Abstract:
A twine restrictor is disclosed having the advantages of simplicity and reliability. The twine restrictor is generally formed from solid or hollow stock. It is left free floating while being restrained sufficiently to avoid loss. Twine is passed over a substantially horizontal surface of a twine arm assembly and the twine restrictor is simply placed on the twine, providing a force up to a value equal to its weight on the twine. The twine restrictor is unaffixed and no springs are required.

Description:
TECHNICAL FIELD  
       [0001]     The principles disclosed relate to improvements to round balers used for harvest of agricultural crops. More particularly, the invention relates to improved reliability of a mechanism that feeds and controls twine to a formed cylindrical bale for wrapping the bale. The invention further relates to a feed mechanism configured to minimize potential negative influences related to movement of the twine during the portion of the baling cycle when the bale is being formed, while the twine is being held in position, ready to wrap the bale.  
       BACKGROUND  
       [0002]     Many mechanisms have been developed for wrapping bales with filament typically referred to as twine. The twine is held in a staging position while a bale is being formed. An end of the twine is positioned to engage the moving periphery of the formed bale. This engagement pulls the twine which subsequently wraps the bale.  
         [0003]     Restricting or tensioning devices usually comprise a spring-loaded plate, wherein the twine is held under spring tension between the plate and another surface. Adjustments are required when changing twine types and as conditions change.  
         [0004]     Meiers, in U.S. Pat. No. 4,502,646, discloses such a twine tensioning device comprising a plate held against the twine by a spring.  
         [0005]     U.S. Pat. No. 5,215,006 by Jennings et al. is for a twine clamp used in large round balers. The clamp is not usually used for providing tension while the twine is feeding onto the bale, but Jennings et al. disclose that the clamp could be used thus. No details are included.  
         [0006]     There is need, therefore, for a reliable, simple twine restrictor.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the present invention is to provide a twine restricting device with improved reliability for large round balers. An additional object of this invention is to provide a simple tensioning device having a minimum of moving parts. Still another object is to provide a method and apparatus for twine restricting not needing adjustment when using different styles or brands of twine.  
         [0008]     To accomplish the aforementioned goals, twine strands are passed under a twine restrictor of a predetermined weight, to provide restriction to its travel. In an additional embodiment, the twine passes over the twine restrictor. Whether the twine passes over or under the twine restrictor, the path taken by the twine is sufficiently curved or bent so as to provide restriction to its travel.  
         [0009]     The cross-sectional shape of the twine restrictor may be round, rectangular, octagonal, trapezoidal, or other suitable shape. The twine restrictor may be captive in a sufficiently enclosed framework so as to keep it engaged with the twine most of the time. In an additional embodiment, the twine restrictor may engage holes in the framework at the twine restrictor&#39;s ends, the holes being sufficiently large to allow the twine restrictor to be free-floating, yet held captive to avoid being lost.  
         [0010]     For the purposes of the present disclosure, “free floating” shall be defined as unaffixed, that is, not bolted, screwed, clamped, etc. A free floating twine restrictor may be constrained so as to avoid being lost. Such a constraint may comprise an enclosure in which the twine restrictor is free floating, or the ends of the twine restrictor may engage oversized holes whereby the restrictor is constrained but free floating. In particular, a twine restrictor held in place with a bolt and spring and allowed to flex only with the spring is not free floating according to this definition.  
         [0011]     The twine restrictor may be made from various materials and in various forms. That is, it may be made from solid steel bar stock, hollow stock, aluminum, or other materials or forms depending on the required weight. The present invention is not limited in material or form. Preferably, the twine restrictor will be made from a non-corrosive material or be coated with a plating that resists corrosion. Resistance to wear may also be an issue with some twines in some applications.  
         [0012]     Typically, the twine restrictor of the present invention is located on an end of the twine arm assembly closest to the bale. However, the present invention is not limited to a particular location for the twine restrictor. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a schematic side view of a left side of a round baler;  
         [0014]      FIG. 2  is a schematic front view showing the tongue beam and twine tie of a round baler;  
         [0015]      FIG. 3  is a schematic top view of the tongue and twine tie assembly in an intermediate position;  
         [0016]      FIG. 4  is a schematic top view of the tongue and twine tie assembly in a retracted position;  
         [0017]      FIG. 5  is a schematic top view of the tongue and twine tie assembly in an extended position;  
         [0018]      FIG. 6   a  is a cross-section taken along  6 - 6  identified in  FIG. 4 ;  
         [0019]      FIG. 6   b  is a cross-section taken along  6 - 6  identified in  FIG. 4 ;  
         [0020]      FIG. 7  is an isometric view of the twine arm assembly of the present invention with two strands of twine;  
         [0021]      FIG. 8  is an isometric view of the twine arm assembly of the present invention with four strands of twine;  
         [0022]      FIG. 9  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor;  
         [0023]      FIG. 10  is a side elevation view of the exit end of the twine arm assembly showing two twine restrictors;  
         [0024]      FIG. 11  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor having an octagonal cross-section;  
         [0025]      FIG. 12  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor having a rectangular cross-section;  
         [0026]      FIG. 13  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor having a trapezoidal cross-section in a first orientation;  
         [0027]      FIG. 14  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor having a trapezoidal cross-section in a second orientation;  
         [0028]      FIG. 15  is a side elevation view of the exit end of the twine arm assembly showing a twine restrictor residing beneath the twine;  
         [0029]      FIG. 16  is an isometric view of the twine arm assembly of the present invention with an additional embodiment of the twine restrictor;  
         [0030]      FIG. 17   a  is a cross-sectional view of a cylindrical twine restrictor made from solid bar-stock; and  
         [0031]      FIG. 17   b  is a cross-sectional view of a cylindrical twine restrictor made from hollow stock. 
     
    
     DETAILED DESCRIPTION  
       [0032]     With reference now to the various figures in which identical elements are numbered identically throughout, a description of various exemplary aspects of the present invention will now be provided. The preferred embodiments are shown in the drawings and described with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the embodiments disclosed. Any references, herein, to directions will be determined by facing in the direction of travel of the baler during normal operation.  
         [0033]      FIG. 1  illustrates a schematic side view of the left side of one configuration of a round baler  16 , known as a variable chamber baler. The baler  16  is shown with a formed bale  12 , and illustrates the main functional components. In this type of baler, a number of bale forming belts  20 , of a known flat configuration, typically approximately one quarter to one half inch in thickness and four to fourteen inches in width, are routed over several belt rollers in fixed positions, including the rollers  32 ,  34 ,  36 ,  38 ,  42 ,  44 ,  46  and  48 . These fixed belt rollers  32 ,  34 ,  36 ,  38 ,  42 ,  44 ,  46  and  48  are supported by bearings mounted to a left side panel and to a right side panel for rotation so that the belts are able to move, rotating the forming bale  12  in the direction indicated by the arrow  13 . The panels are not shown, as many configurations of the panels are well known. The side panels are spaced apart by various components including the rollers  32 ,  34 ,  36 ,  38 ,  42 ,  44 ,  46  and  48  and a tongue  66 . The spacing between the side panels defines the width of the bale forming chamber and the length of the cylindrical bale  12  that that will be formed by the baler. The belts  20  are kept under tension by a belt tightener  82 , so that the belts  20  define a variable-sized bale chamber.  
         [0034]     Another type of round baler, known as a fixed chamber baler, does not include the variable size bale chamber feature, and typically includes rolling elements that are in fixed positions to define a bale chamber of a fixed diameter. The present invention is useful for either fixed or variable chamber balers.  
         [0035]     At least one of the fixed position rollers  32 ,  34 ,  36 ,  38 ,  42 ,  44 ,  46  and  48  of the baler  16  is powered by a drive system that includes a right-angle gearbox  62  connected at its input shaft to a driveline  64 . The gearbox  62  transfers power from a towing vehicle  10  through an output shaft to chains and sprockets that transfer power to the driven roller(s) and to the pickup  80 , which functions to lift crop material  14  from the ground and into engagement with a roller  72 , belts  20 , and a starter roller  55  which cooperate to form the crop material  14  into a cylindrical bale  12  enveloped by the belts  20 . The chains and sprockets are not illustrated.  
         [0036]     Once a bale  12  has reached its desired size, a wrapping material is applied to the outer circumference of the bale  12  while still in the baler  16 . After the bale  12  is thus wrapped, a tailgate, which comprises a portion of the side panels and the rollers  42 ,  44 , and  46 , will pivot around a tailgate pivot  94 , allowing the finished bale  12  to drop out of the baler  16 .  
         [0037]     The known wrapping materials include either a filament, typically know as twine, made from either natural fibers or various types of plastic, and sheet-type netwrap, typically made of a type of plastic material. Twine is typically inserted into a crop inlet area  90  of the baler  16  by a mechanism  100  and applied in a spiral fashion by moving from one side panel across to the opposite side panel while the bale  16  is rotating. Sheet-type netwrap is known to be applied to the bale  16  by a netwrap mechanism  18 , as described in coassigned, copending patent application U.S. Ser. No. 10/719,460, herein incorporated by reference.  
         [0038]     Twine is stored on both sides of the baler  16 , in a supply roll known as a twine ball  92 , typically with more than one twine ball  92  on each side of the baler  16 . The twine is routed from the twine ball  92 , along the front of the baler  16  to the twine mechanism, along a path generally labeled as  96 . There can be a single strand or multiple strands of twine routed from each side to the twine tie mechanism  100 . The twine routing is typically defined by tubes and other guides, which are not illustrated in this disclosure, and each strand of twine passes through a tension plate  98 , located near the twine ball. The tension plate  98  clamps the twine to ensure that the twine is under some tension as it passes along the path  96 .  
         [0039]     The twine is routed to the twine tie mechanism  100 , illustrated in  FIG. 2  as located beneath the tongue  66 , including a drive assembly  110 , a twine arm assembly  200  and twine cutter assembly  300 .  
         [0040]     The drive assembly  110  can be seen in more detail in  FIG. 3 , with the twine arm assembly  200  in a partially extended position, to include an actuator  112  connecting to a drive gear  114  which pivots about a first axis  116 . The drive gear  114  meshes with a driven gear  204 , which pivots about a second pivot axis  206 . The actuator  112  can extend to rotate the twine arm assembly  200  counter-clockwise, toward a fully extended position as illustrated in  FIG. 5 , or retract to rotate the twine arm assembly  200  clockwise towards the fully retracted position as illustrated in  FIG. 4 . In the fully retracted position the twine arm assembly  200  is positioned beneath the tongue  66 , cut-away in  FIG. 4  to better illustrate the twine cutter assembly  300  including a link  302 , a bracket  304  pivoting about an axis  306 , a twine knife  308 , and a reaction bracket  310 .  
         [0041]      FIGS. 6   a  and  6   b  illustrate the twine arm assembly  200  and twine cutters of the present invention in more detail, with the twine arm assembly  200  in a position with the strands of twine  96 L and  96 R being pulled in a direction  97  by the bale in  FIG. 6   a . As the twine tie cycle reaches the end of the cycle the twine arm assembly  200  will move from left to right to a position where the twine is cut as shown in  FIG. 6   b , as happens when the twine arm assembly  200  activates the rod  302  which rotates the twine knife  308  into the path of the twine, pressing it against the reaction bracket  310  to guarantee the twine is cut.  
         [0042]      FIGS. 6   a  and  6   b  further illustrate the twine arm assembly  200  of the present invention to include a twine restrictor  220 , which is constructed of a round bar. The restrictor  220  is shown on top of the strands of twine  96 L and  96 R.  FIG. 7  further illustrates a right-side twine strand  96 R and left-side twine strand  96 L passing from a twine guide  240 , illustrated as a porcelain insulator, at a twine entry end  212 , near the driven gear  204 , to an exit end  214 . Each strand of twine  96 L and  96 R is selectively located in one of several alternative apertures in a guide block  268  at the exit end  214 , allowing control of the spacing between the strands of twine  96 L,  96 R as it is installed on the baler  16 .  
         [0043]     Each strand of twine  96 L and  96 R passes under a restrictor  220  that is located near the exit end  214 . The twine arm assembly  200  is constructed in two parts; a bottom U-shaped channel  216 , and a top U-shaped cover  218 , as shown in  FIG. 6   a . To initially route the twine strands through the twine arm assembly  200 , preparing it to wrap a bale  12 , the top cover  218  is removed by the operator, and the twine strands routed from the twine entry end  212  to the exit end  214 , while the twine restrictor  220  is removed with the cover  218 . The operator will position the twine strands  96 R,  96 L to extend beyond the end of the twine arm assembly  200  to ensure proper (reliable) operation. Once the twine is properly positioned, the twine restrictor  220  is installed on top of the twine strands  96 R,  96 L, as illustrated in  FIG. 7 , with the cover  218  still removed. The twine restrictor  220  is supported by the top surface  260  of the U-channel  216  while being retained in that position by the sides  262 ,  264  and a front side  266 , which is formed by the guide block  268 . The cover plate  218  will be secured to the U-channel  216 , as illustrated in  FIG. 6   a , to hold the twine restrictor  220  in place.  FIG. 16  illustrates an alternate embodiment where the twine restrictor  228  is longer than the width of the U-channel, and passes through oversized slots while roll pins  229  retain the twine restrictor  228  to the twine arm assembly  200 , even with the cover  128  removed. The apertures in the sides of the U-channel, not shown, will be sized such that the weight of the restrictor  228  is supported by the top surface  260 , or strands of twine  96 R,  96 L. The twine restrictor  228 , bearing on top of the twine strands, minimizes the possibility of undesirable movement of the twine strands, while the twine arm assembly  200  is held in the position under the tongue  66 , as shown in  FIG. 4 , while a bale  12  is being formed.  
         [0044]     Once the bale  12  is formed, the twine arm assembly  200  is rotated, moving the exit end  214  towards the formed bale  12 , to initiate the wrapping process. As the exit end  214  reaches the formed bale  12 , the twine strands  96 R,  96 L that extend from the twine arm assembly  200  will be pulled into the baler  16 . The twine strands  96 R,  96 L will then be moving rapidly, causing the twine restrictor  200  to roll, while twine is being pulled from the supply balls  92  and through the twine tension plates  98 . At the end of the twine cycle the twine arm assembly  200  will be rotated to the position illustrated in  FIG. 6   b , where the twine  96 R,  96 L will be cut. The restrictor  220  of the present invention will restrict the twine&#39;s  96 R,  96 L tendency to snap back as the tension in the twine  96 R,  96 L is suddenly eliminated after it is cut. It will also again minimize the possibility of undesirable movement of the twine strands  96 R,  96 L, while the twine arm assembly  200  is held in the position under the tongue  66 .  
         [0045]     In this manner the single element, twine restrictor  220 , is able to hold more than one strand of twine.  FIG. 8  illustrates the twine arm assembly  200  with four strands of twine, as would be possible by routing two strands  96 L 1  and  96 L 2  from the left side and two strands  96 R 1  and  96 R 2  from the right side.  
         [0046]      FIG. 9  illustrates a detailed side view of the exit end  214  of the twine arm assembly  200  with the bottom U-Shaped channel  216  supporting the twine restrictor  220 , positioned on top of the twine strands  96 L and  96 R. If the twine is not being pulled into the baler  16 , the weight of the twine restrictor  220  traps the twine and holds it in position. As the twine arm assembly  200  is extended into the baler  16 , to introduce the strand of twine so that the twine is pulled into the bale  12  in order to wrap the bale  12 , the twine restrictor  220  will continue to bear on the twine strands. As the twine moves, the roller will rotate, causing little drag. If a single twine restrictor  220  is not sufficient to hold the twine strands  96 R,  96 L, then a plurality of twine restrictors  220  may be utilized, as illustrated in  FIG. 10 . Other options are shown in  FIG. 11 , where the twine restrictor  222  is constructed from a shaft with an octagonal cross-section, and  FIG. 12  with a square cross section  224 .  FIGS. 13 and 14  illustrate restrictors  226  with trapezoidal cross-sections, providing a certain restriction to twine movement when installed in a first orientation as shown in  FIG. 13 , and a different restriction when installed in a second orientation as shown in  FIG. 14 . In certain cases, the system may function best when there is no added restriction, in which case the system of the present invention can easily be adapted as illustrated in  FIG. 15 , with the twine being routed on top of the restrictor  220 . The appropriate cross-section, or orientation of the twine restrictor and twine can be selected to provide a desired restriction to the movement of the twine strands  96 L and  96 R.  
         [0047]      FIGS. 17   a  and  17   b  illustrate cross sections of twine restrictors  220  to show that the twine restrictors  220  may be fashioned from solid ( FIG. 17   a ) or hollow ( FIG. 17   b ) stock depending on weight requirements. Any of the embodiments of twine restrictors  220 ,  222 ,  224 ,  226 ,  228  shown herein may be constructed of solid or hollow stock. The present invention is not limited to a particular material from which the twine restrictor  220  is made.  
         [0048]     With regard to the forgoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the size, shape and arrangement of the parts without departing from the scope of the present invention. The true scope and spirit of the invention are indicated by the broad meaning of the following claims.