PATENT ABSTRACT
Hand trucks and methods for displacing an object with a hand truck are disclosed. An example hand truck includes a lifting toe and a lift apparatus coupled to the lifting toe and configured to displace the lifting toe. A microprocessor is configured to output a plurality of control signals. An actuator is coupled to the lift apparatus and is configured to displace the lift apparatus responsive at least in part to the microprocessor outputting at least one of a plurality of control signals. An example method includes changing the load on a lifting toe from a first weight to a second weight and activating an actuator responsive at least in part on changing the load. A lift sled is moved in a first direction responsive to the activation of the actuator and the lifting toe is moved in the first direction by the lift sled.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims priority to Provisional Application No. 61/332,769, filed May 8, 2010, which application is incorporated herein by reference, in its entirety, for any purpose. 
     
    
     TECHNICAL FIELD 
       [0002]    Embodiments of the present invention relate generally to hand trucks, and more specifically, in one or more of the illustrated embodiments, to programmable electric hand trucks. 
       BACKGROUND OF THE INVENTION 
       [0003]    The use of hand trucks is well known. Hand trucks have long been used to assist in transporting objects, such as perishables, appliances, furniture, tools, and containers. However, many hand trucks require repetitive combinations of bending and lifting to add and remove items from the hand truck toe. This process can be both taxing and time consuming for a user, particularly for those in involved with product delivery and product distribution. Additionally, many hand trucks are not equipped to help with deliveries requiring multiple specific toes. One delivery for example, may require a forked toe for pallets, a flat toe for boxes, and a hoist toe for lifting heavy items. Thus, in many cases, a single delivery may require several different hand trucks to provide different toes. 
         [0004]    Therefore, a need exists for a hand truck that can adjust the height of a toe to reduce the amount of strain on a user loading and unloading objects. There may be an additional need for a hand truck providing a modular toe system to allow for transport of a variety of objects in a single delivery. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the various embodiments of the present disclosure, it is believed that the embodiments will be better understood from the following description taken in conjunction with the accompanying Figures. 
           [0006]      FIG. 1  is a front perspective view of a hand truck according to an embodiment of the invention. 
           [0007]      FIG. 2  is a front perspective view of a hand truck according to an embodiment of the invention. 
           [0008]      FIG. 3  is a front perspective view of a hand truck according to an embodiment of the invention. 
           [0009]      FIG. 4  is a block diagram of a control box according to an embodiment of the invention. 
           [0010]      FIG. 5  is a rear perspective view of a hand truck according to an embodiment of the invention. 
           [0011]      FIG. 6  is a perspective cut-away view of hand truck  100  according to an embodiment of the invention. 
           [0012]      FIG. 7  is a perspective view of a lift sled according to an embodiment of the invention. 
           [0013]      FIG. 8  is a front perspective view of a hand truck according to an embodiment of the invention. 
           [0014]      FIG. 9  is a front perspective view of a lifting toe according to an embodiment of the invention. 
           [0015]      FIG. 10  is a front perspective cut-away view of a hand truck according to an embodiment of the invention. 
           [0016]      FIG. 11  is a front perspective view of a hand truck according to an embodiment of the invention. 
           [0017]      FIG. 12  is a front perspective cut-away view of a hand truck according to an embodiment of the invention. 
           [0018]      FIG. 13  is a front perspective view of a hand truck according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Embodiments of the invention are directed toward a programmable electric hand truck. Certain details are set forth below to provide a sufficient understanding of embodiments of the invention. However, it will be clear to one skilled in the art that embodiments of the invention may be practiced without these particular details. Moreover, the particular embodiments of the present invention described herein are provided by way of example and should not be used to limit the scope of the invention to these particular embodiments. 
         [0020]      FIG. 1  illustrates a hand truck  100  according to an embodiment of the invention. Hand truck  100  may comprise a base  110  and a tower  130 . Tower  130  may include a handle  132 , side members  134 , and an actuator  150 . The handle  132  may be coupled to side members  134  by brackets  133 . Brackets  133  may be fixed to side members  134  using any method of coupling known by those skilled in the art. For example, brackets  133  may be attached to side members  134  using screws, bolts, welding, or adhesives. 
         [0021]    In some embodiments, brackets  133  may be configured to receive handle  134  such that handle  134  may be removable and/or interchangeable with other handles. Moreover, handle  134  may be U-shaped, T-shaped, H-shaped, or separate, dual handle bars. In other embodiments, brackets  133  may be permanently fixed to handle  132  or handle  134  may be directly coupled to side members  134 . 
         [0022]    Side members  134  may extend at least from base  110  to brackets  133  in a substantially linear manner and define a width of tower  130 . Support braces  136  may be coupled to side members  134 , spanning across the width of tower  130 . In one embodiment, support braces  136  may be in spaced-apart parallel relation to one another and substantially perpendicular to side members  134 . Additionally, in some embodiments, support braces  136  may be attached to side members  134  using any method of coupling known by those having skill in the art. For example, screws, bolts, welding, or adhesive may be used. 
         [0023]    Tower  130  may further include an actuator  150 . As will described in more detail below, the actuator  150  may be used to provide lifting force to a lifting toe  116 . In some embodiments, the actuator  150  may be a mechanical linear actuator and coupled to support braces  136  by support rings  137 . Alternatively, actuator  150  may be directly attached to support braces  136  using any method of coupling known by those having skill in the art, such as screws, bolts, clamps, welding, or adhesives. Actuator  150  may substantially span the length of tower  130  and further include a lift bar  152 . 
         [0024]    With reference to  FIGS. 3 and 5 , base  110  may include wheels  112 , axle  118 , and a base plate  122 . Base plate  122  may be coupled to a longitudinal end of each side member  134  and protrude outward from tower  130 . In at least one embodiment, base plate  122  is substantially planar. In other embodiments, base plate  122  may be curved or multi-planar. 
         [0025]    Tower  130  and base plate  122  may further be coupled to the wheels  112 . Additionally, in at least one embodiment, wheels  112  may be coupled together by the axle  118  in such fashion that wheels  112  rotate together. In another embodiment, wheels  112  may include brakes (not shown) and/or wheel locks (not shown) that may be configured to partially or fully prevent wheels  112  from rotating. Wheels  112  may comprise rubber, but those having skill in the art will recognize that wheels  112  may comprise any rigid material, including steel, sheet metal, plastic, wood, combinations thereof, or other suitable materials for adequate rolling, wear, and friction properties. 
         [0026]    With reference to  FIGS. 3 and 6 , a lifting toe  116  may be coupled to a lift sled  140 . As will be explained in more detail below, the position of lifting toe  116  may be adjusted by moving the attached lift sled  140  up or down relative to base  110 . In at least one embodiment, the actuator  150  may be activated to cause lift bar  152  to raise or lower and in turn displace the lift sled  140  coupled to the lift bar  152 . Thus, any object positioned on or suspended from lifting toe  116  may be displaced in substantially the same direction and distance as the lift bar  152  when moved by actuator  150 . 
         [0027]    Elements of hand truck  100 , for example, those shown in  FIG. 1 , may comprise a metallic material such as extruded aluminum, extruded magnesium, bonded aluminum, or steel, but those having skill in the art will recognize that these elements may comprise any rigid material, including plastic, wood, carbon fiber, or combinations thereof, and further may be of any thickness. 
         [0028]    In one embodiment, hand truck  100  may include an actuator  250  as illustrated in  FIG. 2 . Unlike the embodiment illustrated in  FIG. 1 , the lift sled  140  is not coupled to the actuator  250  using a lift bar. The lift sled  140  may be coupled, for example, to a threaded lift bracket (not shown) instead of a lift bar  152 . The lift bracket may be coupled to a screw shaft  254  of the actuator  250  such that rotation of the screw shaft  254  causes the lift bracket and an attached lift sled  140  to be raised or lowered. 
         [0029]    In operation, when actuator  250  is activated, screw shaft  254  may begin to rotate around its longitudinal axis and move threaded lift bracket up or down based on the direction of rotation. Because lift sled  140  is coupled to threaded lift bracket, as threaded lift bracket moves up or down, lift sled  140  may also be displaced. Thus, the height of lifting toe  116  attached to lift sled  140  may be controlled with actuator  250 . In some embodiments, actuator  250  may be a ball screw actuator, a roller screw actuator, or other actuators known by those having skill in the art. 
         [0030]    In other embodiments, hand truck  100  may not include an actuator and displace lift sled  140  with other devices. For example, in other embodiments, hand truck  100  may include a cable and pulley apparatus (not shown) or a hand crank for manual displacement of lift sled  140 . Those having skill in the art will appreciate that various implementations are possible, and that the present invention is not limited to these particular embodiments. 
         [0031]    Hand truck  100  may further include a battery  361 , control box  362 , and motor  363  as illustrated in  FIG. 3 . Battery  361 , control box  362 , and motor  363  may be located between side members  134 , but also may be located elsewhere on hand truck  100 . 
         [0032]    In some embodiments, battery  361  may be swappable and/or rechargeable. For example, battery  361  may be a nickel cadmium battery, but those having skill in the art will recognize that battery  361  may comprise any type of rechargeable battery, including nickel metal hydride, lithium ion, and lithium ion polymer. Additionally, battery  361  may be recharged from any standard power source, such as a car battery or wall outlet. 
         [0033]    In operation, motor  363  may derive power from battery  361  and activate actuator  150  based on control signals received from a microprocessor  401  ( FIG. 4 ) in control box  362 . As described above, because lifting toe  116  is coupled to lift sled  140  to which the lift bar  152  is attached, when actuator  150  is activated and lift bar  152  is displaced, lifting toe  116  may also be displaced. In at least one embodiment, control signals received by motor  363  may indicate the direction lifting toe  116  is to be displaced. For example, a control signal may cause motor  363  to raise lifting toe  116  by raising lift bar  152  with actuator  150 . In other embodiments, control signals  363  may control the rate, distance, and/or power with which lifting toe  116  is to be displaced. 
         [0034]      FIG. 4  illustrates a block diagram of a control box  362  according to an embodiment of the present invention. Control box  362  may include a programmable microprocessor  401  comprising random access memory, read only memory, a central processing unit and/or control logic. A wireless interface  402  may be coupled to microprocessor  401  and configured to interface with a remote control  460  and/or a user control interface  461 . In one embodiment, wireless interface  402  is a receiver capable of receiving data. In another embodiment, wireless interface  402  is a transceiver capable of both receiving and transmitting data. Wireless interface  402  may be configured to transmit with any wireless communication protocol known by those having ordinary skill in the art. For example, wireless interface  402  may be configured to communicate over Bluetooth, RF, or wireless Ethernet protocols. 
         [0035]    Microprocessor  401  may further be coupled to a sensor  450  that may communicate with microprocessor  401  to provide data corresponding to objects supported by lifting toe  116 . For example, sensor  450  may be a weight sensor and measure the weight of objects placed on lifting toe  116 . 
         [0036]    In at least one embodiment, microprocessor  401  may have a program mode, a user mode, and an upgrade mode. In program mode, programmed sequences may be executed in microprocessor  401  to dictate how the height of lifting toe  116  may be adjusted relative to base  110  in response to changes in parameters. In at least one embodiment, microprocessor  401  may be configured to increase or decrease the height of lifting toe  116  a predetermined distance each time sensor  450  senses an item has been added to or removed from lifting toe  116 . In another embodiment, microprocessor  401  may be configured to displace lifting toe  116  a distance proportionate to an amount of weight added to or removed from lifting toe  116 . In yet another embodiment, microprocessor  401  may be programmed to adjust the height of lifting toe  116  based on a time and/or time intervals. 
         [0037]    For example, if a product A weighing 6 lbs. and having a height of 8 inches, is placed on lifting toe  116 , sensor  450  may detect the additional 6 lbs. added to lifting toe  116  and couple data corresponding to the parameter change to microprocessor  401 . Microprocessor  401  may be programmed to associate 6 lbs. of added load to a product having a height of 8 inches, and upon receiving the signal from sensor  450 , lower lifting toe  116  8 inches. This may allow the next object to be added to lifting toe  116  at the same height as product A. Additionally, other weights may be mapped to other heights in microprocessor  401  to allow for a variety of objects to be stacked on lifting toe  116  and for the height of lifting toe  116  to be adjusted accordingly. 
         [0038]    Microprocessor  401  may further be configured to execute sequences in reverse as well. For example, upon removal of product A from lifting toe  116 , the reduced weight on lifting toe  116  may be sensed and the height of lifting toe  116  raised by the appropriate amount. Those having skill in the art will appreciate that various implementations are possible, and that the present invention is not limited to these particular embodiments. 
         [0039]    In a user mode, microprocessor  401  may receive and execute manual commands. For example, microprocessor  401  may receive commands from remote control  460  or user interface  461  indicating a direction and distance in which to displace lifting toe  116 . Additionally, user commands may specify the rate, length of time, and/or force with which the lifting toe  116  is to be displaced. In at least one embodiment, user commands may enable or disable the microprocessor  401  and/or the motor  363 . In another embodiment, user commands may specify the mode in which microprocessor  401  may operate. 
         [0040]    Microprocessor  401  may also utilize an upgrade mode for operation. Upgrade mode may allow microprocessor  401  to receive and implement new configurations for program mode, user mode, or control of coupled devices. 
         [0041]      FIG. 5  illustrates a rear perspective view of hand truck  100 . With reference to  FIG. 4 , user interface  461  may be included on a control bracket  510 . Thus, user interface  461  on control bracket  510  may be used to update configurations in microprocessor  401  and/or control operation of hand truck  100  as discussed above. In one embodiment, control wires coupling control signals from user interface  461  to control box  362  may be routed through a conduit (not shown) or inside a side member  134 . In another embodiment, control signals may be transmitted wirelessly. 
         [0042]    Hand truck  100  may further include a shield plate  525  that spans across the width of hand truck  100 . Shield plate  525  may be placed between base  110  and axle  118  and partially enclose base  110 . Shield plate  525  may comprise a metallic material such as extruded aluminum, extruded magnesium, bond aluminum, or steel, but those having skill in the art will recognize that shield plate  525  may comprise any rigid material, including plastic, wood, carbon fiber, or combinations thereof. In at least one embodiment, shield plate  525  may have an arc shape. In other embodiments, shield plate may be planar or multi-planar. 
         [0043]      FIG. 6  illustrates a perspective cut-away view of hand truck  100  according to an embodiment of the invention wherein some of the elements of hand truck  100  have been omitted for clarity. Hand truck  100  may include a lift sled  140  coupled to guide blocks  141 . Lift sled  140  may coupled to guide blocks  141 , for example, with bolts and nuts. Guide blocks  141  may comprise a rigid material, such as metal, but those having skill in the art will appreciate that any suitable rigid material may be used. 
         [0044]    Guide blocks  141  may be partially enclosed in side members  134  and configured to slide within side members  134 . In one embodiment, side members  134  may be C-channels and guide blocks  141  may be substantially rectangular in shape. In another embodiment, side members  134  may contain grooves and guide blocks  141  may comprise guide wheels that roll within the groove of side members  134 . As previously described, when actuator  150  is activated, lift bar  152  may move and cause lift sled  140  to move. When lift sled  140  is raised or lowered, guide blocks  141  may be correspondingly raised or lowered within side members  134 . As a result, guide blocks  141  may provide stability as the lift sled  140  is raised or lowered. 
         [0045]      FIG. 7  shows lift sled  140  and lifting toe  116  of hand truck  100  according to an embodiment of the invention. Lift sled  140  may be configured to receive various lifting toes. In one embodiment, lifting toe  116  may be coupled to lift sled  140  ( FIG. 5 ) by mating the back of lifting toe  116  with a recess  710  in lift sled  140 . Threaded fastening devices  715  may then be used to tighten the mated connection between the lifting toe  116  and lift sled  140 . In another embodiment, lifting toe  116  may be directly connected to lift sled  140 . For example, the back of lifting toe  116  may be bolted, snapped, adhered, or screwed to lift sled  140 . 
         [0046]    As described above, various lifting toes may be used with hand truck  100 . Lifting forks  816  illustrated in  FIG. 8 , for example, may be attached to lift sled  140  ( FIG. 6 ). In at least one embodiment, lifting forks  816  may be laterally moved relative to one another to adjust distance between the forks. In another embodiment, lifting forks  816  may be fixed relative to one another. 
         [0047]    Additionally, lifting toes attached to lift sled  140  may be modified by adding an attachment. For example, as illustrated in  FIG. 9 , roller wheels  920  may be attached to forks  816  with pins  925  to create a lifting toe  916 . In alternative embodiments, roller wheels  920  may snap or strap onto forks  816 . It will be appreciated that other approaches, such as screwing or bolting, may also be used to add an attachment to a lifting toe and the present invention is not limited to these particular embodiments. 
         [0048]    Base plate  122  may also be modified by adding an attachment. For example, as shown in  FIG. 10 , a castor apparatus  1010  may be added to base plate  122 . The castor apparatus  1010  may include castor wheels  1012  and an attachment body  1014 , and may be coupled to base plate  122  by pins  1025 . The castor apparatus  1010  may be attached to the base plate  122  by other attachment techniques as well. In at least one embodiment, pins  1025  may be removed to allow castor apparatus  1010  to be detached from base plate  122 . When hand truck  100  has been modified with castor apparatus  1010 , hand truck  100  may be moved along a surface in an upright position. 
         [0049]    At least one embodiment of hand truck  100  may include lifting toe  1110  as illustrated in  FIG. 11 . The lifting toe  1110  illustrated in  FIG. 11  is attached to the lift sled  140 . Other attachment techniques can be used as well, for example, attaching the lifting toe  1110  to lifting toe  116 . Lifting toe  1110  may include a suspension apparatus  1112  and support arm  1114 . Suspension apparatus  1112  may be a chain, rope, cable, belt, or other suitable suspension line. In one embodiment, hand truck  100  may utilize lifting toe  1110  and castor apparatus  1010  ( FIG. 10 ) simultaneously. As a result, hand truck  100  may be used to hoist objects above a surface and move the objects while hand truck  100  is in an upright position. 
         [0050]    As illustrated in  FIG. 12 , base  110  of hand truck  100  may be permanently modified with an attachment. For example, permanent castor wheel attachments  1210  may be attached to ends of side members  134  and surface of base plate  122 . Permanent castor wheel attachments  1210  may allow for additional support of hand truck  100  and allow hand truck  100  to be moved in an upright position. 
         [0051]      FIG. 13  illustrates hand truck  100  with a lifting toe  1316  according to an embodiment of the invention. Lifting toe  1316  may comprise a support bracket  1323 , a support line  1320 , base arms  1321 , and a clamp arm  1322 . Support line  1320  may be coupled to a support bracket  1323  as well as clamp arm  1322 . Base arms  1321  may also be coupled to clamp arm  1322 . Support bracket  1323  may further be coupled to an end of each side member  134 . 
         [0052]    In operation, clamp arm  1322  may be secured to an object A. Lifting toe  1316  may subsequently be raised by actuator  150  to suspend the object secured by clamp arm  1322  at a desired height. Clamp arm  1322  may also be rotated at pivot  1324  to change the orientation of the object relative to hand truck  100 . The object may then be moved with hand truck  100  in an upright position. 
         [0053]    From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.