Patent Publication Number: US-6668520-B1

Title: Modular sliding door grid

Description:
TECHNICAL FIELD 
     The present invention relates generally to case packing. More particularly, the present invention relates to a modular sliding door grid for use in ultra high-speed case packing. 
     BACKGROUND OF THE INVENTION 
     In response to the demands for diversity in today&#39;s case packing market (e.g., full depth RSC or Bliss cases), the case packing industry has been modifying case packer technology to provide customers with grids that handle a wider variety of multi-packed products. Not only are multi-packs in greater demand, but the variety of pack styles has also proliferated in recent years. Quick changeover and higher speeds are required to meet this recent surge in demand. 
     The speed and changeover limitations of the older technology are directly related to the complexity and shortfalls of “trap door” grids, such as are described in U.S. Pat. No. 4,583,351 to Fallas. The required movement of the trap door&#39;s vertical swing during case packing limits the maximum speed of case packing operations. For applications requiring speeds of 20 cases or less per minute, this is generally not a concern. 
     U.S. Pat. No. 4,644,734 to Hartness describes a low speed case packer employing two horizontally acting trap doors actuated by pneumatic cylinders. Bottles are indexed onto the trap door by fours until three rows are filled. Pneumatic cylinders are then actuated to slide the trap doors and drop the bottles. The Hartness device provides a low cost, reliable packing device, but it is not suitable for ultra-high speed case packing. 
     What is needed in the art is a low cost solution for ultrahigh speed case packing. 
     SUMMARY OF THE INVENTION 
     The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the modular sliding door grid of the present invention. The modular sliding door grid includes a sliding door mounted on a low profile frame. The sliding door is actuated by at least one pivot bar, connected at one end to the sliding door and at the other end to a mechanical linkage. Actuation of a frame bar, which is linked to the mechanical linkage, in a forward direction causes pivot bar to move around a center-point to allow the sliding door to move in a backward direction. 
     The pivot bar configuration described shows a rugged design that allows for rapid actuation and retraction, such that the 40 or more cases may be packed in one minute. Further, the modularity of the sliding door grid allows a user to install or change out the sliding door grid in five minutes or less to accommodate varying packaging requirements based on the products to be packaged. 
    
    
     The above description and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings and appended claims. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings wherein like elements are numbered alike in the several FIGURES: 
     FIG. 1 is a cross sectional side view of an assembled case packing machine including the present modular sliding door grid; 
     FIG. 2 is an overhead view of the modular sliding door grid; 
     FIG. 3 is a cross sectional side view of the sliding door and top door guide assembly; 
     FIG. 4 is a cross sectional side view of the sliding door and pivot arm assembly; 
     FIG. 5 is a cross sectional side view of the sliding door and side door guide assembly; 
     FIG. 6 is an overhead view showing discrete actuated positions of the sliding door and pivot arms; 
     FIG. 7 is a side aspect of the grid basket installation into the mounting frame of the present modular sliding door grid; and 
     FIG. 8 is an overhead view of an exemplary modular sliding door grid including two sliding doors. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, a modular sliding door grid is generally shown assembled at  10  between an upper assembly, shown generally at  12 , and a lower assembly, shown generally at  14 . Upper assembly  12  includes lane guides  16  for positioning of a case load  18  over the sliding door grid  10 . Lower assembly  14  includes a grid basket  20  further including grid fingers  22 , which accept a case load  18  discharged through the sliding door grid  10  and which guide the discharged case load  18  properly into case  24 . 
     Referring still to FIG. 1, modular sliding door grid  10  includes a mounting block  26 , first and second frame bars  28 ,  30 , a fixed door  32  mounted thereto, a sliding door  34 , a pivot bar  36 , attached to the sliding door  34  by a connecting pin  38 , and a mechanical linkage  40 , attached to the pivot bar  36  by connecting pin  42 . The mechanical linkage  40  is connected at an opposite end to a first frame bar  28  by connecting pin  44 . A mechanical pivot pin  46  is shown provided through the pivot bar  36 , into the mounting block  26  of the sliding door grid  10  and into the grid basket of the lower assembly  14 . 
     Turning now to FIG. 2, an overhead view of the modular sliding door grid  10  shows a sliding door  34  attached to two pivot bars  36 ,  48  by connecting pins  38 ,  50 . Pivot pins  46 ,  52  are shown provided centrally through the pivot bars  36 ,  48 . Mechanical connecting pins  42 ,  54  link pivot bars  36 ,  48  to the mechanical linkages  40 ,  56 . Connecting pins  44 ,  58  link mechanical linkages  40 ,  56  to first frame bar  28 . The sliding door  34  is shown in an extended position relative to the fixed door  32 . A shoulder stud  60  aids in the extension and retraction of the sliding door  34  by securing the sliding door  34  to the frame  26 , thus ensuring the sliding door remains in a sliding position along the first door guide  62 . 
     Referring now to FIG. 3, section A—A of FIG. 2, the sliding door  34  is shown underneath and against the first door guide  62 , which is mounted to the mounting block  26 . Referring now to FIG. 4, section C—C of FIG. 2, a second door guide  64  is shown, providing a track at  66  to allow door stud  60 , which is attached to the sliding door  34 , to slide with the sliding door  34  during extension and retraction. 
     Referring now to FIG. 5, section B—B of FIG. 2, the sliding door  34  connects to the pivot bar  36  by the mechanical connecting pin  38 . Across the pivot pin  46  on the pivot bar  36 , the mechanical linkage  40  connects to the pivot bar  36  by the mechanical connecting pin  42 . The mechanical linkage  40  connects to the first frame bar  28  by the mechanical connecting pin  44 . 
     Turning now to FIG. 6, the sliding door  34  is shown connected to pivot bars  36 ,  48 , as in FIG.  2 . Pivot bars  36 ,  48  are shown in two positions, such that the sliding door  34  is extended (A) and retracted (B). In operation, the first frame bar  28  is actuated horizontally towards the pivot pins  46 ,  52 , causing the pivot bars  36 ,  48  to rotate around the pivot pin  46 ,  52 . The connecting pins  38 ,  50 , attached to the sliding door  34 , move in a counterclockwise direction with the pivot bars  36 ,  48  to urge the sliding door  34  toward the first frame bar  28 , thereby widening the gap between the sliding door  34  and the fixed door  32  and causing the case  18  to drop. Though movement of connecting pins  38 ,  50  are shown to be counterclockwise, the present invention contemplates alternate setups, where movement of connecting pins  38 ,  50  in a clockwise direction widens the gap between the sliding door  34  and the fixed door  32 . 
     At extended position (A), the sliding door  34  and the fixed door  32  together define an area of support for products to be packaged. This area depends entirely upon the size of particular products to be packaged, the number of products to be packaged in one case, and the desired packaging configurations. The present sliding door grid contemplates variation in the number of rows and columns and the numbers and types of products to be packaged. 
     Turning now to FIG. 7, the modularity of the present sliding door grid  10  is shown with respect to the lower assembly  14 . Grid basket  20  is affixed to the underside of sliding door mounting block  26  by first and second grid basket support bars  68 ,  70 . Actuation of the sliding door ( 34  in FIG. 1) causes release of products through grid fingers  22  and into packaging ( 24  in FIG.  1 ). Grid basket  20  may be affixed to sliding door mounting block  26  in any known manner, but is preferably slidably and removably affixed as shown in FIG.  7 . 
     FIG. 7 shows the exemplary embodiment where each end of the first grid basket bar  68  is placed on two tracks  72 ,  74  running underneath sliding door mounting block  26 . Tracks  72 ,  74  are attached to the mounting block  26  at end  76  of sliding door mounting block  26  by connecting pins  78 ,  80 . Tracks  72 ,  74  are attached to the mounting block  26  at end  82  by hinges  72 ,  74 . The grid basket  20  is positioned underneath the mounting block  26  by placing the first grid basket bar  68  on the two tracks  72 ,  74  and pushing the second grid basket bar  70  until the grid basket  20  locks in place. Quick release members  84 ,  86  on the second grid basket bar  70  allow the grid basket  20  to be rapidly detached for easy lowering and removal from underneath the sliding door mounting block  26 . 
     Turning now to FIG. 8, another exemplary embodiment includes dual sliding doors  34 ,  88 . Connectivity for sliding door  34  is as described above for FIG.  1 . In this embodiment, sliding door  88  is linked to pivot bars  90 ,  92  by connecting pins  94 ,  96 . Pivot bars  90 ,  92  are pierced by pivot pins  98 ,  100 . Opposite connecting pins  94 ,  96 , mechanical linkages  102 ,  104  connect to pivot bars  90 ,  92  at connecting pins  106 ,  108 . The mechanical linkages  102 ,  104  connect to second frame bar  110  at connecting pins  112 ,  114 . 
     The present modular sliding door grid advantageously moves each door horizontally to release the product for its descent into the case. This action can occur more rapidly, and the retraction can occur almost immediately, allowing the packer to prepare for the next cycle. Exemplary operation of the sliding door grid allows for field operation of at least 40 cases per minute for 8 oz. PET multi-packs. 
     Speed of packaging machinery is an important industry factor. Thus where speed is a particular concern, it is preferred that the sliding door  34  be opened and closed by an automated system such as is known in the art, that recognizes factors such as a product drop time, product size, and number reset time for second cycle positioning, and receptacle case removal and replacement time. Consideration of these factors, among others, allows sliding doors to be opened and closed at optimal times for efficiency of packaging. 
     The present modular sliding door grid also advantageously provides reduced infeed elevation as a result of the horizontal motion of the sliding door design versus the vertical swing of prior art trap door grids. This advantage reduces required elevations by up to 6 inches over the prior art and allows the operator easier top access to the bottle infeed. 
     Additionally, the modular sliding door grid, because it is modular, advantageously allows the grid to be provided as an upgrade for existing case packers or as a replacement for the older trap door grids. The sliding door grid can handle hi-cones, mead-wraps, contour packs and shrink bundles, among others, packed into RSC cases, HSC cases, tab-locked cases, bliss cases and low-walled trays, among others. 
     Finally, conventional trap door designs were large, preventing their use as part of a quick change assembly. In contrast, this modular sliding door grid can be part of a quick release mechanism that enables quick changeovers and higher speeds. U.S. Pat. No. 4,406,111 to John Raudat, which is incorporated herein in its entirety by reference and which discloses a “Quick Release Subassembly for Shifting Grid Case Packer”, describes a quick change mechanism of which the modular siding door can be a part. This modular sliding door has a low profile, a design that enables, essentially guarantees simultaneous release of the mechanism from the connections with the case packer. In other words, this simplified, low profile design enables improved, high speed operation and quick changeover from one sliding door mechanism to another (e.g., due to different size cases or the like). 
     While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.