Patent Publication Number: US-11639566-B2

Title: Method for knitting three-dimensional fabric with variable thickness through a flat knitting machine

Description:
FIELD OF THE INVENTION 
     The present invention relates to a method for knitting a three-dimensional fabric, and particularly relates to a method for knitting a three-dimensional fabric with variable thickness through a flat knitting machine. 
     BACKGROUND OF THE INVENTION 
     The existing knitting of a three-dimensional fabric with variable thickness is generally realized by a warp knitting machine, as disclosed in patents of CN 102704180A, CN 102978823A and CN 105220347A. 
     However, the problem that the existing flat knitting machine cannot knit the foregoing mentioned fabric results from the flat knitting machine is defined by fixed knock-over bits, which is causing that the flat knitting machine can only knit the three-dimensional fabric with a single thickness. 
     SUMMARY OF THE INVENTION 
     The main purpose of the present invention is to solve the problem that the existing flat knitting machine cannot knit the three-dimensional fabric with variable thickness. 
     To achieve the above purpose, the present invention provides a method for knitting a three-dimensional fabric with variable thickness through a flat knitting machine, including the following steps: 
     step (1): moving two cam groups onto two needle beds which are disposed relatively, and driving a plurality of needles to knit a first piece of knitting by a starting cam system included in one of the two cam groups; 
     step (2): moving the two cam groups onto the two needle beds which are disposed relatively, and driving the plurality of knitting needles to knit a second piece of knitting by a middle cam system included in the other one of the two cam groups; 
     step (3): moving the two cam groups onto the two needle beds which are disposed relatively, and driving the plurality of knitting needles to knit a supporting yarn by two tail cam systems respectively included in the two cam groups, wherein two ends of the supporting yarn are respectively interwoven with the first piece of knitting and the second piece of knitting, and moving each of a plurality of knock-over bit cams controlled by each of the tail cam systems which depends on a gap size corresponding to a knitting length of the supporting yarn, so as to promptly change a thickness of the three-dimensional fabric along the length change of the supporting yarn in a knitting process; and 
     step (4): repeating the step (1) to the step (3) to complete the three-dimensional fabric. 
     In an embodiment, the step (3) includes a substep: controlling a flat knitting machine yarn feeder to adjust a position of a yarn feeding arm in the gap according to the gap size. 
     In an embodiment, the step (4) includes a substep: controlling the starting cam system and the middle cam system of the other one of the plurality of knock-over bit cam to implement displacement and adjustment according to the gap size after the previous step. 
     In an embodiment, the step (4) includes a substep: controlling the flat knitting machine yarn feeder to adjust the position of the yarn feeding arm in the gap based on the gap size after the previous step. 
     In an embodiment, the step (4) includes a substep: controlling at least one flat knitting machine mangling device to adjust a mangling position based on the gap size after the previous step. 
     As previously disclosed in the present invention, compared with the prior art, the present invention comprises the following characteristics: the method disclosed in the present invention enables the flat knitting machine to achieve the knitting of the three-dimensional fabric with variable thickness. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a structural schematic diagram of a flat knitting machine in an embodiment of the present invention; 
         FIG.  2    is an implementation diagram (I) when two cam groups conduct knitting in an embodiment of the present invention; 
         FIG.  3    is an implementation diagram (II) when two cam groups conduct knitting in an embodiment of the present invention; 
         FIG.  4    is a flow chart of a method in an embodiment of the present invention; 
         FIG.  5    is a flow chart of a method in another embodiment of the present invention; and 
         FIG.  6    is a schematic diagram of a three-dimensional fabric in an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The details and technical contents of the present invention will be described below with reference to drawings. 
     By referring to  FIGS.  1 ,  2 ,  3 ,  4  and  5   , the present invention provides a method  500  for knitting a three-dimensional fabric with variable thickness through a flat knitting machine. Before the method is described, a flat knitting machine structure  100  of the present invention is described. A gap  10  of the present invention is defined by a plurality of knock-over bits  16  facing each other in two needle beds  11  and  12  which are disposed in the flat knitting machine structure  100 . The flat knitting machine structure  100  includes a plurality of cam systems  13  and  14  for changing a gap size, a plurality of flat knitting machine yarn feeders  20  change yarn feeding positions according to the gap size, and a plurality of flat knitting machine mangling devices  40  and  48  change mangling positions according to the gap size. The plurality of cam systems  13  (or  14 ) are used in a single knitting procedure. In a knitting process, a plurality of knitting needles  15  and the plurality of knock-over bits  16  on each of the needle beds  11  (or  12 ) are respectively controlled by each of the plurality of cam systems  13  (or  14 ). Each of the plurality of cam systems  13  (or  14 ) comprises at least one knock-over bit cam  132  to control the plurality of knock-over bits  16 . The knock-over bit cam  132  changes the positions of the plurality of knock-over bits  16  in the knitting process, and the flat knitting machine promptly changes the gap size in the knitting process according to knitting requirements. Moreover, the plurality of cam systems  13  (or  14 ) are sequentially assembled into a cam group  18  (or  19 ). Further, the cam group  18  of the present invention is formed by three of the cam systems  13 . According to a motion direction of a machine head of the flat knitting machine, the three of the cam systems  13  are defined as a starting cam system  181 , a middle cam system  182  and a tail cam system  183  in sequence. However, the flat knitting machine belongs to a weft knitting machine. The motion direction of the machine head is reverse displacement but not one-way. Briefly, the machine head displaces repeatedly along a straight track, as shown in directions  590  and  591  in  FIGS.  2  and  3   . Therefore, the cam systems  13  defined as the starting cam system  181  in the previous knitting process would be defined as the tail cam system  183  is in the next knitting process. In addition, the other one of the cam groups  19  also comprises three of the cam systems  14  defined as a starting cam system  191 , a middle cam system  192  and a tail cam system  193 . 
     In another aspect, by referring to  FIG.  6   , the three-dimensional fabric  90  of the present invention is formed by a first piece of knitting  91 , a second piece of knitting  92  which is spaced from the first piece of knitting  91 , and a supporting yarn  93  which is separately interwoven with the first piece of knitting  91  and the second piece of knitting  92 , wherein the supporting yarn  93  may be a nylon yarn. The height of the supporting yarn  93  is the thickness of the three-dimensional fabric  90 . By referring to  FIG.  6   , the figure shows that the three-dimensional fabric  90  with variable thickness. The thickness is thinner upon knitting in the previous knitting process  94 , and the thickness is thicker upon knitting in the subsequent knitting process  95 . 
     By referring to  FIGS.  1 ,  2 ,  3  and  4   , the method  500  includes the following steps: 
     step (1)  51 : moving the two cam groups  18  and  19  onto two needle beds  11  and  12  which are disposed relatively, and driving the plurality of knitting needles  15  to knit the first piece of knitting  91  by the starting cam system  181  (or  191 ) included in one of the two cam groups  18  (or  19 ); 
     step (2)  52 : moving the two cam groups  18  and  19  onto the two needle beds  11  and  12  which are disposed relatively, and driving the plurality of knitting needles  15  to knit the second piece of knitting  92  by the middle cam system  192  (or  182 ) included in the other one of the two cam groups  19  (or  18 ); 
     step (3)  53 : moving the two cam groups  18  and  19  onto the two needle beds  11  and  12  which are disposed relatively, and driving the plurality of knitting needles  15  to knit the supporting yarn  93  by the tail cam systems  183  and  193  respectively included in the two cam groups  18  and  19 , wherein the two ends of the supporting yarn  93  are respectively interwoven with the first piece of knitting  91  and the second piece of knitting  92 , and moving each of a plurality of knock-over bit cams  132  controlled by each of the tail cam systems  183  (or  193 ) which depends on a gap size corresponding to a knitting length of the supporting yarn  93 , so as to promptly change the thickness of the three-dimensional fabric  90  along the length change of the supporting yarn  93  in a knitting process; and 
     step (4)  54 : repeating the step (1)  51  to the step (3)  53  to complete the three-dimensional fabric  90 . 
     Referring to  FIG.  2   , it is assumed that the current knitting direction of the machine head is indicated by  590  in the figure. In the step (1)  51 , the two cam groups  18  and  19  are controlled to simultaneously move relative to the two needle beds  11  and  12 . At this moment, the starting cam system  181  of the cam group  18  drives part of the plurality of knitting needles  15  on the needle bed  11  to accept yarn feeding to knit the first piece of knitting  91 . Moreover, when the first piece of knitting  91  is knitted by the starting cam system  181 , the flat knitting machine mangling device  40  disposed correspondingly to the cam group  19  performs a mangling action. 
     Then, the two cam groups  18  and  19  make displacement continuously, and the middle cam system  192  of the other one of the cam groups  19  drives part of the plurality of knitting needles  15  on the needle bed  12  to accept yarn feeding to knit the second piece of knitting  92 . Further, the plurality of knitting needles  15  on the needle bed  12  knit the second piece of knitting  92 , which are disposed in opposition to the plurality of knitting needles  15  on the needle bed  11  to knit the first piece of knitting  91 . Furthermore, when the second piece of knitting  92  is knitted by the middle cam system  192 , the flat knitting machine mangling device  48  disposed correspondingly to the cam group  18  performs a mangling action. Based on this, the step (3)  53  is conducted after the second piece of knitting  92  is completed. The two cam groups  18  and  19  make displacement continuously, and the two tail cam systems  183  and  193  simultaneously drive the plurality of knitting needles  15  of the two needle beds  11  and  12 , and accept yarn feeding to knit the supporting yarn  93 , wherein the two ends of the supporting yarn  93  are respectively interwoven with the first piece of knitting  91  and the second piece of knitting  92 . Furthermore, in the implementation process of the step (3)  53 , the knock-over bit cams  132  of the two tail cam systems  183  and  193  make displacement according to the set length of the supporting yarn  93 , i.e., the two tail cam systems  183  and  193  promptly adjust the gap size according to the set length of the supporting yarn  93  in the knitting process. When the supporting yarn  93  is shorter, the gap size is smaller for knitting. When the supporting yarn  93  is longer, the gap size is larger for knitting. Furthermore, the knock-over bit cams  132  of the two tail cam systems  183  and  193  respectively accept the control of a control device, wherein the control device controls according to a pre-memory knitting process. 
     Based on this, the step (4)  54  is conducted after the step (3)  53  is completed. If the machine head travels to the end at the time, the machine head displaces reversely, as shown in  FIG.  3   . Meanwhile, the two starting cam systems  181  and  191  of the two cam groups  18  and  19  are replaced by the tail cam systems  183  and  193  in the previous knitting process to be used as the starting cam systems  181  and  191  in this knitting process. Similarly, the starting cam systems  181  and  191  in the previous knitting process are used as the tail cam systems  183  and  193  in this knitting process. Next, the step (1)  51  to the step (3)  53  are conducted again until the three-dimensional fabric  90  is accomplished. The implementation process of the step (1)  51  to the step (3)  53  is described previously, and will not be repeated herein. 
     Referring to  FIG.  4   , in an embodiment, the step (3)  53  includes a substep  531 : controlling the flat knitting machine yarn feeder  20  to adjust a position of the yarn feeding arm  26  in the gap  10  according to the gap size. Thus, the plurality of knitting needles  15  does not generate problems such as abnormal yarn snagging due to the change of the gap  10  in the process of the step (3)  53 . 
     Referring to  FIG.  5   , the subsequent knitting process  95  coordinates with the change of the gap  10  in the previous knitting process  94 . In an embodiment, the step (4)  54  includes a substep  541 : controlling the starting cam systems  181  and  191  and the middle cam systems  182  and  192  of the other of the knock-over bit cams  132  to implement displacement and adjustment according to the gap size after the previous step. In addition, the step (4)  54  includes a substep  542 : controlling the flat knitting machine yarn feeder  20  to adjust the position of the yarn feeding arm  26  in the gap  10  based on the gap size after the previous step. Further, the step (4)  54  includes a substep  543 : controlling at least one flat knitting machine mangling device  40  (or  48 ) to adjust a mangling position based on the gap size after the previous step. 
     In conclusion, the foregoing mentioned structure and the method in the present invention allow that the flat knitting machine is not limited to implement a single thickness but variable thickness according to the design of the three-dimensional fabric  90  in the knitting process.