Patent Publication Number: US-10759561-B2

Title: Molded plastic pallet having a snap in signal transmitter and method of making same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 16/220,478 filed Dec. 14, 2018 and claims in part the priority date of that application and U.S. Provisional Application Ser. No. 62/599,125 filed on Dec. 15, 2017; the contents of which are incorporated herein by reference. 
    
    
     SUMMARY 
     This application discloses a twin sheet thermoformed plastic pallet having a recess formed in a bottom surface to receive and hold a signaling device such as a GPS transponder. The recess in the pallet bottom is formed during the thermoforming process using an insert and is shaped to generally conform to the outside surface shape of the transponder. The recess has retainer tabs with shapes that allow the transponder to be installed far enough into the recess so that the transponder surface above the pallet bottom surface where it is is protected against inadvertent damage from objects engaging the pallet bottom surface. One or more slots or other details are formed in the recess wall or walls to allow access of a pry tool such that the transponder can be removed for service and/or replacement. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The invention described herein is the combination of a locator transponder with a molded plastic pallet having a top load-bearing surface and bottom surface with support legs extending therefrom to allow forklift entry. Formed in the bottom surface of the pallet is a recess which shaped to receive and conform to the side surfaces of a signal transmitter such as a GPS transponder. The recess has one or more retainer structures such as tabs formed on the wall or walls of the recess so that the transponder can be snapped into the recess above the retainers to be held firmly in place. The recess is also provided with one or more access slots or openings to allow entry of a pry tool so that the transponder can be removed for service and/or replacement. The depth of the recess and the locations of the retainers is such that the exposed surface of the transponder is well within the recess where it is protected against inadvertent damage as the pallet is moved about with a forklift truck and settled on various surfaces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present invention will be best understood from the within detailed description of an embodiment thereof selected for purposes of illustration and shown in the accompanying drawings in which: 
         FIG. 1  is a perspective view of the top surface of a twin sheet thermoformed pallet taken from U.S. Pat. No. 5,950,545; 
         FIG. 2  is a perspective view of the bottom surface of the pallet of  FIG. 1  showing the recess in the bottom surface with a GPS transmitter/transponder fitted therein; 
         FIG. 3  is a close-up view of the pallet bottom from  FIG. 2  showing the undercuts in the recess side wall and the lateral extension for removal purposes in greater detail; 
         FIG. 4  is a close-up of the pallet bottom showing the empty recess and the depth thereof; 
         FIG. 5  shows another pallet bottom with an alternative configuration for the GPS receiving recess, this recess having four lateral extensions for removal of the transmitter; 
         FIG. 6  is an image of a disk-shaped transmitter/transponder suitable for use in the apparatus of  FIGS. 1-5 ; 
         FIG. 7  is a schematic drawing of the pallet recess showing schematically how a grooved GPS transmitter is snapped into place within the recess; 
         FIG. 8  is a rendering of a thermoforming insert which is used to modify a thermoforming mold so as to form the cavity of  FIGS. 1-4  in the pallet bottom; 
         FIG. 9  is a perspective view of a rectangular GPS transponder; 
         FIG. 10  is perspective view of the bottom of an inverted pallet showing the details of the recess with its retainer tabs and pry tool access slots for the rectangular transponder of  FIG. 9 ; 
         FIG. 11A  is a detail of the pry tool access slot found in each corner of the recess for the rectangular GPS transponder; 
         FIG. 11B  is a detail of the recess showing the configuration of a retainer tab with undercut, again in inverted orientation; and 
         FIG. 12  is a view of the rectangular GPS transponder fully inserted into the rectangular recess in the pallet bottom. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT 
       FIG. 1  shows an exemplary twin sheet molded plastic pallet  10  in perspective view. This drawing is taken from issued U.S. Pat. No. 5,950,545, issued Sep. 14, 1999; the inventor is Lyle H. Shuert. The pallet has a generally planar top loading surface  16 , a bottom surface which does not show in  FIG. 1  and nine thermoformed pallet legs  18  which afford four-way entry of a forklift for handling purposes. This particular twin sheet pallet is merely representative of a variety of molded plastic pallets that can be used in connection with the invention disclosed herein. The important factor is that the pallet structure has a depth between the bottom surface and the top loading surface to accommodate a recess for a signal device. This depth may, for example, be about 1½ to 3 inches. The thickness of the transponder is less than the recess depth. 
       FIG. 2  shows the bottom surface  20  of the nine-legged pallet to include thermoformed therein a general circular deep recess  24  shaped and sized to receive a generally disk-shaped, battery-powered signal transmitter/transponder  22  therein. In this case, the transmitter  22  is a GPS transmitter/transponder with a circular shape but can be any of a variety of other signal sources capable of sending RF signals representing such information as location, temperature and other metrics or conditions. As shown in  FIGS. 2 and 7 , the recess  24  is deep enough that the exposed surface of the transmitter/transponder is above the bottom surface of the pallet  10 . The location is arbitrary, but it is preferably in a smooth generally planar surface away from the bosses shown in  FIG. 2  and the adjacent legs. 
     Referring to  FIGS. 3 and 4 , the shape and depth of the recess  24  is shown in detail to include a generally circular side wall having diametrically opposed circumferential and non-continuous arcuate undercut snap tabs  26  and  28  formed therein. In addition, a lateral extension  30  of the recess side wall  24  is formed in the recess between the undercuts to provide clearance for any external protuberances on the side surface of the transmitter/transponder  22  and to allow access for a pry tool to pry the transmitter/transponder  22  from the recess for recovery and/or servicing purposes. Again, the circular shape is shown by way of example rather than by way of limitation. 
       FIG. 5  shows an alternative embodiment in which the cavity is formed with four lateral extensions  31  and at least two undercuts  33  to provide access for a user&#39;s fingers or a pry tool for removal of the GPS device. 
       FIG. 6  shows a representative commercially available GPS transmitter/transponder  22 . While shown as circular with a circumferential, “belt line”  32 , the shape of the device is arbitrary and can be square or rectangular, the recess being shaped to correspond to the shape of the device. 
       FIG. 7  is a schematic drawing of a recess  24  in the thermoformed plastic pallet  10  showing the undercut snap tabs  26  and  28 .  FIG. 7  also shows the circular outer wall  32  of the GPS device  22 . 
       FIG. 8  is an illustration of an insert  36  which is placed in the mold structure in the thermoforming process to form the recess in the bottom of what would otherwise be a conventional twin sheet pallet. The embossed arrow  38  creates a guide in the final molded article to indicate the extrusion direction of the plastic sheet material that was used in the thermoforming process to form the twin sheet pallet. The extension  30  in the recess is formed by an appendix  40  on the side of insert  36 . 
     Summarizing, the insert  36  is used in the thermoforming process for the production of a twin sheet thermoformed nine-legged plastic pallet to form a deep recess in the bottom surface of the pallet of a shape and depth to receive the battery-operated signaling device in the form of a GPS/transponder. Undercuts in the recess allow the device to be snapped into the recess with the exposed surface of the transmitter/transponder below the bottom surface of the pallet to prevent damage to the device during transportation and handling of the pallet and the associated load. 
     The transmitter/transponder is battery operated and preferably requires no external antenna wires. It may be activated by a signal to transmit, for example, an omni-directional GPS signal containing the coordinates of the location of the transmitter/transponder and the pallet into which the device is installed. With this arrangement, the location of the pallet can be determined at all times whether it be in a warehouse or other locations, loaded or unloaded, or in a transportation medium enroute to an assigned destination. The transmitter can be easily snapped into place without the use of tools and removed by a simple prying operation. 
     Referring now to  FIG. 9 , there is shown a GPS transponder  52  of generally rectangular configuration with an off/on switch  54 . 
       FIG. 10  shows the pallet bottom in inverted orientation with a recess formed therein during the thermoforming process to receive the rectangular GPS transponder  52  of  FIG. 9 . The recess has a peripheral rim  44  which tapers toward the walls  45  of the recess, and a flat bottom  48  integral with all four of the recess walls. 
     Formed on the recess walls  45  are retainer tabs  46 , also shown in  FIG. 11B . The tabs have tapered outer surfaces to allow the transponder  52  to slide over the tabs and fully into the recess against the floor  48  but have top edges or undercuts to bear against the exposed surface of the transponder  52  as shown in  FIG. 11B  to hold the transponder in place against the bottom  48  once it has been fully inserted into the recess. The dimensions of the tabs  46  are such as to create a distance d between the top exposed surface of the transponder  52  and the pallet bottom  42  thereby to protect the transponder against damage during use. 
     Also formed into the recess are corner slots  50  with a semi-rounded wall which tapers at an angle between about 5° and 15° into and toward the bottom wall  48  of the recess so as to allow angled entry of a pry tool such as a screw driver into the recess where it can engage a corner of the transponder  52  and pry or lift the transponder out of the recess for replacement or service. 
       FIG. 12  show the GPS transponder  52  fully inserted into the recess so as to snap above the undercuts on the retainer tabs  46  and well above the bottom surface  42  of the pallet. The transponder  52  is held in place by tabs  46  on all four of the walls of the rectangular recess shown in  FIGS. 10 and 12 . 
     It is to be understood that the invention has been illustrated and described with respect to illustrative embodiments and the that various modifications and changes to the invention may be made without departing from the spirit and scope of the invention as defined by the claims.