Abstract:
A hand truck includes a quick release/attach mechanism operating according to a method for quickly and easily exchanging various tools with the hand truck, the quick release/latch mechanism including biased locking pins movably located within tubular frame members integral to the hand truck and proximal holes in the tubular frame members for receiving a projection member of the tool and spaced a predetermined distance from a hangar portion of the tool and wherein the hangar portion may be hung on a crossbar of the tubular frame and then the projection members of the tool may be coupled with and retained by the locking pins of the tubular frame. The arrangement requires no hand tools such as wrenches or screwdrivers, and no external fasteners such as pins or bolts. The geometry of the cross bars on the hand truck allow tool attachments to be captured or releases simply by tilting the hand truck forward or backward. The tool attachments are then locked to the truck by means of locking rods and pins that operate inside the two main tubes of the hand truck.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority to and incorporates by reference herein for all purposes U.S. Patent Application No. 61/973,920, filed Apr. 2, 2014, to Darryl Edward Berlinger and entitled HAND TRUCK EXCHANGEABLE TOOL ATTACHMENT METHOD. 
    
    
     FIELD 
     The present disclosure relates to light material handling equipment. Light material handling equipment encompasses a wide variety of wheeled carts, trollies and hand trucks (e.g., dollies). These devices are typically manually operated by an operator who pushes or pulls the equipment. There are also motor-assisted (i.e., motorized) devices which may include some type of device or mechanism to propel the device or cart without the operator having to exert a significant (or even zero) effort to cause the device to move. 
     BACKGROUND 
     Generally it is known to provide a wheeled device that typically stands vertically on two wheels and has an upper portion to be held by the operator to load carry cargo and to then tilt the loaded cargo and wheel the loaded cargo to a different location. It is also known to provide a hand truck including rear stabilizer wheels which allow the hand truck to be tilted or leaned back and rested on the primary wheels and the rear stabilizer wheels. There are a wide variety of application-specific hand trucks based upon the above generally known designs. Such known application-specific hand trucks may be known as drum dollies (for moving 55-gallon drums), cylinder trucks (for moving high pressure gas cylinders), tree dollies (for moving trees with ball roots), and water dollies (for moving multiple 5-gallon tanks of drinking water) to name only a few. It is generally known that any of these examples may be manually-operated or may be motor-assisted devices. 
     It is also generally known that there are a vast amount of known hand trucks for many different uses. The known hand trucks vary a great deal and may include simple mechanical clamping mechanisms to secure the load to the truck as well as manual braking devices. It is also further known to provide more complex and motorized hand trucks that can lift and lower loads. There are many adaptations and versions of hand trucks to meet the many varying needs of specific uses or applications since a hand truck may be used in so many ways and in so many industries. 
     SUMMARY 
     In one embodiment, a hand truck including a mechanism for providing a quick and easy way to capture, lock and unlock application-specific tools to the hand truck is disclosed. 
     In one embodiment of the present invention, a cross baron the hand truck is used to hang the tool at the top, with two pins that are slid into receiving tabs at the bottom of the tool attachment to retain and lock it to the truck. 
     The cross bar(s) and the locking pins are located on the hand truck. 
     The profile at the top of the tool attachment and the locking tabs at the bottom of the tool attachment mate with the cross bar and locking pins on the hand truck. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a hand truck including a quick release/attach mechanism for quickly attaching and releasing a tool to the hand truck. 
         FIG. 2  is an alternate perspective view detailing the quick release/attach mechanism for the hand truck of  FIG. 1 . 
         FIG. 3  is a partial perspective view of the hand truck including the quick release/attach mechanism with the tool released from the hand truck. 
         FIG. 4  is an alternate partial perspective view of the hand truck including the quick release/attach mechanism with the tool released from the hand truck. 
         FIG. 5  is a perspective view of the hand truck including the quick release/attach mechanism with the tool removed and the quick release/attach mechanism shown in phantom within a tubular frame of the hand truck. 
         FIG. 6A  is a partial, side view a handle control of the quick release/attach mechanism and the control rod within the tubular upright of the frame of the hand truck taken along the line  6 A of  FIG. 5 . 
         FIG. 6B  is a partial, side view the locking pin and hole of the quick release/attach mechanism and the control rod within the tubular upright of the frame of the hand truck taken along the line  6 B of  FIG. 5 . 
         FIG. 7  is a perspective view of the hand truck of  FIG. 1  in an alternate position. 
         FIG. 8  is an alternate, partial, perspective, partially exploded view of the bottom of the hand truck of  FIG. 1  showing the glide members located in the bottom of the upright members of the tubular frame of the hand truck. 
         FIGS. 9A-9C  are a progression of side views of the hand truck of  FIG. 1  showing the method of attaching the tool to the hand truck. 
         FIG. 10  is a perspective view of a hand truck including a quick release/attach mechanism for quickly attaching and releasing a tool to the hand truck for use with a tool for carrying gas cylinders. 
         FIG. 11  is a perspective view of a hand truck including a quick release/attach mechanism for quickly attaching and releasing a tool to the hand truck for use with a tool for carrying a large bin such as a trash bin. 
         FIG. 12  is a perspective view of a hand truck including a quick release/attach mechanism for quickly attaching and releasing a tool to the hand truck for use with a tool for carrying an inflatable. 
     
    
    
     DETAILED DESCRIPTION 
     Referring in general to all of the drawings, and in particular to  FIGS. 1 and 2 , there is disclosed a hand truck  10  having a tubular frame  20 , including wheels.  14 , a support frame  18  and including a motor  16  and related components as may also be referred to as a wheeled dolly for use in transporting a variety of relatively heavy and/or bulky objects. The hand truck  10  may preferably include a quick release/attach mechanism  50  for relatively easily and quickly attaching and detaching a tool  40  as more fully described herein. The mechanism  50  may include a latching device that is at least partially, and in one embodiment, entirely located within the tubular frame  20  of the hand truck  10  except for an actuator handle  51 , supported by the tubular frame  20  as best shown in  FIG. 2 . The actuator handle  51  may be moved upward (against the force of gravity or against a biasing mechanism such as springs  57  (see  FIG. 6A )) and downward with respect to the tubular frame  20  to move the latching mechanism  50  between the unlatched and latched positions for attaching and detaching the tool  40  from the frame  20  of the hand truck  10 . 
     The tubular frame  20  of the hand truck  10  may preferably include an upper or handle portion  22  and a first or left side upright tubular frame member  21  and a second or right side upright tubular frame member  23  having a generally U-shaped construction. The tubular frame  20  may preferably be made from a metal material of any known or appropriate type. The tubular frame  20  may preferably also have a generally hollow interior passage  26  (as best shown in  FIG. 6A ). The first and second upright tubular frame members  21  and  23 , respectively, may have any known or appropriate shaped cross-section but, more particularly, may preferably have a round or circular shaped cross-section. Notwithstanding, it is expressly contemplated that the cross-sectional shape of the interior passage  26  may differ from the cross-sectional shape of the outer perimeter of the tubular frame  20 . The interior passages  26  of the first and second tubular frame members  21  and  23 , respectively, may preferably extend from a portion proximal the upper handle portion  22  to the lower ends  24  and  25 , respectively, of the first and second tubular frame members  21  and  23 . The latching mechanism  50  of the hand truck  10  may further include first and second passages or holes  28  and  29 , located a predetermined distance from the lower ends  24  and  25 , respectively, of the first and second tubular frame members  21  and  23  as best shown in  FIGS. 3 and 4 . Each of the holes  28  and  29  may preferably have a generally horizontal extent and be in communications with the respective interior passage  26  of the first and second upright tubular frame members  21  and  23 , respectively, and may be shaped for receiving a respective extension tab or portion  44  and  45  of the tool  40  for being securely received in the respectively passage  26  and for being engaged with the latching mechanism  50 . 
     The latching mechanism  50  may include the handle actuator member  51  which may generally extend horizontally between the first and second upright tubular frame members  21  and  23 , respectively. The handle actuator member  51  may be lifted by the operator toward an unlatched position (which is toward the upper handle or control portion  22 ) for releasing the latching mechanism  50  and releasing the tool  40  from the hand cart  10 . When the handle actuator member  51  is not being moved toward the unlatch position  50 , the weight of the mass of the components of the latching mechanism weigh the device downward in the interior passages  26  of the first and second tubular frame members  21  and  23 , respectively, and toward the latched position. 
     The latching mechanism  50  may further include a first connector member  53  having a generally longitudinal extent and having an outer cross-sectional shape complimentary of the cross-sectional shape of the interior passage  26  of the tubular frame  20 . The first connector member  53  has a first or upper end  54  located proximal the handle actuator member  51 , which may be coupled to the handle actuator member  51  using a fastener  59 , external of the tubular frame member  21  and extending through a passage  27  ( FIGS. 2, 5 and 6A ) which has a longitudinal extent of a given distance for setting the limits of travel of the handle actuator member  51  and the first connector members  53 . The latching mechanism  50  may further include a second connector member  53  having a generally longitudinal extent and having an outer cross-sectional shape complimentary of the cross-sectional shape of the interior passage  26  of the second upright member  23  of the tubular frame  20 . The second connector member  53  has a first or upper end  54  located proximal a handle actuator member  51 , which may be coupled to the handle actuator member  51  using a fastener  59 , and located external of the tubular frame member  23  and extending through a passage  27  which may extend longitudinally a given distance for setting the limits of travel of the handle actuator member  51  and the second connector member  53 . It is expressly contemplated that the latching mechanism  50  may include a biasing mechanism  57  ( FIG. 6A ), located proximal the upper ends  54  of the connector members  53 , to bias or force the connector members  53  downward within the internal hollow passages  26  of the first and second upright tubular frame members  21  and  23 , respectively, and to move a lower end  55  of the connector members  53  and a coupling member or pin  56  toward the lower ends  24  and  25  of the thereof first and second upright tubular frame members  21  and  23 . Each lower end  55  of the first and second connector members may include the coupling member or pin  56  which may include a leading angled portion or end  58  ( FIG. 6B ) aligned with a respective passage or opening  28  and  29  in the first and second upright tubular frame members  21  and  23 , respectively. It should be understood that while the preferred embodiment of the present disclosure includes first and second connector members  53  located in the first and second upright tubular frame members  21  and  23 , respectively, it is expressly contemplated that the latching mechanism  50  may include a single connector member  53  located in either one of the first and second upright tubular frame members  21  and  23 , respectively. 
     The tubular frame  20  may further include a plurality of shaped, cross-members  30  extending between the first and second upright tubular frame members  21  and  23 , respectively. Each shaped cross member  30  may preferably be rigidly coupled or connected to each of the first and second upright tubular frame members  31  and  33 , respectively, using any known or appropriate coupling mechanism or technique including, in a particularly preferred embodiment, by welding. Each cross member  30  may preferably include a upper surface  31  extending across the front to rear width of each of the first and second upright tubular frame members  21  and  23 , respectively, and being angled with respect to the horizontal cross-section of the first and second upright tubular frame members  21  and  23 , respectively. As best shown in  FIGS. 9A-9C , the upper surface  31  may preferably be angled with respect to the perpendicular cross-section of the tubular upright frame members  21  and  23 , respectively, at an angle of approximately 30°. The upper surface  31  may preferably be angled with respect to the perpendicular cross-section of the tubular upright frame members  21  and  23 , respectively, at an angle of between approximately 25° and approximately 35° for providing a geometric cross-sectional profile of the cross member  30 , for improving the method of attachment of the tool  40  to the tubular frame  20  in a manner using no tools and a minimalized amount of effort and motion by an operator. It may be noted that the angled geometry and profile of the cross members  30  support the ability of the hand truck  10  to be tilted forward to catch the top of the tool  40  to provide a more efficient, effective and easy attachment and detachment of the tool  40  with the hand truck  10  according to a method of operating (attaching and detaching the tool  40  with) the hand truck  10  of the present disclosure using the quick release/attach mechanism  50 . 
     The hand truck  10  may further include the tool  40  as best shown in  FIGS. 3, 4 and 9A-9C . The tool  40  may be usable with a variety of objects to be transported by the hand truck  10 . The tool  40  has a standardized geometry and coupling  41  for quickly, efficiently and effectively attaching and detaching (releasing) the tool  40  with the frame  20  of the hand truck  10 . In particular, proximal the portion of the tool  40 , there is provided a hangar member  42  for hanging the tool  40  from the cross members  30  of the frame  20  of the hand cart  10 . The hangar member  42  may preferably include an angled surface portion  43  designed to be complementary of the upper surface  31  of the cross-member  30  for hanging the tool  40  a cross member  30  and providing a first engagement point for the coupling of the tool  40  and the hand truck  10 . As best shown in  FIGS. 9A-9C , the angled surface portion  43  of the tool  40  may preferably be angled with respect to a horizontal, perpendicular cross-section of the tubular upright frame members  21  and  23 , respectively, at an angle of approximately 30° with respect thereto. The angled surface portion  43  may preferably be angled with respect to the horizontal, perpendicular cross-section of the tubular upright frame members  21  and  23 , respectively, at an angle of between approximately 25° and approximately 35° for providing the coupling portion  41  of the quick release/attach mechanism  50  of the hand truck  10 . 
     To provide a second engagement point for coupling the tool  40  and the hand truck  10 , the tool  40  may further include first and a second extension or projection tabs  44  and  45 , respectively, located a predetermined distance from the hangar  42  of the tool  40 . The tool  40  may preferably include a hangar portion  42  located proximal a first portion of the tool  40 . Together, the hangar portion  42  and the first and second projection tabs  44  and  45 , respectively, form the coupling portion of the tool  40 . The first and second projection tabs  44  and  45 , respectively, are located a corresponding predetermined distance as that of one of the cross-members  30  and the first and second passages  28  and  29  of the first and second upright tubular frame members  21  and  23 , respectively. Accordingly, when the tool  40  is hung on a cross-member  30  of the frame  20 , the first and second projection tabs  44  and  45  will align with and pass into the first and second passages  28  and  29 . Each of the first and second projection tabs  44  and  45  include a centrally-located locking hole or passage  46  (see  FIGS. 4, 9A and 9B ). 
     The quick release/attach mechanism  50  may further include a first and second glide members  70  located in the lower ends  24  and  25  of the first and second upright frame members  21  and  23 , respectively, as best shown in  FIGS. 5, 6B, 8 , and  9 A- 9 C. Each glide member  70  may include a lower end  71  including a portion  74  extending from the ends  24  and  25  of the first and second upright frame members  21  and  23  for providing a ground engaging end portion  71  having a lower coefficient of friction than the material of the frame  20  and for making it easier to move the frame  20  of the hand truck  10  along a ground surface as best shown in the progression of views in  FIGS. 9A through 9C  showing the attachment method for coupling the tool  40  to the hand truck  10 . 
     In one method of attaching the tool  40  to the hand truck  10 , it should be noted that the geometry/profile of each of the cross members  30  also allows the hand truck  10  to be tilted forward ( FIG. 9A ) to catch the top coupling portion  41  including the hangar portion  42  of the tool  40  and to then move the lower end of the hand truck  10  by gliding or sliding the gliding members  70  of the first and second upright frame members  21  and  23  of the frame  20  in an opposite rotational movement of the hand truck  10  (see the arrow in  FIG. 9B ) so that the lower ends  24  and  25  of the frame members  21  and  23  move the openings  28  and  29  thereof move toward the first and second extension members  44  and  45  which may be received therein to allow the attachment extension members  44  and  45  to move into position the locked position ( FIG. 9C ) and to move the latch pins  56  of the connector members  53  upward in the hollow interior passages  26  of the first and second upright tubular frame members  21  and  23  so that the locking pins move out of the way and then are moved into and located in the holes or passages  46  of the first and extension members  44  and  45  of the tool  40  to efficiently, effectively and quickly secure the tool  40  to the hand truck  10 . 
     To detach or unlock the tool  40  from the hand truck  10 , the operator may actuate the quick release/attach mechanism  50  by moving the handle member  51  upward to retract the connector members  53  and to retract the locking or latch pins  56  from the holes or passages in the first and second projection or extension members  44  and  45  of the tool by the action of the operator. 
     The tool  40  attachments are specifically designed so that the top  42  of the tool  40  matches the cross-sectional profile  31  of the specifically designed cross bars  30  on the hand truck  10 . The quick release/attach mechanism  50  may further include the angled cross-section of the cross member  30  which supports the ability to quickly and efficiently attach and detach a variety of tools  40  without any need of the operator to move, pickup, or otherwise handle the tool  40 . These features of the hand truck  10  including the tubular frame  20  and the cross member  30  in combination with the quick release/attach mechanism  50  significantly help in providing a more efficient, effective and safe method of attaching and detaching the tool  40  to a hand truck  10 . Notably, the quick change hand truck  10  and tool  40  may provide a significantly greater ability to utilize a standardized or common hand truck  10  of the present disclosure with a variety of tools  240 ,  340 ,  440  that may be customized for transporting a plethora of loads such as the gas cylinders  200  of  FIG. 10 , the bin  300  of  FIG. 11  and the inflatable container  400  of  FIG. 12 .