Abstract:
The present invention is a dolly comprising a plurality of stems integrally formed with the dolly body. The plurality of integrally formed stems extend downwardly from the body. An equal number of collars are concentric with the plurality of stems, wherein the collars are also integrally formed with the body. The body, stems, and collars are made of a durable material capable of withstanding large weights. An equal number of wheel casters are configured to be engageable with and freely rotatable about the plurality of stems.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/675,633 entitled, “Plant Dolly,” filed on Apr. 28, 2005 in the United States Patent and Trademark Office. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention.  
         [0004]     The present invention relates to dollies for supporting and moving objects, and more particularly to an inexpensive plant dolly comprised of integrally formed body and stems.  
         [0005]     2. Description of the Related Art.  
         [0006]     Prior art in the field of plant dollies have included plastic bodies with separate metal stems for attaching casters. The separate metal stems provided reinforced support for heavy loads the plant dolly may support. While this design is effective in providing a durable load-bearing plant dolly, it is not cost effective because the metal stems are expensive compared to the remaining components of the plant dolly.  
         [0007]     U.S. Pat. No. 1,834,617, issued to Harpine et al. on Dec. 1, 1931 discloses a caster assembly having two cups arranged such that an outer cup, integrally formed with the caster housing, forms a socket for an inner cup located on the bottom of a leg of a piece of furniture. A stem, or shank, is secured to the caster housing and is held within a circumferential collar within the furniture leg. Downward force on the furniture leg causes the inner cup to sit within the outer cup, thereby distributing the downward force around the inner cup wall to the bottom of the outer cup. Simultaneously, the top of the outer cup wall rests on the bottom of the furniture leg.  
         [0008]     U.S. Pat. No. 2,025,448, issued to Hebbinghaus on Dec. 25, 1935 discloses a furniture caster having a stem affixed to a fork, which holds the roller. The fork is slidingly retained within an inner sleeve, the fork being biased to hold the roller in a lowered position wherein furniture may be moved. The inner sleeve is fixedly retained within a bell having an aperture through which the roller passes when the furniture is being moved. Pressure to the furniture pushes the roller upward so that the furniture rests on the bell. A spring pushes two ball bearings outwardly apart toward respective cavities to provide a detent for the position in which the rollers are in a lowered position.  
         [0009]     U.S. Pat. No. 4,283,810 issued to Demrick on Aug. 18, 1981 discloses a caster assembly having a socket to receive a swivel stem. The stem disclosed has an integrally-formed flange that may abut the top of socket. Nothing is disclosed about the assembly adjoined to the stem.  
         [0010]     It would therefore be advantageous to provide a plant dolly that could be constructed with an integrally formed body and stems.  
       BRIEF SUMMARY OF THE INVENTION  
       [0011]     The present invention addresses the aforementioned need. According to one embodiment of the invention, a body, with a plurality of integrally formed stems extending downwardly from the body. An equal number of collars are concentric with the plurality of stems, wherein the collars are also integrally formed with the body. The body, stems, and collars are made of a durable material capable of withstanding large weights. An equal number of wheel casters are engageable with the plurality of stems. The wheel casters are configured such that the wheel casters are freely rotatable about the plurality of stems.  
         [0012]     Other features and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a side view of an unloaded plant dolly.  
         [0014]      FIG. 2  is a side view of a plant dolly supporting a load-bearing object.  
         [0015]      FIG. 3A  is a detailed view of the bottom surface of the plant dolly with integrally formed stems.  
         [0016]      FIG. 3B  is a zoomed view of the integrally formed stem and collar.  
         [0017]      FIG. 4  is a side view of the wheel guard.  
         [0018]      FIG. 5  is a bottom view of the wheels and wheel guard.  
         [0019]      FIG. 6  is a detailed view of the bottom surface of an alternate embodiment of the plant dolly.  
         [0020]      FIG. 7  is a cross section of the alternate embodiment of the plant dolly and stem. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0021]     The preferred embodiment of dolly  100  is depicted in  FIGS. 1-3B . Dolly  100  is comprised of body  110 , stem  120 , collar  130 , wheel  140 , and wheel guard  150 .  
         [0022]     Body  110  is defined by body perimeter  111 , which circumscribes body  110 . Body  110  has body top surface  112  and body bottom surface  113 . Body top surface  112  is planar, thereby providing a level surface capable of supporting an object. Similarly, body bottom surface  113  is planar. Body  110  can be constructed out of plastic, wood, or other durable materials known in the art, so long as the material provides sufficient strength for supporting a load-bearing object.  
         [0023]     A plurality of stems  120  extend downwardly perpendicular with respect to body bottom surface  113 . Stems  120  provide support for body  110 . Stem  120  is preferably cylindrical, with a stem diameter  121 . Stem  120  terminates at stem upper terminal end  122  and stem lower terminal end  123 . Stem upper terminal end  122  is proximate body bottom surface  113  and is integrally attached to body bottom surface  113 . Stem notch  124  is formed into stem  120  proximate stem lower terminal end  123 . Stem notch  124  circumscribes stem  120 , thereby providing a surface for attaching wheel  140  to stem  120 . Body  110  and stem  120  are preferably a unitary structure simultaneously formed from a molded plastic.  
         [0024]     In the preferred embodiment, collar  130  extends downwardly from body bottom surface  113 . Collar  130  is circular and encompasses stem  120 . Collar  130  is typically concentric with stem  120 . Preferably, collar  130  is formed of a molded plastic, simultaneously with body  110 . Alternatively, collar  130  can be formed of similarly rigid material known in the art and can be fixedly attached to body bottom surface  113  subsequent to unitarily forming body  110  and stem  120 .  
         [0025]     Referring to  FIGS. 1, 2 , and  5 , wheel guard  150  is comprised of guard fender  151 , guard crossbar  146 , and guard arm  156 . Guard fender  151  is semi-circular and has a fender diameter  152 . Guard fender  151  terminates at first fender terminal end  153  and second fender terminal end  154 . First fender terminal end  153  and second fender terminal end  154  are integrally connected by guard crossbar  146 , wherein guard crossbar  146  is perpendicular to first fender terminal end  153  and second fender terminal end  154 . Guard crossbar  146  provides a means of connecting wheel  140  to wheel guard  150 . This connection occurs through an orifice (not shown) in guard crossbar  146 .  
         [0026]     Guard arm  156  upwardly extends from guard fender  151  and is preferably offset from fender apex  155 . Guard arm  156  is cylindrical and defines a guard arm socket  157 . Guard arm socket  157  has an arm socket diameter  158 , which is larger than stem diameter  121 . Guard arm socket  157  receives stem  120 , wherein stem lower terminal end  123  is inserted into guard arm socket  157  until stem notch  124  engages with arm socket latch (not shown). Once engaged, wheel guard  150  is freely rotatable about stem  120 .  
         [0027]     Wheel  140  provides movement to dolly  100 . Wheel  140  comprises first wheel member  141  and second wheel member  142 . First wheel member  141  and second wheel member  142  are connected by wheel journal  143 . First wheel member  141  is positioned proximate crossbar first side  148  and second wheel member  142  is positioned proximate crossbar second side  149 , with wheel journal  143  extending through the orifice (not shown) in guard crossbar  146 . Wheel journal  143  intersects wheel center point  144  of first wheel member  141  and second wheel member  142 . Wheel journal  143  provides a rotational axis for first wheel member  141  and second wheel member  142 .  
         [0028]      FIG. 1  depicts dolly  100  with no load applied to body  110 . When dolly  110  is not bearing a load, collar  130  and fender  151  do not interact. Therefore, the configuration of collar  130  and fender  151  provides clearance  170 . While clearance  170  can be of any distance, clearance  170  should not be excessive. If clearance  170  is too great, stem  120  will bear the entire load exerted against body  110 , possibly resulting in breaking stem  120 . Therefore, clearance  170  is preferably between 0.015 inches and 0.070 inches.  
         [0029]      FIG. 2  depicts dolly  100  with a load applied to body  110 . The load exerts a normal force against body  110 , thereby resulting in compressing body  110  a distance equal to or less than clearance  170 . When the load is applied to body  110 , collar  130  compresses. If a large enough load is exerted against body  110 , collar  130  will contact fender  151  approximate fender apex  155 . Therefore, when dolly  100  bears a load exceeding a predetermined weight, clearance  170  is zero. When collar  130  contacts fender  151 , fender  151  provides additional support for body  10 , thereby distributing the normal forces and relieving stress from stems  120 .  
         [0030]     An alternative embodiment is depicted in  FIGS. 6-7 , wherein stem  220  is formed separately from body  210 . In the alternative embodiment, stem  220  is fixedly attached to body  210 . This configuration is particularly desireable when body  210  is formed of a natural material, such as wood.  
         [0031]     As seen in  FIG. 6 , body  210  has a plurality of body mounting surfaces  212 , which are configured for receiving a plurality of stems  220 . Body mounting surface  212  may be of any material, but is preferably 33% glass filled nylon Type 6/6. Body mounting surface  212  may be fixedly attached to body  210 , as seen in  FIG. 6 . Alternatively, body mounting surface  212  may be integrally formed with body  210  (not shown). Body mounting surface  212  has a body orifice  214  passing therethrough. Body orifice  214  provides an insertion point for stem  220 . Body orifice  214  is preferably circular, and has a body orifice diameter  215 . Alternatively, body orifice  214  can be of any shape known in the art.  
         [0032]     Referring to  FIGS. 6 and 7 , stem  220  is integrally formed by stem engaging end  222 , stem notch  226 , and collar  230 . Stem engaging end  222  is preferably comprised of a plurality of ribs  223  oriented about stem  220  proximate stem engaging end  222 . Ribs  223  are configured for insertion into body orifice  214  and engagement with body  210 . Stem engaging end  222  has an engaging end diameter  223 . Engaging end diameter  223  is sized to fit within body orifice  214 ; thus, engaging end diameter  223  is smaller than body orifice diameter  215 . Stem notch  226  is located distal stem engaging end  222 . Stem notch  226  provides a surface for engaging stem  220  with wheel  140  (seen in  FIG. 1 ). In the alternative embodiment, collar  230  replaces collar  130 , depicted in  FIG. 1 . Collar  230  circumscribes stem  220  and is located between stem engaging end  222  and stem notch  226 . Collar  230  extends a collar distance  232  from stem  220 . Collar distance  232  should be sufficient to extend to at least the apex of fender  151 . Similar to collar  130  depicted in  FIG. 1 , collar  230  distributes weight exerted against dolly  100 .  
         [0033]     The foregoing description of the invention illustrates a preferred embodiment thereof. Various changes may be made in the details of the illustrated construction within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the claims and their equivalents.