Patent Publication Number: US-7716955-B2

Title: Sinker set for the manufacture of plush

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application claims the priority of European Patent Application No. 08 103 408.4, filed Apr. 7, 2008, the subject matter of which, in its entirety, is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to a sinker set for knitting systems for the manufacture of plush goods, in particular for use in circular knitting machines. In terms of the present patent application, a knitting system comprises all parts necessary for the formation of a pair of stitches, said pair consisting of a base stitch and a plush stitch. 
   For example, knitting systems as have been known from DE 30 35 582 C2, DE 31 45 307 C2 or even DE 41 29 845 A1 are used for the manufacture of plush. Such knitting systems comprise at least one needle as well as a sinker with one slit-like recess extending in transverse direction of the needle. Above the slit, the sinker has a (downholder) lug aligned in transverse direction of the needle, said needle&#39;s upper edge being disposed to receive a plush loop. The edge located in the slit acts as the coulier edge. 
   Considering this, document DE 30 35 582 discloses a special solution which provides a second sinker in addition to the sinker with the slit, said second sinker&#39;s flat side abutting against the first-mentioned sinker. The second sinker has a projection which can partially cover the slit of the first sinker. In so doing, it is possible to change the effective slit length due to the relative shift between the two sinkers, for example, in order to restretch the plush loops after the associated needle has been driven out. 
   This mode of operation of such a known stitch-forming system follows a common principle. Base and plush threads are separately fed to a suitable thread guide. In the conventional manner, the base thread comes to lie on the drawing-down (coulier) edge of the plush sinker, whereas the plush thread lies on said upper sinker lug that is raised relative to the coulier. Subsequently, the newly formed stitches, base threads and plush threads are drawn down together. Known embodiments with only one sinker per knitting system as well as systems with two sinkers per knitting system follow this principle. 
   In so doing, the height of the plush loops results from the distance of the coulier of the plush sinker from the inside edge of the hook of the (latch-type) needle and thus from the dimensions of the plush sinkers that are being used. If the plush loop height is to be changed, the plush sinkers must be exchanged. This involves a considerable effort, considering the, e.g., 4000 sinkers per circular knitting machine. 
   In addition, special sinkers have been known from prior art, said sinkers permitting an adjustment of the plush loop height. Regarding these, reference is made to document JP 2005-299056 A. This publication discloses a base sinker having a drawing-down edge and a plush sinker that is pivotally supported on the base sinker and has a lug projecting at a variable distance beyond the drawing-down edge. The plush sinker is associated with an adjustment device disposed so as to allow the defined adjustment of the pivot position of the plush sinker. 
   The adjustment of the pivot position of the plush sinker is critical. If the pivot position is not the same for all knitting systems and plush sinkers, uniform plush goods cannot be obtained. Rather, the formation of streaks would have to be expected. 
   Considering this, it is the object of the invention to provide a possibility of adjusting the plush loop height on a knitting machine as desired. 
   SUMMARY OF THE INVENTION 
   In accordance with the invention, the above object is achieved with a sinker set in accordance with Claim  1 : 
   The sinker set in accordance with the invention permits a simple adjustment of the plush loop height. Its use requires neither a complex plush sinker pivot mechanism nor is an exchange of the sinkers in a circular knitting machine required when the plush loop height is to be adjusted. This is achieved in that sinker pairs consisting of a coulier sinker and a plush sinker are provided, said coulier sinker and said plush sinker being associated with different guiding surfaces of a sinker bed. Preferably, both sinkers are arranged together in a single channel of the sinker ring. The sinkers may be controlled in the conventional manner by sinker cams that act on the sinker feet. Basically, a cam path shared by both sinkers is sufficient for driving. The sinkers are synchronously moved through this cam path in the longitudinal direction of the sinkers. Alternatively, it is possible to provide two or more cam paths to allow the separate control of the sinkers, i.e., to be able to move them back and forth, independently of each other. 
   The idea of the invention permits the adjustment of the coulier sinker and the plush sinker relative to each other in a height direction. The height direction is understood to be perpendicular to the bottom of the channel of the sinker ring, i.e., parallel to the channel walls and transverse to the sinker longitudinal direction. Preferably, only the height of the plush sinker is adjusted, whereas the coulier sinker is not adjusted. Accordingly, the plush sinker is associated with height-adjustable guiding surfaces of the sinker bed, whereas the coulier sinker is associated with height-non-adjustable guiding surfaces of the sinker bed. The adjustable guiding surfaces are provided on the correspondingly adjustable support elements. In so doing, the height of the coulier sinker may be adapted to the needle stroke that is not variable in most cases. Due to the height adjustment of the plush sinker, the length of the plush loops and thus also the pile height of the plush to be produced can be adjusted. 
   Preferably, the guiding surfaces of the sinker bed are adjustable support elements that are arranged in the channels of the sinker ring or can be separate elements, e.g., elements arranged on the knitting cylinder. The adjustable elements and their guiding surfaces extend transversely to the channels in which the sinkers are seated. The relative adjustment of the coulier sinker and the plush sinker may also be accomplished by a the relative adjustment of the sinker ring and the knitting cylinder, e.g., when the coulier sinkers are supported on the knitting cylinder and the plush sinkers are supported on the sinker ring. 
   The coulier sinker and the plush sinker are seated on the guiding surfaces, preferably with their straight edges, and slide on the guiding surfaces. In so doing, the guiding edges are preferably aligned in the longitudinal direction of the sinkers. The guiding edges of the coulier sinker and the guiding edges of the plush sinker are preferably at a distance from each other in longitudinal direction in order to come into engagement with the different guiding surfaces of the sinker bed. Additionally or alternatively, the guiding edges of the plush sinker may be at a distance from the guiding edges of the coulier sinker in height direction, i.e., in a direction transverse to the longitudinal direction of the edge. In so doing, a compact construction of the guide elements can be achieved. 
   Preferably, at least one of the two sinkers is provided with a recess at the location where the adjacent sinker has a guiding edge. In this manner, it can be ensured that each sinker comes into engagement only with its associate guiding surface. In so doing, the coulier sinkers associated with the sinker set in accordance with the invention are different from those in accordance with prior art in that, basically, recesses are provided that prevent the height adjustment device associated with the plush sinkers from acting on the coulier sinkers. 
   The two sinkers of the sinker set in accordance with the invention are arranged together in a channel of the sinker ring. Therefore, the plush sinker is not situated on the bottom of the guide channel but on at least a support element, said element being height-adjustable. A second support may be provided in that a height-adjustable holding element comes into engagement, e.g., with a front-side recess of the plush sinker. 
   The plush sinker may be configured with or without a downholder lug. The individual elements of the height adjustment device may be arranged at various points of the circular knitting machines, for example, on the sinker carrier ring and/or on the knitting cylinder. 
   In principle, the plush sinker and the coulier sinker may be connected to each other, whereby the connection permits a relative movement of the two sinkers at least as to height. Preferably, the plush sinker and the coulier sinker, however, are in a loose relationship with each other. That is, they are not connected to each other, but they are seated together—flat side against flat side—in the guide channel of the respective sinker bed (for example, of the sinker ring) and are held together by the walls of the sinker channel. 
   Additional details of advantageous embodiments of the invention are obvious from the description, the drawings or the claims. The descriptions is restricted to essential aspects of the invention and miscellaneous situations. The drawings are to be referred to in a supplementary manner. They disclose additional details. 
   The drawings illustrate examples of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic vertical sectional view of a knitting system embedded in the sinker ring and the knitting cylinder. 
       FIG. 2  is a corresponding illustration of a knitting system, in a modified embodiment. 
       FIG. 3  is a vertical sectional view of another exemplary embodiment of a knitting system. 
       FIG. 4  is a plan view of the knitting systems in accordance with  FIG. 3 . 
       FIG. 5  is a front view of the knitting systems in accordance with  FIG. 3 . 
       FIG. 6  is a schematic vertical sectional view of another modified embodiment of a knitting system. 
       FIG. 7  is a vertical sectional view of another modified embodiment of the knitting system. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a knitting system for the manufacture of a knitted material with plush. The knitting system comprises a needle  2 , e.g., in the form of a latch-type needle. The needle  2  has a shaft which has a hook  3  at its end. This hook is associated with a pivotally supported latch  4 . The needle  2  is held in a needle channel  5  of a knitting cylinder  6  so as to be movable in longitudinal direction, i.e., considering the exemplary embodiment, in vertical direction. Cylinder springs  7  retain the needle  2  in the respective needle channel. 
   The knitting cylinder  6  is associated with a sinker ring  8  that has radially oriented channels  9  for receiving sinker pairs  10 . Channel walls oriented radially and vertically and delimiting the channel  9  do exist, however, are not shown. Each sinker pair  10  comprises a coulier sinker  11  and a plush sinker  12 . The coulier sinker  11  and the plush sinker  12  are flat sheet metal parts that abut against each other on their flat sides that face each other. Each of said sinkers has a driving foot  13 ,  14  that extends into a cam channel  15  of a sinker cam  16 . A relative rotation of the sinker cam  16  against the sinker ring  8  about a vertical axis of rotation, said axis being concentric to the axis of rotation of the needle cylinder  6 , results in a synchronous movement of the coulier sinker  11  and the plush sinker  12  whose driving feet  13 ,  14  follow the non-circular cam channel  15 . 
   Referring to  FIG. 1 , the coulier sinker  11  has, on its lower narrow side, a guiding edge  17 ,  18  that is interrupted by a recess  19  and that faces the bottom  20  of the sinker channel  9 . The bottom  20  forms a guiding surface for the guiding edge  17 ,  18 . The coulier sinker  11  slides back and forth on the bottom  20  in longitudinal direction  21  of the sinker, said direction coinciding with the radial direction of the sinker ring  8  and coinciding with the longitudinal direction of the guiding edge  17 ,  18 . 
   The guiding edge  17  may have a length such that it moves past the needle  2  in order to slide, if required, on another guiding surface  22  that is provided, for example, on the upper ring-shaped end face of the needle cylinder  6 . 
   The guiding edge  17  may also be configured as two parallel planes that are at a distance from each other in view of height. 
   The height of the coulier sinker  11  is not adjustable. Independent of any other selected setting, said sinker operates on the bottom  20  by sliding back and forth at the given height. Said sinker&#39;s upper edge  23  provided on its front end is disposed to act for couliering the knit fabric. 
   The plush sinker  12  belonging to the sinker pair  10  is arranged so as to be height-adjustable. To do so, a channel  24  extending along the bottom  20  of the sinker ring  8  is provided, said channel extending transversely to the sinker channel  9 . The channel  24  contains a height-adjustable support  25  whose upper side forms a guiding surface  26  for the plush sinker  12 . On its underside, the plush sinker  12  has a straight guiding edge  27  that can slide back and forth on the guiding surface  26  in longitudinal direction of the edge (arrow  21 ). In so doing, the support  25  preferably remains at rest and defines the height position on which the plush sinker  12  is sliding. The actual guiding edge  27  is that part of the lower narrow side of the plush sinker  12  that can come into contact with the support surface  26 . Considering the support surfaces  20 ,  22 , the same applies with respect to the guiding edge  17 . Like the guiding edge  17  of the sinker  11 , the guiding edge  27  of the plush sinker  12  may also be located in two parallel planes at a distance from each other as to height. 
   On its front end adjacent to the head of the needle  2 , the plush sinker  12  may have a longitudinal slit  28  that is delimited by two preferably straight edges  29 ,  30 . This longitudinal slit  28  extends in longitudinal direction of the needle. Said longitudinal slit is disposed to act as a support slit for the support of the plush sinker  12  on a height-adjustable support  31  that is provided, e.g., on the end face of the knitting cylinder  6 . The edges  29 ,  30  form guiding edges that are preferably associated with planar guiding surfaces  32 ,  33  of the height-adjustable support  31 . Strips  47  (indicated in dashed lines in  FIG. 1 ) may be provided between the individual pairs of sinkers  20  on the support  31 , whereby the coulier sinker  11  and the plush sinker  12  are mounted between said strips. 
   As is obvious from  FIG. 1 , the guiding edges  17 , 18  of the coulier sinker  11  are at a distance from the guiding edge  27  of the plush sinker, relative to the longitudinal direction  21  of the sinker. As opposed to this, the guiding edges  27 ,  30  of the plush sinker  12  are at a distance from the guiding edge  17  of the coulier sinker  11 , i.e., relative to the direction of height. In the vicinity of the guiding edge  27  of the plush sinker  12 , the coulier sinker  11  has the recess  19 . In its end region away from the driving foot  14  and in the vicinity of the guiding edge  17  of the coulier sinker  11 , the plush sinker  12  has a recess in the form of the slit  28 . In its end region away from the driving foot  13 , the coulier sinker  11  has a slit  48 . The dimensions of this slit  48  are greater than those of the slit  28  of the plush sinker  12 ; preferably, it is of a greater height. As a result of this, the support  31  that extends into the slit  48  may be adjustable as to height, without thereby affecting the position of the coulier sinker  11 . In addition, the support  31  extends into the slit  28  of the plush sinker  12  and may be used to adjust the height of said sinker. The height of the slit  48  of the coulier sinker  11  defines the range of motion of the slit  28  in vertical direction of the plush sinker  12 . 
   The plush sinker  19  has a plush lug  34  for the temporary accommodation of a half-stitch for the formation of plush loops. By adjusting the height of the plush sinker  12  with respect to the coulier sinker  11 , it is possible to adjust the vertical distance of the upper edge of the plush lug  34  from the edge  23 , and thus the size or length of the plush loops. The plush lug  34  additionally acts as a downholder for the knit fabric located below said plush lug. 
   The knitting system described so far works as follows: 
   During operation, the needle  2  is moved up and down in vertical direction, whereby—in driven-out state, said needle picks up a base thread and a plush thread, respectively. With the base thread, the needle forms a knit fabric in that—during its reverse stroke—it pulls the thread through the half stitch seated on the needle shaft, said half stitch being seated on the edge  23 . In so doing, the needle sets the plush thread on the plush lug  34 . 
   If large plush loops are to be knitted, the plush sinker  12  must be adjusted upward. This is accomplished in that the supports  25 ,  31  are adjusted upward in vertical direction, i.e., synchronously to each other and relative to the knitting cylinder and to the sinker ring  8 . As opposed to this, in order to make the plush loops smaller, the supports  31 ,  25 , are adjusted downward in vertical direction. The adjustment motion is approximately parallel to the drive-out motion of the needle  2  and transverse to the longitudinal direction  21  of the sinkers  11 ,  12 . 
     FIG. 2  illustrates a slightly modified exemplary embodiment. Using the same reference signs, the above description applies accordingly. In addition, it is pointed out that the coulier sinker  11  is provided with a downholder  35  indicated in dashed lines, said downholder being located next to the plush lug  34 . The downholder  35  is disposed to prevent the rising of the knit fabric when the needle  2  is driven out. This function that is usually performed by the plush lug  34  of the plush sinker  12  is now transferred to the downholder  35  of the coulier sinker  11 . As a result of this, larger adjustment strokes between the coulier sinker  11  and the plush sinker  12  are possible, without negatively affecting their function. 
     FIGS. 3 through 5  show a modified embodiment of the above-described knitting system. In the description hereinafter, the same names and reference signs are used for the parts that essentially correspond to the above-described parts, in particular regarding their function, while reference is made to the above description in addition to the explanation hereinafter. 
   Referring to the embodiment in accordance with  FIG. 3 , the plush sinker  12  is arranged in the sinker channel of the sinker ring  8 , whereas the drawing-down sinker or coulier sinker  11  is seated in corresponding channels provided on the knitting cylinder  6 . In this exemplary embodiment, the sinker ring  8  assumes the function of the support  25 , and the guiding surface  26  assumes the function of the bottom  20 . Preferably, the coulier sinker  11  is held in a positive-locking manner on the knitting cylinder  6 . As a result of this, the coulier sinker  11  is held in place in a stationary manner and does not have a driving foot. Such channels may extend, for example starting from the end face of the knitting cylinder  6 , over one of its wall surfaces. The drawing-down sinker  11  that is used for stitch formation overlaps with the working part of the plush sinker  12  in the vicinity of the needle  2  or the hook  3 . Preferably, the plush sinker  12  is configured as a flat piece of sheet metal that may be laterally angled on the plush lug  34  and on its adjoining part. As is shown by  FIG. 5 , this feature may be utilized to adjust the upper edge  36  of the plush sinker  12  in the center between adjacent needles  2 ,  2 ′ or their hooks  3 ,  3 ′. As is shown in particular by  FIG. 4 , the drawing-down sinker  11  may have a wide support section  37  that bridges the distance between adjacent plush sinkers  12 . 
   Referring to this embodiment, the entire sinker ring  8  may be configured so as to be height-adjustable. Likewise, the sinker cam  16  may be synchronously height-adjustable in order to maintain a constant distance between the sinker cam  16  and the sinker ring  8 . The sinker ring  8  may be supported so as to be vertically adjustable by means of linear guides  38 ,  39 . The linear guides  38 ,  39  may be arranged on a sinker carrier ring  40 . For height adjustment, a height adjustment device  41  is then provided, e.g., between the sinker carrier ring  40  and the sinker ring  8 . The sinker carrier ring  40  may be attached to the needle cylinder  6  by means of a clamping device  42 . 
     FIG. 6  shows another modified embodiment. Fundamentally, is based on the embodiment in accordance with  FIG. 1  or  2 , whereby using the same reference signs, reference is made to the corresponding description. Different from the respective description, however, the support  31  is not arranged on the knitting cylinder  6  but on the sinker ring  8 . A corresponding projection of the support  31  comes into engagement with a slit  28 ′ that is located on the rear end of the plush sinker  12 . As opposed to this, the support  25  is arranged at a radial distance from the support  31 , e.g., on the end of the sinker ring  8  facing the knitting cylinder  6 . Whereas the guiding edges  27 ,  29 ,  30  of the plush sinker  12  are supported on the adjustable supports  25 ,  31 , the guiding edges  17 ,  18  of the coulier sinker  11  are supported on elements and surfaces  20 ,  22  that are stationary relative to the driving-out direction of the needle  2 . 
   The adjustment of the plush size is achieved by adjusting the height of the plush lugs  34  with respect to the edge  23  of the coulier sinker  11  as described above. 
   Based on the above-described embodiments, another embodiment of the invention is possible, whereby the coulier sinker  11  is driven by the plush sinker  12 . Only the plush sinker  12  has the foot  14 , whereas the coulier sinker  11  is connected to the plush sinker  12 , viewed in longitudinal direction  21  of the sinker. Viewed in the adjustment direction that corresponds to the driving-out direction of the needle, the coulier sinker  11  may be moved toward the plush sinker  12 . This is made possible by linear guides, for example, cam guides configured as long holes  43 ,  44  that are provided in one of the sinkers, for example, the plush sinker  12 ; whereas lugs, pins or other projections  45 ,  46  extending into these long holes  43 ,  44  are effective to attach the coulier sinker  11 . The adjustment of the plush sinker  12  relative to the coulier sinker  11  is achieved by the height adjustment of the coulier sinker  11  by means of the support  31 . The latter comes into engagement with the slit  28 ′ which, in this case, is provided on the coulier sinker  11 . This feature also allows a height adjustment of the plush loops. 
   A sinker set is being suggested, with the sinker set comprising a coulier sinker  11  and a plush sinker  12 . The sinkers  11 ,  12  can be moved together in a direction transverse to a knitting needle  2 . Said sinkers have spaced apart edges for the accommodation of stitches. In order to adjust the distance between these edges, the sinkers  11 ,  12  can be moved relative toward each other in the driving-out direction of the needle. To do so, they have spaced apart guiding edges  17 ,  18 ;  27 ,  29 ,  30  that are in contact various support surfaces or guiding surfaces  20 ,  22 ;  26 ,  32 ,  33 . 
   It will be appreciated that the above description of the present invention is susceptible to various modifications, changes and modifications, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. 
   LIST OF REFERENCE NUMERALS 
   
       
         1  Knitting system 
         2 ,  2 ′ Needle 
         3 ,  3 ′ Hooks 
         4  Latch 
         5  Needle channel 
         6  Knitting cylinder 
         7  Cylinder springs 
         8  Sinker ring 
         9  Sinker channel 
         10  Sinker pair 
         11  Coulier sinker 
         12  Plush sinker 
         13 ,  14  Driving foot 
         15  Cam channel 
         16  Sinker cam 
         17 ,  18  Guiding edge 
         19  Recess 
         20  Bottom 
         21  Sinker longitudinal direction 
         22  Guiding surface 
         23  Edge 
         24  Channel 
         25  Support 
         26  Guiding surface 
         27  Guiding edge 
         28 ,  28 ′ Longitudinal slit 
         29 ,  30  Edges/guiding edges 
         31  Support 
         32 ,  33  Guiding surfaces 
         34  Plush lug 
         35  Downholder 
         36  Edge 
         37  Support section 
         38 ,  39  Linear guide 
         40  Sinker carrier ring 
         41  Height adjustment device 
         42  Clamping device 
         43 ,  44  Long holes 
         45 ,  46  Lugs 
         47  Strips 
         48  Slit