Abstract:
The modular dolly is a manually operated device facilitating the transport of large, heavy, and/or bulky objects. The dolly includes four smaller wheels and two larger diameter wheel and brake assemblies for temporary installation to the sides of the dolly platform for movement over soft, rough, and/or uneven surfaces. A ramp is removably attachable to the loading end of the platform coplanar therewith to facilitate loading the dolly. The ramp also attaches removably to the opposite anchor end of the platform and normal thereto, to serve as a backstop or anchor for a load placed on the platform. A smaller secondary panel may be installed in the anchor end when the ramp is in use during loading, or may be assembled coplanar to the ramp or platform to lengthen the ramp or platform. The dolly may also be used with a stair-climbing hand truck, forklift, pallet jack, or the like.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/272,168, filed Aug. 25, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to manually operated hand trucks, carts, dollies and the like, and particularly to a modular dolly having various repositionable panels and wheels to provide for the loading of large, heavy and/or bulky articles thereon and the transport of such articles over soft, rough and/or uneven terrain. The dolly is also adapted for use as a ramp and with a stair-climbing hand truck. 
     2. Description of the Related Art 
     Innumerable dollies, carts, hand trucks, and the like have been developed in the past for various general and specialized purposes. Such devices are generally used for the carriage and transport of relatively large, bulky, and/or heavy articles, e.g., large appliances, console-size office machines such as copiers and the like, etc. Most such devices are relatively simple in their construction and configuration and accordingly have various limitations relating to their use, e.g., lifting large and/or heavy appliances, carrying such appliances over rough and uneven terrain, etc. 
     Such limitations are readily apparent when attempting to transport a large console-size office machine (copier, printer, document shredder, etc.) to and from its site in an office or the like. The need to lift or move the machine onto and from the dolly is apparent, and is quite strenuous when using a conventional dolly, hand truck or the like. Moving the appliance or machine onto and from a truck (van, pickup, etc.) is also often quite a project with conventional moving equipment. Once the dolly or cart and its appliance are resting on the surface, it is generally necessary to move the loaded dolly across various surfaces that are not compatible with the relatively small diameter wheels generally installed on such dollies, e.g., pavement gutters, expanses of relatively soft grass or gravel, doorway thresholds, etc. Even when each of the above problems has been resolved, it is often necessary to negotiate one or more flights of stairs when delivering or removing such equipment. 
     Thus, a modular dolly solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The modular dolly includes a generally rectangular platform having a relatively small wheel beneath each corner thereof. Two of the wheels are preferably steerable or caster wheels (i.e., wheels mounted on a swivel), and two of the wheels (they may be the same wheels) have selectively operable brakes. A pair of larger diameter wheel and brake assemblies may be selectively attached medially to the sides of the platform to facilitate moving the platform and any load thereon over soft, rough, and/or uneven terrain. 
     A ramp may be selectively installed or secured to either end of the platform. The ramp is coplanar with the platform when secured to the first or loading end thereof, facilitating the movement of a heavy object up the ramp and onto the platform. The ramp is perpendicular to the platform when secured to the opposite second or anchor end thereof, and serves as a generally vertical anchor or tiedown for the object being transported on the dolly. A smaller or shorter secondary panel may be installed as a perpendicular backstop in the anchor end of the platform in place of the ramp during loading operations or as a coplanar extension of the platform anchor end, or with the ramp in the loading end of the platform as an extension of the ramp. Another optional short platform extension may also be removably attached to the first or loading end of the platform, if desired. The various ramps and panels and their various provisions for attachment to the primary structure also enable the device to be used as a ramp between, e.g., a vehicle (moving truck, etc.) and steps or other structure, as required. 
     The modular dolly is adapted for use with a conventional stair-climbing hand truck, enabling the dolly to transport a large, heavy, and/or bulky object up or down a flight of steps or stairs when used in combination with the stair-climbing hand truck. Such a stair-climbing hand truck is described in U.S. Patent Publication No. 2006/182,578 (now abandoned), which is hereby incorporated by reference. The stair-climbing hand truck adaptation of the dolly may also be used to lift the dolly using a forklift, pallet jack, or other similar device. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a modular dolly according to the present invention, illustrating its basic components. 
         FIG. 2  is a perspective view of the assembled dolly of  FIG. 1 . 
         FIG. 3  is a side elevation view of the assembled dolly of  FIGS. 1 and 2 . 
         FIG. 4  is a partial section view along lines  4 - 4  of  FIG. 3 , showing details of the removable auxiliary wheel attachment. 
         FIG. 5  is a section view along lines  5 - 5  of  FIG. 4 , showing details of the brake apparatus for an auxiliary wheel. 
         FIG. 6  is an environmental side elevation view of a modular dolly according to the present invention, showing the initial step in the loading of a large appliance onto the dolly. 
         FIG. 7  is an environmental side elevation view of a modular dolly according to the present invention, showing a subsequent step in the loading of the large appliance onto the dolly. 
         FIG. 8  is an environmental side elevation view of a modular dolly according to the present invention. 
         FIG. 9  is an environmental side elevation view of a modular dolly according to the present invention, showing the dolly and its load being lifted by a hand truck having load-lifting capability. 
         FIG. 10  is an environmental side elevation view of a modular dolly according to the present invention, showing the dolly lifted by the hand truck and using one of the platform modules of the dolly as loading bridge or ramp. 
         FIG. 11  is an environmental side elevation view of a modular dolly according to the present invention, showing the dolly loaded onto a stair-climbing hand truck, negotiating a flight of stairs. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The modular dolly is adapted for the transport of relatively large, heavy, and bulky articles, e.g., office machines such as copiers, etc.  FIG. 1  of the drawings provides an exploded perspective view of the dolly  10  illustrating the basic removable or separable components thereof, while  FIG. 2  illustrates the assembled dolly  10 . The modular dolly  10  includes a platform  12  having opposite first and second ends, respectively  14  and  16 , and opposite first and second sides or side members, respectively  18  and  20 . The platform  12  is constructed of a series of extruded panels with additional hollow beam extrusions forming the two side members  18  and  20 . 
     Four relatively small wheels are provided beneath the platform  12 , with two of the wheels  22  and  24  depending from beneath the first end  14  of the platform  12  and the other two wheels  26 ,  28  depending from beneath the second end  16  of the platform; wheel  28  is shown in  FIG. 10 . The first end wheels  22 ,  24  may be non-castering, i.e., directionally fixed, but each of these first end wheels preferably includes a conventional lever actuated brake mechanism  30 . The opposite second end wheels  26 ,  28  are caster or swiveling wheels, and do not necessarily include brakes. The four smaller diameter wheels  22  through  28  are preferably formed as solid discs of hard rubber or other suitable material. 
     Additional removable wheel assemblies are provided to facilitate movement of the dolly  10  over rough, soft, and/or uneven surfaces. First and second auxiliary wheel assemblies, respectively  32  and  34 , removably attach to the first and second sides  18  and  20  of the platform  12 , respectively. The two auxiliary wheel assemblies  32 ,  34  have considerably larger diameters than the four relatively small permanently installed wheels  22  through  28 . Even though the axles of the auxiliary wheels  32 ,  34  are essentially coplanar with the platform  12  while the axles of the smaller permanent wheels  22  through  28  are below the platform, the considerably larger diameters of the auxiliary wheel assemblies  32 ,  34  result in the bottoms of those wheels, when installed, extending below the bottoms of the smaller permanent wheels, as shown in  FIG. 3  of the drawings. The larger diameters of the auxiliary wheels and their location substantially at the medial point of the platform  12  allow the auxiliary wheel assemblies  32 ,  34  to support the entire dolly  10  and any load thereon while the smaller, permanently installed wheels  22  through  28  remain clear of the underlying surface, generally as shown in  FIG. 3  of the drawings. The larger diameter auxiliary wheel assemblies provide greatly reduced rolling resistance over relatively rough, soft, and/or uneven surfaces, in comparison to the smaller diameter (and narrower) permanently installed wheels  22  through  28 . 
       FIGS. 4 and 5  provide detailed views of the structure of the first auxiliary wheel assembly  32 , with it being understood that the second auxiliary wheel assembly  34  is a mirror image of the first assembly  32 . Each wheel assembly  32 ,  34  is pneumatic, as generally shown in the section view of  FIG. 5 , i.e., having a wheel hub  36  with a pneumatic tire  38  installed thereon. Each of the wheel assemblies  32 ,  34  includes an axle  40  ( FIG. 5 ) affixed normal to and extending outwardly from a generally L-section platform attachment member  42 . The platform attachment member  42  includes a longitudinal channel-engaging track  44  ( FIG. 4 ) extending therealong, and a plate  46  extending therefrom and forming one leg of the L. The plate  46  includes a passage  60  therethrough. A pin  50  is selectively insertable into and through the passage  60 . A bracket  52  depends from the plate  46 . The pin  50  is secured in the bracket  52  by a spring  54 . The spring  54  selectively holds the pin  50  in either a wheel-securing position (as shown in  FIG. 5 ) wherein the pin  50  is held upwardly by the spring  54  to engage a lower passage  48  in the side member  18  or  20  of the platform  12  (as described below), or is held downwardly in a release position clear of the side member passage  48  to allow the removal of the wheel assembly from the platform  12 . 
     Each of the two sides  18  and  20  of the platform  12  is of a hollow, generally rectangular configuration, with the two sides  18 ,  20  being mirror images of one another. Each side, e.g., the first side  18  shown in section in  FIG. 4 , includes an outer face  56  with a longitudinal channel  58  formed therein, with the lower passage  48  formed through the bottom surface or wall of the side member or beam  18 . Each wheel assembly  32 ,  34  is attached to its respective side member  18 ,  20  generally as shown in  FIG. 1  of the drawings. The channel-engaging track  44  of the platform attachment member  42  slides into the channel  58  of the side member, e.g., side member  18 , from the first end  14  of the platform  12 . The wheel assembly, e.g., assembly  32 , is then slid rearwardly along the side member until the hole or passage  60  of the platform attachment plate  46  aligns with the corresponding hole or passage  48  through the bottom wall of the side member  18 . The pin  50  is then pushed home through the two passages  48  and  60 , to lock the wheel assembly  32  along the side member  18 . The pin  50  may be pushed inwardly before the two holes  48  and  60  align, with the spring  54  snapping the pin into the hole  48  of the side member bottom wall when the two holes or passages  48  and  60  align. 
     Brakes are provided on the two auxiliary wheel assemblies  32  and  34 , with  FIG. 5  particularly showing the details of the brake assembly for the first auxiliary wheel assembly  32 . A brake bar  62  slides longitudinally fore and aft relative to the axle  40  and other wheel assembly structure. The brake bar  62  includes a pair of tire contacts or shoes  64  that make contact with the inboard sidewall of the tire  38  when the brake is engaged, as shown in broken lines in  FIG. 5 . A kick plate  66  is provided at each end of the brake bar  62 , for the operator of the modular dolly  10  to kick the brake bar  62  forward to engage the brake shoes  64  with the tire  38  as shown in broken lines in  FIG. 5 , or to kick the brake bar  62  rearwardly to release the brakes, as shown in solid lines. 
     A relatively large primary ramp  68  may be removably affixed to either end of the platform  12 , as desired. The primary ramp  68  has an area approximately the same size as that of the platform  12  and a width equal thereto and includes a first end  70 , opposite second end  72 , first side  74 , and opposite second side  76 . The primary ramp  68  is formed in much the same manner as the platform  12 , i.e., using a series of extruded panels with a hollow beam extrusion forming each side member. 
     The hollow extrusions of the side members  74 ,  76  provide for the insertion and permanent, immovably affixed attachment of a tine  78  therein and extending therefrom at the first end  70  of the primary ramp  68 . Each of the side members  18  and  20  of the platform  12  includes a socket  80  at the second end of the platform, with the sockets  80  formed of tubular material having essentially the same cross sectional dimensions and configuration as the platform side members  18  and  20 . The two sockets  80  are normal to the orientation of the side members  18  and  20 , and provide for the removable installation of the corresponding tines  78  extending from the primary ramp  68 . This allows the primary ramp  68  to be removably affixed to the second end  16  of the platform  12  and normal thereto, as shown in  FIGS. 2 ,  3 ,  9 , and  11 . Retaining pins  82  may be provided to prevent unintentional removal of the tines  78  from the sockets  80 . 
     The hollow cores of the two side members  18  and  20  of the platform  12  also permit the tines  78  to be removably installed therein at the first end  14  of the platform. The installation of the tines  78  within the side members  74 ,  76  of the primary ramp  68  and into the side members  18 ,  20  of the platform  12  assures that the primary ramp  68  will be substantially coplanar with the platform  12  when assembled thereto, as shown in  FIGS. 6  through  8  and  10 . As in the attachment of the primary ramp  68  to the second end  16  of the platform  12 , retaining pins (not shown, but essentially the same as the pins  82  at the second end of the platform  12 ) may be used to provide positive attachment of the primary ramp  68  to the first end  14  of the platform  12 . 
     A shorter auxiliary ramp  84  may be provided In addition to the primary ramp  68 , if so desired. The auxiliary ramp  84  is constructed similarly to the platform  12  and primary ramp  68 , i.e., formed of a series of extruded panels and having opposite first and second ends  86 ,  88  and opposite first and second sides or side members  90 ,  92 . The side members  90 ,  92  are of the same configuration as the side members  18 ,  20  of the platform  12  and side members  74 ,  76  of the primary ramp  68 . A tine  94  extends from each side member  90  and  92 , with the tines  94  providing for the attachment of the auxiliary ramp  84  to the platform  12  or primary ramp  68  as desired. The auxiliary ramp tines  94  are somewhat longer than the primary ramp tines  78 , due to the beveled second end portions of the side members  74  and  76  of the primary ramp  68  to allow the second end  72  of the ramp  68  to rest essentially level with the underlying surface when deployed. 
     The auxiliary ramp  84  may be secured coplanar to the second end  72  of the primary ramp  68  if so desired, as shown in  FIGS. 1 through 3 . The assembly of the primary and auxiliary ramps  68  and  84  may be used to provide a longer ramp length where required, or to extend the height of the assembly when used as a backstop normal to the platform  12 , as shown in  FIGS. 2 and 3 . One or more handles  96  (shown in  FIG. 3 ) may be provided on the back side of the auxiliary ramp  84 , to facilitate maneuvering the modular dolly  10  when the ramp assembly is installed as shown in  FIGS. 2 and 3 . Alternatively, the auxiliary ramp  84  may be installed directly in the sockets  80  at the second end  16  of the platform  12  and normal thereto to serve as a short backstop to prevent a load from rolling beyond the second end  16  of the platform during loading operations when the primary ramp  68  is extended from the first end  14  of the platform, as shown in  FIGS. 6 through 8 . A further alternative auxiliary ramp  84  installation is shown in broken lines in  FIG. 1 . A slot  95  may be provided in the rear of each of the sockets  80  at the second end  16  of the platform  12 , to accept the tines  94  of the auxiliary ramp  84 . The tines  94  pass through the slots  95  and into the hollow cores of the two side members  18  and  20  of the platform  12 . The tines  94  are locked in place in the respective side members  18  and  20  by retaining pins  82 . 
     In addition to the primary and auxiliary ramps  68  and  84 , an optional extension ramp  100  may be added to the platform  12 , if so desired, as illustrated in  FIGS. 1 and 2 . The extension ramp  100  is constructed and configured similarly to the platform  12  and the primary and auxiliary ramps  68  and  84 , i.e., the extension ramp  100  is formed of extruded panels and has opposite first and second ends  102 ,  104  and opposite first and second sides or side members  106 ,  108 . The side members  106 ,  108  are of the same configuration as the side members  18 ,  20  of the platform  12  and side members  74 ,  76  of the primary ramp  68  and side members  90 ,  92  of the auxiliary ramp  84 . A tine  110  extends from each side member  106  and  108 . The tines  110  provide for selective attachment of the auxiliary ramp  100  to the platform  12  or primary ramp  68  (if sufficient length is provided for the auxiliary ramp tines  110 ), if desired, in the manner described further above for the removable attachment of the primary ramp  68  to the platform  12  and the auxiliary ramp  84  to the primary ramp  68 . 
       FIGS. 6 through 8  illustrate the basic procedure in loading a large, heavy, and/or bulky article of equipment E, e.g., a console copy machine, etc., onto the modular dolly  10 . In  FIGS. 6 through 8 , the primary ramp  68  has been installed to the first end of the platform  12 , and extends outwardly therefrom and coplanar therewith. The modular dolly  10  is relatively lightweight, particularly in comparison to a conventional console size article of equipment E such as a console copier or the like. Moreover, the length of the primary ramp  68  when installed to extend coplanar with the platform  12  acts as a relatively long lever arm about the first end wheels  22  and  24 , which serve as a fulcrum. Thus, the weight and lever arm of the primary ramp  68  will cause the distal or second end  72  of the primary ramp  68  to drop to the underlying surface to facilitate loading operations, pivoting the assembly about the first end wheels  22  and  24  and raising the opposite second end wheels  26  and  28  and second end of the platform  12  above the underlying surface, even without the placement of a load on the primary ramp  68 . When the second end  72  of the primary ramp  68  is lowered to the underlying surface, the weight of the equipment E resting thereon provides additional stability for the tilted assembly, as shown in  FIG. 6 . 
     The beveled ends of the side members  74 ,  76  allow the second end  72 , or more precisely the floor of the ramp  68  at the second end thereof, to rest directly upon the underlying surface with a minimal lip or discontinuity to negotiate with the equipment E. Large, heavy, and/or bulky articles of equipment E such as large copy machines, etc., are typically equipped with very small rollers or casters, typically on the order of about two inches in diameter, more or less. In some cases the equipment may not have any wheels, and it may be necessary to load the equipment onto a small dolly for movement onto the modular dolly  10 . Such smaller dollies are also conventionally equipped with quite small wheels, with the beveled ends of the side members  74 ,  76  of the primary ramp  68  facilitating the transfer of the equipment (or dolly upon which it may rest) onto the modular dolly  10 . 
     In  FIG. 7 , the equipment load E has been moved farther along the auxiliary ramp  68  so that approximately half of its weight is resting on the auxiliary ramp  68  and half is resting upon the platform  12 . At this point, the load is very nearly balanced over the first end wheels  22  and  24 . As the equipment E is moved closer to the opposite second end of the platform  12 , the center of gravity of the equipment E and dolly  10  shifts to a point between the first end wheels  22 ,  24  and the second end wheels  26 ,  28 , thus lowering the second end wheels  26 ,  28  to the underlying surface and leveling the platform  12 . The leveling of the platform  12  facilitates the completion of the positioning of the equipment E thereon, generally as shown in  FIG. 8  of the drawings. The auxiliary ramp  84  was previously installed in the sockets  80  at the second end of the platform  12 , with the auxiliary ramp  84  serving as a stop to prevent the movement of the equipment E past the second end of the platform  12 . 
     Once the equipment E has been positioned atop the platform  12  as desired, the auxiliary ramp  84  may be removed from the platform sockets  80  and the primary ramp  68  installed therein, generally as shown in  FIGS. 2 ,  3 ,  9 , and  11 . The primary ramp  68  includes a cargo strap for securing the equipment E or other load on the dolly  10 . A first portion  98   a  of the strap is attached to and extends from the first side  74  of the primary ramp  68 , with a second portion  98   b  attached to and extending from the opposite second side  76  of the primary ramp. The two strap portions  98   a ,  98   b  are preferably conventional, having mating buckle or latch and tongue attachments and adjustment for length as is typically found in such installations. The cargo strap portions  98   a ,  98   b  are secured about the equipment E or other load generally as shown in  FIGS. 9 and 11  to prevent the equipment from rolling from the first end  14  of the platform  12  during transport of the equipment E and dolly  10 . 
     Once the equipment E has been loaded and secured to the modular dolly  10 , the dolly may be used to transport the equipment E to a truck or other suitable vehicle for further transport as required. The platform  12  of the dolly  10  has a relatively low height above the underlying surface, even with the auxiliary wheels  32  and  34  installed thereon. Accordingly, it will generally be necessary to elevate the dolly  10  so the platform  12  is level with the floor or bed of the truck or other vehicle used to transport the equipment E. This may be accomplished by loading the dolly  10  onto a hand truck capable of elevating or lifting the dolly  10  to the height of the truck floor, generally as shown in  FIG. 9 . Such hand trucks are well known, and the exemplary hand truck  112  illustrated in  FIGS. 9 through 11  is also capable of climbing steps or stairs to facilitate the movement of the equipment to or from an upper level in a building, where no other practicable means is provided for doing so. Such a stair climbing hand truck is disclosed in U.S. Patent Application Publication No. 2006/0182578, published on Aug. 17, 2006, which is hereby incorporated by reference in its entirety. 
     In many instances it may be necessary to bridge some difficult terrain between the modular dolly  10  or hand truck  112  and the transport vehicle. This may be accomplished by placing the dolly  10  on the hand truck  112  generally as shown in  FIG. 10 , and extending the primary ramp  68  from the first end of the platform  12 . The hand truck  112  is used to elevate the platform  12  and its extended primary ramp  68  to a level even with the floor of the truck or vehicle, whereupon the hand truck  112  may be maneuvered to place the distal second end  72  of the primary ramp  68  on or over the rear bumper or the edge of the rear floor of the vehicle, generally as shown in  FIG. 10 . 
     In  FIG. 11 , the modular dolly  10  is shown loaded onto the stair climbing hand truck  112  and being transported up a flight of stairs. The stair climbing hand truck  112  incorporates a set of supplementary wheels or rollers that are adjustable along the length or height of the hand truck, and which may be progressively positioned on the treads of the steps to raise the load up the steps. The heights or positions of the supplementary wheels can be lowered relative to the hand truck  112  by an electric motor installed with the hand truck, thereby raising the hand truck relative to the wheels to lift the load up the steps. Reversing the procedure allows the load to be lowered down the steps. 
     Accordingly, it will be seen that the modular dolly  10  with its various attachments greatly facilitates the movement and transport of large, heavy, and/or bulky articles of equipment. The stair climbing hand truck incorporated therewith further facilitates such operations. While a console copier is shown herein as an exemplary article of equipment, it will be understood that the use of the modular dolly  10  and hand truck  112  are not limited to such use, but may be used to move and transport innumerable articles having considerable size, bulk, and/or weight. Moreover, the versatility of the modular nature of the dolly  10  and its various components allow the device to be adapted to various other uses in addition to those illustrated, e.g., as a ramp between a vehicle and the surface or another vehicle, etc., as desired. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.