Abstract:
This invention is a collapsible, detachable shelf for two-wheeled hand trucks, as well as other hand-propelled utility vehicles, designed to provide users with a table-like work surface and storage compartment. The shelf adapts universally to all existing models and brands of hand trucks and convertible carts, by use of clamps using hanging rods or like methods. Further original hand truck and shelf designs may accommodate new shelves, thus excluding clamp usage. The work surface benefits occupations, including but not limited to stock clerks and delivery persons, providing portable workspace suitable for writing and holding paper and office supplies. An alternate shelf has a storage compartment which holds job-appropriate items such as scanning devices, hand-held computers, pricing guns, and printers. The shelf, in its collapsed position, lies recessed within or behind the vehicle, providing no interference with normal freight.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Application Ser. No. 61/549,432; Priority of which is claimed based on previous filing of Provisional Patent Filing Date Oct. 20, 2011 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    The present invention is in the field of Hand Trucks. 
         [0005]    No prior art was found, and the problem I am addressing with the present invention has yet to be solved. I have noticed delivery people with their hand trucks in one hand and their paperwork or computer in the other hand, trying to maneuver their way through parking lots, doorways, crowded store aisles, and up stairs. Why do they not have a place on the hand truck to attach the paperwork, computer, price gun, or items they are trying to carry? Would it not make their life much easier to use both hands while driving their cart? Millions of these carts are currently on the market, and to offer a new cart would be a great solution, but would there be a way to retro-fit the existing vehicles that are on the market today? To accomplish this task, more than one version of this device will need to be offered, because there is more than one type of hand truck, cart, U-boat, and hand-propelled vehicle. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to a shelf or tray, and more particularly is an invention that may be used by, but is not confined or restricted to, people who frequently deliver product, goods, or services, and are carrying items such as paperwork, personal office supplies, a handheld computer, handheld printer, pricing gun, and any other related items, while pushing hand-propelled vehicles. The present invention, simply put, is a shelf or tray mountable on a hand truck, 2 wheeled dolly, U-boat cart, or like vehicles, either by using a clamp, creating a hole in the leg or post of the hand truck, or any other like method. This shelf will extend perpendicularly from the vehicle and serve as a portable work space. When finished with work or paperwork, the collapsible shelf swings down and locks into place, and is out of the load bearing area of the cart. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows extended perspective view from the front, of the shelf that goes onto carts made of round tubular material. 
           [0008]      FIG. 2  shows extended perspective view of shelf in  FIG. 1  from the front with shelf open 
           [0009]      FIG. 3   a  front collapsed view of the same shelf 
           [0010]      FIG. 3   b  shows a shelf mounted directly into tubular members of hand truck 
           [0011]      FIG. 4  is a side extended perpendicular view of same shelf 
           [0012]      FIG. 5  is a detailed view of the mechanical workings and clamps used for trays attached onto carts made from round tubular material. 
           [0013]      FIG. 6  side view of clamp from  FIG. 5  showing hand knob screw 
           [0014]      FIG. 7  opposite side view of clamp showing round opening 
           [0015]      FIG. 8  shelf with lid from  FIG. 1-4 , between clamps mounted on each hand truck leg 
           [0016]      FIG. 9  shelf shown from top without lid 
           [0017]      FIG. 10  rear view of hand truck having square members, with shelf mounted 
           [0018]      FIG. 11  perspective view of hand truck and shelf from  FIG. 10   
           [0019]      FIG. 12  spring steel latch 
           [0020]      FIG. 13  view of shelf holding handheld computer, printer, paper 
           [0021]      FIG. 14  top view of shelf in  FIG. 13   
           [0022]      FIG. 14   b  side view of forward bent hardened steel plate  239   
           [0023]      FIG. 15  back view of shelf from  FIG. 13 ,  14  mounted on clamps 
           [0024]      FIG. 16  clipboard shelf open view 
           [0025]      FIG. 17  back view of shelf from  FIG. 16  mounted on clamps 
           [0026]      FIG. 18  angle view of clamp from  FIG. 13 ,  15 ,  17  designed for truck having square members 
           [0027]      FIG. 19  close-up view of shelf from  FIG. 13 ,  14 ,  15   
           [0028]      FIG. 20  close-up side view of shelf from  FIG. 19   
           [0029]      FIG. 21  side view of clipboard shelf from  FIG. 16 ,  17  lining up with clamp  FIG. 18   
           [0030]      FIG. 22  side view of same as  FIG. 21 , from a perpendicular sliding angle 
           [0031]      FIG. 23  perspective view of hand truck and clipboard shelf 
           [0032]      FIG. 24  rear view of  FIG. 23   
           [0033]      FIG. 25  extended closed clipboard shelf front view 
           [0034]      FIG. 26  collapsed side view of  FIG. 23   
           [0035]      FIG. 27  shelf from  FIG. 1 ,  2 ,  3  positioned before extended view  4   
           [0036]      FIG. 28  shelf from  FIG. 1 ,  2 ,  3  after moved back into extended position view  4   
           [0037]      FIG. 29  clamp from  FIG. 18  prior to mounting 
           [0038]      FIG. 30  clamp from  FIG. 18 ,  29  mounted on square member 
           [0039]      FIG. 31  clamp back view 
           [0040]      FIG. 32  shelf sliding straight down into latch from back of hand truck 
           [0041]      FIG. 33  bottom of shelf meeting spring steel latch 
           [0042]      FIG. 34  shelf after having cleared latch in  FIG. 32  and resting in collapsed position 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    Referring now to the invention in more detail, in  FIG. 1  shows a hand truck  100 , having a front side  101  and a backside  102 , with a shelf  108   FIG. 1 ,  2 ,  3 ,  4  attached thereto. This type of hand truck has round support members and provides a support surface that is curved inwards. The hand truck  100  has a first leg  103 , a second leg  104 , a vertical support member  106 , and a cross member  105 . A removable support member  107  is reversibly attached to the hand truck legs  FIG. 3   b  by being placed directly into round openings or holes in the tubular legs  103 ,  104 . A removable support member  107   FIG. 3 ,  5 ,  8  is reversibly attached to the legs using clamps  128 . The shelf  108  is suspended from the 2 clamps  128   FIG. 1 ,  4 ,  5 ,  6 ,  7 ,  8  in its collapsed position  FIG. 3 ,  3   b  by this support member  107 . 
         [0044]      FIG. 9  shows the shelf  108  is constructed from a U-shaped frame  112  having a back  109 , two legs  114  and a back frame member  110  connecting the two free ends of legs  114 . There is a space or open end  113  from the back frame member and the end of the legs  114   FIG. 5 ,  9 . The support member  107   FIG. 5 ,  8  passes through the ends of the legs  114  through elongated openings  115 .  FIG. 5  the support member  107  is constructed from a hollow tube  116  having two elongated open slots  117  and a spring  118 . A first metal rod  119  is positioned slidably into one open end of the hollow tube, a compression spring  118  is inserted into the other end of the hollow tube  116  and then a second metal rod  120  is positioned slidably, or slid into the same open end of the hollow tube  116 . A handle  122  is fastened to each metal rod  119 ,  120  and the handles protrude through the elongated openings  117 . The handles  122  hold the rods  119 ,  120  inside the tube  116 , and allow the rods  119 ,  120  to be pushed together. 
         [0045]    Clamps  128   FIG. 6. 7  are mounted  FIG. 8  on each member  103 ,  104  in an area below the cross member  105 . Clamps  128  made to fit the diameter of the round tubular hand truck  100  are mounted by tightening a Hand Knob Screw  129  into the outside wall of both legs  103 ,  104   FIG. 8  of the U-shaped clamp  128  until it is firmly gripped onto the leg. Clamps shown mounted with shelf  108  attached in  FIG. 1-4 .  FIG. 6 , shows the clamp  128  with a hand knob screw  129  on the side.  FIG. 7  shows the same clamp  128  has a round opening or hole  130  in the opposite side large enough for the rods  119 ,  120  to penetrate, illustrated in  FIG. 5 ,  8 .  FIG. 8  shows how the support member  107  will be reversibly attached to the hand truck legs  103 ,  104 , by the rods  119 ,  120  going into the openings  130  of the clamps  128 . The hollow tube  116   FIG. 5 ,  8  has a spring  118  in its interior positioned between the first metal rod  119  and the second metal rod  120 . The spring  118  biases the metal rods  119 ,  120  away from each other and out from the hollow tube  116 . The handles  122  allow a user to push the two metal rods  119 ,  120  together to shorten the overall length of the support member  107  to prepare it for mounting. In this manner the support member  107  can be inserted through the elongated openings  115  in the ends of the legs  114  of the U-shaped frame  112 , as shown in  FIG. 5 ,  8 , and then into the holes  130  in the clamps  128 , mounted on the legs  103 ,  104  of the hand truck  100 . 
         [0046]      FIG. 28  show the shelf  108  pushed towards the cross member  105  so that the ends of the legs  114  of the U-shaped frame  112  pass under the cross member  105 . In this configuration the shelf  108  cannot rotate downward and remains in a position perpendicular to the hand truck  100  so that the shelf  108  may be used  FIG. 1 ,  4 . It is placed into this position by rotating the front of the shelf upward  FIG. 27  and then pushing the entire shelf  108  towards the backside  102  of the hand truck  100  so that the ends of the legs  114  move under the cross member  105 . It is possible for a notch to be placed in this leg  114  to help secure it into place, if necessary. When pulled away from the cross member  105 , the shelf  108  can be rotated downward for storage,  FIG. 3 , and out of the load bearing area  125   FIG. 3 ,  3   b ,  4  of hand truck  100 . Fastening straps  121   FIG. 1 ,  2 ,  4  may be used as a method of securing the shelf  108  to the vertical support member  106 . It is possible to use a different method to secure the shelf in this collapsed state  FIG. 3 ,  3   b.    
         [0047]      FIG. 2  shows a top view of the shelf  108  with the lid  111  opened, showing the interior  124  of the shelf  108 . Dividers  125  can be placed within the interior  124  of the shelf  108 .  FIG. 8  further shows a rod hinge  126  upon which the lid  111  rotates to open and close the shelf  108 . There is a need for access to the inside of the shelf  124   FIG. 2 , this shelf  108  has a round opening, or hole  127  in the front part of the lid  111   FIG. 1 ,  2 . It is possible for a secure latch to be added. 
       DETAILED DESCRIPTION OF SHELF OR TRAY FOR OTHER HAND TRUCKS 
       [0048]      FIG. 10  shows a hand truck  200  viewed from the front  201 , and the same hand truck  200  in  FIG. 11  is shown from the back side  202 . This hand truck has square support members, and provides a flat carrying surface. This hand truck  200  has in  FIG. 10 ,  11  a first leg  203  and a second leg  204 . Clamps  FIG. 18-22  are attached to the legs  203 ,  204 . The clamps  211  hold a shelf or tray  207 ,  230   FIG. 10 ,  11 ,  13 ,  15 ,  17 ,  23 ,  24 ,  25  onto the hand truck  200  securely either in a collapsed position  FIG. 10 ,  11 ,  15 ,  17 ,  23 ,  24 ,  26  or in a perpendicular position  FIG. 13 ,  25 . There are two types of shelves or trays: a shelf or tray that will be used primarily as a clipboard and an office caddy type device  207   FIG. 13 ,  14 , and a shelf or tray that will be used to store or hold electronics, tools, or other devices or things that need to accompany someone  230   FIG. 16 ,  17 . 
         [0049]    Clamps  211   FIG. 10 ,  11 ,  13 ,  18 ,  19 ,  20 ,  21 ,  22  allow retro-fit to most hand trucks with square members. A clamp  211  will have a hand knob screw  222   FIG. 19 ,  20  to fasten the clamp to the leg  203 ,  204  Fig. A rounded hanging rod  223  will allow the shelf  207 ,  230  to hang in the collapsed position, or pivot between the collapsed and perpendicular position. A bottom horizontal shelf support  227  and a top horizontal shelf support  228   FIG. 18 ,  21 ,  22  allow the shelf&#39;s hanging plate  224   FIG. 21 ,  22  to line up with the hanging rod  223 . These supports  227 ,  228  also hold the shelf  207 ,  230  in the perpendicular position. 
         [0050]    Shelf  207  was designed to hold electronics, specifically a handheld computer and a portable, rechargeable Bluetooth enabled printer. This shelf may be reconfigured, perhaps with a lid or cover, to hold any type of tool such as a pricing gun, hardware tools, or anything of this proportional size that is often used or carried by people while they have access to or are using a hand truck. 
         [0051]    This shelf  207  has a front  208   FIG. 10 , a back  209   FIG. 11 . Three compartments  216 ,  217 ,  218  and a divider  219   FIG. 10  are added to separate components. Slots  220   FIG. 10 ,  14  have been machined into the top side surfaces allowing for strap fasteners to hold in the devices. A handle  221   FIG. 10 ,  13 ,  19  on the end makes it easy to grab and carry. To hold the computer in tightly, spring steel was inserted on the inside of the shelf  238   FIG. 14 . This opposing force holds the computer inside its compartment when inserted under the forward bent hardened steel divider  239   FIG. 14B . Paper rolls, or other products  FIG. 13   218  are held into their compartment by strap fasteners placed through the slots  220 . 
         [0052]    Shelf or tray  230  is a rectangular box with a lid  231  hinged  206   FIG. 16  in the rear, with a second hinge  234   FIG. 16 ,  25  between the first hinge  206  and the latch  FIG. 16 ,  25   232 . On the lid  231  is mounted  FIG. 24 ,  25  a strong coiled spring-clamping action vertical paper stop  241 . This shelf  230  is designed with compartments  233  to separate items carried inside. There is a front  237  with a slot  236  prepared to receive the latch  232  when in the closed position  FIG. 25 . Each side  235  will have attached or affixed near the front  237  a hanging plate  224  on which the shelf  230  will hang in a collapsed position from the hand truck  200   FIG. 10 ,  11 ,  13 ,  17 ,  23 ,  24 ,  25 . 
         [0053]    To place a shelf  207 ,  230  on the hand truck  200 , the clamps  211  must first be mounted onto the legs  203 ,  204  of the hand truck, cart, U-boat or other and propelled vehicle. This is easily done by sliding a clamp  211  onto a leg  203   FIG. 29  while the hand knob screw  222   FIG. 19 ,  20 ,  29 ,  30 ,  31  is in an unscrewed position. When the clamp  211  is completely mounted onto leg  203   FIG. 30 ,  31 , the clamps  211  are considered to be in a mounting position. The knob  222  is then tightened  FIG. 31  into the leg  203  until clamp  211  is firmly secured on the vehicle. This is to be done on both sides in an equally measured position from the lower cross member  205   FIGS. 10 ,  23 , and  24 . 
         [0054]    The shelf  207 ,  230  may be mounted onto the clamp  211  in two ways  FIG. 21 ,  22 . The first way would be to slide the shelf  207 ,  230  downward into a hanging position  FIG. 21 , lining up the hanging plate  224   FIG. 32  with the hanging rod  223  that is fastened onto the clamp  FIG. 18 ,  29 ,  30 ,  31 . The hanging rod  223  slides along the side  235  of the shelf  207 ,  230   FIG. 32  until it meets the hanging plate  224  and is guided into a machined cavity or pouch  226  where it can firmly hold the shelf  207 ,  230  in a hanging collapsed secure position  FIG. 10 ,  11 ,  22 ,  24 ,  26 . This is referred to as the collapsed position. The shelf  207 ,  230  will rest in a collapsed position  FIG. 10 ,  11 ,  22 ,  24 ,  26  on the back side  202  of the hand truck  200 , and the back part of the clamps  211  when the hand truck  200  is in use. 
         [0055]    To remove the shelf  207 ,  230  from this position simply lift up, or reverse the previous motion, and the shelf  207 ,  230  will be easily removed. The shelf  207 ,  230  may be locked into a secure position when it makes contact with  FIG. 33  the spring steel latch  210 . This latch  210  is attached to the hand truck  200  through an opening  213  around the lower cross member  205 . This latch  210 , made from 2 pieces of hardened spring steel, is bent into the desired shape, and slots  214  allow the latch  210  to be adjusted forward or backward, and upward or downward. The latch is angled downward  215  in the front to allow the shelf  207 ,  230  to push the latch downward  FIG. 33 , when it the shelf  207 ,  230  swings into its&#39; secure position. The shelf  207 ,  230  pushes down the spring steel latch  210  until the front of the shelf  207 ,  230  has passed over the latch  210 , and then it will pop up into a latching position  FIG. 34 , securing the shelf  207 ,  230  in its resting or collapsed position  FIG. 34 . 
         [0056]    From the collapsed position the shelf  207 ,  230  may be pivoted backwards toward the latch  210  until the shelf  207 ,  230  touches the latch. Still going further,  FIG. 12  while the latch  215  is being pressed down  FIG. 33 , the shelf  207 ,  230  may be moved in an outward circular motion until the entire shelf is in a perpendicular position, and it then may be pushed forward 
         [0057]      FIG. 25 . When the shelf  207 ,  230  is pulled back, the hanging rods  223  are to be kept tight in their pouch  226 , at a point where the shelf  207 ,  230  is horizontal, and perpendicular to the hand truck  200 , the shelf  207 ,  230  may be slid into the clamps  211  to go forward between the bottom horizontal support  227  and the top horizontal support  228   FIG. 22 . Sliding the shelf  207 ,  230  forward until the desired portion is on the front side  201  of the hand truck  200   FIG. 13 ,  25  creates a great opportunity for hands free writing, order entry, printing, or the like. The clipboard  230  is hinged  234   FIG. 16 ,  25  in an area that will allow the shelf  230  to be held by the clamps  211  in a perpendicular position  FIG. 25  and still to be able to open up and operate much as it does in  FIG. 4 . Pulling the shelf  207 ,  230  forward and away from the hand truck  200  will allow the use of the shelf  207  and clipboard  230  as a separate tool, apart and away from the hand truck. To re-attach, simply hold shelf  207 ,  230  in a horizontal position (the same position the shelf  207 ,  230  was in when it was pulled off of the clamps  211  earlier), and slide the shelf  207 ,  230  in between the bottom horizontal support  227  and the top horizontal support  228   FIG. 22 . Keep a steady backward sliding motion until the hanging plate  224  contacts the hanging rod  223  and slides into the machined pouch or cavity  226 . The shelf  207 ,  230  will make a downward, swinging motion and should press down the latch  210   FIG. 33  and lock into place  FIG. 34 . 
         [0058]    The construction details of the invention as shown above are that the shelves  108 ,  207 ,  230  may be made of aluminum or of any other sufficiently rigid and strong material such as high-strength plastic, metal, and the like. Further, the various components of the clamps  128 ,  211  can be made of different materials. 
         [0059]    The advantages of the present invention would be to help one&#39;s work become more productive and allow a person to carry more items in fewer trips. Currently no prior art is found on a collapsible removable shelf with a compartment, and there are many advantages to having this item mounted on a hand truck. The shelf  108  may be used as an extra work station. Many convenience stores and other locations may not have adequate space for a work area, and this shelf can be used in a small proximity. The storage inside is a great way to store paperwork, and to organize any office supplies needed on the job. The clipboard shelf  230  provides a great writing surface, a lightweight work surface when mounted, and will open to organize paperwork and office supplies. The shelf  207  holds various types of items including, but not limited to handheld computers, portable printers, barcode scanners, pricing guns, tools, RFID readers and any other device or item it can be configured or designed to house. Since all of these are removable they can be used on or off of the hand truck. They may be used in the delivery truck, in the store, in the office, or at home. 
         [0060]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. Further, while the hanging rod and plate is a method of securing the shelf to the hand truck, current and future development may incorporate various methods of attaching the shelf to the hand truck, dolly, cart, or other hand propelled vehicle.