Patent Publication Number: US-7707856-B2

Title: Take-off comb element

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application claims the priority of European Patent Application No. 07 024 749.9, filed Dec. 20, 2007, the subject matter of which, in its entirety, is incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to a take-off element for a take-off comb for a knitting machine or loop-forming machine. 
   In a knitting machine or loop-forming machine the stitches must be pulled off the needles after the stitch-forming operation. Frequently, a take-off comb is used for the start of the knit fabric. This comb is disposed to grasp the first row of stitches and pull them away from the knitting site in a controlled manner. 
   Such a take-off comb has been known, for example, from DE 10 2006 005 384 A. This comb comprises take-off elements that are held in a base body and are oriented parallel to each other, whereby said elements are provided with a head at their ends. This head acts as a hook. A slider is accommodated in the take-off element so as to be movable in longitudinal direction. This slider has a sharp end pointing at the head, which end can be pushed toward the head and away therefrom in order to close or open a thread-enclosing space. 
   A similar take-off element is known from EP 0 477 484 B1. In this case the take-off element provided with a head accommodates a slider that has a finger-like extension. The take-off element is provided with an opening that is diagonally oriented to the longitudinal direction and is delimited on parallel flanks, whereby the finger-like extension may extend through said opening in order to close or clear a thread-enclosing space. 
   The same literature reference also discloses a thread-take-off element that uses a hook supported in the thread take-off element for thread enclosure. This hook is provided on a slider. The hook tip may be pushed in or out of the thread-receiving space. 
   Furthermore, such an arrangement has been known from DE 40 03 667 C2. Again, a slider supported in the take-off element and being provided on the end side with a hook is used for grasping and releasing the thread. 
   When such take-off combs and take-off elements are used, neither the threads nor the take-off elements are to be subjected to excessive stress or even damage. 
   SUMMARY OF THE INVENTION 
   Therefore, it is the object of the invention to provide take-off elements that are robust and are gentle on the thread. This object generally is achieved with the take-off element in accordance with the invention that comprises a first part that has a thread-receiving opening. In addition, the take-off element comprises a second part with a head that is disposed to close the thread-receiving opening of the first part when both parts are moved relative to each other. The thread-receiving opening extends away from the head, and the head has an oblique surface facing the thread-receiving opening. 
   If the thread-receiving opening is open, i.e., for receiving or also for releasing a thread, the head is located at a distance from and in front of the thread-receiving opening. Considering the longitudinal direction of the parts, the head is moved away from the thread-receiving opening in longitudinal direction and is thus positioned longitudinally in front of the opening. When the thread-receiving opening is closed, the head is immersed at least a minimal distance into the thread opening in order to block said opening. 
   The oblique surface provided on the head acts as a sliding surface. It is oriented obliquely relative to the longitudinal direction of the individual parts of the take-off element. Preferably, said surface forms an acute angle with the slide-out direction of the second part that bears the head. 
   The first part and the second part are arranged so that they can be shifted relative to each other. In so doing, the term “longitudinal” refers to the longitudinal direction of the elongated parts and, at the same time, to the shifting direction of the two parts relative toward each other. Preferably, the two parts are supported against each other, for example, in that a first part of the two parts is supported in a longitudinally extending hollow space or channel of the second part of the two parts. In so doing, the second part may be fully or partially U-shaped, L-shaped or even be designed so as to be closed in cross-section all around along its entire longitudinal extension or a part thereof. In other words, the channel for the accommodation of the first part may be open at one or more points or also be closed across its longitudinal direction. 
   The thread-receiving opening of the second part preferably extends toward said part&#39;s free end and thus terminates at the face of the second part. Preferably, the thread-receiving opening comprises a section extending in longitudinal direction of the second part. This section is oriented parallel to, or at an acute angle, relative to the longitudinal direction. Preferably, the thread-receiving opening widens toward the face end of the second part. This can be achieved in that the thread-receiving opening of the second part has a funnel-shaped edge. Such an edge can be formed in that the flank of the thread-receiving opening that is initially oriented parallel to the longitudinal direction is provided in the end region—located in the region of the opening—at an acute angle relative to the longitudinal direction. It is sufficient if this is applicable to that flank of the thread-receiving opening that is located opposite the second part or a thin rod section thereof. In so doing, the thread can be guided between the respective flank and the first part or its head into and out of the thread-receiving opening. 
   Preferably, the head of the first part has an oblique surface that is adapted to the flank or to the edge of the thread-receiving opening. This adaptation may comprise, e.g., the feature that the oblique surface of the first part is oriented essentially parallel to the edge of the second part. 
   On the opposite side the head may be provided with a top surface that is inclined in the inverse direction relative to the oblique surface. In other words, the oblique surface and the top surface subtend an acute angle together with the longitudinal direction, whereby the vertices of these two acute angles face away from each other. 
   Additional details of advantageous embodiments of the invention are the subject matter of the drawing, the description and the claims. The description is restricted to essential aspects of the invention and miscellaneous situations. The drawings disclose additional details and are to be referred to as being supplementary. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a simplified illustration, vertically in section, of a knitting machine and a take-off device. 
       FIG. 2  is a perspective schematic representation of a take-off comb in accordance with  FIG. 1 . 
       FIG. 3  is a perspective view of the take-off comb in accordance with  FIG. 2 . 
       FIG. 4  is a longitudinal section of a take-off element as arranged in a large number in the take-off comb in accordance with  FIG. 3 . 
       FIG. 5  is a sectional view, along line V-V of the take-off element in accordance with  FIG. 4 . 
       FIGS. 6 through 10  show the take-off element in accordance with  FIG. 4  in various phases of grasping and releasing the thread. 
       FIG. 11  is a side view, in section, of an alternative embodiment of the take-off element. 
       FIG. 12  is a sectional view, along line XII-XII, of the take-off element in accordance with  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a take-off comb  1  on a knitting machine that is configured as a flat-bed knitting machine and uses two needle beds  2 ,  3 . Each of the needle beds  2 ,  3  comprises two parallel needle channels with needles  4 ,  5  supported therein, said needles being used to produce a knit fabric. Cams for driving the needles  4 ,  5  do exist, however, are not illustrated. Between the needle beds  2 ,  3  and the needles  4 ,  5  is a comb space  6  in which a take-off comb  7  may enter from the bottom. At that location, it is also possible to provide additional take-off means such as, for example, two take-off rollers  8 ,  9  that may come into engagement with the knit fabric when the knit fabric has been moved downward far enough by means of the take-off comb  7 . 
     FIG. 2  shows the take-off comb  7  by itself. This comb has a row of take-off elements  10  that are arranged next to each and are the same. The take-off comb  1  is shown again in  FIG. 3 . Said comb maintains the take-off elements  10  in parallel alignment at a distance from each other. The take-off elements  10  are elongated and each consists of at least two parts  11 ,  12  that are supported so as to be movable relative to each other in a longitudinal direction  13 . To achieve this, the first part is stationarily supported on an appropriate bed  14 . The bed  14 , for example, is a bent sheet metal component with teeth, between which the first part  11  is set. The second part  12 , for example, is set on a rail  15  that can be moved toward the bed  14 . The specific adjustment of the rail  15  in longitudinal direction  13  is achieved with a suitable drive  16 , for example, configured as a rail  17  that can be shifted in a direction transverse to the longitudinal direction  13 . The rail  15 , e.g., is connected to a foot of the second part  12  in order to move said second part relative to the part  11 . 
   One take-off element  10  is illustrated as being representative of all those illustrated in  FIG. 4  in longitudinal direction and in  FIG. 5  in cross-section. Its second part  11  forms an elongated body that comprises a channel  18  that is continuous in longitudinal direction. As is shown by  FIG. 5 , the channel  18  has, for example, a rectangular cross-section and is delimited by two lateral walls  19 ,  20 , as well as by two narrow-sided walls  21 ,  22 . Referring to the present exemplary embodiment, the second part  11  is thus configured as a rectangular pipe. Its end  23  (see  FIG. 3 ) that is set in the bed  14  is not shown in  FIG. 4 . The other end  24  ( FIG. 4 ) is disposed to receive a thread  25 . To accomplish this, said end has a thread-receiving opening  26  that extends from the face end  24  into the second part  11  and, in so doing, extends through the lateral walls  19 ,  20 , in particular. 
   The thread-receiving opening  26  has a slit-like section  27  that is delimited by two preferably straight flanks  28 ,  29 . The closed end of the section  27  is preferably formed by a rounded arch that connects the flanks  28 ,  29  to each other. Toward its open end  24 , the thread-receiving opening  26  widens. Whereas the flank  29  is straight up to the end  24 , the flank  28  preferably terminates in a slightly curved manner in an inlet section  30  that diverges away from the flank  28 . The inlet section  30  ends at the wall  21 . Below this end point  31 , the flank  29  may start diverging toward the wall  22 . This may be achieved in a curved, oblique or otherwise expedient form. In contrast, the inlet section  30  is preferably essentially straight. In so doing, a funnel-shaped mouth is formed between the flank  29  and the inlet section  30 . 
   The first part  12  is supported so as to be shiftable in channel  18 . The end  32  of the first part in engagement with the rail  15  is shown by  FIG. 3 , however, is not shown by  FIG. 4 . The first part  12  extends through the channel  18 , and its one end  33  projects from the end of the channel  18 , as shown by  FIG. 4 . Whereas the end  33  forms a head  34 , the first part  12  continues—extending from the head  34 —as a straight shaft  35  through the channel  28 . The preferably straight back of the shaft  35  abuts against the preferably also straight wall  22 . In the region of the thread-receiving opening  26 , said shaft&#39;s height measured from that point is preferably the same or slightly less than the distance of the inside surface of the wall  22  from the flank  29 . Outside the thread-receiving opening  26 , the shaft  35  of part  12  may have a height that is different therefrom, in particular, a greater height. 
   At least adjoining the head  34 , the shaft  35  has—at its site next to the thread-receiving opening  26 —a straight front  36  that is arranged parallel to the flank  29  or is in alignment or congruent therewith. Adjoining this front, the head  34  has an oblique surface  37  which, preferably, essentially follows a straight line. In contrast, the oblique surface  37  may terminate in the front  36  by way of a curvature. The oblique surface  37  is inclined at an acute angle α against the longitudinal direction  13 . This angle opens away from the end  24  of the second part  11  and thus its vertex faces the thread-receiving opening  26 , i.e., the first part  12 . 
   The oblique surface  37  of the first part  12  is preferably oriented approximately parallel to the inlet section  30  of the second part  11 . This need not be perfectly parallel. A few degrees of angular deviation are acceptable and useful in some cases. 
   The head  34  has a height which is preferably less than the distance between the walls  21 ,  22 . The oblique surface  37  terminates in a plateau  38  that is preferably arranged approximately parallel to the back  39  of the first part  12 . In so doing, the head  34  may move into the channel  18 —partially or fully—if needed. 
   With a rounded section, the plateau surface  30  terminates in a top surface  40  that extends up to the extreme tip  41  of the head  34 . The top surface  40  may be rounded or, as shown, consist of straight sections, or overall, of a single straight surface. Together with the longitudinal direction  13 , said surface subtends an acute angle β whose vertex faces away from the second part  12 . Consequently, the angles α and β face in different directions. In other words, the oblique surface  37  and the top surface  40  are inclined in different directions, i.e., independent of whether they have a straight or curved configuration. 
   The width of the first part  12  is smaller than the internal distance of the lateral walls  19 ,  20  from each other, so that a certain play exists, as is obvious from  FIG. 5 . This makes it possible for the parts  11 ,  12  to be shifted relative to each other and into each other in longitudinal direction. 
   The take-off element  10  described so far is disposed to work during take-up, enclosure and release of the thread  25  as is obvious from  FIGS. 6 through 10 : 
   In order to take up the thread the first part  12  is shifted relative to the second part  11 , in accordance with  FIG. 6 . In so doing, the head  34  moves out of the end  24  of the first part  11 . Its oblique surface  37  forms, with the inlet section  30 , a wide, preferably somewhat parallel-flanked, delimited gap that terminates in the section  27  of the receiving opening  26  and is at an oblique angle with respect thereto. In this state, the thread  25  may move into the thread-receiving opening  26 , as is shown by a series of arrows  42 . In so doing, it is not possible for the thread  25  to be caught at an edge, a hook or any other part of the take-off element  10 . 
   When the thread  25  has been received by the thread-receiving opening  26 , the parts  11 ,  12 —as indicated by the arrow in FIG.  8 —are moved relative to each other, so that the head  34 —as indicated in FIG.  8 —penetrates into the end  24  of the second part  11 . In so doing, the oblique surface  37  enters the channel  18  and arrives behind the inlet section  30 . In so doing, the thread-receiving opening  26  is closed and the thread  25  is trapped therein. In this condition, the knit fabric comprising the thread  25  can be taken off as indicated in  FIG. 9 . 
   The thread  25  may be released as shown by  FIG. 10 . To accomplish this, the parts  11 ,  12  are again moved toward each other in such a manner that the head  34  moves out of the channel  18  and that the oblique surface  38  delimits a gap with the inlet section  30 . This gap preferably has a size at least equal to the width of the section  27 . The thread-receiving opening  26  is thus cleared. The thread  25  may slide out of the thread-receiving opening  26 , as indicated by a series of arrows  43 . 
   Neither on its path into the thread-receiving opening  26  ( FIG. 7 ) nor on its path out of the thread-receiving opening  26  ( FIG. 10 ) is it possible for the thread  25  to become caught on parts of the take-off element  10 , to bend said element or cause any other wear. In addition, the thread  25  is treated gently. It can neither be pierced nor torn. 
   The described embodiment may be modified. For example,  FIG. 11  shows an embodiment with a partially open channel  18 . Referring to this embodiment, parts of the otherwise existing wall  21  have been omitted. Thus, in accordance with  FIG. 12 , the part  12  is configured as an open U-profile. Other than that, the above description applies analogously with reference to the same reference signs. 
   A take-off element  10  for the gentle treatment of the thread and for simple handling comprises two parts  11 ,  12 , whereby at least one of said parts is arranged so as to be adjustable in longitudinal direction relative to the other. Whereas one of the parts  11  has a longitudinal slit  27  for receiving a thread  25 , the other part  12  is provided with a head  34  extending on one side away from the shaft  35 , said head being movable from the outside to the thread-receiving opening  26  in order to close said opening and away therefrom in order to clear said opening. The head  34  has an oblique surface  37  which is disposed to close the thread-receiving opening  26 . The new take-off element  10  does not have a hook and thus does not exhibit any problem regarding process reliability. Its part  12  has a robust slider head, thus avoiding potential deformations on the head. Considering process reliability, the take-off element  10  permits a perfect insertion and release of the thread  25  of a knit fabric. 
   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  Take-off comb 
         2 ,  3  Needle beds 
         4 ,  5  Needles 
         6  Comb distance 
         7  Take-off comb 
         8 ,  9  Take-off rollers 
         10  Take-off element 
         11  Second part 
         12  First part 
         13  Longitudinal direction 
         14  Bed 
         15  Rail 
         16  Drive 
         17  Rail 
         18  Channel of the second part  11   
         19 ,  20  Lateral walls 
         21 ,  22  Walls 
         23 ,  24  Ends of the second part  11   
         25  Thread 
         26  Thread-receiving opening 
         27  Section of the thread-receiving opening  26   
         28 ,  29  Flanks of the thread-receiving opening  26   
         30  Inlet section of the thread-receiving opening  26   
         31  End point of the inlet section  30   
         32 ,  33  Ends of the first part  12   
         34  Head of the first part  12   
         35  Shaft of the first part  12   
         36  Front of the shaft  35   
         37  Oblique surface of the head  34   
         38  Plateau surface of the head  34   
         39  Back of the first part  12   
         40  Top surface 
         41  Tip 
         42 ,  43  Arrows