Abstract:
A handcart having a deck and a handle is disclosed which deck is pivotable between a generally horizontal load-carrying position and a tilted loading/unloading position by pivoting the handle. The handle is shiftable between first and second positions to lock and unlock the tilting mechanism. A method of using the subject handcart is also disclosed.

Description:
FIELD OF THE INVENTION 
     This invention is directed to a handcart for use in transporting and unloading heavy loads such as baled materials, packaged wares, loaded pallets, and the like, and in particular, to a handcart having a pivotable cargo deck suited for receiving, transporting, and unloading baled materials prepared in a baling machine. 
     BACKGROUND OF THE INVENTION 
     A wide range of handcarts and hand trucks are known from the prior art that are designed to reduce the strain and labor associated with loading, transporting and unloading bulk materials in industrial, retail, and warehouse operations. Some of these devices include a pivot mechanism that facilitates the lifting and transporting of heavy bulk materials. For example, U.S. Pat. No. 3,826,512 to Palmer discloses a cart that includes a cargo deck adapted to pivot between a tilted loading position, in which the front edge of the cargo deck is lowered to facilitate the loading of goods, and a horizontal position for transporting goods. Similarly, U.S. Pat. No. 5,593,271 to Hall discloses a convertible barrow with a cargo deck that shifts between a lowered horizontal loading position and a raised horizontal transporting position. 
     Such devices reduce strain associated with loading heavy loads onto handcart decks. However, these devices either include no locking mechanism to control the shifting of the cargo deck between loading and unloading positions or use complicated locking mechanisms that require a user to stop the cart, remove at least one hand from the cart handle and manipulate the lock with his hand or, alternately, using his foot. This need to stop the moving handcart prevents operators from using the energy of the moving cart to facilitate discharging the goods from its cargo deck. For example, if Palmer&#39;s moving cart could be unlocked shortly before it reaches the unloading site, the cargo deck could be tilted to its lowered position and the momentum of the moving goods could be used to discharge the goods from the cart. Prior art tilting handcarts provide either hand or foot operated locking devices that can only be operated safely when the carts are stationary. It would therefore be desirable to provide a handcart that shifts between a horizontal carrying position and a tilted loading and unloading position, which cart can be locked in the carrying position with an easy-to-use handle-actuated mechanism that can optionally be engaged and disengaged while the cart is in motion. 
     SUMMARY OF THE INVENTION 
     These problems and others are addressed by the present invention which comprises a handcart having a handle and a support platform with a front edge that can be lowered to facilitate loading by pivoting the cart handle downwardly away from the cart and raised by returning the handle to a vertical position. In the preferred embodiment, the handle includes a catch mechanism that prevents it from pivoting until it is lifted by a user to release the catch from a keeper on another portion of the cart. Alternately, the keeper could be located on the handle and the catch associated with the support platform. In this manner, the pivoting mechanism can be locked and unlocked without the user removing his hands from the cart handle. The cart of the preferred embodiment includes a support platform or cart deck supported by one or more pairs of support wheels and a pivot mechanism supported by at least one wheel and pivotably connected to the cart deck. The pivot mechanism further includes a pivot wheel extending from the pivot mechanism in a direction opposite from the cart deck which pivot wheel engages the ground and serves as a fulcrum when the handle is pivoted downwardly. This motion also raises the pivot mechanism support wheel from the ground. 
     It is therefore a principal object of the present invention to provide a carrier having a front edge that can be moved relative to the ground. 
     It is a further object of the present invention to provide a cart having a deck that can be shifted between a generally horizontal transport position and an angled loading position. 
     It is another object of the present invention to provide a cart having a handle and a deck that can be shifted between a generally horizontal transport position and an angled loading position and selectively locked in the former position by manipulating the cart handle. 
     It is still another object of the present invention to provide a handcart having a locking handlebar arrangement that is operated to lock or unlock a tilting cargo deck. 
     It is still a further object of the present invention to provide a handcart with a tilting cargo deck capable of being locked or unlocked when the handcart is moving. 
     It is yet another additional object of the present invention to provide a handcart having a pivot connection positioned between two sets of running wheels. 
     It is an additional object of the present invention to provide an improved method for discharging a load from a handcart. 
     In satisfaction of the foregoing objects and advantages, the present invention provides a handcart comprising a cargo deck assembly supported on running wheels, a pivot assembly supported on running wheels and a pivot connection rotatably attaching the cargo deck assembly to the pivot assembly. The cart further includes a handlebar moveable within a fitting attached to the pivot assembly and a lock mechanism that is operated to releaseably lock the pivot connection to prevent or enable rotation between the cargo deck and the pivot assembly. The lock mechanism operates in response to handlebar movement within the fitting. 
     Another aspect of the invention comprises a cart having a first wheeled assembly including a load-bearing platform, at least one support wheel and a keeper which first assembly is pivotably connected to a second wheeled assembly including at least one support wheel. A handle is attached to the second wheeled assembly and includes a catch and is shiftable between a first position wherein the keeper retains the catch and a second position wherein the keeper is spaced from the catch. 
     A further aspect of the invention comprises a cart having a first wheeled assembly including a load-bearing platform and at least one support wheel and a second wheeled assembly pivotably connected to the first wheeled assembly and having at least one support wheel and at least one pivot wheel. A handle is attached to the second wheeled assembly and is pivotable about a first axis between a first position in which the first wheel engages a surface supporting the cart and a second position wherein the second wheel engages the surface. 
     A method for delivering a load using a handcart having a first handcart portion coupled to a second handcart portion, wherein the handcart is selectively supported on at least two sets of running wheels and at least one pivot wheel, is also disclosed. The method includes the steps of providing a rigid handcart by adjusting the position of a handlebar within a sliding fitting attached to the second handcart portion to engage a lock mechanism that rigidly couples the first handcart portion to a second handcart portion and thereafter positioning a load on the first handcart portion. Next, the rigid handcart is rolled toward a selected unloading site. The rigid handcart is then converted to an articulated handcart by adjusting the position of the handlebar within the sliding fitting to disengage the lock mechanism so that the first handcart portion is flexibly coupled to the second handcart portion. A force is applied to the rolling articulated handcart to rotate the pivot wheel to a position that supports the handcart and tilts the first handcart portion in a forward direction. Lastly, the handcart is stopped and the load is discharged. 
     Finally, a method of moving a load is disclosed that includes the steps of providing a cart having a first wheeled assembly having a load-bearing platform and least one support wheel and a second wheeled assembly pivotably connected to the first wheeled assembly and having at least one support wheel. A handle is attached to the second wheeled assembly, and a lock for locking the first assembly with respect to the second assembly is provided. The handle is moved to a first position to unlock the first assembly from the second assembly and pivoted to lower an edge of the platform. Next, a load is placed on the platform and the handle is pivoted to raise the edge of the platform. Lastly, the handle is moved to a second position to lock the first assembly to the second assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention illustrated in the accompanying drawings, wherein: 
     FIG. 1 is a top plan view of a handcart having a lockable pivot mechanism according to the present invention which handcart is shown with a portion of the handcart handlebar cut away. 
     FIG. 2 is a cross-section view taken along line  2 — 2  of FIG.  1 . 
     FIG. 3A is a side elevational view of the lockable pivot mechanism of claim 1 in a locked position with the cart deck horizontal. 
     FIG. 3B is side elevational view of the lockable pivot mechanism of claim 1 in an unlocked position with the cart deck horizontal. 
     FIG. 3C is side elevational view of the lockable pivot mechanism of claim 1 in an unlocked position with the cart deck tilted. 
     FIG. 4 is a side elevational view of the handcart of FIG. 2 with the handle in the lowered position. 
     FIGS. 5A-5J show various steps of a method for using the present handcart invention to transport a load. 
     FIG. 6 is a side elevational view of a second embodiment of the handcart of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description of the present invention is directed to a handcart for use in transporting and unloading heavy loads such as baled materials, packaged wares, loaded pallets, and the like, to a delivery site. Referring now to the drawings, wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting same, FIGS. 1 and 2 show a handcart  1  having a wheeled cargo deck assembly  2 , a wheeled pivot assembly  3  fastened to the cargo deck assembly, and a handlebar  4  including a lock mechanism  5  that is operable to selectively allow tilting of the cargo deck  2 . The handlebar  4  is broken away in FIG. 1 so that the pivot assembly  3  may be seen more clearly. 
     The cargo deck assembly  2  comprises a deck plate  6  supported on a structural framework that includes longitudinal side rails  7 , a plurality of transverse channel members  9  that extend across the cargo deck below deck plate  6 , and intermediate longitudinal rails  8  spaced apart between the side rails  7  and the channel members  9 . The tilting cargo deck assembly is supported on at least one set of running wheels  10  rotatably fastened to the side rails  7  and/or intermediate rails  8  at a location proximate the front-end of the cargo deck opposite the handlebar  4  which is attached to the pivot mechanism at the rear end of the deck. The pivot assembly  3  is supported on a second set of running wheels  11  positioned rearward with respect to a pivot connection  12  that rotatably couples the pivot assembly  3  to the tilting cargo deck assembly  2 . Because the pivot connection  12  is located between the two sets of running wheels, the handlebar lock mechanism  5  may be selectively operated to unfasten the tilting cargo deck  2  and thereby provide independent suspension between the tilting cargo deck and pivot assemblies  2  and  3  respectively. Such independent suspension may enable the tilting cargo deck assembly  2  and the pivot assembly  3  to separately navigate over certain surface irregularities such as ramps encountered between loading and unloading sites. 
     The pivot assembly  3  includes one or more pivot wheels  13  rotatably mounted within a yoke assembly  14  extending in a rearward direction (away from deck  2 ) from the above pivot connection  12 . Each yoke assembly  14  is rotatably fastened to the tilting cargo deck assembly  2  at its respective pivot connection  12  with a pivot pin  15  (FIG. 2) that extends through apertures provided in the tilting cargo deck structural framework, for example the longitudinal side rails  7  and/or the longitudinal intermediate rails  8 . Each yoke assembly further includes a tubular member  16  adapted to receive and slidably retain therein integral leg portions  4   a  of handlebar  4 . A mounting plate  17  extends between the spaced apart yoke assemblies  14 , and the mounting plate is fixed to the yoke assemblies by welding, bolting, or other suitable means. One or more holes  18  (FIG. 2) are drilled through mounting plate  17  at spaced apart locations to correspond with the tubular members  16 . The drilled holes  18  are positioned to receive handlebar leg portions  4   a  extending through the tubular members  16 , and an end cap  19  is fixed to the bottom end of each leg portion  4   a  to capture the handlebar legs within their respective tubular members and corresponding drilled holes  16  and  18 . Other suitable means, such as pins extending through the pipes, could also be used for slidably retaining the leg portions  4   a  of the handlebar in the tubular members. 
     The second set of running wheels  11 , comprising at least a single running wheel, and preferably two or more running wheels, is fastened to the mounting plate  17 . The first set of running wheels  10 , located toward the front-end of the tilting cargo deck assembly  2 , and the second set of running wheels  11 , attached to the pivot assembly  3 , cooperate so that the tilting cargo deck assembly is rigidly supported on the running wheels  10  and  11  when the handlebar lock mechanism  5  is operated to lock the pivot connection  12  by engaging the tilting cargo deck assembly, and the tilting cargo deck assembly is flexibly supported on the running wheels  10  and  11  when the handlebar lock mechanism  5  is operated to unlock pivot connection  12  by disengaging the tilting cargo deck assembly. 
     In the preferred embodiment the handlebar  4  is U-shaped and includes a pair of handlebar legs  4   a  integrally formed with a crosspiece  4   b  extending between the upper ends of the legs. Each leg member  4   a  has one end inserted through one of the tubular members  16  that is attached to one of the corresponding yoke assemblies  14 , and also through one of the corresponding holes  18  extending through the mounting plate  17 . The end caps  19  are fastened to the ends of each handle bar leg member  4   a  to prevent the inserted legs from being pulled upwardly through the mounting plate holes  18  or the tubular members  16 . The resulting sliding connection between the handlebar legs and the pivot assembly provides an arrangement for operating the lock mechanism  5  by either pulling or pushing handlebar  4  to raise or lower the handlebar as shown at arrow  20  (FIG. 2) to disengage or engage lock mechanism  5 . End caps  19  limit the length of the pulled or pushed handlebar stroke by providing a stop that engages against the bottom surface of mounting plate  17 . The handlebar lock mechanism includes at least one catch or hook  21  positioned to engage a keeper such as lock bar  22  when the handlebar pushed downward to a locking position, and disengage the  20  lock bar  22  when handlebar  4  is pulled upward to an unlocked position. Lock bar  22  is fixed to the tilting cargo deck assembly  2  so that when hook  21  engages lock bar  22 , the pivot connection  12  is locked to prevent rotation, thereby fixing the cargo deck assembly to prevent tilting. 
     Referring to FIGS. 3A-3C, showing an enlarged view of the lock mechanism, when handlebar  4  is pushed downward to its lowered locking position, as shown at arrow  20   a  (FIG.  3 A), the first set of running wheels  10  and the second set of running wheels  11  cooperate to support the cargo deck assembly  2 . When the tilting cargo deck is locked in its load transporting position, as shown in FIG. 3A, the mouth portion  23  of hook  21  engages lock bar  22  and prevents the cargo deck assembly  2  from rotating about the pivot connection. The locked pivot connection  12  also prevents rotation of the yoke assemblies  14  so that pivot wheels  13  are held at their rearward position, to prevent the pivot wheels from contacting the ground  24  when a load is being moved. Referring to FIG. 3B, if the handcart encounters a change in surface elevation, the handlebar may be pulled upward (arrow  20   b ) to disengage hook  21  from the lock bar  22  and thereby unlock the pivot connection  12  so that the tilting cargo deck assembly  2  and the pivot assembly  3  are free to rotate about the pivot connection. Because the unlocking operation may be preformed without removing an operators hands from the handlebar, the tilting cargo deck assembly may be unlocked to provide flexibility while the handcart is moving toward either a loading or unloading site. When handcart  1  is moved in its unlocked condition, the pivot wheels  13  may or may not contact the ground surface  24  depending upon particular loading and surface conditions. 
     Similarly, when the handcart of the present invention reaches an unloading site, the lock mechanism  5  is disengaged, as disclosed above for FIG.  3 B. However, as shown in FIG. 3C, when the rolling handcart is near, or when the rolling handcart has finally reached its unloading site and the handcart is stopped, a combined rearward and downward rotational force is applied against handlebar  4  so that pivot assembly  3  rotates about pivot connection  12 . The applied rotational force engages pivot wheels  13  against the ground or other support surface  24 , and the continuing application of force tilts the cargo deck assembly  2  toward its front end to facilitate unloading. FIG. 4 shows the handcart in this unloading position. 
     FIG. 6 shows a second embodiment of the invention. The same reference numerals are used in this Figure to identify elements common to both embodiments. In this embodiment, cargo deck assembly  2  includes a second set of running wheels  26  in addition to first set of running wheels  10 . The second set of running wheels provides additional support for the cargo deck and may be useful when transporting particularly heavy loads, but otherwise does not affect the functioning of the handcart. 
     EXAMPLE 
     Referring to FIGS. 5A-5J, a series of steps are shown for loading and delivering a load using the present handcart invention. In FIG. 5A, handcart  1  is prepared to receive a load by operating the lock mechanism  5  to engage hook  21  against lock bar  22 . This prevents rotation about pivot connection  12  and tilting of cargo deck assembly  2 . The locked handcart  1  is then rolled toward a loading site to receive a load. Referring to FIG. 5B, in this example, handcart  1  is pushed into the discharge end of a scrap bailer  27  to receive a load of bailed scarp material  28 . Such scrap bailers are manufactured by, for example, the Marathon Equipment Company. However, it should be understood that the scrap bailer shown in FIGS. 5B and 5J is only exemplary, and that the scope of the invention includes any type load loaded onto the present handcart invention. 
     Referring to FIG. 5C, after a load  28  is placed on the tilting cargo deck  2 , the loaded handcart is rolled toward an unloading site on its running wheels  10  and  11 . Because the locked handcart  1  is supported on at least two sets of running wheels, load placement is not critical with respect to balancing the load on the cargo deck as compared to prior art handcarts on which the load is balanced on a single set of running wheels. 
     When the loaded handcart  1  approaches an unloading site (FIG.  5 D), and while the handcart  1  may continue to roll on its running wheels  10  and  11  toward the unloading site, the handlebar  4  is pulled upward as shown at arrow  20   b  to disengage hook  21  from lock bar  22  and unlock the pivot connection  12 . A combined rearward and downward rotational force is applied against the unlocked handlebar  4  so that the pivot assembly  3  rotates about the pivot connection  12 , as shown by arrow  20   c  in FIG.  5 E. The applied rotational force engages pivot wheels  13  against the ground  24 , and the continuing rotational force may drive the pivot wheels  13  in a forward direction and raise and tilt the cargo deck assembly  2  toward its front end. When the tilted handcart  1  reaches the unloading site  29 , shown in FIGS. 5F and 5G, it is stopped (FIG.  5 F), and the energy of the forward moving load  28  facilitates discharging at least a portion of the load from the tilted cargo deck assembly  2 . If load  28  is not completely discharged from the tilted deck  2  as shown in FIG. 5F, the tilted deck  2  is easily pulled from beneath load  28  as illustrated in FIG.  5 G. 
     After load  28  is removed from the tilted cargo deck assembly  2 , handlebar  4  is rotated in an upward and forward direction, as shown by the arrow  20   d  in FIG. 5H, to return the handlebar to the locking position shown in FIG. 51, where the handlebar is pushed in a downward direction to engage hook  21  against lock bar  22 . Referring to FIG. 5J, after handlebar  4  is pushed in a downward direction to engage the lock hook  21  against lock bar  22 , the cargo deck assembly  2  is ready for insertion into the scrap bailer  27  to receive a new load  28 , or handcart  1  is ready to receive a different load from a different loading site. 
     It should be understood that while this invention has been described in terms of a preferred embodiment, it is capable of further modifications, uses, and/or adaptations following the general principles of the invention set forth above. All such departures from the present disclosure that fall within known or customary practice in the art to which the invention pertains, and as may be applied to the central features hereinbefore set forth, are intended to be included within this invention to the extent they are included within the scope of the several claims appended hereto.