couplings that are to be manually operated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The invention will be explained in more detail by means of exemplary embodiments. In the figures: 
           [0012]      FIG. 1  shows a perspective partial view of a long arm quilt and lockstitch machine assembly; 
           [0013]      FIG. 2  shows a perspective illustration of a belt overload coupling and blocking device (engaged); 
           [0014]      FIG. 3  shows a front view of the belt overload coupling and blocking device (engaged); 
           [0015]      FIG. 4  shows a perspective view of the belt overload coupling and blocking device (disengaged); 
           [0016]      FIG. 5  shows a perspective sectional illustration of a belt pulley having an overload coupling flange-fitted thereto; 
           [0017]      FIG. 5 a    shows a section through the overload coupling between the belt pulley and the flange housing; 
           [0018]      FIG. 6  shows a front view of the belt pulley having overload protection by way of a shear bolt; 
           [0019]      FIG. 7  shows a front view of the belt pulley and, in front thereof, of the pivot arm and of the coil spring; 
           [0020]      FIG. 8  shows a view of the belt pulley and of the pivot arm according to  FIG. 7 , from the direction of the arrow P; 
           [0021]      FIG. 9  shows a plan view of the belt pulley and of the dual-arm lever and the flange housing; 
           [0022]      FIG. 10  shows a detailed view of the dual-arm lever in a sectional illustration along the line IX-IX in  FIG. 9 ; and 
           [0023]      FIG. 11  shows a cross section through a further overload coupling on a belt. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    A long arm quilt and lockstitch machine assembly, hereunder referred to as the machine assembly for short, is illustrated having the reference sign  1 . This machine assembly comprises a base framework  3  having four support legs  5  of which only the two laterally disposed support legs  5  are visible. The support legs  5  in the region of the upper ends thereof are fixedly interconnected by four horizontal profiled elements  7 , forming a rectangular lower guide frame  8 . Lower rail tracks  9  on which an upper rectangular guide frame  11  having two upper rail tracks  13  is placed so as to be capable of travel are placed on two of the profiled elements  7  that lie so as to be parallel and mutually opposite. Four suitable rollers or roller pairs  15  which roll along the lower rail tracks  9  are rotatably mounted on the upper guide frame  11 . 
         [0025]    A long arm sewing machine  19  is mounted displaceably on the upper rail tracks  13 , on two supports  17  that lie parallel and bridge the upper rail tracks  13 . Of the sewing machine  19 , the arm bed  21 , the machine pedestal  23 , and in portions the head  25  having the needle bar  27  are visible. The needle-hole plate  29  lies below the needle bar  27  having the needle, so as to be at the end of the arm bed. The two supports  17  are mounted by means of rollers or roller pairs (rollers not illustrated) that roll along the upper rail tracks  13 . 
         [0026]    A first drive device  31  for driving the upper guide frame  11  of the upper rail tracks  13  on the lower rail tracks  9  is fastened to one of the profiled elements  7 . The drive device, preferably an electric motor  31 , on the take-off side has a belt pulley or sprocket  75  on which an endless belt  33  revolves. The belt pulley  75  is protected by a protective cover  35  and is therefore not visible in  FIG. 1 , but will be in  FIGS. 5 and 6 . A flat belt, a timing belt, or a perforated steel band may be employed as a first belt  33 . A coupling  47  between the first belt  33  and the upper guide frame  11  is visible as a schematically represented cuboid in  FIG. 1  and will be described in detail at a later stage. 
         [0027]    In a manner analogous to the drive of the upper guide frame  11 , a second drive motor  39  having a take-off side belt pulley  75  under a covering hood  41  is disposed on the profile  37  that connects the two upper rail tracks  13  at the end sides. An upper belt  43  which at the profile  37  at the opposite end side revolves on a redirection disk that is fastened to said profile  37  is guided over the take-off side belt pulley  75 . The belt pulley  75  is disposed under a safety cover  41 . One of the belt leads of the upper belt  43  on one of the two supports  17  is releasably fastened to a coupling  47 . The coupling  47  is illustrated as a cuboid in  FIG. 1 . 
         [0028]    In  FIGS. 2 to 4 , the coupling  47  is illustrated so as to be released from the machine assembly  1 . Said coupling  47  comprises a cuboid housing  49  which is configured so as to be connectable to the support  17  or to the upper guide frame  11 , respectively. A cylindrical disk  53  is mounted so as to be rotatable with slight play in a cylindrical bore  51  in the housing  49 . An activation lever  55  for rotating the disk  53  is fastened to the aft end face of the disk  53 . At least one axially running groove  57  is configured in the shell face of the disk  53  (cf. also  FIGS. 2 and 3 ). A ball  59  that is impinged with an axially acting spring tension, or a cylinder that is provided with a semi-spherically shaped end (not illustrated), engages in one of the grooves  57 . The ball  59  and the spring  61  that in  FIG. 1  pushes the former to the right are guided in a guide bore  63  in the housing  49 . The tension of the spring  61  and thus the compressive force of the ball  59  that acts on the groove  57  may be set by way of a set screw  65  which is guided in a threaded portion  67  in the guide bore  63 . 
         [0029]    Two guide pins  69  protrude from the forward end face of the housing  49 . A retaining pin  71  which is fastened to the forward end face of the disk  53  deflects the belt  33  or  43 , respectively, which from above is supported by the two guide pins  69 , from below toward the top, because the axes of the three pins  69 ,  71  lie in approximately one plane. Depending on the configuration of the belts  33  or  43 , respectively, as flat belts or as timing belts, the vertical offset of the pins  69  in relation to the retaining pin  71  is larger or smaller. Should the lower retaining pin  71  bear on the disk  53  between two teeth of a belt  33 ,  43  that is designed as a timing belt, then the offset in terms of height is to be chosen to be smaller than in the case of a flat belt in order for approximately the same retaining forces of the belt  33 ,  43  on the coupling  47  to be achieved. 
         [0030]    The functional mode of the coupling  47  will be described hereunder, proceeding from the “manual” operative state in which there is no drive connection between the two belts  33 ,  43  and the upper rail tracks  13 , and the sewing machine  19 , respectively, and in which the two belts  33  and  43 , respectively, are not pressed against the upper guide pins  69  by the lower retaining pin  71  ( FIG. 4 ). The elements (sewing machine  19  and upper guide tracks  13 ) that are completely decoupled from the belts  33 ,  43  enable a substantially friction-free displacement of the sewing machine  19  on the guide tracks  9  and  13  in the X-direction and the Y-direction. The belts  33 ,  43  herein are not moved. 
         [0031]    If quilting or lock-stitching in the automatic mode is now desired, it is inevitable that a friction-fitting or a form-fitting connection between the sewing machine  19  and the drive (belts  33 ,  43 ) of the upper guide tracks  9  and  13  has to be performed ( FIGS. 2 and 3 ). For this purpose, a rotation movement of the disk  53  by 90° is performed, using the activation lever  55  on the housing  49  of the coupling  47 , on account of which the lower retaining pin  71  deflects the belts  33  and  43 , respectively, toward the top, a form-fitting connection in the case of a timing belt  33 ,  43 , or a force-fitting connection between the belts and the coupling, or the elements that are fastened to the coupling  47 , respectively, being consequently established. Quilting and lock-stitching may now be performed by way of a respective controller (controller not illustrated) in that the drive motors  31  and  39  initiate the X-movements and Y-movements of the sewing machine  19 . 
         [0032]    Should a finger, a hand, or an item of clothing make its way into the travel region of the sewing machine  19  and/or of the upper guide tracks  13  during automatic quilting, tangential forces that attempt to rotate the disk  53  counter to the resistance of the ball  59  which engages in the groove  57  act on the retaining pin  71 . Upon exceeding a settable value at which the ball  59  is urged out of the groove  57 , emergency triggering is performed by a rotation of the disk which as a result guides the lower retaining pin  71  away from the belts  33 ,  43  and consequently guides the belt  33 ,  43  in a manner freely displaceable in relation to the coupling  47 . Consequently, the coupling  47 , on the one hand, serves for coupling or connecting, respectively, the sewing machine  19  or the upper guide frame  13 , respectively, to the belts  33 ,  43 , and on the other hand serves as an overload protection from forces that act on these elements. 
         [0033]    In order for work in the automatic mode being able to be resumed after the incident, the activation lever  55  is rotated back until the ball  59  latches into the groove  57  again and the belt  33 ,  43  is again fixedly connected to the coupling  47 . 
         [0034]    Alternatively or additionally to the coupling  47  which acts on the belts  33  and  43 , respectively, in the further design embodiment of the invention according to  FIGS. 5 and 6  an overload coupling  73  is disposed directly on a take-off sprocket  75  on the drive motors  31  and  39 , respectively. The overload coupling  73  is accommodated in a disk-shaped flange housing  77  which is placed in a rotationally fixed manner onto the take-off shaft of the drive motor  31  or  39 , respectively. The overload coupling  73  comprises a pivotable arm  79  which is mounted on a bolt  91  which is mounted on the flange housing  77 . The arm  79  is supported on a coil spring  85  which is held and guided in the flange housing  77 . The connection between the upper end of the coil spring  85  which is settable by way of a set screw  86 , and the end of the arm  79  is performed by a retaining cam  87  that is disposed there. A latching pin  81  is inserted in the arm  79 . The latching pin  81  engages in the axial direction into a depression  93  (depression  93  in the take-off sprocket  75 ) that has the shape of a segment of a circle ( FIG. 5  and  FIG. 5 a   ). 
         [0035]    By way of the form-fitting connection of the latching pin  81 , the flange housing  77  which comprises the overload coupling  73  is coupled to the take-off sprocket  75 , and the torque of the drive motor  31  or  39 , respectively, is consequently transmitted via the flange housing  77  to the take-off sprocket  75  for the belts  33  and  43 . 
         [0036]    Should one of the belts  33  or  43 , respectively, during the operation of the machine assembly  1  be decelerated by an object such as a finger, a hand, or an item of clothing, the tangential force acting on the latching pin  81  is increased in such a manner that the latter, counter to the force of the spring  85 , is pushed out of the depression  93  and, on account thereof, the operative connection (torque transmission) between the flange housing  77  and the take-off sprocket  75  is interrupted. After the latching pin  81  has slid out of the depression  93 , the arm  79  is pivoted counter to the force of the coil spring  85 . The latching pin  81  thereafter slides on the internal face of a recess  95  on the take-off sprocket  75 . The latching pin  81  may return into the depression only once there is no resistance acting on the belt  33 ,  43 . 
         [0037]    The connection of the flange housing  77  to the take-off shaft of the drive motor  31  or  39 , respectively, is performed in a known manner by a key which engages in the keyway  97  on the flange housing  77 . 
         [0038]    In one further design embodiment of the coupling  73  ( FIG. 6 ), a shear bolt  99  takes the place of the latching pin  81  or of a ball that is placed on top thereof. This shear bolt  99  ruptures when a load that causes the shear bolt  99  to rupture acts by way of the take-off sprocket  75  on the coupling. The shear bolt may be inserted directly in a bore  100  in the housing  77  and engage in a bore, aligned with said bore  100 , in the sprocket  75 . 
         [0039]    If and when an overload coupling  73  according to  FIGS. 5, 5   a,  and  6  is used, no coupling having an overload protection is required for the connection between the belts  33 ,  43  and the upper guide frame  11 , or the sewing machine  19 . In this instance, a coupling assembly which only enables parts that are connected by the coupling to be coupled or decoupled suffices. 
         [0040]      FIG. 11  shows an overload coupling in a simple embodiment. A latching element  101  that is fastened to the belt  43  comprises laterally a clearance  103  in the shape of a conical or semi-spherical clearance in which a ball  105 , or a bolt which is provided with a spherical tip and which is pre-tensioned by means of a spring  107 , engages. The ball  105 , or the resiliently mounted bolt, respectively, may be set by way of a set screw  109 . The spring  107  sits in a bore  111  in a retaining element  113 . The retaining element  113  is configured so as to be fastenable to the upper guide frame  13 , or to the support  17 , respectively. 
         [0041]    Should one of the belts  33  or  43  be decelerated or stopped by an object, the ball  105  is lifted out of the clearance  103 , and the form-fitting connection between the belt  33  or  43 , respectively, and the travel-capable elements is interrupted. 
       LIST OF REFERENCE SIGNS 
       [0042]      1  Lockstitch machine assembly 
         [0043]      3  Framework 
         [0044]      5  Support leg 
         [0045]      7  Profiled elements 
         [0046]      8  Lower guide frame 
         [0047]      9  Rail track (lower) 
         [0048]      11  Upper guide frame 
         [0049]      13  Upper rail track 
         [0050]      15  Rollers 
         [0051]      17  Support 
         [0052]      19  Sewing machine 
         [0053]      21  Arm bed 
         [0054]      23  Machine pedestal 
         [0055]      25  Machine head 
         [0056]      27  Needle bar 
         [0057]      29  Needle-hole plate 
         [0058]      31  First drive motor 
         [0059]      33  First belt 
         [0060]      35  Covering hood 
         [0061]      37  End profiles 
         [0062]      39  Second drive motor 
         [0063]      41  Covering hood 
         [0064]      43  Upper belt 
         [0065]      45  Safety cover 
         [0066]      47  Coupling 
         [0067]      49  Housing 
         [0068]      51  Bore 
         [0069]      53  Cylindrical disk 
         [0070]      55  Activation lever 
         [0071]      57  Groove 
         [0072]      59  Ball 
         [0073]      61  Spring 
         [0074]      63  Guide bore 
         [0075]      65  Set screw 
         [0076]      67  Threaded portion 
         [0077]      69  Guide pin 
         [0078]      71  Retaining pin 
         [0079]      73  Overload-protection coupling 
         [0080]      75  Take-off sprocket 
         [0081]      77  Flange housing 
         [0082]      79  Dual-arm lever 
         [0083]      81  Latching pin 
         [0084]      85  Coil spring 
         [0085]      86  Set screw 
         [0086]      87  Retaining cam 
         [0087]      91  Bolt 
         [0088]      93  Depression 
         [0089]      95  Recess 
         [0090]      97  Keyway 
         [0091]      99  Shear bolt 
         [0092]      100  Bore 
         [0093]      101  Latching element 
         [0094]      103  Clearance 
         [0095]      105  Ball 
         [0096]      107  Spring 
         [0097]      109  Set screw 
         [0098]      111  Bore 
         [0099]      113  Retaining element