Patent Abstract:
A tufting machine configured to provide needles co-linearly along a tufting plane from opposing needle holders provided in a needle module. The needle holders may be selectively latched with latch pins connected to limbs extending from a yoke connected to the push rod of the tufting machine. The needle holders are biased in a dis-engaged position with compression springs which extend between caps on the needle holders and a guide plate which locates the needle holders laterally while spacing the opposed needle holders from one another.

Full Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to tufting machines and more particularly to a tufting machine wherein the needles are selectively engageable and are carried in needle modules characterized by opposing pairs of needle holders which retain needles in an in-line, or linear arrangement. 
     Tufting machines which produce carpet typically include a large frame having a head within which a rotatable mainshaft is mounted and from which needle driving structure is supported for reciprocation of a multiplicity of needles. The frame also includes a bed within which oscillating loopers or hooks are mounted for cooperating with the needles to form loops of yarn, knives being used in conjunction with the hooks to cut the loops in many tufting machines. 
     As the tufting art has developed, there have been a substantial number of innovations to obtain unique patterning effects. One such innovation has been to shift the needles laterally in accordance with a pattern. Another innovation has been to provide each needle with a sew/no-sew capability by mounting the needles on individual needle holders which are reciprocated selectively by either being latched to or disengaged from a reciprocating latch bar, the latter being reciprocably driven continuously from mechanism driven by the rotating mainshaft. When latched to the latch bar, the needle reciprocates into cooperation with the hook to form a loop. The latching occurs by means of latch pins on pneumatic cylinders driven in accordance with a pattern. Machines of this type are known as controlled needle machines, and when each needle is individually controlled in this manner, it is known as an individually controlled needle machine. 
     A significant development in the tufting art was to combine the individual controlled needle machine concept with the shifting needle concept, and to feed the backing material intermittently. This provides a tufting machine wherein the needles may be threaded with a number of different yarns, e.g., yams of different colors, and a needle having a yarn of a particular color may be inserted into the backing at any of a selected number of locations so that precise multi-color patterns may be produced similar to the fine woven carpets produced by looms. A machine of this type is illustrated in Bardsley, U.S. Pat. No. 5,653,184. 
     Over the years, a number of improvements have been made to this design. Specifically, Bardsley, U.S. Pat. No. 5,974,991 provided an improvement to tufting machines to provide needle holders which are individually latched to a reciprocating drive bar and include externally mounted springs, each spring biasing a ratchet clamp which provides for sew/no-sew capability for respective needles 
     Other tufting machine designs apart from individually controlled needle machines have employed opposing pairs of needle holders including Bardsley, U.S. Pat. No. 4,790,252 and Price, U.S. Pat. No. 4,815,402. The &#39;252 patent allowed for only one, or the other, of the needle holders to be operated at by a particular push rod. This allowed for opposing needles to have different type yarns to create unique patterning effects. However, it was not possible to operate both pairs of opposing needle holders at the same time. 
     The &#39;402 patent discloses that opposing pairs of needles may be moved simultaneously, but does not teach the orientation of opposing pairs of needles in a single linear relationship. Furthermore, the &#39;402 patent does not contemplate opposing needle holders to be constructed in an easily replaceable needle module or modules. 
     Along with efforts to create unique patterning effects, an increase in detail has been desired. One way to increase the detail of the patterning effects is to decrease the gauge, i.e., the average distance between needle centerlines across the tufting machine. Although it appears that one would only need to reduce the diameter of the needles themselves and/or the thickness of the needle holders to decrease the gauge, this unfortunately weakens these components and increases their failure rate. 
     The &#39;402 patent teaches one way of decreasing the gauge of tufting machines, but improvements to this basic design are necessary in many applications. For instance, the &#39;402 patent contemplates two parallel and spaced apart rows of needles. The gauge on either of the two rows is half the gauge of the asserted gauge of the machine. The finer gauge is achieved as a result of staggered needles, not a single row of needles. While staggered needles may be satisfactory for some applications, tails of yarn formed by start up of needles in front row of needles are sewn through by rear needles. This is not desirable. 
     SUMMARY OF THE INVENTION 
     Consequently, it is a primary object of the present invention to provide a tufting machine having opposing needle modules providing a single row of needles arranged in a linear relationship. 
     It is another object of the invention to provide a needle module having two or more needle holders connected by guide plates to a mounting block adapted to be secured within a tufting machine. 
     It is a further object of the present invention to provide a needle module which supports two or more needle holders and a mounting block adapted to be secured within a tufting machine. 
     It is still a further object of the invention to provide a tufting machine with roughly half the gauge of adjacent needle holders. 
     Accordingly, the present invention provides a tufting machine having opposing sets of needle holders connected together in the form of needle modules. This configuration provides increased rigidity to the needle holders and is believed to speed the replacement of spent parts. The needle holders are preferably offset one from the other so that the gauge of the needle module may be half the gauge of either of the sets of opposing needle holders. Furthermore the needles from the opposing sets of needle holders are preferably arranged in a single linear relationship relative to one another. 
     Not only do needle holders gain stability from being connected to opposing needle holders, but the mounting block preferably connects the needle module to a post for lateral stability of the needle module. The connection to the post may allow for up and down adjustment of the needle module, while retaining the mounting block in a fixed position during operation of any of the individual needle holders. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a fragmentary vertical cross section view taken substantially through a tufting machine constructed in accordance with the principles of the present invention; 
     FIG. 2 is a fragmentary vertical cross section view taken substantially through a needle module shown in the tufting machine of FIG. 1; 
     FIG. 3 is a top view of a portion of the needle module shown in FIG. 2, namely the mounting block connected to guide plates, the needle holders and spring rods have been removed; and 
     FIG. 4 is an elevational perspective view of the needle module shown in FIG.  2 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In most senses, the tufting machine to which the present invention is applicable has a conventional construction. Thus, a detailed explanation of the workings of the machine will not be provided here. 
     The tufting machine  10  has a head  12  within which is mounted a conventional drive mechanism for reciprocably driving a plurality of laterally spaced push rods  14 , one of which is illustrated in FIG.  1 . The lateral direction is defined as transverse relative to the longitudinal direction in which a base material is being fed through the machine from the front to the rear thereof, as hereinafter described. The details of the drive mechanism within the head are not required for a disclosure of the present invention, but may be obtained from the disclosure in U.S. Patent No. 3,881,432 among others. 
     Adjacent the lower end of each push rod  14  is a yoke  18  somewhat similar to the yoke utilized in U.S. Pat. No. 4,815,402. The yoke  18  has a spanning member  20  secured to the push rod  14 , and a pair of downwardly depending limbs  22 , 24  spaced apart in the direction from front to rear of the machine. A laterally elongated latch carrying bar  26  having a substantially L-shaped cross section configuration is connected to the lower end of the limb or limbs  22  while a similar latch carrying bar  28  is connected to the lower end of the limb or limbs  24 . The latch carrying bars  26 , 28  have latch pins  30 , 32  which may be extended from within the latch carrying bars  26 , 28  as shown in FIG. 1 in a similar manner as described in the &#39;402 patent to selectively move individual needle holders  42 , 44  up and down as described in further detail below. 
     The needle module  40  is shown in FIG.  2 . The needle module  40  is comprised of at least two, and preferably more needle holders  42 , 44  which are on opposing sides of tufting axis  46 . FIG. 1 shows at least three needle holders  42 , 44 , 48  while FIG. 3 contemplates each needle module  40  having thirty five needle holders  42 , 44  disposed one per slot  50  or slot  52  in the guide plates  54 , 66 . Needle holder  42  is one of a set that opposes needle holder  44 , 48  about the tufting axis  46 . 
     FIG. 2 shows the needle module  40  comprised of a plurality of needle holders  42 , 44  which are connected to needles  58 . Tufting axis  46  is perpendicular to the tufting row  60 , shown in FIG. 4, to create a tufting plane wherein the needles  58  are substantially co-linear. As can be seen in FIG. 4, opposing needle holders  42 , 44  are constructed to overlap along base portions  62 , 64  so that the needles  58  may be arranged in a co-linear relationship. 
     Referring back to FIG. 2, one or more guide plates  54 , 66  are utilized to provide lateral support to the needle holders  42 , 44  while allowing the needle holders to move up and down within slots  50 , 52  in the guide plate. 
     The guide plates  54 , 66  shown in FIG. 3 are configured to work adjacent to one another such as containing a plurality of needle holders  42  and  44 . The guide plates have interfitting edges  68 , 70  which cooperate with one another to allow there to be no decrease in gauge where the adjacent guide plates  54 , 66  contact one another. The guide plates  54 , 66  are also preferably machined so that slots  50  substantially surround at least three sides of a needle module, while slots  52  may or may not be as encompassing as slots  50  are illustrated. 
     In order to assemble a needle module  40 , the needle holders  42 , 44 , are fitted with needles  58  and placed in the slots  50 , 52  of the guide plates  54 , 66 . Rods  72 , 74  are then placed through bores  76 , 78  in the base  62 , 64  of the needle holder. The rods  72 , 74  have compression spring members  80 , 82 . The compression spring members  80 , 82  allow for the spring members  80 , 82  and/or rods  72 , 74  to connect into caps  84 , 86  on the needle holder  42 , 44  by compressing the members  80 , 82  and inserting the rods  72 , 74 . The caps  84 , 86  have bores  88 , 90  which receive one of the spring members  80 , 82  or rods  72 , 74 . The caps  84 , 86  may be integral to the needle holder  42  or  44  or may connected thereto. The caps  84 , 86  or other portion of needle holder  42  or  44  may have ledges  92 , 94  which limit the travel of the needle holder  42  or  44  relative to the latch carrying bars  26 , 28  illustrated in FIG. 1 or other portions of the limbs  22 , 24  in a vertical direction. These ledges  92 , 94  may also assist in returning the needle holders  46 , 48  to top on release of latch pin  30 , 32 . 
     The guide plates  54 , 66  are connected to a mounting bar  96  such as with bolts  98 , 100  or otherwise. The mounting block arrangement provides horizontal stability to the needle holders  42 , 44  and thus to the needles  58  during tufting operation. 
     In prior art constructions, such as illustrated in FIG. 1 of U.S. Pat. No. 5,974,991, the only additional horizontal stability was provided by arm  26 . While this improvement is also present as arm  110 , it has been found that horizontal stability closer to the needles  58  is also advantageous. Guide  112  may also provide some horizontal stability for needle modules  42  and thus for the needle module  40 . 
     FIG. 3 show detail concerning the mounting block  96  and top plate  114  which is held by bolt  98  into mounting block  96 . Bottom plate  116  is utilized in a similar manner with bolt  100  to secure the guide plates  54 , 66  there between. The guide plates  54 , 66  are substantially parallel to one another and connected at spaced apart portions on the mounting block  96 . 
     FIG. 1 illustrates the operation of the tufting machine  10 . During operation the push rod  14  reciprocates up and down, thereby driving yoke  18  and limbs  22 , 24  up and down. The plurality of latch pins  30 , 32  are preferably individually controlled in order to tuft a desired pattern onto the backing  106 . When the latch pins  30 , 32  are extended into receivers, illustrated as channels  115 , of the needle holders  42 , 44  the needles  58  connected to the latched needle holders  42 , 44  are driven through the backing with yarn  118 , 120 . 
     If a particular needle holder  48  is not latched in its respective channel  115  during the downward stroke of the push rod  14 , the respective needle  58  carried by the needle holder  48  is not driven through the backing  106  for that particular stroke of the push rod  14 . Needle holders  42 , 44  have been latched, needle holder  48  has not been latched. 
     The mechanics of the needle module  40  during operation may be better understood by examining the enlarged illustrations in FIGS. 2 and 4. FIG. 2 shows needle holders  42 , 44  in a down position relative to the guide plates  54 , 66 , as well as the mounting bar  96 . The compression member  80 , 82  are at least partially compressed and the position would result in the needles  58  being driven through the backing (not shown in this Figure); this is an engaged position since the spring members  80 , 82  would be more compressed than when disengaged as shown by needle holder  48  in FIG.  1 . FIG. 4 shows needle modules  42 , 44  in an up position relative to the guide plates  54 , 66 , and the mounting bar  96 . The spring members  80 , 82  are not as compressed in FIG. 4 as they are in FIG.  2 . Note how the mounting bar  96  and guide plates  54 , 66  are lower in FIG. 4 than in FIG.  2 . The spring members  80 , 82  in FIG. 4 preferably are still under some compression so that the rods  72 , 74  are retained relative to the needle holders  42 , 44  since the rods  72 , 74  assist in maintaining the needle holders  42 , 44  in position relative to the guide plates  54 , 66  and thus the mounting block  96 . 
     As specific needle holders  42 , 44  are latched and driven to tuft, these particular needle holders  42 , 44  are driven downwardly while the guide plates  54 , 66 , the mounting bar  96 , and the needle holders  48  not latched remain stationary. In the latched needle holders  42 , 44 , the spring members  80 , 82  are compressed and the needle holders  42 , 44  continue through the downward stroke of the push rod  14 . On the upward stroke of the push rod  14 , the needle holders  42 , 44  may be unlatched or continue to be latched for another stitch. A bridge plate  122  may add to the stability of the guide plates  54 , 66  and thus to the needle module  40 . 
     Numerous alternations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Technology Classification (CPC): 3