Abstract:
A pick-up truck bed having controllably magnetized areas for retaining cargo or attachment devices. A first permanent magnet may be attached below the lower surface of the truck bed with a second permanent being rotatable relative to the first permanent magnet to control the magnetic flux provided to retain objects in the truck bed. Alternatively, one or more electromagnets may be provided that may be turned on to retain objects in the truck bed and turned off to allow removal of objects.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to a pick-up truck bed that includes areas that magnetically hold objects in the truck bed. 
       BACKGROUND 
       [0002]    Pick-up trucks have truck beds that are used to transport a wide variety of objects. Pick-up truck beds normally provide an undivided area that receives objects that may be tied down with ropes, bungee cords, and the like. Tying down objects is time consuming and, if the objects are not properly secured, they may become unsecured during transit, loading or unloading. 
         [0003]    Attaching magnets to objects to be stored in or on a truck or other vehicle is proposed in US 2012/292359. A permanent magnet is proposed to be attached to a container or truck bed divider to hold the object in place during transit. The publication also discloses the concept of providing a magnet embedded in the truck box floor or in a bed liner. One problem with this approach is that the magnetic force holding the object in place also resists unloading objects from the truck bed so the degree of magnetic force provided must be limited to allow unloading. Limiting the magnetic force holding the object increases the risk that the object may become dislodged during transit or in a collision. 
         [0004]    U.S. Pat. No. 8,172,309 discloses a magnetic bar attached to the rear edge of a truck bed for preventing metal objects such as nails or screws from falling off the back of the truck bed. The magnetic bar attached to the rear edge of the truck bed as disclosed is not intended to secure objects to be transported but is intended to prevent nails or screws from falling off the truck bed. The magnetic force of the permanent magnet is constant and no mechanism is disclosed for changing the magnetic force applied by the magnet. 
         [0005]    This disclosure is directed to solving the above problems and other problems as summarized below. 
       SUMMARY 
       [0006]    According to one aspect of this disclosure, a magnetic cargo retainer is disclosed for a pick-up truck bed. The cargo retainer includes a first permanent magnet that creates a first magnetic field applied to objects disposed in the bed. A second permanent magnet creates a second magnetic field. The second permanent magnet is attached to the bed to move relative to the first permanent magnet to change a level of magnetic force applied to objects in the bed. 
         [0007]    According to other aspects of this disclosure relating to the cargo retainer, the first permanent magnet may be fixed to the bed and the second permanent magnet may be attached to a pin that extends through an opening defined by the first permanent magnet. The second permanent magnet is rotatable relative to the first permanent magnet. 
         [0008]    The first and second permanent magnets each have a north pole and a south pole, the second permanent magnet being rotatable from a retention position with the north pole of the second magnet aligned with the north pole of the first magnet to a release position with the north pole of the second magnet aligned with the south pole of the first magnet. 
         [0009]    The cargo retainer may further comprise a handle operatively attached to the second permanent magnet and extending through an opening in the truck bed. The handle is accessible inside the truck bed to rotate the second permanent magnet. 
         [0010]    The cargo retainer may further comprise a servo motor operatively attached to the second permanent magnet, wherein the motor may be selectively actuated to rotate or pivot the second permanent magnet. 
         [0011]    According to another aspect of this disclosure, a cargo retaining system is disclosed for a pick-up truck bed. The cargo retaining system includes a first plurality of stationary magnets creating a first plurality of magnetic fields that are applied to objects disposed in the bed. A second plurality of rotatable magnets creates a second plurality of magnetic fields and are attached to the bed to move relative to the first plurality of stationary magnets. The second plurality of rotatable magnets is rotated to change a level of magnetic force applied to objects in the bed. A plurality of driven wheels may be attached to each one of the rotatable magnets. A continuous flexible drive element is wrapped around each of the driven wheels to rotate the rotatable magnets. A drive apparatus is disclosed that includes a driving wheel that is rotated to move the flexible drive element and rotate the rotatable magnets. 
         [0012]    According to other aspects of the cargo retaining system, the driven wheels may be sprockets and the drive element may be a belt. Alternatively, the drive apparatus may be a servo motor. In another alternative, the drive apparatus may be a handle operatively attached to the drive apparatus that extends through an opening in the truck bed that is accessible inside the truck bed to rotate the drive apparatus. 
         [0013]    According to a further aspect of this disclosure, an electromagnetic cargo retainer is disclosed for a pick-up truck bed. The cargo retainer includes an electromagnet attached to the pick-up truck bed and a power source. A switch electrically connects the electromagnet and the power source to turn the electromagnet on to provide magnetic flux inside the truck bed for retaining a magnetically attracted object in the truck bed and off to reduce the magnetic flux provided by the electromagnet inside the truck bed. 
         [0014]    The electromagnet may be one of a plurality of electromagnets attached to the pick-up truck bed and the switch may be electrically connected to each of the plurality of electromagnets to independently turn the electromagnets on and off. 
         [0015]    The magnetically attracted object may be a partition secured to the truck bed by the electromagnet. 
         [0016]    According to another aspect of this disclosure, a pick-up truck is disclosed that includes a truck bed and a magnet attached to a lower surface of the truck bed. The pick-up truck also includes means for changing the magnetic force applied by the magnet to objects disposed in the truck bed that are attracted to the magnet. 
         [0017]    The magnet may be an electromagnet. Alternatively, the magnet may be a first permanent magnet, and the means for changing the magnetic force applied may be a second permanent magnet that may be rotatable to modify the level of magnetic force applied to objects in the truck bed. 
         [0018]    The above aspects of this disclosure and other aspects will be described below with reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a right rear perspective view of a pick-up truck made according to one embodiment of this disclosure. 
           [0020]      FIG. 2  is a fragmentary top plan view of a pick-up truck bed provided with a cargo retention system in accordance with the embodiment of  FIG. 1 . 
           [0021]      FIG. 3  is a cross-sectional view taken along the line  3 - 3  in  FIG. 2 . 
           [0022]      FIG. 4  is a fragmentary cross-sectional view slightly enlarged showing part of the cargo retention system shown in  FIG. 3 . 
           [0023]      FIG. 5  is a top plan view of a pick-up truck including a truck bed having a motor driven cargo retention system. 
           [0024]      FIG. 6  is a side elevation view partially broken away of the pick-up truck in  FIG. 5 . 
           [0025]      FIG. 7  is a diagrammatic view of an electromagnetic cargo retention system. 
           [0026]      FIG. 8  is a diagrammatic view of a cargo retention system and controller for another embodiment that includes an individual servo motor for each set of paired permanent magnets as described with the embodiment of  FIGS. 1-4 . 
           [0027]      FIG. 9  is a fragmentary top plan view of a pick-up truck showing the truck bed being provided with a plurality of electromagnets with some of the magnets being used to support a removable partition. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    The illustrated embodiments are disclosed with reference to the drawings. However, it is to be understood that the disclosed embodiments are intended to be merely examples that may be embodied in various and alternative forms. The figures are not necessarily to scale and some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed are not to be interpreted as limiting, but as a representative basis for teaching one skilled in the art how to practice the disclosed concepts. 
         [0029]    Referring to  FIG. 1 , a pick-up truck  10  is illustrated that includes truck bed  12 . Several objects  14  are shown disposed in the truck bed  12 . The objects  14  are ferrous objects or objects that are subject to magnetic attraction or magnetic forces. A first permanent magnet  16 , or stationary magnet, and a second permanent magnet  18 , or rotatable magnet, are provided below the truck bed  12 . The permanent magnets may be “rare earth” or neodymium magnets, but could also be another type of permanent magnet. The first and second permanent magnets  16  and  18  as shown are arranged as a cargo retainer or cargo retention system. A removable handle  20  is shown inserted into the truck bed  12  that is used to rotate or pivot the second permanent magnets  18  from 0° to 180° to increase or decrease the magnetic force applied by the magnets  16 ,  18  to objects  14  disposed in the truck bed  12 . The handle  20  is inserted into a handle mounting assembly  21  to adjust the magnetic force applied to an object  14 . The permanent magnets  16 ,  18  do not require power after being set in position and provide a magnetic retention force even when the vehicle power supply is off. 
         [0030]    Referring to  FIG. 2 , one embodiment of a pick-up truck  10  having a bed  12  is illustrated that includes the first permanent magnet  16  and the second permanent magnet  18  (shown in  FIGS. 3 and 4 ). The handle  20  (shown in  FIG. 1 ) is inserted into a handle mounting assembly  21 , or bearing, to rotate a driving wheel  28 , or a sprocket. The driving wheel  28  engages and rotates the continuous flexible drive element  26 , such as a belt or chain. Rotation of the belt  26  causes the driven wheels  24 , or sprockets, to rotate and change the position of the second permanent magnet  18  relative to the first permanent magnet  16 . The first and second permanent magnets  16 ,  18  are part of the cargo retention system. 
         [0031]    Referring to  FIGS. 3 and 4 , the truck bed  12  is shown in cross section taken through the handle mounting assembly  20  and two of the first and second permanent magnet assemblies  16  and  18 . The first permanent magnet  16  (as shown in  FIG. 3 ) has a north pole that is to the left side of the pin  29 . The second permanent magnet  18  has a south pole to the left side of the pin  29 . Pin  29  extends through the driven wheels  24  and is received in a bushing  31 . The bushing  31  is connected to the first magnet  16  and extends through the second magnet  18 . The driven wheels  24  are connected by fasteners  25  to the second magnet  18 . 
         [0032]    In the release position shown in  FIG. 3 , the north pole of the permanent or stationary magnet  16  is in alignment with the south pole of the second permanent magnet  18  that is also referred to as a rotatable magnet  18 . In this orientation, the magnetic flux provided above the truck bed  12  is reduced due to the attraction of the first permanent magnet  16  to the second permanent magnet  18 . 
         [0033]    Referring to  FIG. 4 , the first permanent magnet  16  and the second permanent magnet  18  have north poles that are aligned. In the retention position, a greater amount of flux is directed through the truck bed  12  and the ability of the cargo retainer system to retain objects in the truck bed  12  is enhanced. The truck bed  12  is preferably an aluminum truck bed, or could possibly be a composite truck bed. With either an aluminum or composite truck bed, magnetic flux penetrates the truck bed  12  to a greater extent than would be expected with a steel truck bed. 
         [0034]    Referring to  FIGS. 3 and 4 , the handle  20  is inserted through an opening  22  formed in the truck bed  12 . The handle  20  is received in the bearing  21 , or handle mounting assembly, and may be used to rotate the driving wheel  28 . Rotation of the driving wheel  28  causes the flexible drive element  26  to rotate the driven wheels  24 . 
         [0035]    The driven wheels  24  are connected to the second permanent magnet  18  and are effective to rotate the second permanent magnets  18  relative to the first permanent magnets  16 . 
         [0036]    Referring to  FIGS. 5 and 6 , another alternative embodiment is shown in which a servo motor  40  is used to rotate the second permanent magnets  18 . In the embodiment of  FIGS. 5 and 6 , a power source  32 , such as a vehicle battery, is selectively connected by a switch  34  to the servo motor  40 . The switch  34  may be an internal switch control of a controller, or may be a manual toggle switch. The switch  34  is accessible within the passenger compartment of the pick-up truck  10 . If desired, the switch  34  may be incorporated in a key fob to allow the motor  40  to be remotely operated when it is desired to load or unload objects from the truck bed  12 . The motor  40  rotates a driving wheel  28  that engages the flexible drive element  26 . The flexible drive element  26  is operable to rotate the driven wheels  24 . The driven wheels  24  rotate the second permanent magnet  18  relative to the stationary first permanent magnet  16  to change the strength of the magnetic field used to retain objects on the truck bed  12 . 
         [0037]    Referring to  FIG. 7 , another alternative embodiment is shown wherein a plurality of electromagnets  30  are connected to a controller  36 . The electromagnets  30  may be attached to the truck bed (as shown in  FIG. 9 ) in a spaced relationship inside the truck bed. The controller  36  may receive inputs from switches  34  that may be used to control the individual magnets as a group or individually. The controller  36  is electrically connected to the electromagnets  30  that are secured to the truck bed  12  by fasteners  42  that hold the electromagnets  30  against the truck bed  12 . 
         [0038]    The electromagnets may be controlled by the switches  34  that may send control signals to the body control module that controls the supply of power to the electromagnets  30  in the truck bed  12 . The body control module may integrate the signal with the vehicle speed and steering inputs to adjust the power provided to the electromagnets based upon vehicle dynamics. Power consumption of the electromagnets  30  may be reduced by limiting the power supplied when kinetic forces applied to objects  14  in the truck bed  12  are reduced. 
         [0039]    Referring to  FIG. 8 , another alternative embodiment is shown in which a plurality of servo motors  40  are used to rotate the second permanent magnet  18  relative to a first permanent magnet  16 . A plurality of switches  34  provide inputs to a controller  36 . The switches  34  and controller  36  may be used to individually control the separate servo motors  40 . In the embodiment of  FIG. 8 , a single servo motor  40  is attached to each of the second permanent magnets. 
         [0040]    The servo motor  40  may be attached to the truck bed (as shown in  FIG. 9 ) to provide a plurality of magnetic cargo retention areas in the truck bed  12 . The servo motor  40  rotates with the permanent magnets  16  and  18  relative to each other to control the magnetic field acting on the partitions  46 . Alternatively, the electromagnets  30  may be used to hold the partitions  46  in place in the truck bed  12 . The partitions  46  may take a wide variety of shapes and may extend horizontally in the lateral direction or in the longitudinal direction. Hooks, rings, or other attachment devices may be retained on the truck bed  12  instead of the partitions  46 . Other types of attachment devices may be held in place by the electromagnets  30  permanent magnets  16  and  18 . For example, a hook, loop or block can be secured to the magnetic area to facilitate tying down any size or shape of cargo. Placing the magnets below the floor of the pick-up truck bed maximizes flexibility and does not consume cargo space within the truck bed. 
         [0041]    The embodiments described above are specific examples that do not describe all possible forms of the disclosure. The features of the illustrated embodiments may be combined to form further embodiments of the disclosed concepts. The words used in the specification are words of description rather than limitation. The scope of the following claims is broader than the specifically disclosed embodiments and also includes modifications of the illustrated embodiments.