Abstract:
The present invention is a plant support comprising a horizontal base for supporting a plant, a mobilizing mechanism positioned beneath the base which is vertically extendable from the base and vertically retractable toward the base, and a mechanism housing wall extending down from the base. Preferably, when the mobilizing mechanism is in a retracted position, the bottom of the mobilizing mechanism and the bottom of the mechanism housing wall are at substantially the same vertical position. The plant support optionally has a pot wall extending up from a perimeter of the horizontal base.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     None. 
     BACKGROUND OF THE INVENTION 
     This invention relates to a plant, shrub, or tree support or pot which allows for mobility of the plant contained therein. In particular, the invention relates to a plant mobilizer in which casters, wheels, rollers, or the like extend and retract from the bottom of the mobilizer, thereby offering mobility while the pot is being moved, and stability while the pot is stationary. 
     It is common to move plants around a building or landscape setting to change the aesthetic appearance of a room, dwelling, or landscape; to rotate or move the plants so they can receive sunlight; or for any other purpose. Very large plants in particular pose the problem of being very difficult to move because of their size and weight. One solution to this problem consists of using lighter weight materials in the construction of plant pots. For example, large plastic pots may be found which imitate the look of much heavier terra cotta or clay pots. However, even these lighter weight plastic pots become very heavy with the addition of soil, water, and plant material. 
     Thus, various prior art teachings show the use of pot transporting devices or stands featuring wheels or casters. Such uses are shown by Rivero, U.S. Pat. No. 4,638,595; Lee, U.S. Pat. No. 5,094,031; Spitz, U.S. Pat. No. 1,820,843; Delogne, U.S. Pat. No. 3,676,953; Bates, U.S. Pat. No. 5,309,670; and Commenator, U.S. Pat. No. 5,950,358. However, a problem with such devices is that they may be unstable while stationary. This instability may be contributed to a number of factors. First, the use of the casters or wheels raises the center of gravity of the potted plant, thereby making it easier for the plant to tip when blown by the wind or accidentally nudged. Second, the surface area of the wheels or casters in contact with the ground is quite small in comparison to the mass supported by the wheels or casters. This not only leads to instability, but also increases the chances that the wheels will sink into the ground under the weight of the potted plant, thereby making it very difficult to move the plant from its location. Third, if the potted plant is placed on an uneven surface, such as an incline, the plant may inadvertently roll from the desired location. 
     Finally, wheels do not generally add to the aesthetic value of a potted plant. Various prior art patents have taught apparatuses which attempt to camouflage the appearance of such wheels. These teachings include patents by Bachman, U.S. Pat. No. 3,041,782; Marcandalli, U.S. Pat. No. 3,528,676; Skoretz, U.S. Pat. No. 4,969,290; and Klonel, et al., U.S. Pat. No. 6,128,853. One attempt at solving the stated problems of the use of wheels is taught by Gridley in U.S. Pat. No. 585,931. While the Gridley invention does address the problems of tipping, sinking, rolling, and undesirable wheel appearance, it does present additional problems of its own. For example, the large handle used for mobility is aesthetically unpleasing when attached to the support, and may be easily lost if not attached to the support. Additionally, each time the pot support is moved, the support must first be wheeled out of the base plate, the base plate then repositioned at the desired location, and then the pot wheeled back into the base plate. This process requires the user to make multiple trips back and forth to place each part of the pot support. 
     Thus, there remains a need for a plant pot or support which is easily movable yet avoids the traditional problems associated with the use of the wheels, including tipping, sinking, rolling, and undesirable aesthetics. In addition, the pot or support should be easy to use, and is preferably unitary, without detachable parts which may become lost or misplaced as the unit is moved from place to place. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a plant support comprising a horizontal base for supporting a plant, a mobilizing mechanism positioned beneath the base which is vertically extendable from the base and vertically retractable toward the base, and a mechanism housing wall extending down from the base. Preferably, when the mobilizing mechanism is in a retracted position, the bottom of the mobilizing mechanism and the bottom of the mechanism housing wall are at substantially the same vertical position. The plant support optionally has a pot wall extending up from a perimeter of the horizontal base. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a preferred embodiment of the mobilizer of the present invention. 
     FIG. 2 is a perspective view of the embodiment of FIG. 1, showing the mobilizer in a raised position. 
     FIG. 3 is an exploded perspective view of a preferred embodiment of the mobilizer of the present invention. 
     FIG. 4A is a sectional elevation view taken along line  4 — 4  of FIG. 3, showing a preferred embodiment of the present invention with the wheels retracted. 
     FIG. 4B is a sectional elevation view taken along line  4 — 4  of FIG. 3, showing a preferred embodiment of the present invention with the wheels extended. 
     FIG. 5 is a bottom plan view of a preferred embodiment of the mobilizer of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention is a plant support and mobilizer which overcomes the disadvantages of the prior art by offering mobility while the plant is being moved, stability while the pot is stationary, and a unitary design which is durable and easy to use. While the preferred embodiment is shown as a pot, it is also contemplated that the teachings of this invention may be adapted to various other plant support structures, such as stands or bases to be used with separate pots. 
     The present invention comprises a structure having a mobilizing mechanism such as wheels, casters, rollers, or the like which extend and retract substantially vertically from the base of the plant support. Any known mechanism may be used to extend and retract the wheels, casters or rollers from the bottom of the structure. The mechanism may be mechanical, hydraulic, pneumatic, electrical or may have a motorized feature. The mechanism may be activated, for example, by turning a switch, stepping on a pedal, or turning a handle. 
     FIG. 1 is a perspective view of a preferred embodiment of plant support and mobilizer  10 . Mobilizer  10  includes pot  12  which contains soil  14  and plant  16 . The body of pot  12  is preferably molded from a plastic material which is lightweight, economical, durable, easy to clean, and able to imitate the appearance of other materials. It is contemplated that a wide range of other material may also be used, including, for example and without limitation, metal, wood, concrete, stone, and clay. Pot  12  includes slot  18  for access to actuating mechanisms which will be explained with reference to later figures. Slot  18  is closed by plug  20  in a preferred embodiment to lend a more finished aesthetic to pot  12 . Plug  20  may be a snap-fit plug with grip handle  22 , as shown. Alternatively, the closure for slot  18  may comprise, for example, a sliding, pivoting, or hinged closure. In a preferred embodiment, plug  20  is attached to pot  12  so that it will not be lost or misplaced when removed from slot  18 . 
     FIG. 2 is a perspective view of mobilizer  10 , raised on casters  24 . Casters  24  extend down from the bottom of pot  12  to raise pot  12  from a ground surface, thereby allowing movement of mobilizer  10  on casters  24 . Each caster  24  is preferably rated for at least 100 pounds of load. The mechanisms for the raising and lowering of pot  12  with respect to casters  24  can be actuated by a user through slot  18 . In one embodiment, a user first grasps plug  20  (shown in FIG. 1) by plug grip  22  and pulls to thereby remove plug  20 . The user can then insert crank handle  26  through slot  18 , thereby engaging an actuating mechanism within pot  12 . By rotating crank handle  26 , the user can raise and lower pot  12  on casters  24 . 
     FIG. 3 is an exploded perspective view, showing the components of a preferred embodiment of the present invention. To raise and lower pot  12 , a user inserts crank handle  26  of FIG.  2  through slot  18  to engage drive stub  28 . The end of crank handle  26  mates closely with hole  30  of non-circular cross-section in drive stub  28 . Drive stub  28  is fixedly attached to an end of shaft  32  of scissor jack assembly  34 . The components of scissor jack assembly  34  are preferably made of a durable and inexpensive material such as steel, or a durable, corrosion-resistant material such as plastic, titanium, stainless steel, aluminum or fiber-reinforced polymers or composites. Shaft  32  includes threaded end  36  opposite drive stub  28 . For purposes of the discussion, we will refer to rear end  38  and front end  40 . Externally threaded end  36  passes through internally threaded bore  42  in rear cross piece  44 . 
     Inside scissor legs  46  are pivotally attached to rear cross piece  44 . Outside scissor legs  48  are pivotally attached to inside scissor legs  46  at intersections  50 . Outside scissor legs  48  are also pivotally attached at front end  40  to bottom frame  54 . Inside scissor legs  46  are pivotable and slidably mounted to top frame  52 . Outside scissor legs  48  are pivotally attached to top frame  52 . Inside scissor legs  46  are not attached to bottom frame  54 , thereby allowing for relative lateral movement of rear cross piece  44 . It is important to note that while both ends of outside scissor legs  48  are laterally fixed, both ends of inside scissor legs  46  are able to slide laterally with respect to top frame  52  and bottom frame  54 . As scissor assembly  34  opens, thereby extending casters  24 , the top ends of inside scissor legs  46  slide toward the rear  38 . Simultaneously, the bottom ends of inside scissor legs  46 , as well as rear cross piece  44 , slide forward toward front  40  along threaded end  36  of shaft  32 . 
     When a user turns crank handle  26  of FIG. 2, drive stub  28 , and therefore shaft  32  rotate with crank handle  26 . Rotation of shaft  32  causes movement of rear cross piece  44  along threaded end  36  of shaft  32 . As rear cross piece  44  moves forward along threaded end  36 , scissor assembly  34  opens, i.e., top frame  52  moves away from bottom frame  54 . Because inside scissor legs  46  are pivotally connected to outside scissor legs  48  at intersections  50 , the top ends of inside scissor legs  46  simultaneously slide toward rear  38 . When crank  26  is rotated in the opposite direction, rear cross piece  44  moves along threaded end  36  of shaft  32  toward rear end  38  of scissor assembly  34 . As it does so, the top ends of inside scissor legs  46  slide forward again and scissor assembly  34  retracts into a flattened configuration. 
     In a preferred embodiment, top plate  56  is mounted onto top frame  52 , and bottom plate  58  is mounted onto bottom frame  54 . Top plate  56  may be mounted onto pot  12  by any known means; for example, with the use of fasteners such as screws or bolts and nuts. Washers may be used to reinforce such connections. Bottom plate  58  provides a convenient surface for the mounting of casters  24 . Bottom plate  58  may be eliminated, and casters  24  may be mounted directly onto bottom frame  54 . However, the use of bottom plate  58  allows casters  24  to be distributed more symmetrically under pot  12 . Casters  24  may be mounted onto bottom plate  58  by any known means, such as with the use of fasteners, adhesives, or weldments. Washers may be used to reinforce such connections. When all of the components of FIG. 3 are assembled, the opening or extension of scissor assembly  34  causes casters  24  to extend downward from pot  12 . In the opposite manner, the collapse or flattening of scissor assembly  34  causes casters  24  to retract back underneath pot  12 . 
     Walking through the steps of operation, a user will encounter a pot that is initially in the state illustrated in FIG. 1, with casters  24  retracted under pot  12 , so that mobilizer  10  rests stably upon a ground surface. To move mobilizer  10 , a user moves plug  22 , inserts crank handle  26  through slot  18  into hole  30  of drive stub  28 , and turns crank handle  26 . The rotation of crank handle  26  in one direction causes rear cross piece  44  to move forward along threaded end  36  of shaft  32 . As rear cross piece  44  moves forward, connected inside scissor legs  46  cause scissor assembly  34  to open, thereby extending casters  24  and causing pot  12  to lift with respect to the ground surface. This lifted position is illustrated in FIG.  2 . The user can then easily rotate or wheel mobilizer  10  to a new location. To return mobilizer  10  to the stable configuration of FIG. 1, the user then cranks handle  26  in the opposite direction. This causes rear cross piece  44  to travel rearward along threaded end  36  of shaft  32 . Thus, inside scissor legs  46  move to collapse scissor assembly  34 , thereby retracting casters  24  and lowering pot  12  back to ground level. Plug  22  can be replaced, and mobilizer  10  will reassume the configuration illustrated in FIG.  1 . 
     Typically, mobilizer  10  will not stay in the raised position of FIG. 2 for extended period of time. Normally, it will be in that position only long enough to be rotated or moved to a new position or location. In that case, no locking mechanism is required to keep scissor assembly  34  in the extended position, because the friction between its components, especially between externally threaded end  36  of shaft  32  and internally threaded bore  42  of rear cross piece  44  is usually enough to keep scissor assembly  34  in the raised position for the necessary period of time. 
     While extended rod crank  26  is shown, it is contemplated that any rotating mechanism may be used. For example, it may be desirable to provide a crank or handle which can be stored with or within mobilizer  10 , thereby adding to the user&#39;s convenience. The crank or handle may also be attached to pot  12 , so that it cannot be lost. The crank or handle may be of any suitable shape or configuration. Drive stub  28  may also be rotated by, for example, a ratchet wrench or powered screwdriver. 
     FIG. 4A is a cross-sectional elevation view of a preferred embodiment of the present invention, taken along line  4 — 4  of FIG.  3 . FIG. 4A depicts mobilizer  10  with casters  24  retracted into pot  12 , as shown in FIG.  1 . FIG. 4A additionally shows exterior pot walls  60 , vertical interior housing walls  62 , horizontal interior housing wall  63 , base wall  64  over slot  18 , and base wall  66  around the remaining perimeter of pot  12 . Horizontal interior housing wall  63  provides a base for supporting plant  16  (shown in FIG.  1 ). Base wall  64  is raised relative to base wall  66 , allowing for recess  68 , which accommodates the passage of crank shaft  26  through slot  18  and into hole  30  of drive stub  28 . In a preferred embodiment, interior walls  62  are spaced from exterior walls  60  to form soil holding area  70 . When filled with soil  14  or other material, soil holding area  70  enhances the stability of mobilizer  10  by lowering the center of gravity of the filled mobilizer unit. While casters  24  are shown as retracted above a ground surface, they may also be retracted to a level even with the ground surface. The ground contact of casters  24  as well as base wall  66  distributes the weight of mobilizer  10  and its contents to minimize the sinking of mobilizer  10  into a soft ground surface. 
     FIG. 4B is an cross-sectional elevation view, taken along lines  4 — 4  of FIG. 3, and showing casters  24  extended under pot  12 , as in FIG.  2 . It is important to note that slot  18  must be long enough to accommodate the vertical travel of crank shaft  26  between retracted position A in FIG. 4A, and extended position B in FIG.  4 B. As discussed earlier, outside scissor legs  48  are pivotally attached to top frame  52  and bottom frame  54 . Thus, the movement of casters  24  follows a slightly canted path indicated by arrow  71 . The term “substantially vertical” is defined as including such a canted path as well as a truly vertical path. 
     FIG. 5 is a bottom plan view of a preferred embodiment of the present invention. FIG. 5 additionally shows a plurality of drain holes  72  disposed along a bottom surface of base wall  66 . Interior housing walls  62  and base walls  64  and  66  preferably isolate scissor jack assembly  34  from the contents of pot  12 , thereby shielding the actuating mechanism from soil, moisture, and debris. Casters  24  are preferably mounted on bottom plate  58  symmetrically and as far from each other as possible, to provide a wide and stable base upon which mobilizer  10  can move. 
     Although the description of the preferred embodiment has been quite specific, it is contemplated that various modifications could be made without deviating from the spirit of the invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims rather than by the description of the preferred embodiment. For example, while one mechanism of extending and retracting the casters is taught, it is contemplated that other mechanisms may be used, such as electric, hydraulic, pneumatic, and/or other types of jacks. Additionally, while casters are shown, it is contemplated that rollers, coasters, ball wheels, and other mobilizing structures maybe used. These structures preferably allow for rotational as well as translational movement. Furthermore, while four casters are shown connected to a single jack screw scissor assembly, it is contemplated that fewer or more mobilizing structures in different configurations with different extending and retracting mechanisms may be used. Additionally, mobilizer  10  and its components may be constructed of any suitable material and of any suitable size. Additionally, while it is shown that the casters extend and retract in a vertical direction, there may be also be a horizontal component to the motion. For example, the wheels may spread farther apart as they extend, thereby resulting in a wider and therefore more stable base for movement. Moreover, the structure may be provided with one or more handles to facilitate movement. 
     In summary, the present invention offers a plant pot or support having a base that contacts the ground when the pot or support is in a non-mobile state and mobilizing mechanisms, wherein there is relative vertical movement between the bottom surface of the base and the bottom surface of the mobilizing mechanisms. In a preferred embodiment, casters extend down with respect to the base, thereby allowing a user to easily move or rotate the plant as desired. The casters also retract back up with respect to the base, thereby hiding aesthetically unpleasing wheels, preventing inadvertent rolling or tipping, and minimizing sinking. Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, the important aspect of the invention is the relative vertical movement between the bottom surface of the base and the bottom surface of the casters. In an alternative embodiment, the casters may remain vertically stationary, and the base may actually move up and down vertically, as in the case of a sleeve circumscribing the perimeter of the pot or support. The sleeve may be lifted to expose the casters and thereby allow movement. Once the pot or support is relocated, the sleeve may be lowered to prevent further unintentional rolling.