Abstract:
To palletize packages, a wrapping vehicle includes a vertically mounted drive screw having a plurality of ball nuts mounted at wrapping-effective distances from each other on the vertically mounted drive screw. Each ball-nut has a corresponding cantilever mounted to the ball nut to support a roll of wrapping material. A tension adjustment mechanism is mounted to adjust the resistance to motion of each roll of wrapping material and thus the tension on the wrapping material. The ball nuts are each connected to side support guide plates positioned to slide against the sides of mast housing the drive screw wherein said ball nuts are supported against tilting movement.

Description:
RELATED CASES 
       [0001]    This application is a continuation in part application of U.S. provisional patent application 60/878,303, filed Jan. 2, 2007, by Patrick J. Vanderheiden and Michael A. Herman. The benefit of provisional patent application 60/878,303 is claimed. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to wrapping machines and methods of using them. 
         [0003]    It is known to mount rolls of wrapping material such as for example stretch wrapping plastic on movable carts such as push carts and to use the movable carts to wrap materials and apparatuses in place. A typical movable wrapping cart is easily maneuverable by hand to permit circling of the object or objects to be wrapped. One end of a roll of wrapping material is fastened to the objects at a starting point and the roll is moved around the objects to wrap them together. Commonly, the objects are positioned together on a pallet and stretch wrap material is wound around them to hold them together in a process referred to at times as palletizing. Three wheeled push carts with a low horizontal support bed with three wheels mounted below the horizontal support bed and a vertical mast extending from the top of the support bed are one form of maneuverable push/pull cart that may be used. Two front wheels provide support for one end of the mast and one or two turnable rear wheels permit easy maneuverability. A roll of wrapping material is mounted to the mast by a movable carriage. Some prior art wrapping push/pull carts are disclosed in U.S. Pat. Nos. 6,526,734 and 7,051,492. 
         [0004]    The prior art wrapping carts utilize one roll of wrapping material that is applied to materials or apparatuses that are being wrapped. These prior art wrapping carts have a disadvantage of being slow and at times difficult to use. Moreover, the positioning and adjustment as to tension of the rolls of wrapping material are clumsy and difficult. 
       SUMMARY OF THE INVENTION 
       [0005]    Accordingly, it is an object of the invention to provide a novel wrapping cart. 
         [0006]    It is a further object of the invention to provide a novel method of wrapping materials or apparatuses to form palletized materials and apparatuses. 
         [0007]    It is a still further object of the invention to provide a fast and economical method of wrapping apparatuses and materials. 
         [0008]    It is a still further object of the invention to provide a novel wrapping cart capable of wrapping materials with exceptional speed. 
         [0009]    It is a still further object of the invention to provide a novel wrapping method that applies wrapping material from multiple rolls of wrapping material at the same time. 
         [0010]    It is a still further object of the invention to provide a novel wrapping apparatus that applies wrapping material from multiple rolls of wrapping material at the same time. 
         [0011]    It is a still further object of the invention to provide a novel method and apparatus for controlling the tension applied to stretchable wrapping materials as they are being used. 
         [0012]    It is a still further object of the invention to provide a novel method for inserting and removing rolls of wrapping material. 
         [0013]    It is a still further object of the invention to provide a multiple roll wrapping apparatus in which individual rolls may be independently removed and have the tension on the wrapping material adjusted. 
         [0014]    It is a still further object of the invention to provide wrapping apparatus and a method in which the user may bring the wrapping material to the desired elevation easily and conveniently. 
         [0015]    In accordance with the above and further objects of the invention, an electrically controlled drive mechanism on a vehicle such as a push/pull cart positions rolls of wrapping material (wrapping paper or wrapping film) in elevation under the control of a switch on the handle of the vehicle. In the preferred embodiment, the drive mechanism is an electric actuator which can be actuated by the user from his location when using the vehicle. In the preferred embodiment, the vehicle is a push/pull cart with four wheels, two forward wheels being at the front of the push/pull cart and two rear wheels being at the rear of the cart with the two rear wheels being steerable by a handle mounted at the rear of the cart. However, the push/pull cart may also include three wheels, two forward wheels being at the front of the push/pull cart and one rear wheel being at the rear of the cart with the rear wheel being steerable by a handle mounted at the rear of the cart. Multiple rolls of wrapping material are mounted at vertically spaced positions and simultaneously wrapped around objects or apparatuses to be wrapped. This reduces the time in which the wrapping is performed. For example, with two rolls, two wraps may be applied simultaneously to reduce the time of wrapping by as much as twofold. Similarly, three rolls vertically spaced may reduce the time as much as by threefold and reduce the number of times that a particular item must be encircled by the operator. 
         [0016]    Individual rolls of wrapping material may be connected to the apparatus at vertically spaced-apart positions with respect to each other and the resistance to rotation of each roll and thus the tension on the wrapping material may be individually adjusted for that particular roll. If one roll runs out before the other, it may be replaced without having to move the other rolls of wrapping material. Tension is easily manually adjusted by mounting the rolls between an upper adjustable member and a lower adjustable member. The distances between the rolls of wrapping material are wrapping effective distances. In this specification, the words “wrapping effective distances” means distances selected to permit rolls of wrapping material having a weight that can be supported by cantilevers that extend from ball nuts, with widths and a spacing provided to accommodate uneven objects to be securely wrapped without the rolls interfering with one another. The width of the wrapping material is the length of the roll. 
         [0017]    The wrapping vehicle or machine of this invention has several advantages, such as for example: (1) it is labor saving; (2) it is fast because of the ability to wrap more than one turn of wrapping material in one revolution about the objects being wrapped; (3) it permits easy positioning of the wrapping material in elevation; and (4) it permits effective adjustment of tension on the rolls of wrapping material. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The above noted and other features of the invention will be better understood from the following detailed description when considered in the light of the accompanied drawings, in which: 
           [0019]      FIG. 1  is a perspective view of a wrapping machine mounted to a push/pull cart in accordance with one embodiment of the invention; 
           [0020]      FIG. 2  is a fragmentary perspective view of a lower portion of the wrapping machine of  FIG. 1 ; 
           [0021]      FIG. 3  is a perspective view showing another portion of the lower part of the wrapping machine of  FIG. 1 ; 
           [0022]      FIG. 4  is a fragmentary simplified perspective view showing the upper portion of the wrapping machine of  FIG. 1 ; 
           [0023]      FIG. 5  is a detailed perspective fragmentary view of a movable support member which is part of the embodiment of  FIG. 1 ; 
           [0024]      FIG. 6  is a schematic diagram of a drive mechanism in the embodiment of  FIG. 1 ; 
           [0025]      FIG. 7  is a schematic circuit diagram of a circuit used to operate the drive mechanism of  FIG. 6 ; 
           [0026]      FIG. 8  is a fragmentary perspective view of a portion of another embodiment of the push/pull cart showing the rear wheels and handle of a four wheel push/pull cart; 
           [0027]      FIG. 9  is a perspective view showing the use of the wrapping machine of  FIG. 1 ; and 
           [0028]      FIG. 10  is a perspective view of the use of the wrapping machine of  FIG. 1  in another position. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    In  FIG. 1 , there is shown a perspective view of a wrapping vehicle  10  having a vehicle bed  12 , a wrapping material assembly  14  and a handle assembly  16 . In the embodiment of  FIG. 1 , the vehicle  10  is a push/pull cart and the handle assembly  16  includes an actuator switch assembly  18  that controls the vertical location of wrapping material mounted to the vehicle. The vehicle bed  12  in  FIG. 1  includes three wheels  20 A- 20 C (wheels  20 A and  20 C being shown in  FIG. 1 ) and a horizontal support  22 . Two wheels,  20 A and  20 B are mounted forward on the bed  12  (only  20 A being shown in  FIG. 1 ) and a third wheel  20 C is mounted in the back. The third wheel  20 C is pivotable to steer the vehicle. While a three-wheeled push/pull cart is shown in  FIG. 1 , a four-wheeled push/pull cart could be used having two forward wheels at the front of the push/pull cart and two rear wheels ( FIG. 8 ) at the rear of the cart with the two rear wheels being pivotable by the handle mounted at the rear of the cart. Obviously, a pulling cart, a stationary wrapping machine that cooperates with a movable pallet, or a motorized vehicle such as a scooter with rolls of wrapping material attached or any other suitable configuration may also be used. 
         [0030]    The wrapping material assembly  14  includes adjustable wrapping material, which in the preferred embodiment is three rolls of wrapping material  24 A,  24 B and  24 C positioned one above the other, a plurality of corresponding tension adjustment mechanisms  26 A,  26 B and  26 C, one for each roll of wrapping material, a mast  28  and a battery  30 . The rolls of wrapping material  26 A- 26 C are vertically adjustable as a group and the number of rolls and vertical spacing between the rolls can be changed. The width of the wrapping material is changed by changing the rolls of wrapping paper. The mast  28  includes a drive mechanism that lifts the entire assembly of wrapping material upwardly or lowers it downwardly as called for during the wrapping operation. 
         [0031]    The handle assembly  16  controls the angle of the rear wheel  20 C in the preferred embodiment but the wrapping vehicle  10  may be steered by other mechanisms that alter the angle of the front wheels or the angle of an intermediate joint between the rear wheels and the front wheels. The actuator switch assembly  18  on top of the handle assembly  16  is connected by an electrical connector  32  to the battery  30  that supplies power through an electrical connector  34  to the drive mechanism. In this specification, the word, “front” means the side of the vehicle that is at the front of the direction in which the vehicle is intended to move and the word “rear” means the side of the vehicle having a handle for pushing the vehicle. 
         [0032]    While a movable vehicle is described in connection with  FIG. 1 , the objects to be wrapped may instead be mounted on a movable member and the wrapping material on a stationery member or both may be movable to create movement between the two and thus a wrapping operation of the wrapping material on the object to be wrapped. Thus, a turntable may mount an object or objects that are to be wrapped and a stationary wrapping assembly may be connected to the objects and the objects turn so that the wrapping material is wrapped around the objects. The elevation of the wrapping material may be controlled by an operator to wrap the entire desired vertical length of an object or objects. Moreover, the wrapping vehicle or wrapping machine  10  may contain a plurality of parallel wrapping material assembles and the rolls of the wrapping material may be at overlapping positions on the different wrapping material assemblies to apply overlapping wraps in a single loop around a pallet. 
         [0033]    In  FIG. 2 , there is shown a fragmentary perspective view of the vehicle bed  12 , the wrapping material assembly  14  and the handle assembly  16 . The wheels  20 A- 20 C are shown supporting the horizontal support  22  of the vehicle bed  12  with the battery  30  mounted on a rearward section of the horizontal support  22  and the handle assembly  16  supported by the turnable wheel  20 C and connected to the rearmost end of the horizontal support  22 . The wrapping material assembly  14  is shown without rolls of wrapping material to make visible a lower vertically-moveable ball-nut driven cantilever  38 , a lower wrapping material roll bottom support  42 , a lower wrapping material roll tension adjustment mechanism  26 C, a middle vertically-moveable ball-nut driven cantilever  40  and a middle wrapping material roll bottom support  44 . As shown in this view, a vertical central support post  48  extends through and connects the vertically-moveable ball-nut driven cantilevers  38 ,  40  and  58  ( 38  and  40  being shown in  FIG. 2 ) and corresponding wrapping material roll tension adjustment mechanisms  26 A- 26 C ( 26 C for the lower roll  24 C ( FIG. 1 ) being shown in  FIG. 2 ) so that each roll fits between a bottom support such as  42  shown in  FIG. 2  and a tension adjustment mechanism such as  26 C shown in  FIG. 2 . The tension adjustment mechanisms  26 A- 26 C ( FIG. 1 ) may be tightened toward the bottom supports  42 ,  44  and  46  ( FIG. 1 ) to adjust the tension in the rolls with the vertical post  48  permitting rotation of the rolls as the wrapping material is removed for application to an object. 
         [0034]    The vertical support post  48  is formed in sections with each section extending between a bottom roll support such as lower vertically-moveable ball-nut driven cantilever  38  and lower wrapping material roll support  42  and a tension adjustment mechanism such as tension adjustment mechanisms  26 C so that the sections can be disconnected for replacement of a roll if desired. Each of the vertically-moveable ball-nut driven cantilevers such as the lower vertically-movable ball-nut driven cantilever  38  and the middle vertically-movable ball-nut driven cantilever  40  is separately mounted by a roller nut to a drive screw within a mast enclosure  36  to be separately supported and thus permit removal of a roll at any position for replacement with a full roll. The mast  28  is supported by a central section  50  of the support bed  22  by two parallel struts  52 A and  52 B that connect a forward edge of the central section  50  to two parallel sides of the mast enclosure  36 . 
         [0035]    In  FIG. 3 , there is shown a fragmentary view of the mast  28  of the wrapping machine  10  supported by the parallel struts  52 A and  52 B and a mast support plate  54  which are mounted to two extending legs of the horizontal support  22 . As shown in this view, the vertical axial central support post  48  extends upwardly forwardly of the mast  28  and includes a plurality of vertically-moveable ball-nut driven cantilevers  38 ,  40  and  58  ( 38  being shown in  FIG. 3 ), bottom supports  42 ,  44  and  46  ( 42  being shown in  FIG. 3 ) and movable ball-nut driven cantilevers  38 ,  40  and  58  ( 38  being shown in  FIG. 3 ). 
         [0036]    In  FIG. 4 , there is shown a fragmentary view showing a switch  18  at the top of the handle assembly  16 , a motor compartment  56  at the top of the mast enclosure  36  for moving the top vertically-movable ball-nut driven cantilever  58  for the bottom of the wrapping roll  24 A ( FIG. 1 ) and the middle movable support  44  for the bottom of the middle wrapping material roll  24 B ( FIG. 1 ). The motor  56  rotates a screw lift to move the middle roll bottom support  44  and the upper roll bottom support  46  to adjust the wrapping material to the location on the object being wrapped. 
         [0037]    In  FIG. 5 , there is shown a fragmentary perspective view of the mast  28  with a vertically movable ball-nut driven cantilever  40  mounted to a support guide plate  62 . The support guide plate  62  fits slideably within a channel of the vertical mast  28  to be movable upwardly and downwardly in response to the drive screw  66  ( FIG. 6 ). As it moves upwardly or downwardly, it carries the wrapping roll vertically-movable ball-nut-driven cantilever  40  with it. 
         [0038]    In  FIG. 6 , there is shown a schematic diagram of the mast  28  which is shaped as a channel to provide side members to support guide plates  62  and having a motor  64  mounted within the motor compartment  56  and adapted to drive the drive screw  66 . The drive screw  66  is mounted within a ball nut  68  to move the ball nut  68  upwardly or downwardly depending on the direction of rotation of the motor  64 . The ball nut  68  is connected to the support guide plate  62  to move the support guide plate  62  upwardly or downwardly and thus move the wrapping material rolls  24 A- 24 C ( FIG. 1 ) upwardly or downwardly in response to the actuation of the switch  18  ( FIG. 4 ). The motor  64  is a 12 volt DC motor attached to the drive screw  66  through a worm gear case  70 . The ball nut  68  is a ⅜ inch diameter standard housing nut held in place to the support guide plate  62  by a bolt  72  to move the support guide plate  62  upwardly and downwardly under the control of the switch  18  ( FIG. 4 ). This unit is an actuator unit model 85152 within an 18 inch stroke and a 20 to 1 reduction. The motor is a 6,000 revolutions per minute motor with an H-D break type B. In the preferred embodiment, the drive screw  66  has three ball nuts mounted to it to drive the three cantilevers  38 ,  40  and  58  ( FIGS. 1 ,  2  and  4 ). 
         [0039]    In  FIG. 7 , there is shown a schematic circuit diagram showing the switch assembly  18 , the DC battery  30  and the motor  64  interconnected so that the switch assembly  18  may raise or lower the rolls of wrapping material  24 A- 24 C ( FIG. 1 ). The switch assembly  18  includes first and second normally open, single throw, double pole push button switches  74 A and  74 B each having a first contact  76 A and  76 B respectively electrically connected to the positive terminal of the DC battery  30  and a contact  78 A and  78 B respectively electrically connected to ground. One terminal of the DC motor  64  is electrically connected through a conductor  80 A to a contact  82 A of the double pole push button switch  74 A and to a contact  82 B of the double pole push button switch  74 B. With this arrangement, when the double pole, single throw, push button switch  74 A is depressed, the contact  82 A is connected to the contact  76 A to apply positive voltage through the conductor  80 A to the motor  64 . At the same time, a conductor  80 B is electrically connected through a contact  84 A to ground through the contact  78 A so that the motor  64  rotates in a first direction with a positive potential being applied through one terminal through the conductor  80 A with the conductor  80 B being grounded. 
         [0040]    Similarly, when the push button switch  74 B is depressed, the contact  82 B is connected to the contact  78 B to ground so as to connect the conductor  80 A to ground and a contact  84 B is connected to the contact  76 B to connect the conductor  80 B to the source of positive potential from the battery  30  and thus rotate the motor  64  in the opposite direction. With this arrangement, the rolls of wrapping material can be raised or lowered by depressing the appropriate push button switches  74 A or  74 B of the switch assembly  18  on the handle assembly  16  ( FIGS. 1 ,  2  and  4 ). The operator by using the handle assembly  16  can in this manner raise or lift the rolls of paper and the vertical location at which the wrapping material is being as the operator moves the vehicle around the object or group of objects being wrapped. Similarly, when the object or group of objects is mounted on a turntable, the operator can easily raise or lower the rolls of wrapping material to adjust the elevation at which the wrapping material is being applied to the object or groups of objects. 
         [0041]    In  FIG. 8 , there is shown a perspective view of a rear portion of another embodiment of wrapping vehicle  10 A having four wheels two of which are rear steerable wheels  20 D and  20 E (the two front wheels not being shown in  FIG. 8 ). In  FIG. 8 , the parts of the wrapping machine  10 A that are the same as the corresponding parts in the wrapping machine  10  of  FIG. 1  have the same reference numerals as in  FIG. 1 . In the embodiment  10 A, the two rear wheels  20 D and  20 E, are mounted to an elongated support  94  and are each turnable to permit steering of the vehicle from the handle. 
         [0042]    In  FIG. 9 , there is shown an operator  92  holding the handle of a push/pull cart vehicle  10  with two rolls of wrapping material on it and moving the wrapping material around objects  88  on a pallet  90  to palletize them. With his hand on the handle  16  (handle  16  not shown in  FIG. 9 ) the operator  92  may actuate the switch assembly  18  ( FIGS. 1 and 7 ) to raise or lower the rolls of wrapping material to position them correctly on the objects  88  as the operator  92  pushes the cart around the objects  88  to palletize them. 
         [0043]    In  FIG. 10 , the operator  92  is shown cutting the wrapping material between the push/pull cart vehicle  10  and the palletized objects  88  so that it may be separated from the rolls of wrapping material on the push/pull cart vehicle  10 . 
         [0044]    As can be understood from the above description, the wrapping vehicle or machine of this invention has several advantages, such as for example: (1) it is labor saving; (2) it is fast because of the ability to wrap more than one turn of wrapping material in one revolution about the objects being wrapped; (3) it permits easy positioning of the wrapping material in elevation; and (4) it permits effective adjustment of tension on the rolls of wrapping material. 
         [0045]    While a preferred embodiment of the invention has been described with some particularity, many modifications and variations of the invention are possible within the light of the above teachings, and therefore, it is to be understood that the invention may be practiced other than as specifically described but within the scope of the appended claims.