Abstract:
A hand truck includes a frame, a toe plate connected to the frame, a pair of wheels rotatably secured to the frame, and a handle connected to the frame. A fourth-wheel attachment is pivotally connected to the frame at a first point and removable connected to the frame at a second point. A lever positioned adjacent to the handle causes the removable connection between the fourth-wheel attachment and the frame to be released, allowing the fourth-wheel assembly to pivot away from the frame. An embodiment of a hand truck includes a break back bar. The break back bar is pivotable with respect to the frame. The break back bar may be deployed and stood on by a user to prevent movement of the hand truck while pivoting a load.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to a hand truck and, more specifically, to a hand truck with new integrated safety and improved use features. 
       BACKGROUND 
       [0002]    Many devices have been developed over the years to aid people in the movement and transportation of items that otherwise would be too heavy or unwieldy to move. There exists a multitude of powered devices such as cranes, forklifts, hydraulic ramps, etc. that simplify moving. A similar variety of non-powered devices also exist for people to choose from. Non-powered devices, such as pulleys, ropes, clamps, levers and hand trucks, are commonly available to consumers. The ease of use of contemporary hand trucks makes the hand truck an ideal tool for transporting heavy objects and has led to the common use of hand trucks by tremendous numbers of people. 
         [0003]    The wide utilization of hand trucks has caused many manufacturers to research improvements in the design of the modem hand truck. Today, industrial quality hand trucks are produced that have frames made of sturdier, tougher materials to simplify transporting appliances and other items that are too large for smaller sized hand trucks. These industrial quality hand trucks are useful for transporting exceedingly larger items, and are often even capable of handling appliances or equipment that are much greater in size than the user who is navigating the hand truck. 
         [0004]    One drawback of current hand trucks is the lack of features and capabilities to help users manage large, heavy loads and provide adequate safety precautions. Basic features, such as straps, are commonly used to hold the load in place on the hand truck and prevent it from moving or falling off the truck. However, exceptionally heavy loads often require additional safety features to prevent injury to the user. For example, the common procedure for using hand trucks is to tip the truck to a given angle, such as  45  degrees, to balance the primary weight of the load on the wheels. However, when tipping the truck, exceptionally heavy loads may be hard to manage and may pull the truck away from the user, risking both injury to the user and damage to the load. 
         [0005]    Additionally, some trucks include safety features that can be deployed by the user to assist in handling and navigating the truck when handling large loads. However, often times, users are required to take at least one hand off of the primary handling location of the hand truck in order to activate or deploy such safety or load assist features. Removing one or both hands from the hand truck may be dangerous and maybe defeat the purpose of the safety feature altogether if the load or truck becomes unstable. 
         [0006]    Accordingly, an improved hand truck is needed in the art. 
       SUMMARY 
       [0007]    A hand truck is generally presented. The hand truck includes a frame, a toe plate connected to the frame, a pair of wheels rotatably secured to the frame, and a handle connected to the frame. A fourth-wheel attachment is pivotally connected to the frame at a first point and removable connected to the frame at a second point. A lever is positioned adjacent to the handle. Activation of the lever causes the removable connection between the fourth-wheel attachment and the frame to be released, allowing the fourth-wheel assembly to pivot away from the frame. 
         [0008]    In an embodiment, the fourth wheel assembly includes a latch connected to the frame. The latch is configured to interconnect with a latch bar positioned on the fourth-wheel attachment. The handle is connected to a first end of a cable or connecting device. The cable or connecting device is connected at a second end to the latch. Activating the lever may pull the cable or connecting device upward and apply a force on the spring to release the latch. 
         [0009]    The cable or connecting device may be connected at a third end to the fourth-wheel attachment. Activating the lever may pull the cable or connecting device upward and apply a force to the fourth-wheel attachment to move the fourth-wheel attachment from a deployed position toward an upright position. 
         [0010]    In an embodiment, a hand truck includes a frame, a toe plate connected to the frame, a pair of wheels rotatably connected to the frame, and a break back bar pivotably connected to the frame. The break back bar may be biased toward the upright position. 
         [0011]    The break back bar may be pivoted to a down position to contact the ground. A weight applied to the break back bar when in a down position may prevent the hand truck from rolling. 
         [0012]    The break back bar may be biased by a spring. The spring may be positioned on an axis positioned between portions of the frame. The axis may also be connected to the wheels to allow them to rotate with respect to the frame. 
         [0013]    In an embodiment, a hand truck includes a frame, a toe plate connected to the frame, a pair of wheels rotatably connected to the frame, a handle connected to the frame, and a break back bar pivotably connected to the frame. The hand truck further includes a fourth-wheel attachment pivotally connected to the frame at a first point and removable connected to the frame at a second point and an activation lever adjacent to the handle. Activation of the lever causes the removable connection between the fourth-wheel attachment and the frame to be released, allowing the fourth-wheel assembly to pivot away from the frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The operation of the invention may be better understood by reference to the detailed description taken in connection with the following illustrations, wherein: 
           [0015]      FIG. 1  illustrates a perspective view of a hand truck in upright position; 
           [0016]      FIG. 2  illustrates a side view of the hand truck in upright position; 
           [0017]      FIG. 3  illustrates a front perspective view of a hand truck in reclined position; 
           [0018]      FIG. 4  illustrates a side view of a hand truck in reclined position; 
           [0019]      FIG. 5  illustrates a rear perspective view of a hand truck in reclined position; 
           [0020]      FIG. 6  illustrates a perspective view of a fourth-wheel attachment; 
           [0021]      FIG. 7  illustrates a detailed side view of a fourth-wheel attachment connected to a hand truck in upright position; 
           [0022]      FIG. 8  illustrates a perspective view of a fourth-wheel attachment connected to a hand truck in upright position; 
           [0023]      FIG. 9  illustrates a detailed view of a roller axle assembly for a fourth-wheel attachment; 
           [0024]      FIG. 10 a    illustrates a side view of a latch assembly; 
           [0025]      FIG. 10 b    illustrates a perspective assembly view of a latch assembly; 
           [0026]      FIG. 11  illustrates a detailed side view of a handle assembly; 
           [0027]      FIG. 12  illustrates a detailed perspective view of a handle assembly; 
           [0028]      FIG. 13  illustrates a front perspective view of a latch assembly connected to a cable; 
           [0029]      FIG. 14  illustrates a perspective view of a break back bar; 
           [0030]      FIG. 15  illustrates a break back bar in upright position; 
           [0031]      FIG. 16  illustrates a break back bar in activated position; 
           [0032]      FIG. 17  illustrates a rear perspective view of a hand truck having pivot sockets on the fourth-wheel assembly; 
           [0033]      FIG. 18  illustrates a fourth-wheel assembly with pivot sockets in reclined position; 
           [0034]      FIG. 19  illustrates a fourth-wheel assembly with pivot sockets; and 
           [0035]      FIG. 20  illustrates a fourth-wheel assembly with pivot sockets in upright position. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the respective scope of the invention. Moreover, features of the various embodiments may be combined or altered without departing from the scope of the invention. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments and still be within the spirit and scope of the invention. 
         [0037]    A hand truck  10  is generally presented, as illustrated in  FIGS. 1-16 . The hand truck  10  may be configured to receive and move a load, such as an appliance or other large objects. The hand truck  10  may include various new features as described below, including features that assist a user in managing excessively large loads and prevent the hand truck from tipping or slipping away from the user while in use. 
         [0038]    The hand truck  10  may include a frame  12 . The frame may comprise a pair of vertical supports  14  and a plurality of horizontal cross supports  16 . The vertical supports may extend from the base of the hand truck  10  to the near top of the hand truck and may be connected at the top by a connecting bar  18 , such as the u-shaped connected bar  18  illustrated in  FIG. 1 . The horizontal cross supports  16  may connect to and span the vertical supports  14 . The cross supports  16  may be evenly spaced along the height of the frame  12 . The hand truck  10  may include any appropriate number of cross supports  16 . 
         [0039]    The frame  12  may be made of any appropriate material, such as a high strength, lightweight material, such as aluminum or extruded aluminum. However, it will be appreciated that the frame  12  may be made of any appropriate material, such as steel, stainless steel, or high-density plastic, or the like. 
         [0040]    The hand truck  10  may include a toe plate  20 . The toe plate may be located at the base of the frame  12  and may be connected thereto. The toe plate  20  may be any appropriate shape, such as having a  90  degree bend to form two portions, as shown in  FIGS. 1-5 . The first portion  22  may extend vertically from the base of the frame  12  and connect to the frame. The second portion  24  may extend horizontally away from the fame  12  and close to the ground when the hand truck  10  is in use. The toe plate  20  may be configured to receive a load thereon and hold the load in place during transportation and balancing of the hand truck  10 . The toe plate  20  may be made of any appropriate material, such as steel, aluminum, or the like. 
         [0041]    The hand truck  10  may include wheels  26 . The wheels  26  may be any appropriate size and may be positioned near and connected to the base of the frame  12 . The wheels  26  may be connected to an axle  27  to allow them to rotate with respect to the frame  12 . The axle  27  may be spaced a distance away from the frame  12  by a bracket or other connecting feature, to provide space for the wheels to rotate. The wheels  26  may allow a load on the toe plate  20  to be pivoted and transported. 
         [0042]    The hand truck  10  may include one or more handles  28 . The handles  28  may be connected to a portion of the frame  12 , such as an upper portion of the frame  12 . The handles  28  may protrude from the frame  12  in an opposite direction as the toe plate  20 . The handles  28  may comprise a curved portion, such as illustrated in  FIGS. 1-5 . The handles may be covered with padding or other grip friendly material to assist with handling. 
         [0043]    The hand truck  10  may include various features to assist in maintaining the load positioning on the hand truck  10 . For example, the hand truck  10  may include one or more wing plates  30 . The wing plates  30  may be connected to the vertical supports  14  and may extend beyond the perimeter of the frame  12  to provide support for wide loads. The wing plates  30  may be any appropriate shape, such as generally rectangular, and may be made of any appropriate material, such as steel, aluminum, or the like. 
         [0044]    The hand truck  10  may further include on or more strap assemblies  32 . The strap assemblies may be mounted to the rear side of the frame  12 , opposite the toe plate  20 , as illustrated in  FIGS. 1-5 . The strap assemblies  32  may include a base and a strap for securing a load to the frame  12 . The strap may wind around the base for storage and may be unwound and connected to itself or another strap or to the frame to fix the load in place. As shown, the straps may comprise retractable straps, such as retractable straps contained within enclosures. Alternatively, the straps may include loose or manually adjustable straps, such as e-track straps, that may be manually positioned and adjusted by a user to the desired length and position. 
         [0045]    In an embodiment, the hand truck  10  may include a fourth-wheel attachment  34 . The fourth-wheel attachment, as illustrated in  FIG. 6 , may comprise a pair of side supports  36  connected by a support bar  38 . A wheel  40 , such as a caster wheel as illustrated in  FIG. 6 , may be connected to a bottom end of each side support. 
         [0046]    The fourth-wheel attachment  34  may be connected to the frame  12  and capable of pivoting with respect to the frame  12 . For example, as illustrated in  FIG. 4 , a bracket  42  may be connected to each of the vertical supports  14 . The side supports  36  may be pivotally connected to the brackets  42  to allow the fourth-wheel attachment  34  to pivot with respect to the frame  12 . 
         [0047]    The fourth-wheel attachment  34  may include a sliding axle  44 . The sliding axle  44  may be connected to the side supports  36  and configured to move or slide with respect to the supports  36 . For example, the side supports  36  may each include an inner channel or opening  46 , as shown in the detailed view in  FIG. 9 . A bearing  48  may be positioned within each channel  46  and capable of sliding within the channel  46 . The bearing  48  may be a plastic self-lubricating bearing  48 , or any appropriate bearing  48 . The upper and lower boundaries of the channels  46  may be closed to prevent the bearings  48  from escaping out of the channel. The sliding axle  44  may connect to the bearings  48  at each end of the axle  44  to allow the sliding axle  44  to slide with respect to the fourth-wheel attachment  34 . 
         [0048]    As best seen in  FIGS. 4 and 7 , a brace  50  may interconnect the sliding axle  44  and the frame  12 . The brace  50  may comprise a bar, such as a portion of aluminum extrude. The brace  50  may connect at a first end to the sliding axle  44 . For example, the first end of the brace  50  may be connected to a first collar  52 . The first collar  52  may connect to the sliding axle  44  and be rotatable with respect to the sliding axle  44 . The second end of the brace  50  may be connected to a second collar  53 . The second collar  53  may be connected to a pivot axis  54 . The pivot axis  54  may be connected between the vertical supports  14  near the base of the frame  12 . The second collar  53  may be rotatable with respect to the pivot axis  54 . 
         [0049]    In an embodiment, illustrated in  FIGS. 17-20 , the engagement between the brace  50  and fourth-wheel attachment  34  may include a pair of pivot sockets  56 . The pivot sockets  56  may comprise a hollow body with open ends. The pivot sockets  56  may be positioned around the side supports  36  and slide with respect thereto. An axle  58  may extend between the two pivot sockets  56 . Instead of the bearing  48  positioned within the channel  46 , as shown in  FIGS. 1-16 , the pivot sockets  56  may slide up and down the length of the side supports. The first collar  52  may connect to the axle  58  and pivot or rotate with respect to the axle  58 . 
         [0050]    A latch  60 , positioned on the frame  12 , may be configured to receive and hold the fourth-wheel attachment  34  in a first position, as further described below. The latch  60  may be connected to any appropriate portion of the frame  12 , such as a cross support  16 . The latch may include a mounting bracket  59  to mount and connect the latch  60  to the frame  12 . The latch may further include a spring  64 , locking cam  66 , and pivot cam  68 . The spring  64  may be interconnect and apply a biasing force to the locking cam  66  and pivot cam  68 . The locking cam  66  and pivot cam  68  may be biased to an open position, as shown in  FIG. 10  a, when nothing is held within the latch  60 . In open position, the latch  60  may be capable of receiving a bar therein, expanding the spring  64 , and locking the bar between the locking cam  66  and pivot cam  68 . The bar may be removed from the latch  60  by expanding the spring  64  to relieve the locking force and removing the bar from the latch  60 . 
         [0051]    The brace  50  may include a latch bar  62  to lock the brace  50  and fourth-wheel attachment  34  to the latch  60 . The latch bar  62  may be spaced a distance away from the brace  50  to provide room for the bar to latch within the latch mechanism described above. 
         [0052]    The hand truck  10  may be movable between upright and reclined positions. In upright position, as shown in  FIGS. 1 and 2 , the latch bar  62  may be held within the latch  60  to lock the fourth-wheel attachment  34  into general alignment with the frame  12 . In reclined position, as shown in  FIGS. 3-5 , the fourth-wheel attachment  34  may be removed from the latch  60  and the sliding axle  44  may slide to the distal end of the channel  46 . The side supports  36  may be positioned approximately perpendicular to the ground and the frame  12  may pivot to an angle of approximately  45  degrees with respect to the ground in reclined position. 
         [0053]    The hand truck  10  may include a fourth-wheel attachment release mechanism to provide ease of use for activating and stowing the fourth-wheel attachment  34 . One or more activation handles  70  may be positioned near the handles  28  of the hand truck  10 . As shown in  FIGS. 11 and 12 , the hand truck  10  may include two activation handles  70 , one on each side near the upper portion of the frame  12 . The one or more activation handles  70  may be positioned in near proximity to the hand truck handles  28 , such as 2 inches, 4 inches, or 6 inches from the handles  28 . It will be appreciated that the proximity of the activation handle or handles  70  to the hand truck handles  28  may be important in allowing a user to activate the fourth-wheel attachment  34  without removing their hands from the hand truck handles  28 . Accordingly, the one or more activation handles  70  may be positioned within finger&#39;s reach from the truck handles  28 , such as between the handles  28 , to allow a user to both hold the handles  28  and grasp the activation handle  70  simultaneously. 
         [0054]    The one or more activation handles  70  may be connected to a rod  72 . The rod may extend from the base of the activation handles  70  and span laterally between the vertical supports  14 . In an embodiment having two or more handles  70 , the rod  72  may interconnect the handles  70  such that pulling on any of the handles  70  will rotate the rod  72 . A bracket  74  may extend from a portion of the rod  72 , such as a central portion of the rod  72 . The bracket  74  may be tied to a cable  76  that extends down from the bracket  74 . It will be appreciated that the hand truck  10  is not limited to using a cable  76 , and may instead use any similar or workable device, such as a chain, connecting rod, or the like. Pulling up on the activation handles  70  will apply an upward force on the cable  76 , and releasing the activation handle will allow the cable  76  to return to its original position. 
         [0055]    The cable or connecting device  76  may extend down and connect to the latch  60 , as shown in  FIG. 13 . A twist link  61  may be connected to the end of the cable  76  and connected to the spring  64 . The twist link  61  may comprise a bracket having a quarter or  90  degree turn. The  90  degree turn or twist may allow the twist link  61  to connect to a side of the cable  76  and be properly oriented to connect to the spring  64 . When the activation handle  70  is pulled up and activated, it will pull the cable upward and apply a force on the spring  64 . The force may decompress the spring  64  and pivot the locking cam  66  and pivot cam  68  to release the latch  60  and allow the latch bar  62  to exit the latch  60 . 
         [0056]    A lower end of the cable  76  may extend past the latch  60  and continue further down and connect to the brace  50 . When the fourth-wheel attachment  34  is stowed in upright position, the lower end of the cable  76  may have slack. When the fourth-wheel attachment  34  is employed in the reclined position, the slack in the lower end of the cable  76  may be drawn tight. In the reclined position, when the activation handle  70  is activated the lower cable  76  will apply any upward force on the brace  50 , pulling on the fourth-wheel attachment  34  to make it pivot back up into stowed, upright position. 
         [0057]    In use, the hand truck  10  may be configured in stowed, upright position with the fourth-wheel attachment  34  connected to the latch  60  by the latch bar  62 . To adjust the hand truck  10  into reclined position and deploy the fourth-wheel attachment  34 , one or more activation handles  70  may be activated. Pulling the activation handle  70  will apply an upward force on the cable  76 , which in turn will expand the spring  64  and open the latch  60 . When the hand truck  10  is pivoted about its wheels  26  while the activation handle  70  is activated, the gravitational force may pull the latch bar  62  out of the latch  60  and the fourth-wheel attachment  34  may deploy. The bearings  48  may slide within the channels  46  to a distal end of the channels  46  and the brace  50  may pivot out away from the frame, extending the fourth-wheel attachment  34 . Alternatively, in the embodiment illustrated in  FIGS. 17-20 , the pivot sockets  58  may slide along the side supports  36  toward the wheels  40 , extending the fourth-wheel attachment  34 . The hand truck  10  may then be rested on the fourth-wheel attachment wheels  40  and the hand truck wheels  26  to fully support and transport the load in reclined position. 
         [0058]    To stow the hand truck  10  back into upright position, the truck  10  may be partially pivoted on the wheels  26  back towards upright position. The activation handle  70  may then be actuated, which will apply an upward force on the brace  50 , pivoting the brace  50  and fourth-wheel attachment  34  back toward the frame  12 . The latch bar  62  may engage the latch  60  and lock therein, and the hand truck  10  may be moved back to upright position with the fourth-wheel attachment  34  stowed. 
         [0059]    In an embodiment, the hand truck  10  may include a break back bar  80 , as illustrated in  FIGS. 14-16 . The break back bar  80  may be useful in helping to stabilize the hand truck  10  when pivoting back towards the reclined position to prevent the load from running away from the user. 
         [0060]    The break back bar  80  may be any appropriate shape and size, such as generally thin and rectangular shaped. The break back bar  80  may have an angled end  82  positioned at a slight angle to the remainder of the break back bar  80 . The angled end  82  may include a small opening or handle hole  84 . 
         [0061]    The break back bar  80  may be connected to the wheel axle  27 , as illustrated in  FIGS. 15 and 16 . A collar  86  may be positioned about the axle  27  and rotatable with respect to the axle  27 . The break back bar  80  may be connected to the collar  86  and capable of pivoting with respect to the axle  27  and frame  12  between an up position generally adjacent to the frame  12  and shown in  FIG. 15 , and a down position generally parallel to the ground and shown in  FIG. 16 . 
         [0062]    The break back bar  80  may be biased toward the upright position. For example, the axle  27  may include one or more springs  88  configured to bias the collar  86  to pivot upward toward the frame  12 . The spring  88  may be positioned on and wound about the axle  27  and connected to the collar  86  at one end, as illustrated in  FIG. 15 . It will be appreciated, however, that any type of spring or biasing device may be used to bias the break back bar  80  toward the upright position. 
         [0063]    In use, the break back bar  80  may be biased toward the upright position while the hand truck  10  is also in upright position. A user may pivot the break back bar down toward the ground by applying a force with their hand or foot, and may then step onto the break back bar  80  to apply their entire weight, or a portion thereof, to the bar  80 . The hand truck  10  may then be pivoted to a reclined position without risk of rolling away from the user. Once the hand truck  10  is in a secure, balanced position, the user may remove their foot from the bar  80  and it will return to its upright position. The break back bar  80  may again be used to assist in returning a reclined load to upright position. The user may once again pivot and deploy the break back bar  80  using their hand or foot and step on the bar, pinning the bar to the ground. The load may then be pivoted back to upright position without risk of losing control. Using the break back bar  80  may reduce the strain and potential injury to a user by allowing them to maintain an upright posture while pivoting the load, instead of any awkward bending. 
         [0064]    It will be appreciated that the hand truck  10 , as described herein, may include a break back bar  80  but not a fourth-wheel attachment  34 , or alternatively, may include a fourth-wheel attachment  34  but not a break back bar  80 . Each feature may operate separately from the other and provide the benefits as described herein. 
         [0065]    In an embodiment, as illustrated in the  FIGS. 1-16 , the hand truck  10  may include both a fourth-wheel attachment  34  and a break back bar  80 . The two features may work in concert to assist a user in stabilizing and controlling the hand truck  10 . In use, the hand truck  10  may be stowed in the upright position with the fourth-wheel-attachment  34  positioned adjacent to the frame  12 , and the break back bar  80  biased toward the frame  12  behind the fourth-wheel attachment  34 , as shown in  FIG. 15 . To deploy the fourth-wheel attachment  34 , a user may first pivot and step on the break back bar  80 , as described above. The activation handles  70  may then be actuated to release the fourth-wheel attachment  34  and move the truck  10  into reclined position, as shown in  FIG. 16 . To revert back to upright position, the truck may be tilted towards upright position and the activation handle  70  may again be actuated to pull the fourth-wheel attachment  34  up and latch it into stowed position. The break back bar  80 , which is biased as described above, will then pivot back up into upright position. 
         [0066]    Although the embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be understood that the present invention is not to be limited to just the embodiments disclosed, but that the invention described herein is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the claims hereafter. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.