Patent Publication Number: US-2009235854-A1

Title: Separating and positioning device

Description:
The present invention relates to an apparatus on an embroidering, stitching or sewing machine for applying at least one additional band-like material, which can be fed to a needle by means of a feed device. 
     One form of the combined embroidery techniques is cord or band embroidery, in which the stitch head is provided with a flanged bobbin rotating around the needle, on which the cord or band material can be stored so as to be capable of tangential unwinding. 
     As an alternative to the flanged bobbin rotating around the needle, the band can also be fed from a bobbin rotating around the needle, usually arranged above the stitch head. 
     With this embroidery technique, a band is fed which in the embroidery process is secured on the base material with the aid of the embroidery thread. The band which is applied is not, as a rule, of significance for the actual embroidery formation. This allows for the most widely differing patterns and effects to be achieved, wherein the stitch intervals can be variably adjusted according to the deposition form and the purpose of use. For example, in areas of more substantial bending, smaller stitch lengths are often used. With cord or band embroidery, as a rule only continuous uninterrupted patterns are selected, and return or reversing points running to a tip are avoided. The reason for this is that bands have a tendency, in the area of return or reversing points, to become bunched. 
     The embroidery process in this situation takes place in the following process steps:
     1. Positioning of the stitch base material in a tensioning device;   2. Tensioning the stitch base material;   3. Positioning the tensioning device;   4. Aligning the band end before starting embroidering;   5. Embroidering with the feed of an adequately long band;   6. Cutting of embroidery threads and bands (manually);   7. Onwards conveying of the material and repeat positioning of the material.   

     Cord and band embroidery differs depending on the materials, techniques, and types of application used. With fashionable embroidery applications and in the home textile sector, the materials to be embroidered on are thread-like materials, such as filament yarns, spinning fibre yarns, twists, gimp cord or thread, metal threads, chenille, straw and bast, and also materials in band form, such as woven, knitted, braided, bobbin laced bands, trimmings, or bands with sequins, and leather. 
     Increasingly of interest is band embroidery for technical purposes, such as for fibre composite components, where band-shaped rovings made of carbon or glass multifilaments and natural or ceramic fibres are used. Also of interest for technical applications are chemical fibres such as aramides, PP, PES, PA. 
     Band embroidery for technical applications is only at the beginning of its possibilities. Decisive factors for the use of this new technology for technical textiles are the costs of the method. To increase productivity and quality in the embroidering of technical articles, a means of automation of the embroidery process is urgently required. This applies in particular to the demanding technical embroidery processes, which are predominantly produced on what are referred to as band embroidering machines. 
     One factor with the band embroidery process which is conditioned by the method is the fact that, because of the absence of an automatic positioning and cutting procedure for the band, as a rule the band is only laid in an uninterrupted and continuous manner, and the changes of direction, running to a tip, in particular at the ends of components, cannot be achieved. The depositing of the band is therefore selected in terms of technical programming in such a way that at the points of change of direction there are always adequately large radii present as to be able to lay the band flat on the surface and secure it. The band is therefore continually embroidered. Inasmuch as, by way of example, if it is intended that reinforcement fibres should be embroidered on the base material, this means, disadvantageously, that the arrangement of the reinforcement fibres must deviate at least at the return or reversing points from the ideal course along the main tensioning trajectories. 
     The object of the present invention is to provide a device for an embroidering, stitching or sewing machine with which the band-like material to be secured need no longer be laid continuously. 
     This object is resolved according to the invention with a device with the features of Main Claim  1 . Further advantageous embodiments of this device according to Claim  1  are derived from the features of the sub-claims. 
     The device according to the invention is advantageously characterised in that by means of only one drive, which moves the presser foot back and forth, the cutting device can also be operated. This is advantageously achieved by the fact that the presser foot mechanism or the presser foot itself is coupled by way of a connecting means, for example in the form of a belt, a chain, or a band, as a result of which the movements of the presser foot and the cutting device can be co-ordinated with one another. 
     Inasmuch as a belt, band, or chain is used as the connecting means, this is advantageously deflected around a deflection point, in particular a deflection roller, such that, when the presser foot is moved in the direction of the needle plate, the cutting device or parts of it are moved away from the needle plate. Springs ensure that both the presser foot and the cutting device are subjected to force in the direction of the needle plate, such that, if the presser is moved away from the needle plate, the cutting device or parts of it are moved more or less upwards or downwards in the direction of the needle plate. 
     The presser foot, the cutting device, and the feed device are advantageously arranged at a base part, which can be pivoted around the longitudinal axis of the needle by means of a drive. In this situation the base part is engaged through by the needle and can form the mountings for the presser and/or the cutting device. 
     The cutting device may consist of a part in the form of shears, in which at least one blade can be mounted so as to be able to pivot and/or be displaced in relation to the other. 
     In a particularly advantageous embodiment, by means of moving the cutting device or at least one blade mounted such as to be movable by the movement of the presser, in particular in the direction of the needle plate, the minimum of one movably mounted blade can be moved against a stop, so that the blade pivots and, together with the other blade of the cutting device, carries out the cutting or separating process of the band-like material. 
     Due to the pivoting of the cutting device together with the presser foot around the longitudinal axis of the needle, the cutting device, moved in the direction of the needle plate by the spring force due to upward travel of the presser, or at least a blade of the cutting device, can be brought into the area between the feed device and the band-like material already sewn to the base material, such that, by means of a pivot movement around the axis of the needle, the band-like- material which has not yet been sewn to the base material can be brought or positioned between or above a blade of the cutting device. Due to the following downwards movement of the presser foot, the cutting device or one of its blades is moved upwards, as a result of which the band-like material is separated. 
     It is of course possible for a gear train to be provided instead of the band-like or belt-like connection means, which transfers the movement of the presser foot onto the cutting device. 
     It is likewise possible for the cutting device to have only one movable blade, wherein a second blade is secured to the presser foot itself or to the presser drive device, wherein the two blades interact when the presser foot moves in the direction of the needle plate and shear through the band-like material. 
     Inasmuch as no blade is arranged at the presser, it is also possible for a blade to be arranged secured to the base part, which then interacts with a blade arranged at the cutting device, wherein the cutting device itself is again coupled by way of the connection means to the presser or its adjustment device. 
     A possible embodiment of the device according to the invention is explained in greater detail hereinafter, on the basis of drawings. 
    
    
     
       The drawings show: 
         FIGS. 1-3  Perspective representation of a part of a stitch head, with the securing of a band-like material on a base material; 
         FIG. 4  Lowering of the cutting device; 
         FIGS. 5-6  Positioning of the cutting device by rotating the base part; 
         FIG. 7  Drawing off the band-like material by moving the pantograph; 
         FIG. 8  Lowering of the presser, as a result of which the cutting device is moved away from the needle plate and the separation process is actuated. 
     
    
    
       FIGS. 1 to 3  show the essential parts of a stitch head K, with a device arranged at it for securing band-like material  3  by means of a thread  5 . Mounted such as to be rotatable at the stitch head K is a base B, which can be pivoted around the needle  6  by means of a drive, not shown. The band-like material is wound up on the drum  9  and fed by means of the feed device  4  to the area of the sewing needle  6 . The feed device  4  can be pivoted back and forth horizontally by means of a drive, such that, if the stitch head comes to a standstill, the sewing thread  5  lies transversely over the band-like material  3  and can be sewn, to the left or right of the band  3 , to the stitch base material tensioned in the trimming frame  14 . The feed device  4 , the drum  9 , and the presser foot  1  are mounted or secured on the base. 
     The trimming frame  14  can be moved in the horizontal plane by means of drives, not shown. The stitch head K is rigidly secured to a housing frame of the machine, not shown. 
     A drive, not shown, drives the presser foot  1 , which is formed by a ring of flat spring steel. The ring  1  is secured with its upper part to a part  1   a  secured to the presser rod. Arranged at the part  1   a  is the fixed bearing  1   b  for the belt  12 . The belt  12  is secured with one of its ends in the fixed bearing  1   b  and with its other end at the movably mounted part of the cutting device  10  ( FIG. 4 ). The part of the cutting device mounted on the base B capable of moving or being displaced vertically is subjected to pressure in the direction of the needle plate by means of a spring F. Arranged at the movably mounted part of the cutting device  10 , in the lower part, is the cutting blade  8  in the form of small shears. One of the two blades is fixed, while by contrast the other blade is mounted so as to be able to pivot. If the presser foot  1  is now moved upwards by the presser drive (not shown), the moving part of the cutting device  10 , at which the shears  8  are arranged, is moved by the spring F downwards in the direction of the needle plate, as far as a stop. If, by contrast, the presser foot  1  is moved in the direction of the needle plate, then the shears  8  are moved upwards by means of the belt  12 , which is deflected by the deflection roller  13   a.    
     When securing the band-like material  3 , the band is fed by means of the feed device  4  under the area of the needle  6 . By means of stitch formations the material  3  can be sewn securely to the stitch base material. In this situation, the backwards and forwards movement of the feed device  4  causes the thread  5  to be drawn transversely over the band-like material  3  and therefore secured. By rotating the base part B, the band-like material  3  can be secured in any desired radii on the stitch base material, as is shown in  FIGS. 1 to 3 . 
     In order now to separate the band-like material  3 , the presser foot  1  is moved upwards, as a result of which the shears  8  pass close above the stitch base material ( FIG. 4 ). The shears  8  are in this situation brought into the open position by a spring (not shown). By moving the pantograph or trimming frame  14  respectively, it is now possible, with co-ordinated rotation of the base B, for the band  3 ′ located between the feed device  4  and the band  3 , already secured, to be laid between the blades of the shears  8  ( FIGS. 5 and 6 ). By moving the presser  1  in the direction of the needle plate, it is then possible for the shears  8  to be moved upwards with the band  3 ′ located between the blades, wherein the shears move at the upper part of their movement curve against a stop, as a result of which the moving blade is pivoted. The band  3 ′ is separated as a result. 
     In order to make possible repeat securing of the separated band  3  to the stitch base material, a sufficiently long area  3 ″ of the band must remain, which is already threaded through the feed device  4 . This can be achieved in that, before the cutting process, further band is unrolled or drawn from the drum by the movement of the pantograph or trimming frame ( FIG. 7 ), and only thereafter is the cutting procedure initiated by moving the shears upwards ( FIG. 8 ).