Abstract:
Positioning device adapted to dispose a strip of fabric or other similar material on an article of clothing do as to form a loop, the strips divided into a central portion and two opposite ends, the positioning device rotates at least one of the two ends of the strip in order to bring that end or ends into abutment with the central portion of the strip; and wherein guide means guide the end or ends of the strip during rotation.

Description:
FIELD AND BACKGROUND 
     The present invention refers, in general, to a positioning device for the positioning of loops and to a sewing machine comprising said device. More particularly, the present invention relates to a positioning device and to a sewing machine comprising said device, to appropriately arrange and position a loop on a garment during processing, for instance trousers. 
     As is known, several typologies of garments need loops, which are small fabric or leather strips through which bands, belts, strings or similar elements pass. 
     As represented in  FIG. 1 , a loop  10  is usually fixed on an article of clothing  12  by means of seams  14  of the ends  18 ,  20  of the strip  16  that forms the loop. In particular, in order to make the fixing more stable, the ends  18 ,  20  are turned towards the article of clothing  12  so that the seam  14  is stitched on the portions  22 ,  24  of the strip  16 , these portions being superimposed on the ends  18 ,  20  bent. In this way, it is possible to double the portion of strip sewn on the article of clothing and the seam is made more solid. 
     In order to stitch said seam, the sewing machines of the prior art comprise suitable devices which allow to bend the ends  18 ,  20  of the strip  16  inwards and to position the strip on the fabric area on which the loop has to be formed. 
     In particular, once the positioning devices according to the prior art have grabbed the strip  16  acting as a loop, the positioning devices rotate both ends  18 ,  20  180 degrees so that both ends are arranged under the remaining part of the strip  16 . 
     The positioning devices according to the prior art do not ensure a perfect positioning of the strip ends  18 ,  20  to bend so that an unwished effect is obtained as represented in  FIG. 2  from which it appears how the ends  18 ,  20  are not perfectly hidden under the remaining part of the strip  16 . 
     SUMMARY OF THE INVENTION 
     An aim of the invention is to remove the above-mentioned drawbacks and others, through the realization of a positioning device for the positioning of loops allowing a precise positioning and a perfect alignment of the strip forming the loop on the article of clothing. 
     In particular, an aim of the invention is to provide a positioning device allowing a precise positioning of each portion of the strip, and precisely a perfect overlap of the ends  18 ,  20  with the portions  22 ,  24  of the strip  16 , as represented in  FIG. 3 . 
     Another aim of the invention is to carry out a loop positioning device that must be not only precise but also rapid and reliable at the same time. 
     Another aim of the invention is to carry out a positioning device that must be simple as regards the construction. 
     The above-mentioned aims and others are achieved according to the invention through a positioning device adapted to dispose a strip of fabric or other similar material on an article of clothing on which said strip has to be sewn so as to form a loop, said strip being divided in a central portion and two opposite ends. The positioning device comprises rotation means to rotate at least one of the two ends of the strip in order to bring this end in abutment with the central portion of the strip. 
     The positioning device according to the invention is characterized by the fact of comprising guide means to guide the at least one of said two ends of the strip in the rotation of the same end so that this end is superimposed completely to the central portion of the strip without showing any hems out of the area covered by the central portion. 
     Advantageously, the guide means of the positioning device according to the invention may comprise at least two plates positioned substantially perpendicular to the strip and adapted to be put in contact with the respective opposite side edges of the strip. The two plates allow that the end of the strip is received, in its rotation, between the two plates so as to be guided by said two plates up to go in contact with the central portion of the strip on completely overlapping the same central portion. 
     Besides, the guide means may comprise lifting means to lift the two or more plates so as to allow the positioning of the strip on the article of clothing on which the strip has to be sewn, after the strip has been appropriately bent at its ends. 
     Advantageously, the guide means may comprise first adjusting means to adjust the distance between said two plates acting on the same end of the strip so as to adapt the guide means to the width of the strip. 
     The guide means may comprise at least one support on which the two or more plates are connected by means of a pin and elastic means so that the two plates may rotate in relation to the support on maintaining the contact with the opposite side edges of the strip and are forced to return to their initial rest position by the elastic means. 
     Besides, the rotation means may comprise at least one fork which rotates on itself so as to cause the rotation of one or both of the two ends; since the fork goes in contact, in its rotation, with at least one of the two plates and the two plates are pivoted on the support, the two plates follow the movement of the fork and rotate. 
     The positioning device according to the invention may comprise two first plates and two second plates; the first two plates are adapted to guide a first end of the strip in its rotational motion so as to be completely superimposed to the central portion of the strip; the two second plates are adapted to guide a second end of the strip in its rotational motion so as to be completely superimposed to the central portion of the strip. 
     Advantageously, in the positioning device according to the invention, second adjusting means may be comprised to adjust the distance between the two first plates and the two second plates so as to adapt the guide means to the length of the strip. 
     In addition, chamfers are obtained in the plates and act as invitation in the receiving phase of an end between two plates. 
     In the positioning device according to the invention, hook means may be comprised to lift a part of the central portion of the strip in order to create a sufficient space for the passage of a belt or strap or other equivalent element between the article of clothing and the strip, once said strip has been sewn. It is to be intended that the aims and advantages of the invention are also achieved by a sewing machine comprising a positioning device for the positioning of loops. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Further features and details of the invention can be better understood from the following description which is provided as a non-limiting example as well as from the accompanying drawings wherein: 
         FIGS. 1 ,  2  are side and top views, respectively of a loop, sewn on an article of clothing according to the prior art; 
         FIG. 3  is a top view of a loop positioned and sewn on an article of clothing in the optimal position; 
         FIG. 4  is a side view of a positioning device according to the invention, in the initial phase of the process of positioning of a loop; 
         FIG. 5  is an enlarged view of a portion of device as shown in a cutout “A” in  FIG. 4 ; 
         FIG. 6  is a side view of the device in  FIG. 4  during a first working phase; 
         FIG. 7  is a bottom view of the positioning device according to the invention when it is arranged in the configuration represented in  FIG. 6 ; 
         FIGS. 8 ,  9 ,  11 ,  13  are side views of the device in  FIG. 4  during the following working phases; 
         FIG. 10  is an enlarged view of the portion of device as shown in a cutout “B” in  FIG. 9 ; 
         FIG. 12  is an enlarged view of the portion of device shown in a cutout “C” in  FIG. 11 ; 
         FIG. 14  is a top view of the positioning device according to the invention. With reference to the accompanying figures, in particular  FIG. 4  and following figures, number  100  denotes a positioning device that can be mounted on a frame of a sewing machine. The positioning device  100  is used to suitably bend and position a strip  16  in a wished area of an article of clothing on which the strip has to be sewn in order to obtain a loop  10 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The positioning device comprises:
         a slide and support device  26  for the strip  16 , this device being adapted to bring and support the strip  16  in a processing position in which the strip is prearranged to be sewn;   a first fork  28  and a second fork  30 , each of them being able to cause the rotation of the first end  18  and the second end  20  of the strip  16 , respectively;   a hook device  32  for the lifting of a portion of the strip  16  so as to form a sufficient space between the loop and the article of clothing for the passage of a belt or other similar element;   a straightening device  34  allowing a correct positioning of the first end  18  and second end  20  when these ends are rotated.       

     The slide and support device  26  comprises movement and traction means (not represented in the figures) and more specifically pliers to displace the strip  16  from a loading position to a machining position in which the strip  16  is subjected to the necessary operations in order to be appropriately conformed, as described below, before being sewn on the article of clothing. 
     The slide and support device  26  comprises supporting elements  36  that support the strip  16  in the machining position. 
     The first fork  28  comprises a first tooth  38  and a second tooth  40  which are put side by side and are connected to a first shaft  42 , visible in  FIG. 8 , which may rotate around its own axis. The first tooth  38  is coaxial to the first shaft  42  so that when the first shaft  42  rotates, also the first tooth  38  rotates around itself while the second tooth  40  rotates around the first tooth  38 . 
     Similarly, the second fork  30  comprises a first tooth  44  and a second tooth  46  which are put side by side and are connected to a second shaft  48 , visible in  FIG. 8 , which may rotate around its own axis. The first tooth  44  of the second fork  30  is coaxial to the second shaft  48  so that when the second shaft  48  rotates, also the first tooth  44  rotates around itself while the second tooth  46  rotates around the first tooth  44 . 
     The hook device  32  comprises a support  49  on which an actuator, not visible in the figures, is fixed. An L-shaped element  50  is adjustably united to said actuator and comprises a lower portion  52  which is arranged under the strip  16  and acts as a hook for the lifting of a portion of the strip  16 . 
     The fixing of the L-shaped element  50  to the actuator is obtained by means of a screw  54  that allows to vary the position of the L-shaped element  50  depending on the space to be obtained between the loop  10  and the article of clothing  12 . 
     Besides, a first pin  56  and a second pin  58  are fixed to the support  49  and are arranged at a side of the L-shaped element and above the strip  16  when the strip  16  is in the machining position. 
     The first pin  56  and the second pin  58  are fixed in relation to the support  48  while the L-shaped element  50  is movable. 
     The straightening device  34  comprises a support  60  fixed to the frame of the sewing machine. A block  62  is connected to the support  60  by means of an actuator  64  which may move the block  62  vertically according to a direction E. A return spring  63 , visible in  FIG. 6 , is united through an end to the support  60  and through the other end to the block  62  so that the block  62  is forced to rise when the actuator  64  is not actuated. 
     A rod  66  is fixed to the block  62  rigidly and has an oblong hole  68 . A first support  70  and a second support  72  are fixed adjustably to the rod  66  by means of adjusting screws  74 ,  76  which pass through the oblong hole  68  and may adjust the position of the first support  70  and second support  72  horizontally. 
     Two first plates  78  are pivoted to the first support  70  and similarly, two second plates  80  are pivoted to the second support  72 ; the two first plates  78  as well as the two second plates  80  are separated from each other by a distance equal to the width of the strip  16 . Only in  FIG. 8  it is possible to see the two first plates  78  and the two second plates  80 . 
     In addition, each of the first plates  78  and each of the second plates  80  are connected with first springs  82  and second springs  84  to the first support  70  and to the second support  72 , respectively. The first springs  82  and the second springs  84  allow to bring the first plates  78  and the second plates  80  again in the vertical position in case the plates are forced to tilt. 
     The operations performed by the positioning device  100  to suitably bend and position the strip  16  on the wished area of the article of clothing  12  on which said strip has to sewn to obtain a loop  10  are described below. 
     As it appears from  FIGS. 4 ,  5 , the strip  16  is unrolled from a roll and is brought and supported in the machining position by the slide and support device  26 . In particular, the strip  16  is pulled by the movement and traction means, specifically by the pliers, and supported by the supporting elements  36 . As represented in  FIGS. 6 ,  7 , once the strip  16  is disposed in the machining position, the first plates  78  and the second plates  80  are lowered so that the strip  16  is received between plates  78 ,  80 . 
     In particular, the actuator  64  is actuated so as to lower the block  62  and consequently the bar  66 , the first support  70  and the second support  72  and therefore, also the first plates  78  and the second plates  80 . The first fork  28  and the second fork  30  are advanced so that on a side, the strip  16  is disposed between the first tooth  38  and the second tooth  40  of the first fork  28  and on the opposite side, the strip  16  is disposed between the first tooth  44  and the second tooth  46  of the second fork  30  while centrally, the strip  16  is kept in position on the upper part by the first pin  56  and second pin  58  and on the lower part by the lower portion  52  of the L-shaped element of the hook device  32 , in addition to the support elements  36 . 
     The first tooth  38  and the second tooth  40  of the first fork  28  separate ideally the left end  18  (according to the accompanying drawings) from the central portion of the strip  16  and similarly, the first tooth  44  and the second tooth  46  of the second fork  30  separate ideally the right end  20  (according to the accompanying drawings) from the central portion of the strip  16 . 
     The strip  16 , arranged in its machining position as indicated above, is cut at the opposite end to the pliers according to the wished length. 
     Then, as it appears from  FIG. 8 , the hook device  32  is actuated to lift a portion of the strip  16  in order to obtain a sufficient space between the loop  10  and the article of clothing  12  for the passage of a belt or strap. 
     In particular, the actuator included in the support  49  is actuated to move up the L-shaped element  50  and its lower portion  52  that lifts the central portion of the strip  16 . 
     Then, as represented in  FIGS. 9 ,  10 , the first fork  28  is rotated 180 degrees anticlockwise (considering the point of observation of  FIG. 10 ) so that the first tooth  38  rotates around itself and the second tooth  40  rotates around the first tooth  38 . In this way, the left end  18  is brought below the remaining portion of the strip  16 . 
     The first plates  78  guide the movement of the left end  18  on avoiding that the left end  18  protrudes laterally in respect to the remaining portion of the strip  16  and indeed, causing the left end  18  to be exactly positioned under the strip  16  and more precisely, under the overlying lateral left portion, ideally identified in  FIGS. 1 ,  13  and denoted here by reference number  22 . 
     Likewise, the second fork  30  is rotated 180 degrees clockwise (considering the point of observation of  FIG. 10 ) so that the first tooth  44  rotates on itself and the second tooth  46  rotates around the first tooth  44 . In this way, the right end  20  is brought below the remaining portion of the strip  16 .
 
Like the first plates  78 , the second plates  80  guide the movement of the right end  20  on avoiding that the right end  20  protrudes laterally in respect to the remaining portion of the strip  16  and indeed, causing the right end  20  to be exactly positioned under the strip  16  and more precisely, under the overlying lateral right portion, ideally identified in  FIGS. 1 ,  13  and denoted here by reference number  24 .
 
     As represented in  FIGS. 11 ,  12 , in order to facilitate the sewing of the strip  16  on the article of clothing  12 , the left end  18  and the right end  20  are brought in contact with the strip  16 . 
     In particular, the first fork  28  is rotated  40  degrees so that the second tooth  40  forces the left end  18  to contact and press the overlying lateral left side  22 . The second tooth  40  of the first fork  28  contacts and pushes the first plates  78  which are forced to tilt, even if pulled in the opposite direction by the springs  82 , but which keep the left end  18  in the correct position. 
     Likewise, also the second fork  30  is rotated an additional  40  degrees so that the second tooth  46  forces the right end  20  to contact and press the overlying lateral right side  24 . The second tooth  46  of the second fork  30  contacts and pushes the second plates  80  which are also forced to tilt, even if pulled in the opposite direction by the springs  84 , but which keep the right end  20  in the correct position. 
     Then, as represented in  FIG. 13 , the actuator  64  of the straightening device  34  is deactivated and the return spring  63  provokes the lifting of the block  62 , the bar  66 , the first support  70  and the second support  72 . Consequently, also the first plates  78  and the second plates  80  are lifted and positioned vertically through the action of the respective springs  82 ,  84 . 
     Thus, the strip  16  is so shaped that the strip  16  may be sewn at the lapels made by the positioning device  100 , namely at the overlying lateral left portion  22  and the overlying lateral right portion  24  and consequently, at the left end  18  and the right end  20 . 
     Finally, the positioning device  100  translates the so-shaped strip  16  by means of the first fork  28  and second fork  30  above the article of clothing  12  in the position in which the strip  16  has to be sewn to form a loop  10 . 
     The positioning device  100  according to the invention allows to arrange a strip in the suitable configuration for the realization of a loop; in particular, the positioning device  100  allows to bend the strip ends and place them exactly under the portions of the strip on avoiding unwished projections that would cause undesirable aesthetic effects. 
     The positioning device  100  according to the invention has a considerable flexibility of use and may be used regardless of the size of the loop to obtain; indeed, the presence of oblong holes and adjusting screws allows to horizontally vary the position of the first plates  78  and second plates  80  as well as the position of the first fork  78  and second fork  30  in order to adjust the processing when the length of the strip varies. 
     Besides, also the distance between the two first plates  78  as well as between the second plates  80  may be varied so that it is possible to use the positioning device  100  also when the length of the strip  16  to be shaped varies. Indeed, as it appears from  FIG. 14 , the first support  70  and the second support  72  are provided with two first adjusting screws  86  and two second adjusting screws  88 , respectively. Each of the screws fixes the first plates  78  and the second plates  80  releasably. For instance, by unscrewing one of the two first adjusting screws  86  it is possible to laterally displace one of the two first plates  78  and to vary its position according to the width of the strip  16 . 
     The first plates  78  as well as the second plates  80  are shaped in such a way as to facilitate the insertion of the strip  16  between the plates when the plates are lowered. The shape is represented by a chamfer suitably made to facilitate a correct insertion of the strip  16  between the plates. 
     A technician of the sector may provide amendments or variants that are to consider as included in the scope of protection of the present invention.