Abstract:
A bale binding machine utilizes controlled pins to guide the path of a wire (or strap) around a bale such that strength-reducing bending is not introduced to the wire. The bale binding machine binds bales of fibrous bulk materials such as cotton and nylon.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     None. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a bale binding machine utilizing controlled pins and, more particularly, a bale binding machine that utilizes controlled pins to guide the path of a wire (or strap) around a bale such that strength-reducing bending is not introduced to the wire. The bale binding machine binds bales of fibrous bulk materials such as cotton and nylon. 
     2. Related Art 
     Fibrous bulk materials include cotton and nylon. Fibrous bulk materials are commonly formed into bales by compression and binding. There is a continuing need in the art to improve this bale binding process by improving efficiency, reliability and accuracy. There are various constraints on improvements to the bale binding process including: (1) the nature of the fibrous material; (2) the compressive force or loading; and (3) the loading of the fibrous material into a bale compression box ; (3) wrapping baling wire around the bale. 
     These constraints interact to create control challenges. For example, the compressive force required to compress bulk fibrous material to a certain physical volume fluctuates. Specifically, variations in heat and humidity cause the fibrous material to expand or contract, with an expanded material volume requiring more compressive force to compress the material to a particular volume, and a contracted material volume requiring less force for compression. In addition, when a compressed, originally-contracted material is later exposed to heat and humidity, the material attempts to expand, imposing additional stresses on the baling wire. 
     Due to the very nature of any bulk material, when the material is loaded into the compression box prior to compression, the bulk material can become unevenly distributed within the compression box. When the compressing ram compresses the unevenly distributed bulk material, some portions of material experience greater compression than other portions. After the baling wires are applied and secured around the bale, the compression on the bale is released and the fibrous bulk material of the bale expands in volume. Because the distribution of material in the bale is uneven, a varying amount of tension is experience by the baling straps or baling wires. An excessive amount of tension in baling straps or baling wire applied through the expansion of bulk material can cause the baling strap or wire to fail. Alternatively, the baling wire has the potential to elongate have the length altered in some way. 
     Baling wire or baling strap performance requirements vary depending on the bulk material at issue. Such requirements range from general operational parameters to industry to standard specifications. The Cotton Council has a baling constraint wherein the length of the wire (or strap) around the bale must fall within a particular range and the tension that the wire (or strap) must withstand has a particular range. 
     U.S. Wire Tie, a company based in Carthage, Mo., has an existing system, the 340 Series, for baling bulk materials. This system uses a hydraulic twist knot wire tying system to bind bales. In such systems, 8 gauge wire is utilized as the baling wire. However, hydraulic systems are slowly becoming less desirable because any leak of hydraulic fluid onto the bulk material ruins the material and requires that the baling equipment be cleaned prior to restarting the baling operation. To avoid the ruination of bulk material and prevent the loss of operational time and avoid the accompanying cleaning costs, this, there is a need in the art to provide a power source for a baling machine that does not use hydraulic fluid. 
     As the inventors have explored the feasibility of electric systems, it has been discovered that such systems require electrically-powered, knot-tying heads that are substantially larger than hydraulic knot-tying heads. This larger dimension, however, results in an inability to feed the wire around the bale with enough clearance from the bale to permit tying and still fall within the required length and strength specifications of the Cotton Council. Alternatively, it has been discovered that the baling wire must be sharply bent to achieve the length specification of the Cotton Council. However, any sharp bend in the wire decreases the ability of the wire to withstand the expansion forces of a cotton bale that has been released from compressive force. 
     In addition, as bulk material such as cotton or nylon is a commodity item, production costs are always examined to determine where such costs may be lowered. One heretofore fixed cost is the baling wire or strap. Costs for baling wire or baling strap are generally based on volume. Accordingly there are no options for lowering such cost without increasing purchasing volume. However, if the gauge of the wire can be increased without sacrificing strength, the smaller diameter wire (or strap) will be cheaper, thus reducing overall production cost. 
     Accordingly, there is a need in the art to provide an electrically powered baling system that can meet the requirements of the Cotton Council. 
     There is also need in the art to provide a baling system that utilizes a smaller gauge of wire for baling bulk material. 
     SUMMARY OF THE INVENTION 
     It is in view of the above problems that the present invention was developed. The invention controls stresses applied to a baling wire by employing pull pins. The wire is directed around the pull pins to moderate bending in the baling wire. This is because the pull pins are disposed between a wire track and a wire tying head. Without the pull pins, the baling wire would circle around the wire track and bend sharply to (and travel linearly to) the tying head. With the pull pins, the wire assumes an arcuate shape between the wire track and the tying head. It is critical to the invention that the pull pins are longitudinally movable, with the use of a solenoid. The pull pins are extended to guide the baling wire, and are retracted to avoid interference when the bale is released from a compression box and meets the wire. 
     Because the pins reduce wire stress, while avoiding interference when the bale is released, the present invention permits a reduction in wire size to 10 gauge wire. While less expensive, 10 gauge wire was, until the present invention, considered incapable of reliably binding bales of cotton. 
    
    
     Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings: 
     FIG. 1 is a plan side view of the preferred embodiment of the present invention. 
     FIG. 2 is an exploded perspective view of a wire feeding and tying assemblies in combination with a tie pull pin device of the preferred embodiment of the present invention. 
     FIG. 3 is a side view of a portion of the preferred embodiment of the present invention depicted in FIG. 1 showing the general area of the assembly depicted in FIG.  2 . 
     FIG. 4 is a cross-sectional view taken along line  4 — 4  in FIG. 1 of a wire guide track in a closed configuration for controlling the path of the binding wire. 
     FIG. 5 is a cross-sectional view taken along line  5 — 5  in FIG. 1 of the wire guide track in an open configuration for releasing the binding wire following its fastening into a closed loop. 
     FIG. 6 is a front plan isolated view of the wire guide tracks and tie pull pins of the preferred embodiment of the present invention depicting the tie pull pins in a first position for fastening the wire into a closed loop, wherein portions of the baling machine have been removed to enhance clarity. 
     FIG. 7 is a front plan isolated view of the wire guide tracks and tie pull pins of the preferred embodiment of the present invention depicting the tie pull pins in a second position for releasing the wire during its fastening into a closed loop, wherein portion of the baling machine have been removed to enhance clarity. 
     FIG. 8 is a view of a wire twist knot (right side) with a gentle bend angle resulting from the preferred embodiment of the present invention and a wire twist knot (left side) with a sharp bend angle which results without the benefit of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the accompanying drawings in which like reference numbers indicate like elements, FIG. 1 illustrates a side view of the preferred embodiment of the present invention, a bale forming and binding apparatus  10 , in two arrangements; the solid lines depicting the arrangement wherein the movable wire guide section  48  completes the wire guide track trajectory  45  as when the binding operation is occurring, and the broken lines depicting the arrangement wherein the movable wire guide section  48  is in a position  48   a  when a bale (not shown) is removed from the bale forming and binding station  16 . A floor plate  12  supports vertical support stands  14  on either side of the bale forming and binding station  16 . A binding assembly carriage  18  is borne by stands  14 . The base extension  20  of the carriage  18  carries the fixed tying heads  40  and attached wire guide track sections  39 . The carriage  18  translates in a direction perpendicular to the plane of the drawing along an overhead track  22  attached to the upper rear extent of the stands  14  and its motion is controlled by drive  24 . 
     Extending from the upper forward extent of the stands  14  are a pair of pivot axis brackets  25  holding the pivot axis  26  which carries the movable guide track support strut assembly  28 . Extending forward from the center of the strut assembly  28  is a member  30  pivotally connected at pin  32  to the piston arm  34  which is extended and withdrawn by action of the piston  36 . The action of the piston  36  may be by any means but is preferably pneumatic. 
     Guide track section  44  lies in a channel within the bale forming compressor  42 . Compressor  42  accommodates the wire trajectory above the bale forming station  46  containing the bulk material (not shown). The positions  28   a ,  34   a ,  36   a  and  48   a  show the parts  28 ,  34 ,  36  and  48  in their respective positions when the apparatus is in a second position whereby the movable guide track section  48  is pivoted away from the bale forming station  46 . The upper movable guide track section terminus  50  and the lower movable guide track section terminus  52  meet the guide track sections  46  and  38  respectively to complete the wire guide track. The dashed line  54  illustrates the path of motion of the lower terminus  52  as it transits between arrangements. 
     Referring to FIG. 2, a head frame gusset  56  attached below to the base extension  20  (not shown) anchors head mounting plate  58  which in turn anchors track mount  60 . Head mounting bracket  62  is affixed at its front to head mounting plate  58  and along its side to wire tie head  40  which in turn is attached at the rear and below to tie head motor mount  64  through which a servo motor and gear reducer  66  connect to tie head  40 . Head mounting plate  58  bears along its upper extent electric wire feed and tensioner  41  which is driven by a servo motor and gear reducer  66  through feed and tension servo adapter plate  68 . 90° wire track entry guide  70  connects at its upper rear to tensioner  41  and at its lower front to an entry section of the wire track guide (not shown). Upper and lower tie pull pin assemblies  80  are supported by pin brackets  72  which in turn are affixed to head mounting plate  58  for the upper pin assembly and to track mount  60  for the lower assembly. The brackets  72  bear tie pin cylinders  74  which maintain and control tie pull pins  76  which in turn translate on their longitudinal axis through pin alignment couplers  78 . 
     Referring to FIG. 3, the assembled configuration of the parts shown in FIGS. 1 and 2 is shown in a side view of the apparatus, centered in the area of the tie heads  40 . The tie pins  80  are seen in their spatial relation to the wire guide tack sections  38 ,  44  and  48 ; and in relation to the tie head  40 . The motion of the tie pins  80  is preferably in a linear direction perpendicular to the plane of the Figure in the preferred embodiment. However, this motion is not limited to a linear direction, as any movement which accomplishes the object of selectively modifying the wire path and accomplishes the object of selectively moving out of the wire path is also within the scope of the invention. 
     Referring to FIGS. 4 and 5, cross-sectional schematic views of a wire guide track section  38 ,  44  or  48  in a closed configuration  100  and an open configuration  100   a  are illustrated. FIG. 4 shows the wire  112  in the channel  106  formed between the two sides  102  of the track configuration  100 . A space  104  between the sides  102  is closed to passage of the wire in the configuration  100 . In FIG. 5 an open configuration  100   a  of a wire guide track section  38 ,  44  or  48  is shown wherein the sides  102  are in the arrangement  102   a  spaced sufficiently apart as mediated by the spring means  110  so that channel  106  is decomposed into the opposing hollows  108  and the space  104   a  is able to admit passage of the wire  112  in the direction of the arrow towards the bale (not shown). 
     Referring to FIGS. 6 and 7 the upper cross member  86 , lower cross member  86   b  and a side member  86   a  of the strut assembly  28  are partially illustrated. Two (of six in total, four not shown) wire guide tracks  48  in the positions  81   a  and  81   b  are attached to the strut assembly  28  by stays  84 . In FIG. 6 the tie pull pins  82  are shown in a first position for wire path modification as when the twist knot is being tied. In FIG. 7 the pins  82  are shown in a second position (separated by a remove  83  from the pin position  82   a  of FIG.  6 ). The pins  82  move in the direction of remove  83  when the wire twisting is not occurring. The pins  82  may be moved from their first position to their second position by any means but are preferably controlled pneumatically. 
     Referring to FIG. 8, two wire twist knots are shown. On the left side, a first knot  200  would result without the improvement to the tying action provided by the presence of the tie pull pins. On the right side, a second knot  202  results from the improvement to the tying action caused by the presence of the tie pull pins. In the knot  200  a first bend angle or transition zone  206  to the twisted section  204  is shown to be of substantially greater curvature than the second bend angle or transition zone  208  of the knot  202 . 
     In operation, when the movable guide track support strut assembly  28  is down, the binding wire entering the apparatus  10  from the wire supply (not shown) at the wire control head  41  and enters the tying head  40 . Within tying head  40 , the wire is gripped by a gripper (not shown). The gripper (not shown) rotates to push wire frictionally through the tying head  40  downward to the lower most guide track sections  38  and across, up, back, and then down the other guide track sections  38 , and then back into tying head  40  until the end of the wire actuates a limit switch (not shown). The wire thus forms a loop section with an overlapping wire portion located within tying head  40 . It is preferred to use ten (#10) gauge wire that is sold by U.S. Wire under the trade name ULTRA STRAP GALVANIZED. 
     At this point, tie pins  80  are extended. The tying head  40  twists the wire into a knot, resulting in the knotted portion shown on the right side of FIG.  8 . In order to effect tying, tension is placed on the wire. This tension pulls the wire out of the two sides  102  as shown by the releasing action in FIGS. 4 and 5. As the wire is tensioned and breaks out of channel  106 , the wire is pulled around pins  80 . This assists the wire in assuming a less sharp bend as illustrated in FIG.  8 . 
     Once the tying head  40  has completed the twist knot, tie pins  80  are retracted by solenoid (not shown) which retraction pulls tie pins  80  out of contact with the wire. 
     Then, carriage  18  can translate to a second indexed position along overhead track  22 . Wire is again drawn by gripper (not shown) within tying head  40  to push the wire in a loop through guide track sections  38  and back into tying head  40 . Then, the twist knot process repeats. 
     For cotton bales, six baling wires are used to bind a five hundred pound bale of cotton. Thus, if three indexing heads are mounted to carriage  18 , carriage  18  must index between a first position and a second position to provide six straps. 
     In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained. 
     The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. 
     As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-referenced exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.