Abstract:
A lightweight platform dolly with a one-piece lightweight composite fabricated support platform has a rectangular support platform with at least one bumper block. The bumper blocks can be adjusted to accommodate varying loads and conditions. The adjustable bumper blocks change the length or width of the lightweight platform dolly, raise the load on the lightweight platform dolly for better vertical clearance, and enable the lightweight platform dolly to accommodate uneven bottom items. The bumper blocks are secured with flexible hinges and T-Bar block holders and receivers, which can secure loads.

Description:
This invention relates to a platform dolly and more particularly to a platform dolly which is light weight and adjustable, depending on the item being supported thereon. 
   BACKGROUND OF THE INVENTION 
   Every thing or item used in a business or a home spends some time on a truck, before it reaches its final destination. Whether such an item or movement falls into the class of commercial, industrial, electronic, or residential; it has spent time on a truck. Loading and unloading a truck requires physical labor along with careful planning. Careful planning involves using the space available efficiently, filling the truck as full as possible without exceeding the weight limit. 
   Loading and unloading a truck also requires physical labor. Over the course of time, the moving industry uses a device known generically as a dolly to reduce and support the physical labor. A dolly typically offers a frame, supported on wheels or casters. Once an item is placed on the frame, the item moves with the frame more easily because of the casters on the dolly. 
   Dollies are used to move items or heavy objects of many types. A large object is tipped up and the dolly is placed under it. These objects usually sit on two protective coated bumper blocks. The object and the dolly are then manually rolled to a different location. The objects are not strapped or fastened to the dolly relying on the object&#39;s weight and a non-slip surface to secure the load. 
   Typically dollies in the industry are exemplified by piano dollies, office dollies and machine dollies. Office dollies are commonly used to move office furniture or home furniture. Machine dollies are commonly used to move industrial equipment. Piano dollies are used for the indicated musical instrument. Thus, at least three different types of dollies are used in the moving industry. These dollies customarily vary by height, length and width. 
   For example, a typical piano dolly is shorter in length and higher off the floor than the other dollies, in order to allow the load and the dolly to be tipped up on two wheels to ascend steps and curbs. A typical office dolly is lower in height with smaller wheels because the large office furniture, usually transported thereon, must clear doorways and is not required to ascend steps and curbs. 
   In the moving industry, dollies are available in varying heights and lengths for different load applications. For example, lower dollies are more effective to move tall office furniture through doorways and into elevators. Higher and shorter dollies are designed for items that need to clear steps or be tilted to climb steps. Movers need a variety of dollies on a truck to accommodate different situations. This causes problems with space and cost. 
   Prior art dollies are known. Some such dollies are disclosed in U.S. Pat. No. 4,720,115 to Rehrig issued in 1988; U.S. Pat. No. 4,822,066, to Rehrig issued in 1989; U.S. Pat. No. 5,921,566 to Kern issued in 1999; U.S. Pat. No. 4,077,644 to Roby issued in 1978; U.S. Pat. No. 4,824,129 to Rehrig issued in 1989; U.S. Pat. No. 5,018,930 to Hardin issued in 1991; and U.S. Pat. No. 2,359,016 to Wood issued in 1944. 
   Dollies are typically made of relatively heavy, solid hard wood or plastic in a rectangular frame shape with a caster fastened on the underside of each corner. Other prior art dollies such as these are injection molded plastic with steel added for strength, which adds to the weight of the dolly. These dollies also are heavy with fixed bumpers, which are not adjustable. 
   The rectangular frame form of a dolly is hollow in the middle, which causes difficulty when loading either small items or those items with legs, thereon. This frame type of construction is used instead of a platform, because injected plastic is too heavy. 
   Because dollies are manually propelled and moving industry costs are weight related, the weight of a dolly is a significant factor. Such weight relationships are usually directly proportional. The heavier dolly is harder to move and requires increased physical effort. The heavier dolly also detracts from the cargo weight, or gross weight of the entire vehicle. 
   Protective coverings on dollies are often a problem. Such coverings include carpet and rubber caps fastened with staples, which often come loose and expose sharp staple ends. One prior art dolly has an attempted improvement for the dolly, with protective raised rubber pads on all four sides. However, this padded dolly still consists of an open rectangular frame. The frame provides less area on which a load may be secured than a platform with no adjustability. 
   One prior art dolly is adjustable, but is limited to either items with solid frames and items with toe region indentations. It is heavy, and its low clearance makes it almost impossible to negotiate changes in elevations. 
   Another prior art dolly is adjustable in height only and requires extensive time to strap each item to the dolly. The wheels are hinged, which can cause the load to shift or break the casters. Casters may also buckle and lock, thereby dumping the load. 
   Other prior art dollies have some adjustable features. However, adjustments involve heavy, complex mechanical devices and pertain to relocating the wheel configuration. These devices add considerable weight and make the dolly cumbersome to carry. The adjustable wheel location designs are limited to a specific task or load. These prior art dollies lack universal application and are not easily portable. 
   It thus becomes clear that a lightweight, adjustable platform dolly can provide a great advantage for the moving industry. More work can be handled with a lightweight, adjustable, platform dolly capable of handling many types of items, and serving in many capacities. Such a dolly is substantially unknown in the prior art. 
   SUMMARY OF THE INVENTION 
   Among the many objectives of this invention is the provision of a platform dolly, which allows for moving a variety of items. 
   An additional objective of this invention is the provision of a platform dolly that is considerably lighter. 
   A further objective of this invention is the provision of a platform dolly with adjustments thereon. 
   Yet a further objective of this invention is the provision of a platform dolly, which is light weight. 
   Another objective of this invention is the provision of a platform dolly, to support different items. 
   Still, another objective of this invention is the provision of a platform dolly with a durable support platform. 
   An additional objective of this invention is the provision of a platform dolly, which eliminates the additional manufacturing step of providing steel channels. 
   A further objective of this invention is the provision of a platform dolly as strong as a comparable prior art dolly. 
   Yet a further objective of this invention is the provision of a platform dolly, which is more functional for items with legs. 
   A still further objective of this invention is the provision of a platform dolly, which causes less fatigue for workers moving large objects. 
   Also an objective of this invention is the provision of a platform dolly, which causes less fatigue for workers moving stacks of many dollies. 
   Another objective of this invention is the provision of a platform dolly, which accommodates easier loading of today&#39;s furniture and appliance designs. 
   Still, another objective of this invention is the provision of a platform dolly having adaptability for rolling large containers and speed pack cartons used in manufacturing plants. 
   These and other objectives of the invention (which other objectives become clear by consideration of the specification, claims and drawings as a whole) are met by providing a platform dolly with a strong, lightweight support platform; having a hinged lockable adjusting mechanism. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  depicts an overall perspective view of a lightweight platform dolly  100  according to the invention. 
       FIG. 2  depicts a top plan view of the lightweight platform dolly  100  according to the invention with all of the four bumper blocks  134  in down position  150 . 
       FIG. 3  depicts a top plan view of the bar and receiver assembly  124  for lightweight platform dolly  100 . 
       FIG. 4  depicts a cross-sectioned, side view of the bar and receiver assembly  124  for lightweight platform dolly  100 . 
       FIG. 5  depicts a side view of the lightweight platform dolly  100  with all four bumper blocks  134  in down position  150 . 
       FIG. 6  depicts a side view of the lightweight platform dolly  100  with two of the four bumper blocks  134  rotated 180 degrees to the top position  154  of the support platform  120 . 
       FIG. 7  depicts a side view of the lightweight platform dolly  100  with all four bumper blocks  134  rotated 180 degrees to the top of the support platform  120 . 
       FIG. 8  depicts a side view of the lightweight platform dolly  100  with two bumper blocks rotated 90 degrees and held in position with T-bar block holders  126 . 
       FIG. 9  depicts a side view of the lightweight platform dolly  100  with two bumper block  134  locked in place and loaded with a dresser  102 . 
       FIG. 10  depicts an end view of the lightweight platform dolly  100  with one bumper block  134  locked in place and loaded with a dresser  102 . 
       FIG. 11  depicts a longitudinal sectional view of the lightweight platform dolly  100  taken along the section Line  11 — 11  shown in  FIGS. 1 and 2 . 
       FIG. 12  depicts a detailed cross sectional view of bumper block  134  and flexible hinge  122  attached to support platform  120 . 
       FIG. 13  depicts a longitude cross sectional view of the lightweight platform dolly  100  taken along the section Line  13 — 13  shown in shown in  FIG. 2 . 
       FIG. 14  depicts a block diagram for the lightweight platform dolly  100  of this invention. 
   

   Throughout the figures of the drawings, where the same part appears in more than one figure of the drawings, the same number is applied thereto. 
   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In this invention, because of the lightweight platform construction, a protective coating is applied to the lightweight platform dolly, with adjustable bumper blocks, which assist with items placed on the lightweight platform dolly. This invention solves these problems, because the lightweight platform dolly&#39;s height and length can be easily adjusted. This invention has universal application and is easily portable. 
   Advantages of a lightweight dolly include less fatigue for workers moving large objects and stacks of many dollies. It is easier to carry back to the truck. Because of the thinner platform, less weight, and the handle location, a worker can easily carry four of these dollies at a time. Prior art frame dollies are typically carried two at a time, one in each hand. With a thinner platform more dollies can be stacked higher and with less weight than prior art dollies. 
   Another advantage of the lightweight platform dolly is that it is wider than prior art dollies. The lightweight platform dolly width is sized to accommodate four dollies across a typical truck with minimal excess space for movement during transport. The wider platform has a wider wheel base which provides more stability for tall and large loads. A loaded lightweight platform dolly of this invention can be positioned in a transportation vehicle four across when loaded and easily unloaded in the same fashion. 
   The lighter, wider platform dolly accommodates easier loading of today&#39;s furniture and appliance designs. Computer workstations, overstuffed couches, entertainment centers, and electronic cabinetry are wider and require a larger platform for secure loading. Another advantage of the wider platform dolly is its adaptability for rolling large containers and speed pack cartons used in manufacturing plants. 
   The invention uses a fabricated composite construction to produce a strong, lightweight solid platform dolly. One example of the composite construction is a resin-impregnated carbon fabric. Still, another example of the composite construction is the resin-coated balsa wood. The lightweight construction allows additional features to be incorporated which makes the lightweight platform dolly adjustable and multi-functional. 
   Many suitable lightweight cores, known in the composite industry, may be used in the formation of a lightweight platform dolly of this invention. Balsa wood is very suitable as a lightweight core because of its stiff, lightweight characteristics. Plywood also has attributes similar to balsa wood. 
   Many honeycombed or foamed plastics are suitable lightweight cores too. Foamed polystyrene and foamed polyurethane are suitable cores. Also other foamed polymers are operable. Epoxy is also operable. A honeycomb polymer structure, when coated with a durable polymer or resin, is also acceptable. 
   The resin coated balsa wood is believed to be extremely effective for the lightweight platform dolly of this invention, because lightweight wood is reinforced by the resin. A resin or polymer impregnated fabric covering the balsa wood is very effective. Vacuum-formed plastic is also an effective core. With such reinforcement, the resin coating can take the pounding imposed by the items placed thereon. 
   A plurality of casters is mounted to the bottom of the support platform with a plurality of caster fastening bolts or other suitable device, which are secured in corresponding caster fastening apertures disposed at the corners. The support platform and bumper blocks are covered by a coating to secure and protect loads and walls. The support platform has a through grip aperture parallel to the long dimension of the lightweight platform dolly, which may be used as a handle. 
   In order to point out the features of the present invention, the following preferred embodiments are presented.  FIG. 1  shows an overall perspective view of the lightweight platform dolly  100 . Lightweight platform dolly  100  includes a rectangular support platform  120  with length and width being its greatest dimensions, while thickness is its least dimension. A flexible hinge  122  attaches each of four bumper blocks  134  thereto. 
   Flexible hinge  122  may be made of a flexible plastic; which may be sonic welded, glued, or otherwise fastened to or between support platform  120  and bumper block  134 . Flexible hinge  122  may also be the hinge and pintle combination, nylon strapping or other strong flexible material. 
     FIG. 1  and  FIG. 2  combine to show different views of the preferred embodiment of lightweight platform dolly  100 . The embodiments include caster wheels  132  attached to the underside of each corner of the support platform  120 . Four bumper blocks  134  are attached to the support platform  120  with a flexible material such as flexible hinge  122 . 
   Each bumper block  134  has positioning device  136  to hold it in a desired position. Positioning device  136  serves to hold each bumper  134  adjacent to support platform  120  as desired. Preferably, the positioning device  136  is a hook and loop assembly, commonly available under the registered trademark VELCRO, owned by Velcro Industries B.V. LIMITED LIABILITY COMPANY NETHERLANDS Castorweg 22-24 Curacao NETHERLANDS ANTILLES. Part of positioning device  136  is on the upper face  138  of bumper blocks  134  and the other part on support platform  120 . In this fashion, bumper block  134  can be held on support platform  120  in top position  154 , or released therefrom to down position  150 . 
   On either end of the support platform  120 , a bar and receiver assembly  124  includes T-bar block holder  126 , located in the corner of the support platform  120  on the same longitudinal side of the top plane. The T-bar block holder  126  is a bent wire bar  160  with a T-shaped head  162  and a hinged base  164 . Hinged base  164  is secured by hinge plate  166  to support platform  120 . Hinge plate  166  is secured by screws  170  or other fastener, and permits bent wire bar  160  to rotate 180 degrees therein. 
   The T-bar block holder  126 , at T-shaped head  162  locks into a T-bar receiver  128  on the bumper block  134 . The T-bar receiver  128  is located in alignment with the T-bar block holder  126  on the top plane, that is the top of the support platform  120 . The T-bar receiver  128  is a concave area designed to prevent the bumper block  134  from moving backward or forward. T-bar block holder  126  holds bumper block  134  at a right angle to support platform  120 . 
   The bumper blocks  134  fold up to secure a load such as dresser  102  on a steep incline. When the bumper blocks  134  are rotated to an upright position, they provide greater containment of loads in manufacturing plants and during transport. The bumper blocks  134  can be adjusted and locked in position to accommodate loads that have uneven bottom surfaces, not shown but exemplified by such as desks, big screen televisions, and dressers. 
   Another unique advantage of the bumper blocks  134  is that two blocks  134  can be locked in the 90-degree position by T-bar assembly  124  to secure the rear of a typical dresser  102  in an upright position while accommodating the lower dresser skirt in front. 
   The support platform  120  has a hand grip aperture  130  located near the longitudinal side as a handle to carry the lightweight platform dolly  100 . The coating  118  preferably completely covers support platform  120  and the bumper blocks  134  cushioning and protecting the load, the lightweight platform dolly  100 , and walls that may be contacted during moving. 
     FIG. 5 ,  FIG. 6 ,  FIG. 7  and  FIG. 8  show how the four bumper blocks  134  can be adjusted for varying loads. These figures show the movement of bumper blocks  134  from the end of the support platform  120  to the top of support platform  120 , which varies the height, and length of the lightweight platform dolly  100 . No tools are required for any of these adjustments. The flexible hinges  122  facilitate these adjustments. 
     FIG. 9  (a side view) and  FIG. 10  (an end view) combine to depict. They show the long and short side of the lightweight platform dolly  100 . They show a bumper block  134  in an upright 90-degree position held by a T-bar block holder  126  locked into a T-bar receiver  128 . This position is designed to accommodate the rear bottom of a dresser  102  ( FIGS. 9 and 10 ). Other adjustments of bumper blocks  134  are possible as desired, depending on the piece of furniture to be supported thereon. 
     FIG. 11  depicts a longitudinal section along section Line  11 — 11 , as shown on  FIGS. 1 and 2 , that shows the composite fabricated core construction of the support platform  120  and bumper blocks  134 . The section also shows the flexible hinges  122 . 
     FIG. 12  depicts a detail cross section of the material for flexible hinge  122  attaching bumper block  134  to support platform  120 . Screws  170 , or other appropriate fasteners, secure flexible hinge  122  to both bumper block  134  and support platform  120 . 
     FIG. 13  depicts a short side latitudinal cross section through the platform  120  depicting the view through hand grip aperture  130  and the composite fabricated construction of the support platform  120 , based on Line  13 — 13  of  FIGS. 1 and 2 . Both the support platform  120  and the bumper blocks  134  are formed from resin  140  or composite, fabricated fibers  142  impregnated with a resin and formed, and laminated or coated over a lightweight core  144  for maximum strength and minimal weight. 
   From the description above regarding the use of dollies, a number of advantages of the adjustable lightweight platform dolly  100  of this invention become evident. One of the advantages of the support platform  120  is its ability to hold small objects that can otherwise fall through on a typical frame platform dolly. The support platform  120  also holds items with legs that will go through a typical frame dolly. The major unique advantage of support platform  120  is its flexible hinges  122  supporting bumper blocks  134 . 
   The hinging operation allows objects with an uneven base to be loaded onto lightweight platform dolly  100  in an upright position. For example, large dressers and cabinets are usually tipped on their end or side, which exposes the tops of finished furniture to damage. With the lightweight platform dolly  100  of this invention, dressers can be moved upright which protects tops and prevents drawers and contents from being displaced. 
   The operation of the flexible hinge  122  for bumper blocks  134  also facilitates adjustment of the lightweight platform dolly  100  to lower the object for elevators and doorways. The flexible hinge  122  supporting bumper blocks  134  also permit the lightweight platform dolly  100  to be lengthened for objects such as a chest of drawers instead of tipping the chest of drawers and exposing it to damage. The bumper blocks  134  fold up to secure loads on steep inclines, or for production line applications. They lock in place for is dressers as shown in  FIG. 9  and  FIG. 10 . 
   Some of the most important operational advantages of the lightweight platform dolly  100  of this invention are as follows. It is multi-functional which eliminates the need for multiple dollies. The lightweight construction of the lightweight platform dolly  100  of this invention improves the operation of manually moving objects and manually stacking dollies. A lighter lightweight platform dolly  100  is easier to move under objects and to carry. 
   The coating  118  covers support platform  120  and bumper blocks  134 , which makes the load more secure than on prior art dollies. A load on platform dolly  100  is shown in the form of dresser  102  in  FIGS. 9 and 10 . Load refers to an item or items placed on the platform dolly  100 , for the purpose of moving the same from one place to another. Dresser  102  merely represents the various loads for platform dolly  100 . 
   The adjustable lightweight platform dolly  100  may be constructed of varying composite cores, fabrics, and coverings required for unique situations such as in the chemical, medical, or food industries. The bumper blocks can be reconfigured and customized for unlimited adaptability to specific uses. Because of the lightweight construction, the overall size of the lightweight platform dolly  100  can be altered to meet aviation requirements. 
   The overall protective coating of the lightweight platform dolly  100  of this invention can be made in a variety of colors or with a company logo to prevent theft, to differentiate loads to be disseminated to different locations, to advertise, and to provide other suitable services. The larger support platform  120  for lightweight platform dolly  100  provides more area for logos. 
   With the consideration of  FIG. 14 , the variety of feasible structures for the lightweight platform dolly  100  becomes clear. To support platform  120 , each bumper block  134  is secured by flexible hinge  122 . Support platform  120  is generally rectangular and may have a flexible hinge  122  on every side thereof in order to support as many bumper blocks  134  as desired. Flexible hinge  122  may also be releasable in order to permit adding or removing of bumper blocks  134  as desired. 
   Numerous characteristics, advantages, and embodiments of the invention are described in detail in the foregoing description with reference to the accompanying drawings. However, the disclosure is illustrative only and the invention goes beyond the precisely illustrated embodiments. Various changes and modifications may be effective therein by one skilled in the art without departing from the scope or sprit of the invention. 
   This application; taken as a whole with the abstract, specification, claims, and drawings being combined; provides sufficient information for a person having ordinary skill in the art to practice the invention as disclosed and claimed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure. 
   Because of this disclosure and solely because of this disclosure, modification of this method and device can become clear to a person having ordinary skill in this particular art. Such modifications are clearly covered by this disclosure.